Microlensing of Strongly Lensed Quasars

Space Science Reviews - Tập 220 - Trang 1-91 - 2024
G. Vernardos1,2,3, D. Sluse4, D. Pooley5,6, R. W. Schmidt7, M. Millon1,8, L. Weisenbach9, V. Motta10, T. Anguita11,12, P. Saha13, M. O’Dowd2,3,14, A. Peel1, P. L. Schechter15,16
1Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, Versoix, Switzerland
2Department of Astrophysics, American Museum of Natural History, NY, USA
3Department of Physics and Astronomy, Lehman College of the City University of New York, Bronx, USA
4STAR Institute, Liége, Belgium
5Department of Physics and Astronomy, Trinity University, San Antonio, USA
6Eureka Scientific, Oakland, USA
7Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany
8Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Stanford, USA
9Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, UK
10Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
11Instituto de Astrofísica, Facultad de Ciencias Exactas, Universidad Andres Bello, Santiago, Chile
12Millennium Institute of Astrophysics, Santiago, Chile
13Physik-Institut, University of Zurich, Zurich, Switzerland
14The Graduate Center of The City University of New York, New York, USA
15Department of Physics, Massachusetts Institute of Technology, Cambridge, USA
16Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, USA

Tóm tắt

Strong gravitational lensing of quasars has the potential to unlock the poorly understood physics of these fascinating objects, as well as serve as a probe of the lensing mass distribution and of cosmological parameters. In particular, gravitational microlensing by compact bodies in the lensing galaxy can enable mapping of quasar structure to $<10^{-6}$ arcsec scales. Some of this potential has been realized over the past few decades, however the upcoming era of large sky surveys promises to bring this promise to full fruition. In this article, we review the theoretical framework of this field, describe the prominent current methods for parameter inference from quasar microlensing data across different observing modalities, and discuss the constraints so far derived on the geometry and physics of quasar inner structure. We also review the application of strong lensing and microlensing to constraining the granularity of the lens potential, i.e. the contribution of the baryonic and dark matter components, and the local mass distribution in the lens, i.e. the stellar mass function. Finally, we discuss the future of the field, including the new possibilities that will be opened by the next generation of large surveys and by new analysis methods now being developed.

Tài liệu tham khảo

Abajas C, Mediavilla E, Muñoz JA, Popović LČ, Oscoz A (2002) The influence of gravitational microlensing on the broad emission lines of quasars. Astrophys J 576(2):640–652. https://doi.org/10.1086/341793 Abajas C, Mediavilla E, Muñoz JA, Gómez-Álvarez P, Gil-Merino R (2007) Microlensing of a biconical broad-line region. Astrophys J 658(2):748–762. https://doi.org/10.1086/511023 Abolmasov P, Shakura NI (2012a) Microlensing evidence for super-Eddington disc accretion in quasars. Mon Not R Astron Soc 427:1867–1876. https://doi.org/10.1111/j.1365-2966.2012.21881.x Abolmasov P, Shakura NI (2012b) Resolving the inner structure of QSO discs through fold-caustic-crossing events. Mon Not R Astron Soc 423:676–693. https://doi.org/10.1111/j.1365-2966.2012.20904.x Abramowicz MA, Fragile CP (2013) Foundations of black hole accretion disk theory. Living Rev Relativ 16:1. https://doi.org/10.12942/lrr-2013-1 Abramowicz MA, Czerny B, Lasota JP, Szuszkiewicz E (1988) Slim accretion discs. Astron J 332:646 Agol E, Krolik J (1999) Imaging a quasar accretion disk with microlensing. Astrophys J 524:49–64. https://doi.org/10.1086/307800 Agol E, Jones B, Blaes O (2000) Keck mid-infrared imaging of QSO 22370305. Astrophys J 545:657–663 Alcock C, Allsman RA, Alves DR, Axelrod TS, Becker AC, Bennett DP, Cook KH, Dalal N, Drake AJ, Freeman KC, Geha M, Griest K, Lehner MJ, Marshall SL, Minniti D, Nelson CA, Peterson BA, Popowski P, Pratt MR, Quinn PJ, Stubbs CW, Sutherland W, Tomaney AB, Vandehei T, Welch D (2000) The MACHO project: microlensing results from 5.7 years of Large Magellanic Cloud observations. Astrophys J 542:281–307. https://doi.org/10.1086/309512 Allen JT, Hewett PC, Maddox N, Richards GT, Belokurov V (2011) A strong redshift dependence of the broad absorption line quasar fraction. Mon Not R Astron Soc 410:860–884. https://doi.org/10.1111/j.1365-2966.2010.17489.x Amorim A, Bauböck M, Bentz MC, Brandner W, Bolzer M, Clénet Y, Davies R, de Zeeuw PT, Dexter J, Drescher A, Eckart A, Eisenhauer F, Förster Schreiber NM, Garcia PJV, Genzel R, Gillessen S, Gratadour D, Hönig S, Kaltenbrunner D, Kishimoto M, Lacour S, Lutz D, Millour F, Netzer H, Onken CA, Ott T, Paumard T, Perraut K, Perrin G, Petrucci PO, Pfuhl O, Prieto MA, Rouan D, Shangguan J, Shimizu T, Stadler J, Sternberg A, Straub O, Straubmeier C, Street R, Sturm E, Tacconi LJ, Tristram KRW, Vermot P, von Fellenberg S, Widmann F, Woillez J (GRAVITY Collaboration) (2021) The central parsec of NGC 3783: a rotating broad emission line region, asymmetric hot dust structure, and compact coronal line region. Astron Astrophys 648:A117. https://doi.org/10.1051/0004-6361/202040061 Angonin M-C, Remy M, Surdej J, Vanderriest C (1990) First spectroscopic evidence of microlensing on a BAL quasar? The case of H1413+117. Astron Astrophys 233:5 Anguita T, Schmidt RW, Turner EL, Wambsganss J, Webster RL, Loomis KA, Long D, Mcmillan R (2008) The multiple quasar Q2237+0305 under a microlensing caustic. Astron Astrophys 480:327–334. https://doi.org/10.1051/0004-6361:20078221 Antonucci R (1993) Unified models for active galactic nuclei and quasars. Annu Rev Astron Astrophys 31:473–521. https://doi.org/10.1146/annurev.aa.31.090193.002353 Awad P, Chan JHH, Millon M, Courbin F, Paic E (2023) Probing compact dark matter objects with microlensing in gravitationally lensed quasars. Astron Astrophys 673:A88. arXiv:2304.01320. https://doi.org/10.1051/0004-6361/202245615 Barsdell BR, Barnes DG, Fluke CJ (2010) Analysing astronomy algorithms for graphics processing units and beyond. Mon Not R Astron Soc 408:1936–1944. https://doi.org/10.1111/j.1365-2966.2010.17257.x Barth AJ, Pancoast A, Bennert VN, Brewer BJ, Canalizo G, Filippenko AV, Gates EL, Greene JE, Li W, Malkan MA, Sand DJ, Stern D, Treu T, Woo JH, Assef RJ, Bae HJ, Buehler T, Cenko SB, Clubb KI, Cooper MC, Diamond-Stanic AM, Hönig SF, Joner MD, Laney CD, Lazarova MS, Nierenberg AM, Silverman JM, Tollerud EJ, Walsh JL (2013) The Lick AGN monitoring project 2011: Fe II reverberation from the outer broad-line region. Astrophys J 769:128. https://doi.org/10.1088/0004-637X/769/2/128 Barvainis R (1987) Hot dust and the near-infrared bump in the continuum spectra of quasars and active galactic nuclei. Astrophys J 320:537. https://doi.org/10.1086/165571 Bate NF, Fluke CJ (2012) A graphics processing unit-enabled, high-resolution cosmological microlensing parameter survey. Astrophys J 744:90. https://doi.org/10.1088/0004-637X/744/2/90 Bate NF, Webster RL, Wyithe JSB (2007) Smooth matter and source size in microlensing simulations of gravitationally lensed quasars. Mon Not R Astron Soc 381:1591–1596. https://doi.org/10.1111/j.1365-2966.2007.12330.x Bate NF, Floyd DJE, Webster RL, Wyithe JSB (2008) A microlensing study of the accretion disc in the quasar MG 0414+0534. Mon Not R Astron Soc 391:1955–1960. https://doi.org/10.1111/j.1365-2966.2008.14020.x Bate NF, Floyd DJE, Webster RL, Wyithe JSB (2011) A microlensing measurement of dark matter fractions in three lensing galaxies. Astrophys J 731:71. https://doi.org/10.1088/0004-637X/731/1/71 Bate NF, Vernardos G, O’Dowd MJ, Neri-Larios MD (2018) HST imaging of four lensed quasars. Mon Not R Astron Soc 479:4796–4814. https://doi.org/10.1093/mnras/sty1793 Belle KE, Lewis GF (2000) Microlensing of broad absorption line quasars: polarization variability. Publ Astron Soc Pac 112:320. https://doi.org/10.1086/316523 Bennert N, Falcke H, Schulz H, Wilson AS, Wills BJ (2002) Size and structure of the narrow-line region of quasars. Astrophys J 574:105–109 Benning M, Burger M (2018) Modern regularization methods for inverse problems. Acta Numerica 27:1–111. https://doi.org/10.1017/S0962492918000016. arXiv:1801.09922 Bentz MC, Katz S (2015) The agn black hole mass database. Publ Astron Soc Pac 127:67 Bentz MC, Denney KD, Grier CJ, Barth AJ, Peterson BM, Vestergaard M, Bennert VN, Canalizo G, Rosa GD, Filippenko AV, Gates EL, Greene JE, Li W, Malkan MA, Pogge RW, Stern D, Treu T, Woo JH (2013) The low-luminosity end of the radius-luminosity relationship for active galactic nuclei. Astrophys J 767:149. https://doi.org/10.1088/0004-637X/767/2/149 Bentz MC, Williams PR, Street R, Onken CA, Valluri M, Treu T (2021) A detailed view of the broad-line region in NGC 3783 from velocity-resolved reverberation mapping. Astrophys J 920:112. https://doi.org/10.3847/1538-4357/ac19af Best H, Fagin J, Vernardos G, O’Dowd M (2022) Resolving the vicinity of supermassive black holes with gravitational microlensing. http://arxiv.org/abs/2210.10500 Bhatiani S, Dai X, Guerras E (2019) Confirmation of planet-mass objects in extragalactic systems. Astrophys J 885:77. https://doi.org/10.3847/1538-4357/ab46ac Biggs AD (2023) A vla monitoring study of JVAS B1422+231: investigation of time delays and detection of extrinsic variability. Mon Not R Astron Soc. https://doi.org/10.1093/mnras/stad870 Biggs AD, Browne IWA (2018) A revised lens time delay for JVAS B0218+357 from a reanalysis of VLA monitoring data. Mon Not R Astron Soc 476:5393–5407. https://doi.org/10.1093/MNRAS/STY565 Birrer S et al (2024) Time-delay cosmography: measuring the Hubble constant and other cosmological parameters with strong gravitational lensing. Space Sci Rev 220 Blackburne JA, Kochanek CS (2010) The effect of a time-varying accretion disk size on quasar microlensing light curves. Astrophys J 718:1079–1084. https://doi.org/10.1088/0004-637X/718/2/1079 Blackburne JA, Pooley D, Rappaport S, Schechter PL (2011) Sizes and temperature profiles of quasar accretion disks from chromatic microlensing. Astrophys J 729:34. https://doi.org/10.1088/0004-637X/729/1/34 Blackburne JA, Kochanek CS, Chen B, Dai X, Chartas G (2014) The optical, ultraviolet, and X-ray structure of the quasar HE 0435–1223. Astrophys J 789:125. https://doi.org/10.1088/0004-637X/789/2/125 Blandford RD, Mckee CF (1982) Reverberation mapping of the emission line regions of Seyfert galaxies and quasars. Astrophys J 255:419–439 Bogdanov MB, Cherepashchuk AM (2002) Reconstruction of the strip brightness distribution in a quasar accretion disk from gravitational microlensing data. Astron Rep 46:626–633 Borguet B, Hutsemékers D (2010) A polar+equatorial wind model for broad absorption line quasars. Astron Astrophys 515:A22. https://doi.org/10.1051/0004-6361/200913255 Bourassa RR, Kantowski R (1975) The theory of transparent gravitational lenses. Astrophys J 195:13–21 Bourassa RR, Kantowski R, Norton TD (1973) The spheroidal gravitational lens. Astrophys J 185:747–756 Bozza V (2010) Microlensing with an advanced contour integration algorithm: Green’s theorem to third order, error control, optimal sampling and limb darkening. Mon Not R Astron Soc 408:2188–2200. https://doi.org/10.1111/j.1365-2966.2010.17265.x Braibant L, Hutsemékers D, Sluse D, Anguita T, García-Vergara CJ (2014) Microlensing of the broad-line region in the quadruply imaged quasar HE0435-1223. Astron Astrophys 565:L11. https://doi.org/10.1051/0004-6361/201423633 Braibant L, Hutsemékers D, Sluse D, Anguita T (2016) The different origins of high- and low-ionization broad emission lines revealed by gravitational microlensing in the Einstein cross. Astron Astrophys 592:A23. https://doi.org/10.1051/0004-6361/201628594 Braibant L, Hutsemékers D, Sluse D, Goosmann R (2017) Constraining the geometry and kinematics of the quasar broad emission line region using gravitational microlensing: I. Models and simulations. Astron Astrophys 607:A32. https://doi.org/10.1051/0004-6361/201731086 Brenneman LW, Reynolds CS (2006) Constraining black hole spin via X-ray spectroscopy. Astrophys J 652(2):1028–1043. https://doi.org/10.1086/508146 Bruce A, Lawrence A, MacLeod C, Elvis M, Ward MJ, Collinson JS, Gezari S, Marshall PJ, Lam MC, Kotak R, Inserra C, Polshaw J, Kaiser N, Kudritzki RP, Magnier EA, Waters C (2017) Spectral analysis of four ‘hypervariable’ AGN: a microneedle in the haystack? Mon Not R Astron Soc 467:1259–1280. https://doi.org/10.1093/mnras/stx168 Cackett EM, Gelbord J, Li Y-R, Horne K, Wang J-M, Barth AJ, Bai J-M, Bian W-H, Carroll RW, Du P, Edelson R, Goad MR, Ho LC, Hu C, Khatu VC, Luo B, Miller J, Yuan Y-F (2020) Supermassive black holes with high accretion rates in active galactic nuclei. XI. Accretion disk reverberation mapping of MRK 142. Astrophys J 896:1. https://doi.org/10.3847/1538-4357/ab91b5 Cackett EM, Bentz MC, Kara E (2021) Reverberation mapping of active galactic nuclei: from X-ray corona to dusty torus. iScience 24(6):102557. https://doi.org/10.1016/j.isci.2021.102557 Canizares CR (1982) Manifestations of a cosmological density of compact objects in quasar light. Astrophys J 263:508 Cappellari M (2016) Structure and kinematics of early-type galaxies from integral field spectroscopy. Annu Rev Astron Astrophys 54:597–665. https://doi.org/10.1146/annurev-astro-082214-122432 Cardelli JA, Savage BD (1988) Two lines of sight with exceedingly anomalous ultraviolet interstellar extinction. Astrophys J 325:864–879 Chae K-H, Turnshek DA, Schulte-Ladbeck RE, Rao SM, Lupie OL (2001) Hubble Space Telescope observations of the gravitationally lensed cloverleaf broad absorption line QSO H14131143: imaging polarimetry and evidence for microlensing of a scattering region. Astrophys J 561:653–659 Chan JHH, Rojas K, Millon M, Courbin F, Bonvin V, Jauffret G (2021) Measuring accretion disk sizes of lensed quasars with microlensing time delay in multi-band light curves. Astron Astrophys 647:A115. https://doi.org/10.1051/0004-6361/202038971 Chang K, Refsdal S (1979) Flux variations of QSO 0957+561 A, B and image splitting by stars near the light path. Nature 282:561 Chang K, Refsdal S (1984) Star disturbances in gravitational lens galaxies. Astron Astrophys 132:168 Chartas G, Agol E, Eracleous M, Garmire G, Bautz MW, Morgan ND (2002) Caught in the act: Chandra observations of microlensing of the radio-loud quasar MG J0414+0534. Astrophys J 568(2):509–521. https://doi.org/10.1086/339162 Chartas G, Eracleous M, Agol E, Gallagher Chandra SC (2004) Observations of the cloverleaf quasar H1413+117: a unique laboratory for microlensing studies of a LoBAL quasar. Astrophys J 606(1):78–84. https://doi.org/10.1086/382743 Chartas G, Eracleous M, Dai X, Agol E, Gallagher S (2007) Discovery of probable relativistic Fe emission and absorption in the cloverleaf quasar H 1413+117. Astrophys J 661(2):678–692. https://doi.org/10.1086/516816 Chartas G, Kochanek CS, Dai X, Poindexter S, Garmire G (2009) X-ray microlensing in RXJ1131-1231 and HE1104-1805. Astrophys J 693:174–185. https://doi.org/10.1088/0004-637X/693/1/174 Chartas G, Kochanek CS, Dai X, Moore D, Mosquera AM, Blackburne JA (2012) Revealing the structure of an accretion disk through energy-dependent X-ray microlensing. Astrophys J 757(2):137. https://doi.org/10.1088/0004-637X/757/2/137 Chartas G, Krawczynski H, Zalesky L, Kochanek CS, Dai X, Morgan CW, Mosquera A (2017) Measuring the innermost stable circular orbits of supermassive black holes. Astrophys J 837:26. https://doi.org/10.3847/1538-4357/aa5d50 Chartas G, Cappi M, Vignali C, Dadina M, James V, Lanzuisi G, Giustini M, Gaspari M, Strickland S, Bertola E (2021) Multiphase powerful outflows detected in high-z quasars. Astrophys J 920:24. https://doi.org/10.3847/1538-4357/ac0ef2 Chelouche D (2005) Gravitational microlensing and the structure of quasar outflows. Astrophys J 629:667 Chen B, Dai X, Kochanek CS, Chartas G, Blackburne JA, Morgan CW (2012) X-ray monitoring of gravitational lenses with Chandra. Astrophys J 755(1):24. https://doi.org/10.1088/0004-637X/755/1/24 Chen GCF, Suyu SH, Wong KC, Fassnacht CD, Chiueh T, Halkola A, Hu IS, Auger MW, Koopmans LVE, Lagattuta DJ, McKean JP, Vegetti S (2016) Sharp – III. First use of adaptive-optics imaging to constrain cosmology with gravitational lens time delays. Mon Not R Astron Soc 462:3457–3475. https://doi.org/10.1093/mnras/stw991 Chen B, Kantowski R, Dai X, Baron E, der Mark PV (2017) Accelerating gravitational microlensing simulations using the Xeon Phi coprocessor. Astron Comput 19:60–65. https://doi.org/10.1016/j.ascom.2017.03.005 Chiba M, Minezaki T, Kashikawa N, Kataza H, Inoue KT (2005) Subaru mid-infrared imaging of the quadruple lenses PG 1115+080 and B1422+231: limits on substructure lensing 1. Astrophys J 627:53 Collin S, Boisson C, Mouchet M, Dumont AM, Coupé S, Porquet D, Rokaki E (2002) Are quasars accreting at super-Eddington rates? Astron Astrophys 388:771–786. https://doi.org/10.1051/0004-6361:20020550 Congdon AB, Keeton CR, Osmer SJ (2007) Microlensing of an extended source by a power-law mass distribution. Mon Not R Astron Soc 376:263–272. https://doi.org/10.1111/j.1365-2966.2007.11426.x Cornachione MA, Morgan CW (2020) Quasar microlensing variability studies favor shallow accretion disk temperature profiles. Astrophys J 895:93. https://doi.org/10.3847/1538-4357/ab8aed Cornachione MA, Morgan CW, Burger HR, Shalyapin VN, Goicoechea LJ, Vrba FJ, Dahm SE, Tilleman TM (2020b) Near-infrared and optical continuum emission region size measurements in the gravitationally lensed quasars Q0957+561 and SBS0909+532. Astrophys J 905:7. https://doi.org/10.3847/1538-4357/abc25d Cornachione MA, Morgan CW, Millon M, Bentz MC, Courbin F, Bonvin V, Falco EE (2020a) A microlensing accretion disk size measurement in the lensed quasar WFI 2026–4536. Astrophys J 895:125. https://doi.org/10.3847/1538-4357/ab557a Czerny B, Li Y-R, Hryniewicz K, Panda S, Wildy C, Sniegowska M, Wang J-M, Sredzinska J, Karas V (2017) Failed radiatively accelerated dusty outflow model of the broad line region in active galactic nuclei. I. Analytical solution. Astrophys J 846:154. https://doi.org/10.3847/1538-4357/aa8810 Dai X, Guerras E (2018) Probing extragalactic planets using quasar microlensing. Astrophys J 853:27. https://doi.org/10.3847/2041-8213/aaa5fb Dai L, Pascale M (2021) New approximation of magnification statistics for random microlensing of magnified sources. http://arxiv.org/abs/2104.12009 Dai X, Chartas G, Agol E, Bautz MW, Garmire Chandra GP (2003) Observations of QSO 2237+0305. Astrophys J 589(1):100–110. https://doi.org/10.1086/374548 Dai X, Kochanek CS, Chartas G, Kozłowski S, Morgan CW, Garmire G, Agol E (2010) The sizes of the X-ray and optical emission regions of RXJ 1131-1231. Astrophys J 709:278–285. https://doi.org/10.1088/0004-637X/709/1/278 Dalal N, Kochanek CS (2002) Direct detection of cold dark matter substructure. Astrophys J 572:25–33 Davis SW, Laor A (2011) The radiative efficiency of accretion flows in individual active galactic nuclei. Astrophys J 728:98. https://doi.org/10.1088/0004-637X/728/2/98 Dempsey R, Zakamska NL (2018) The size-luminosity relationship of quasar narrow-line regions. Mon Not R Astron Soc 477:4615–4626. https://doi.org/10.1093/mnras/sty941 Dexter J, Agol E (2011) Quasar accretion disks are strongly inhomogeneous. Astrophys J Lett 727:24. https://doi.org/10.1088/2041-8205/727/1/L24 Di Matteo T (1998) Magnetic reconnection: flares and coronal heating in active galactic nuclei. Mon Not R Astron Soc 299(1):15–20. https://doi.org/10.1046/j.1365-8711.1998.01950.x Di Valentino E, Anchordoqui LA, Akarsu Ö, Ali-Haimoud Y, Amendola L, Arendse N, Asgari M, Ballardini M, Basilakos S, Battistelli E, Benetti M, Birrer S, Bouchet FR, Bruni M, Calabrese E, Camarena D, Capozziello S, Chen A, Chluba J, Chudaykin A, Colgáin EÓ, Cyr-Racine F-Y, de Bernardis P, de Cruz Pérez J, Delabrouille J, Dunkley J, Escamilla-Rivera C, Ferté A, Finelli F, Freedman W, Frusciante N, Giusarma E, Gómez-Valent A, Handley W, Harrison I, Hart L, Heavens A, Hildebrandt H, Holz D, Huterer D, Ivanov MM, Joudaki S, Kamionkowski M, Karwal T, Knox L, Kumar S, Lamagna L, Lesgourgues J, Lucca M, Marra V, Masi S, Matarrese S, Mazumdar A, Melchiorri A, Mena O, Mersini-Houghton L, Miranda V, Moreno-Pulido C, Mota DF, Muir J, Mukherjee A, Niedermann F, Notari A, Nunes RC, Pace F, Paliathanasis A, Palmese A, Pan S, Paoletti D, Pettorino V, Piacentini F, Poulin V, Raveri M, Riess AG, Salzano V, Saridakis EN, Sen AA, Shafieloo A, Shajib AJ, Silk J, Silvestri A, Sloth MS, Smith TL, Solà Peracaula J, van de Bruck C, Verde L, Visinelli L, Wandelt BD, Wang D, Wang J-M, Yadav AK, Yang W (2021) Cosmology intertwined III: \(\mathrm{f}\sigma_{8}\) and \(\mathrm{S}_{8}\). Astropart Phys 131:102604. https://doi.org/10.1016/j.astropartphys.2021.102604 Diego JM, Hannuksela OA, Kelly PL, Pagano G, Broadhurst T, Kim K, Li TGF, Smoot GF (2019) Observational signatures of microlensing in gravitational waves at LIGO/Virgo frequencies. Astron Astrophys 627:A130. https://doi.org/10.1051/0004-6361/201935490 Dobler G, Keeton CR, Wambsganss J (2007) Microlensing of central images in strong gravitational lens systems. Mon Not R Astron Soc 377:977–986. https://doi.org/10.1111/j.1365-2966.2007.11695.x Edelson R, Gelbord JM, Horne K, McHardy IM, Peterson BM, Arévalo P, Breeveld AA, Rosa GD, Evans PA, Goad MR, Kriss GA, Brandt WN, Gehrels N, Grupe D, Kennea JA, Kochanek CS, Nousek JA, Papadakis I, Siegel M, Starkey D, Uttley P, Vaughan S, Young S, Barth AJ, Bentz MC, Brewer BJ, Crenshaw DM, Cáceres EDBADL, Denney KD, Dietrich M, Ely J, Fausnaugh MM, Grier CJ, Hall PB, Kaastra J, Kelly BC, Korista KT, Lira P, Mathur S, Netzer H, Pancoast A, Pei L, Pogge RW, Schimoia JS, Treu T, Vestergaard M, Villforth C, Yan H, Zu Y (2015) Space telescope and optical reverberation mapping project. II. Swift and HST reverberation mapping of the accretion disk of NGC 5548. Astrophys J 806:129. https://doi.org/10.1088/0004-637X/806/1/129 Eigenbrod A, Courbin F, Meylan G, Agol E, Anguita T, Schmidt RW, Wambsganss J (2008a) Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 ≡ the Einstein cross. II. Energy profile of the accretion disk. Astron Astrophys 490:933–943. https://doi.org/10.1051/0004-6361 Eigenbrod A, Courbin F, Sluse D, Meylan G, Agol E (2008b) Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 ≡ the Einstein cross. Astron Astrophys 480:647–661. https://doi.org/10.1051/0004-6361:20078703 Elitzur M, Ho LC, Trump JR (2014) Evolution of broad-line emission from active galactic nuclei. Mon Not R Astron Soc 438:3340–3351. https://doi.org/10.1093/mnras/stt2445 Esteban-Gutiérrez A, Agües-Paszkowsky N, Mediavilla E, Jiménez-Vicente J, Muñoz JA, Heydenreich S (2020) The impact of the mass spectrum of lenses in quasar microlensing studies. Constraints on a mixed population of primordial black holes and stars. Astrophys J 904:176. https://doi.org/10.3847/1538-4357/abbdf7 Esteban-Gutiérrez A, Agües-Paszkowsky N, Mediavilla E, Jiménez-Vicente J, Muñoz JA, Heydenreich S (2022) Abundance of LIGO/Virgo black holes from microlensing observations of quasars with reverberation mapping size estimates. Astrophys J 929:123. https://doi.org/10.3847/1538-4357/ac57c5 Event Horizon Telescope Collaboration (2019) First M87 Event Horizon Telescope results. IV. Imaging the central supermassive black hole. Astrophys J Lett 875:L4. https://doi.org/10.3847/2041-8213/ab0e85 Event Horizon Telescope Collaboration (2022) First Sagittarius A* Event Horizon Telescope results. III. Imaging of the galactic center supermassive black hole. Astrophys J Lett 930:L14. https://doi.org/10.3847/2041-8213/ac6429 Fabian AC, Rees MJ, Stella L, White NE (1989) X-ray fluorescence from the inner disc in Cygnus X-1. Mon Not R Astron Soc 238:729–736. https://doi.org/10.1093/mnras/238.3.729 Fabian AC, Zoghbi A, Ross RR, Uttley P, Gallo LC, Brandt WN, Blustin AJ, Boller T, Caballero-Garcia MD, Larsson J, Miller JM, Miniutti G, Ponti G, Reis RC, Reynolds CS, Tanaka Y, Young AJ (2009) Broad line emission from iron K- and L-shell transitions in the active galaxy 1H0707-495. Nature 459(7246):540–542. https://doi.org/10.1038/nature08007 Fabian AC, Kara E, Walton DJ, Wilkins DR, Ross RR, Lozanov K, Uttley P, Gallo LC, Zoghbi A, Miniutti G, Boller T, Brandt WN, Cackett EM, Chiang C-Y, Dwelly T, Malzac J, Miller JM, Nardini E, Ponti G, Reis RC, Reynolds CS, Steiner JF, Tanaka Y, Young AJ (2013) XMM observation of the narrow-line Seyfert 1 galaxy IRAS 13224-3809: rapid variability, high spin and a soft lag. Mon Not R Astron Soc 429(4):2917–2923. https://doi.org/10.1093/mnras/sts504 Fadely R, Keeton CR (2011) Near-infrared K and L’ flux ratios in six lensed quasars. Astron J 141:101. https://doi.org/10.1088/0004-6256/141/3/101 Falco EE, Gorenstein VM, Shapiro II (1985) On model-dependent bounds on h0 from gravitational images: application to Q0957+561A, B. Astrophys J 289:1 Falco EE, Impey CD, Kochanek CS, Leha J, Mcleod BA, Rix H-W, Keeton CR, Mun JA, Peng CY (1999) Dust and extinction curves in galaxies with \(z >0\): the interstellar medium of gravitational lens galaxies. Astrophys J 523:617–632 Ferland GJ, Hu C, Wang JM, Baldwin JA, Porter RL, Hoof PAMV, Williams RJR (2009) Implications of infalling fe ii-emitting clouds in active galactic nuclei: anisotropic properties. Astrophys J 707:L82. https://doi.org/10.1088/0004-637X/707/1/L82 Ferland GJ, Porter RL, van Hoof PAM, Williams RJR, Abel NP, Lykins ML, Shaw G, Henney WJ, Stancil PC (2013) The 2013 release of cloudy. Rev Mex Astron Astrofís 49:137–163. https://doi.org/10.48550/arXiv.1302.4485 Fian C, Mediavilla E, Hanslmeier A, Oscoz A, Serra-Ricart M, Muñoz JA, Jiménez-Vicente J (2016) Size of the accretion disk in the graviationally lensed quasar SDSS J1004+4112 from the statistics of microlensing magnifications. Astrophys J 830(2):149. https://doi.org/10.3847/0004-637X/830/2/149 Fian C, Mediavilla E, Jiménez-Vicente J, Muñoz JA, Hanslmeier A (2018) Estimate of the accretion disk size in the gravitationally lensed quasar HE 0435-1223 using microlensing magnification statistics. Astrophys J 869:132. https://doi.org/10.3847/1538-4357/aaeed5 Fian C, Mediavilla E, Jiménez-Vicente J, Motta V, Muñoz JA, Chelouche D, Goméz-Alvarez P, Rojas K, Hanslmeier A (2021b) Revealing the structure of the lensed quasar Q 0957+561: I. Accretion disk size. Astron Astrophys 654:A70. https://doi.org/10.1051/0004-6361/202039854 Fian C, Mediavilla E, Motta V, Jiménez-Vicente J, Muñoz JA, Chelouche D, Hanslmeier A (2021a) Microlensing of the broad emission lines in 27 gravitationally lensed quasars: broad line region structure and kinematics. Astron Astrophys 653:A109. https://doi.org/10.1051/0004-6361/202039829 Floyd DJE, Bate NF, Webster RL (2009) The accretion disc in the quasar SDSS J0924+0219. Mon Not R Astron Soc 398:233–239. https://doi.org/10.1111/j.1365-2966.2009.15045.x Fluke CJ, Webster RL (1999) Investigating the geometry of quasars with microlensing. Mon Not R Astron Soc 302:68–74. https://doi.org/10.1046/j.1365-8711.1999.02109.x Fluke CJ, Barnes DG, Barsdell BR, Hassan AH (2011) Astrophysical supercomputing with GPUs: critical decisions for early adopters. Publ Astron Soc Aust 28:15–27 Foxley-Marrable M, Collett TE, Vernardos G, Goldstein DA, Bacon D (2018) The impact of microlensing on the standardisation of strongly lensed type IA supernovae. Mon Not R Astron Soc 478:5081–5090. http://arxiv.org/abs/1802.07738 Galeev AA, Rosner R, Vaiana GS (1979) Structured coronae of accretion disks. Astrophys J 229:318–326. https://doi.org/10.1086/156957 Gallagher SC, Brandt WN, Chartas G, Priddey R, Garmire GP, Sambruna RM (2006) An exploratory Chandra survey of a well-defined sample of 35 large bright quasar survey broad absorption line quasars. Astrophys J 644(2):709–724. https://doi.org/10.1086/503762 Gallo LC, Wilkins DR, Bonson K, Chiang C-Y, Grupe D, Parker ML, Zoghbi A, Fabian AC, Komossa S, Longinotti AL (2015) Suzaku observations of MRK 335: confronting partial covering and relativistic reflection. Mon Not R Astron Soc 446(1):633–650. https://doi.org/10.1093/mnras/stu2108 Gardner E, Done C (2017) The origin of the uv/optical lags in NGC 5548. Mon Not R Astron Soc 470:3591–3605. https://doi.org/10.1093/mnras/stx946 Garsden H, Lewis GF (2010) Gravitational microlensing: a parallel, large-data implementation. New Astron 15:181 Garsden H, Bate NF, Lewis GF (2011) Gravitational microlensing of a reverberating quasar broad-line region – I. Method and qualitative results. Mon Not R Astron Soc 418(2):1012–1027. https://doi.org/10.1111/j.1365-2966.2011.19552.x Gaudi BS, Petters AO (2002a) Gravitational microlensing near caustics. I. Folds. Astrophys J 574:970–984. https://doi.org/10.1086/341063 Gaudi BS, Petters AO (2002b) Gravitational microlensing near caustics. II. Cusps. Astrophys J 580:468 Gil-Merino R, Goicoechea LJ, Shalyapin VN, Oscoz A (2018) New database for a sample of optically bright lensed quasars in the northern hemisphere. Astron Astrophys 616:A118. https://doi.org/10.1051/0004-6361/201832737 Goicoechea LJ, Artamonov BP, Shalyapin VN, Sergeyev AV, Burkhonov OA, Akhunov TA, Asfandiyarov IM, Bruevich VV, Ehgamberdiev SA, Shimanovskaya EV, Zheleznyak AP (2020) Liverpool-maidanak monitoring of the Einstein cross in 2006-2019. Astron Astrophys 637:A89. https://doi.org/10.1051/0004-6361/202037902 Gorenstein VM, Falco EE, Shapiro II (1988) Degeneracies in parameter estimates for models of gravitational lens systems. Astrophys J 327:693 Gott JR (1981) Are heavy halos made of low mass stars? A gravitational lens test. Astrophys J 243:140–146 Gould A, Miralda-Escude J (1997) Signatures of accretion disks in quasar microlensing. Astrophys J 483:13 Graham AW (2007) The black hole mass – spheroid luminosity relation. Mon Not R Astron Soc 379:711–722. https://doi.org/10.1111/j.1365-2966.2007.11950.x Graham AW (2016) Galaxy bulges and their massive black holes: a review. In: Laurikainen E, Peletier R, Gadotti D (eds) Galactic bulges. Astrophysics and Space Science Library, vol 418. Springer, Cham, pp 263–313. https://doi.org/10.1007/978-3-319-19378-6_11 Granot J, Schechter PL, Wambsganss J (2003) The mean number of extra microimage pairs for macrolensed quasars. Astrophys J 583:575–583 Green PJ (2006) Lens-aided multi-angle spectroscopy (LAMAS) reveals small-scale outflow structure in quasars. Astrophys J 644:733. https://doi.org/10.1086/503760 Greencard L, Rokhlin V (1987) A fast algorithm for particle simulations. J Comput Phys 73:315–348 Grieger B, Kayser R, Refsdal S (1988) Gravitational micro-lensing as a clue to quasar structure. Astron Astrophys 194:54 Grieger B, Kayser R, Schramm T (1991) The deconvolution of the quasar structure from microlensing light curves. Astron Astrophys 252:508 Grier CJ, Pancoast A, Barth AJ, Fausnaugh MM, Brewer BJ, Treu T, Peterson BM (2017) The structure of the broad-line region in active galactic nuclei. II. Dynamical modeling of data from the AGN10 reverberation mapping campaign. Astrophys J 849:146. https://doi.org/10.3847/1538-4357/aa901b Grier CJ, Shen Y, Horne K, Brandt WN, Trump JR, Hall PB, Kinemuchi K, Starkey D, Schneider DP, Ho LC, Homayouni Y, Li JI-H, McGreer ID, Peterson BM, Bizyaev D, Chen Y, Dawson KS, Eftekharzadeh S, Guo Y, Jia S, Jiang L, Kneib J-P, Li F, Li Z, Nie J, Oravetz A, Oravetz D, Pan K, Petitjean P, Ponder KA, Rogerson J, Vivek M, Zhang T, Zou H (2019) The Sloan Digital Sky Survey reverberation mapping project: initial C IV lag results from four years of data. Astrophys J 887:38. https://doi.org/10.3847/1538-4357/ab4ea5 Grzędzielski M, Janiuk A, Czerny B, Wu Q (2017) Modified viscosity in accretion disks: application to galactic black hole binaries, intermediate mass black holes, and active galactic nuclei. Astron Astrophys 603:A110. https://doi.org/10.1051/0004-6361/201629672 Guerras E, Mediavilla E, Jiménez-Vicente J, Kochanek CS, Muñoz Ja, Falco E, Motta V (2013a) Microlensing of quasar broad emission lines: constraints on broad line region size. Astrophys J 764:160. https://doi.org/10.1088/0004-637X/764/2/160 Guerras E, Mediavilla E, Jimenez-Vicente J, Kochanek CS, Muñoz JA, Falco E, Motta V, Rojas K (2013b) Microlensing of quasar ultraviolet iron emission. Astrophys J 778:123. https://doi.org/10.1088/0004-637X/778/2/123 Guerras E, Dai X, Mediavilla E (2020) A second-order moment of microlensing variability as a novel tool to constrain source emission size or discrete lens demographics in extragalactic research. Astrophys J 896:111. https://doi.org/10.3847/1538-4357/ab76b9 Guilbert PW, Rees MJ (1988) ‘Cold’ material in non-thermal sources. Mon Not R Astron Soc 233:475–484. https://doi.org/10.1093/mnras/233.2.475 Guo W-J, Li Y-R, Zhang Z-X, Ho LC, Wang J-M (2022) Accretion disk size measurements of active galactic nuclei monitored by the Zwicky Transient Facility. Astrophys J 929:19. https://doi.org/10.3847/1538-4357/ac4e84 Haardt F, Maraschi L (1991) A two-phase model for the X-ray emission from Seyfert galaxies. Astrophys J Lett 380:51. https://doi.org/10.1086/186171 Haardt F, Maraschi L (1993) X-ray spectra from two-phase accretion disks. Astrophys J 413:507. https://doi.org/10.1086/173020 Haardt F, Maraschi L, Ghisellini G (1994) A model for the X-ray and ultraviolet emission from Seyfert galaxies and galactic black holes. Astrophys J Lett 432:95. https://doi.org/10.1086/187520 Hainline LJ, Morgan CW, Beach JN, Kochanek CS, Harris HC, Tilleman T, Fadely R, Falco EE, Le TX (2012) A new microlensing event in the doubly imaged quasar Q 0957+561. Astrophys J 744:104. https://doi.org/10.1088/0004-637X/744/2/104. Hainline LJ, Morgan CW, Macleod CL, Landaal ZD, Kochanek CS, Harris HC, Tilleman T, Goicoechea LJ, Shalyapin VN, Falco EE (2013) Time delay and accretion disk size measurements in the lensed quasar SBS 0909+532 from multiwavelength microlensing analysis. Astrophys J 774:69. https://doi.org/10.1088/0004-637X/774/1/69 Hales CA, Lewis GF (2007) Resolving the structure at the heart of bal quasars through microlensing induced polarisation variability. Publ Astron Soc Aust 24:30–40. https://doi.org/10.1071/AS07002 Hall PB, Noordeh ES, Chajet LS, Weiss E, Nixon CJ (2014) Modelling spikes in quasar accretion disc temperature. Mon Not R Astron Soc 442:1090–1109. https://doi.org/10.1093/mnras/stu890 Hall PB, Sarrouh GT, Horne K (2018) Non-blackbody disks can help explain inferred AGN accretion disk sizes. Astrophys J 854:93. https://doi.org/10.3847/1538-4357/aaa768 Hamann F, Chartas G, McGraw S, Hidalgo PR, Shields J, Capellupo D, Charlton J, Eracleous M (2013) Extreme-velocity quasar outflows and the role of X-ray shielding. Mon Not R Astron Soc 435:133–148. https://doi.org/10.1093/mnras/stt1231 Hartley P, Jackson N, Sluse D, Stacey HR, Vives-Arias H (2019) Strong lensing reveals jets in a sub-microJy radio-quiet quasar. Mon Not R Astron Soc 485(3):3009–3023. https://doi.org/10.1093/mnras/stz510 Hartley P, Jackson N, Badole S, McKean JP, Sluse D, Vives-Arias H (2021) Using strong lensing to understand the microjy radio emission in two radio quiet quasars at redshift 1.7. Mon Not R Astron Soc 508:4625–4638. https://doi.org/10.1093/mnras/stab2758 Hawkins MRS (2015) A new look at microlensing limits on dark matter in the galactic halo. Astron Astrophys 575:A107. https://doi.org/10.1051/0004-6361/201425400 Hawkins MRS (2020) The signature of primordial black holes in the dark matter halos of galaxies. Astron Astrophys 633:107. https://doi.org/10.1051/0004-6361/201936462 Hawkins MRS (2022) New evidence for a cosmological distribution of stellar mass primordial black holes. Mon Not R Astron Soc 512:5706–5714. https://doi.org/10.1093/mnras/stac863 Heyrovský D, Loeb A (1997) Microlensing of an elliptical source by a point mass. Astrophys J 490(1):38–50. https://doi.org/10.1086/304855 Higginbottom N, Proga D, Knigge C, Long KS, Matthews JH, Sim SA (2014) Line-driven disk winds in active galactic nuclei: the critical importance of ionization and radiative transfer. Astrophys J 789:19. https://doi.org/10.1088/0004-637X/789/1/19 Homayouni Y, Trump JR, Grier CJ, Horne K, Shen Y, Brandt WN, Dawson KS, Alvarez GF, Green PJ, Hall PB, Santisteban JVH, Ho LC, Kinemuchi K, Kochanek CS, Li JI-H, Peterson BM, Schneider DP, Starkey DA, Bizyaev D, Pan K, Oravetz D, Simmons A (2020) The Sloan Digital Sky Survey reverberation mapping project: Mg II lag results from four years of monitoring. Astrophys J 901:55. https://doi.org/10.3847/1538-4357/ababa9 Horne K, Welsh WF, Peterson BM (1991) Echo mapping of broad H\(\beta \) emission in NGC 5548. Astrophys J 367:5 Hu C, Du P, Lu KX, Li YR, Wang F, Qiu J, Bai JM, Kaspi S, Ho LC, Netzer H, Wang JM (2015) Supermassive black holes with high accretion rates in active galactic nuclei. III. Detection of Fe II reverberation in nine narrow-line Seyfert 1 galaxies. Astrophys J 804:138. https://doi.org/10.1088/0004-637X/804/2/138 Hubeny I, Agol E, Blaes O, Krolik JH (2000) Non-LTE models and theoretical spectra of accretion disks in active galactic nuclei. III. Integrated spectra for hydrogen-helium disks. Astrophys J 533:710–728 Huchra J, Gorenstein M, Kent S, Shapiro I, Smith G, Horine E, Whipple FL, Perley R (1985) 2237+0305: a new and unusual gravitational lens. Astron J 90:691 Hutsemékers D (1993) Selective gravitational microlensing and line profile variations in the BAL quasar H1413+117. Astron Astrophys 280:435 Hutsemékers D (1994) The use of gravitational microlensing to scan the structure of BAL QSOS. Astrophys Space Sci 216:361 Hutsemékers D, Sluse D (2021) Geometry and kinematics of the broad emission line region in the lensed quasar Q2237+0305. Astron Astrophys 654:A155. https://doi.org/10.1051/0004-6361/202141820 Hutsemékers D, Borguet B, Sluse D, Riaud P, Anguita T (2010) Microlensing in H1413+117: disentangling line profile emission and absorption in a broad absorption line quasar. Astron Astrophys 519:A103. https://doi.org/10.1051/0004-6361/200913247 Hutsemékers D, Sluse D, Braibant L, Anguita T (2015) Polarization microlensing in the quadruply imaged broad absorption line quasar H1413+117. Astron Astrophys 584:A61. https://doi.org/10.1051/0004-6361/201527243 Hutsemékers D, Braibant L, Sluse D, Anguita T, Goosmann R (2017) New constraints on quasar broad absorption and emission line regions from gravitational microlensing. Front Astron Space Sci 4:18. https://doi.org/10.3389/fspas.2017.00018 Hutsemekers D, Braibant L, Sluse D, Goosmann R (2019) Constraining the geometry and kinematics of the quasar broad emission line region using gravitational microlensing: II. Comparing models with observations in the lensed quasar HE0435-1223. Astron Astrophys 629:A43. https://doi.org/10.1051/0004-6361/201731087 Hutsemékers D, Sluse D, Kumar P (2020) Spatially separated continuum sources revealed by microlensing in the gravitationally lensed broad absorption line quasar SDSS J081830.46+060138.0. Astron Astrophys 633:A101. https://doi.org/10.1051/0004-6361/201936973 Hutsemékers D, Sluse D, Savic D, Richards GT (2023) Microlensing of the broad emission line region in the lensed quasar J1004+4112. Astron Astrophys. https://doi.org/10.1051/0004-6361/202245490 Hyde JB, Bernardi M (2009) The luminosity and stellar mass fundamental plane of early-type galaxies. Mon Not R Astron Soc 396:1171–1185. https://doi.org/10.1111/j.1365-2966.2009.14783.x Ichimaru S (1977) Bimodal behavior of accretion disks: theory and application to Cygnus X-1 transitions. Astrophys J 214:840–855. https://doi.org/10.1086/155314 Inoue KT (2016) On the origin of the flux ratio anomaly in quadruple lens systems. Mon Not R Astron Soc 461:164–175. https://doi.org/10.1093/mnras/stw1270 Irwin MJ, Webster RL, Hewett PC, Corrigan RT, Jedrzejewski RI (1989) Photometric variations in the Q2237+0305 system: first detection of a microlensing event. Astron J 98:1989 Jiang Y-F, Davis SW, Stone JM (2016) Iron opacity bump changes the stability and structure of accretion disks in active galactic nuclei. Astrophys J 827:10. https://doi.org/10.3847/0004-637x/827/1/10 Jiménez-Vicente J, Mediavilla E (2019) The initial mass function of lens galaxies from quasar microlensing. Astrophys J 885:75. https://doi.org/10.3847/1538-4357/ab46b8 Jiménez-Vicente J, Mediavilla E (2022) Fast multipole method for gravitational lensing: application to high-magnification quasar microlensing. Astrophys J 941:80. https://doi.org/10.3847/1538-4357/ac9e59 Jiménez-Vicente J, Mediavilla E, Muñoz JA, Kochanek CS (2012) A robust determination of the size of quasar accretion disks using gravitational microlensing. Astrophys J 751:106. https://doi.org/10.1088/0004-637X/751/2/106 Jiménez-Vicente J, Mediavilla E, Kochanek CS, Muñoz JA, Motta V, Falco E, Mosquera AM (2014) The average size and temperature profile of quasar accretion disks. Astrophys J 783:47 Jiménez-Vicente J, Mediavilla E, Kochanek CS, Muñoz JA (2015a) Dark matter mass fraction in lens galaxies: new estimates from microlensing. Astrophys J 799:149. https://doi.org/10.1088/0004-637X/783/1/47 Jiménez-Vicente J, Mediavilla E, Kochanek CS, Muñoz JA (2015b) Probing the dark matter radial profile in lens galaxies and the size of X-ray emitting region in quasars with microlensing. Astrophys J 806:251. https://doi.org/10.1088/0004-637X/799/2/149 Jorstad S et al. (2023) The Event Horizon Telescope image of the quasar NRAO 530. Astrophys J 943:170. https://doi.org/10.3847/1538-4357/acaea8 Jovanović P, Popović LČ, Simić S (2009) Influence of gravitational microlensing on broad absorption lines of QSOs: the case of the Fe K \(\alpha \) line. New Astron Rev 53(7–10):156–161. https://doi.org/10.1016/j.newar.2009.07.008 Kaspi S, Smith PS, Netzer H, Maoz D, Jannuzi BT, Giveon U (2000) Reverberation measurements for 17 quasars and the size-mass-luminosity relations in active galactic nuclei. Astrophys J 533:631–649 Kaspi S, Brandt WN, Maoz D, Netzer H, Schneider DP, Shemmer O (2007) Reverberation mapping of high-luminosity quasars: first results. Astrophys J 659:997 Katz JI (1976) Nonrelativistic Compton scattering and models of quasars. Astrophys J 206:910–916. https://doi.org/10.1086/154455 Katz N, Balbus S, Paczynski B (1986) Random scattering approach to gravitational microlensing. Astrophys J 306:2 Kauffmann G, Heckman TM, White SDM, Charlot S, Tremonti C, Brinchmann J, Bruzual G, Peng EW, Seibert M, Bernardi M, Blanton M, Brinkmann J, Castander F, Csábai I, Fukugita M, Ivezic Z, Munn JA, Nichol RC, Padmanabhan N, Thakar AR, Weinberg DH, York D (2003) Stellar masses and star formation histories for \(10^{5}\) galaxies from the sloan digital sky survey. Mon Not R Astron Soc 341:33–53 Kayser R (1992) Gravitational microlensing. In: Kayser R, Schramm T, Nieser L (eds) Gravitational lenses. Lecture notes in physics, vol 406. Springer, Heidelberg, pp 143–155. https://doi.org/10.1007/3-540-55797-0_94 Kayser R, Refsdal S, Stabell R (1986) Astrophysical aplications of gravitational micro-lensing. Astron Astrophys 166:36 Kedziora DJ, Garsden H, Lewis GF (2011) Gravitational microlensing as a probe of the electron-scattering region in Q2237+0305. Mon Not R Astron Soc 415:1409–1418. https://doi.org/10.1111/j.1365-2966.2011.18787.x Keeton CR, Burles S, Schechter PL, Wambsganss J (2006) Differential microlensing of the continuum and broad emission lines in SDSS J0924 + 0219, the most anomalous lensed quasar. Astrophys J 639:1–6 Khavinson D, Neumann G (2004) On the number of zeros of certain rational harmonic functions. https://doi.org/10.48550/arXiv.math/0401188 Kishimoto M, Hönig SF, Beckert T, Weigelt G (2007) The innermost region of AGN tori: implications from the HST/NICMOS type 1 point sources and near-ir reverberation. Astron Astrophys 476:713–721. https://doi.org/10.1051/0004-6361:20077911 Kishimoto M, Hönig SF, Antonucci R, Barvainis R, Kotani T, Tristram KRW, Weigelt G, Levin K (2011a) The innermost dusty structure in active galactic nuclei as probed by the Keck interferometer. Astron Astrophys 527:A121. https://doi.org/10.1051/0004-6361/201016054 Kishimoto M, Hönig SF, Antonucci R, Millour F, Tristram KRW, Weigelt G (2011b) Mapping the radial structure of AGN tori. Astron Astrophys 536:A78. https://doi.org/10.1051/0004-6361/201117367 Kochanek CS (2004) Quantitative interpretation of quasar microlensing light curves. Astrophys J 605:58–77. https://doi.org/10.1086/382180 Koda J, Blake C, Davis T, Magoulas C, Springob CM, Scrimgeour M, Johnson A, Poole GB, Staveley-Smith L (2014) Are peculiar velocity surveys competitive as a cosmological probe? Mon Not R Astron Soc 445(4):4267–4286. https://doi.org/10.1093/mnras/stu1610 Kollmeier JA, Onken CA, Kochanek CS, Gould A, Weinberg DH, Dietrich M, Cool R, Dey A, Eisenstein DJ, Jannuzi BT, Floc’ EL, Stern D (2006) Black hole masses and Eddington ratios at \(0.3 < z < 4\). Astrophys J 648:128 Koopmans LVE, Bruyn AGD (2000) Microlensing of multiply-imaged compact radio sources evidence for compact halo objects in the disk galaxy of B1600+434. Astron Astrophys 358:793–811 Koptelova E, Shimanovskaya E, Artamonov B, Yagola A (2007) Analysis of the Q2237+0305 light-curve variability with regularization technique. Mon Not R Astron Soc 381:1655–1662. https://doi.org/10.1111/j.1365-2966.2007.12335.x Korista KT, Goad MR (2001) The variable diffuse continuum emission of broad-line clouds. Astrophys J 553:695–708 Korista KT, Alloin D, Barr P, Clavel J, Cohen RD, Crenshaw DM, Evans IN, Horne K, Koratkar AP, Kriss GA, Krolik JH, Malkan MA, Morris SL, Netzer H, O’Brien PT, Peterson BM, Reichert GA, Rodriguez-Pascual PM, Wamsteker W, Anderson KSJ, Axon DJ, Benitez E, Berlind P, Bertram R, Blackwell JH Jr, Bochkarev NG, Boisson C, Carini M, Carrillo R, Carone TE, Cheng F-Z, Christensen JA, Chuvaev KK, Dietrich M, Dokter JJ, Doroshenko V, Dultzin-Hacyan D, England MN, Espey BR, Filippenko AV, Gaskell CM, Goad MR, Ho LC, Huchra JP, Jiang XJ, Kaspi S, Kollatschny W, Laor A, Luminet J-P, MacAlpine GM, MacKenty JW, Malkov YF, Maoz D, Martin PG, Matheson T, McCollum B, Merkulova N, Metik L, Mignoli M, Miller HR, Pastoriza MG, Pelat D, Penfold J, Perez M, Perola GC, Persaud JL, Peters J, Pitts R, Pogge RW, Pronik I, Pronik VI, Ptak RL, Rawley L, Recondo-Gonzalez MC, Rodriguez-Espinosa JM, Romanishin W, Sadun AC, Salamanca I, Santos-Lleo M, Sekiguchi K, Sergeev SG, Shapovalova AI, Shields JC, Shrader C, Shull JM, Silbermann NA, Sitko ML, Skillman DR, Smith HA, Smith SM, Snijders MAJ, Sparke LS, Stirpe GM, Stoner RE, Sun W-H, Thiele U, Tokarz S, Tsvetanov ZI, Turnshek DA, Veilleux S, Wagner RM, Wagner SJ, Wanders I, Wang T, Welsh WF, Weymann RJ, White RJ, Wilkes BJ, Wills BJ, Winge C, Wu H, Zou ZL (1995) Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VIII. An intensive HST, IUE, and ground-based study of NGC 5548. Astrophys J Suppl Ser 97:13 Koshida S, Minezaki T, Yoshii Y, Kobayashi Y, Sakata Y, Sugawara S, Enya K, Suganuma M, Tomita H, Aoki T, Peterson BA (2014) Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies. Astrophys J 788:159. https://doi.org/10.1088/0004-637X/788/2/159 Krawczynski H, Chartas G (2017) Simulations of the Fe K\(\alpha \) energy spectra from gravitationally microlensed quasars. Astrophys J 843(2):118. https://doi.org/10.3847/1538-4357/aa7896 Kundic T, Wambsganss J (1993) Gravitational microlensing: the effect of random motion of individual stars in the lensing galaxy. Astrophys J 404:455. https://doi.org/10.1192/bjp.111.479.1009-a Lamer G, Schwope A, Wisotzki L, Christensen L (2006) Strange magnification pattern in the large separation lens SDSS J1004+4112 from optical to X-rays. Astron Astrophys 454:493–501. https://doi.org/10.1051/0004-6361:20064934 Lančová D, Abarca D, Kluźniak W, Wielgus M, Sądowski A, Narayan R, Schee J, Török G, Abramowicz M (2019) Puffy accretion disks: sub-Eddington, optically thick, and stable. Astrophys J 884:37. https://doi.org/10.3847/2041-8213/ab48f5 Laor A (1991) Line profiles from a disk around a rotating black hole. Astrophys J 376:90. https://doi.org/10.1086/170257 Laor A, Behar E (2008) On the origin of radio emission in radio-quiet quasars. Mon Not R Astron Soc 390:847–862. https://doi.org/10.1111/j.1365-2966.2008.13806.x Lasota JP (2023) Active galactic nuclei. Wiley, New York, pp 1–320. https://doi.org/10.1002/9781394163724 Lasota JP, King AR, Dubus G (2015) X-ray transients: hyper- or hypo-luminous? Astrophys J Lett 801:L4. https://doi.org/10.1088/2041-8205/801/1/L4 Lawrence A (2012) The uv peak in active galactic nuclei: a false continuum from blurred reflection? Mon Not R Astron Soc 423:451–463. https://doi.org/10.1111/j.1365-2966.2012.20889.x Lawther D, Vestergaard M, Raimundo S, Koay JY, Peterson BM, Fan X, Grupe D, Mathur S (2023) Flares in the changing look AGN MRK 590 – I. The UV response to X-ray outbursts suggests a more complex reprocessing geometry than a standard disc. Mon Not R Astron Soc 519:3903–3922. https://doi.org/10.1093/mnras/stac3515 Ledvina L, Heyrovský D, Dovčiak M (2018) X-ray line profile variations during quasar microlensing. Astrophys J 863(1):66. https://doi.org/10.3847/1538-4357/aad0f3 Lehar J, Falco EE, Kochanek CS, McLeod BA, Muñoz JA, Impey CD, Rix H-W, Keeton CR, Peng CY (2000) Hubble space telescope observations of 10 two-image gravitational lenses. Astrophys J 536:584 Lemon C et al (2024) Searching for strong gravitational lenses. Space Sci Rev 220. https://doi.org/10.1007/s11214-024-01042-9 Lewis GF (2020) Gravitational microlensing time delays at high optical depth: image parities and the temporal properties of fast radio bursts. Mon Not R Astron Soc 497:1583–1589. https://doi.org/10.1093/mnras/staa2044 Lewis GF, Belle KE (1998) Microlensing of broad absorption line quasars. Mon Not R Astron Soc 297:69–76 Lewis GF, Ibata RA (1998) Quasar image shifts resulting from gravitational microlensing. Astrophys J 501(2):478–485. https://doi.org/10.1086/305860 Lewis GF, Ibata RA (2004) Gravitational microlensing of quasar broad-line regions at large optical depths. Mon Not R Astron Soc 348(1):24–33. https://doi.org/10.1111/j.1365-2966.2004.07349.x Lewis GF, Irwin MJ (1995) The statistics of micolensing light curves – I. Amplification probability distributions. Mon Not R Astron Soc 276:103 Lewis GF, Miralda-Escudé J, Richardson DC, Wambsganss J (1993) Microlensing light curves: a new and efficient numerical method. Mon Not R Astron Soc 261:647 Lewis GF, Irwin MJ, Hewett PC, Foltz CB (1998) Microlensing-induced spectral variability in Q2237+0305. Mon Not R Astron Soc 295:573–586 Li YR, Wang JM, Ho LC, Du P, Bai JM (2013) A Bayesian approach to estimate the size and structure of the broad-line region in active galactic nuclei using reverberation mapping data. Astrophys J 779:110. https://doi.org/10.1088/0004-637X/779/2/110 Li YP, Yuan F, Dai X (2019) Reconciling the quasar microlensing disc size problem with a wind model of active galactic nucleus. Mon Not R Astron Soc 483:2275–2281. https://doi.org/10.1093/mnras/sty3245 Lightman AP, White TR (1988) Effects of cold matter in active galactic nuclei: a broad hump in the X-ray spectra. Astrophys J 335:57. https://doi.org/10.1086/166905 Luhtaru R, Schechter PL, de Soto KM (2021) What makes quadruply lensed quasars quadruple? Astrophys J 915:4. https://doi.org/10.3847/1538-4357/abfda1 Lynden-Bell D (1969) Galactic nuclei as collapsed old quasars. Nature 223:690–694. https://doi.org/10.1038/223690a0 MacLeod CL, Morgan CW, Mosquera AM, Kochanek CS, Tewes M, Courbin F, Meylan G, Chen B, Dai X, Chartas G (2015) A consistent picture emerges: a compact X-ray continuum emission region in the gravitationally lensed quasar SDSS J0924+0219. Astrophys J 806:258. https://doi.org/10.1088/0004-637X/806/2/258 Makarov VV, Secrest NJ (2022) Quasars with proper motions and the link to double and multiple AGNs. Astrophys J 933(1):28. https://doi.org/10.3847/1538-4357/ac7047 Mao S (1993) Gravitational microlensing of gamma-ray bursts. Astrophys J 402:382–386 Mao S, Schneider P (1998) Evidence for substructure in lens galaxies? Mon Not R Astron Soc 295:587–594 Marconi A, Hunt LK (2003) The relation between black hole mass, bulge mass, and near-infrared luminosity. Astrophys J 589:21–24 Marziani P, Sulentic JW, Zwitter T, Dultzin-Hacyan D, Calvani M (2001) Searching for the physical drivers of the eigenvector 1 correlation space. Astrophys J 558:553–560 McGill P, Anderson J, Casertano S, Sahu KC, Bergeron P, Blouin S, Dufour P, Smith LC, Evans NW, Belokurov V, Smart RL, Bellini A, Calamida A, Dominik M, Kains N, Klüter J, Nielsen MB, Wambsganss J (2023) First semi-empirical test of the white dwarf mass-radius relationship using a single white dwarf via astrometric microlensing. Mon Not R Astron Soc 520(1):259–280. https://doi.org/10.1093/mnras/stac3532 Mediavilla E, Muñoz JA, Kochanek CS, Falco EE, Arribas S, Motta V (2005) The first precise determination of an optical-far-ultraviolet extinction curve beyond the local group (\(z = 0.83\)). Astrophys J 619:749 Mediavilla E, Munoz JA, Lopez P, Mediavilla T, Abajas C, Gonzalez-Morcillo C, Gil-Merino R (2006) A fast and very accurate approach to the computation of microlensing magnification patterns based on inverse polygon mapping. Astrophys J 653:942–953. https://doi.org/10.1086/508796 Mediavilla E, Muñoz JA, Falco E, Motta V, Guerras E, Canovas H, Jean C, Oscoz A, Mosquera AM (2009) Microlensing-based estimate of the mass fraction in compact objects in lens galaxies. Astrophys J 706:1451–1462. https://doi.org/10.1088/0004-637X/706/2/1451 Mediavilla E, Mediavilla T, Muñoz JA, Ariza O, Lopez P, Gonzalez-Morcillo C, Jiménez-Vicente J (2011) New developments on inverse polygon mapping to calculate gravitational lensing magnification maps: optimized computations. Astrophys J 741:42. https://doi.org/10.1088/0004-637X/741/1/42 Mediavilla E, Jiménez-Vicente J, Muñoz JA, Mediavilla T (2015) Resolving the innermost region of the accretion disk of the lensed quasar Q2237+0305 through gravitational microlensing. Astrophys J Lett 814:L26. https://doi.org/10.1088/2041-8205/814/2/L26 Mediavilla E, Jiménez-Vicente J, Muñoz JA, Battaner E (2016) Peculiar transverse velocities of galaxies from quasar microlensing. Tentative estimate of the peculiar velocity dispersion at \(Z \sim 0.5\). Astrophys J 832(1):46. https://doi.org/10.3847/0004-637X/832/1/46 Mediavilla E, Jiménez-Vicente J, Muñoz JA, Vives-Arias H, Calderón-Infante J (2017) Limits on the mass and abundance of primordial black holes from quasar gravitational microlensing. Astrophys J 836:18. https://doi.org/10.3847/2041-8213/aa5dab Mediavilla E, Jiménez-vicente J, Mejía-restrepo J, Motta V, Falco E, Muñoz JA, Fian C, Guerras E (2020) Individual estimates of the virial factor in 10 quasars: implications on the kinematics of the broad-line region. Astrophys J 895:111. https://doi.org/10.3847/1538-4357/ab8ae0 Melo A, Motta V, Godoy N, Mejia-Restrepo J, Assef RJ, Mediavilla E, Falco E, ávila-Vera F, Jerez R (2021) First black hole mass estimation for the quadruple lensed system WGD2038-4008. Astron Astrophys 656:A108. https://doi.org/10.1051/0004-6361/202141869 Merloni A, Fabian AC (2001) Thunderclouds and accretion discs: a model for the spectral and temporal variability of Seyfert 1 galaxies. Mon Not R Astron Soc 328(3):958–968. https://doi.org/10.1046/j.1365-8711.2001.04925.x Metcalf RB, Zhao H (2002) Flux ratios as a probe of dark substructures in quadruple-image gravitational lenses. Astrophys J Lett 567:5–8 Middleton MJ, Heil L, Pintore F, Walton DJ, Roberts TP (2015) A spectral-timing model for ULXs in the supercritical regime. Mon Not R Astron Soc 447:3243–3263. https://doi.org/10.1093/mnras/stu2644 Millon M, Courbin F, Bonvin V, Paic E, Meylan G, Tewes M, Sluse D, Magain P, Chan JHH, Galan A, Joseph R, Lemon C, Tihhonova O, Anderson RI, Marmier M, Chazelas B, Lendl M, Triaud AHMJ, Wyttenbach A (2020a) Cosmograil. XIX. Time delays in 18 strongly lensed quasars from 15 years of optical monitoring. Astron Astrophys 640:105. https://doi.org/10.1051/0004-6361/202037740 Millon M, Galan A, Courbin F, Treu T, Suyu SH, Ding X, Birrer S, Chen GCF, Shajib AJ, Sluse D, Wong KC, Agnello A, Auger MW, Buckley-Geer EJ, Chan JHH, Collett T (2020b) TDCOSMO: I. An exploration of systematic uncertainties in the inference of \(H_{0}\) from time-delay cosmography. Astron Astrophys 639:1–19. https://doi.org/10.1051/0004-6361/201937351 Millon M, Dalang C, Lemon C, Sluse D, Paic E, Chan JHH, Courbin F (2022) Evidence for a milliparsec-separation supermassive binary black hole with quasar microlensing. Astron Astrophys 668:A77. https://doi.org/10.1051/0004-6361/202244440 Mineshige S, Yonehara A (1999) Gravitational microlens mapping of a quasar accretion disk. Publ Astron Soc Jpn 51:497 Minezaki T, Chiba M, Kashikawa N, Inoue KT, Kataza H (2009) Subaru mid-infrared imaging of the quadruple lenses. II. Unveiling lens structure of MG0414+0534 and Q2237+030. Astrophys J 697:610–618. https://doi.org/10.1088/0004-637X/697/1/610 Moore GE (1965) Cramming more components onto integrated circuits. Electron Mag 38:4 Morgan CW, Kochanek CS, Morgan ND, Falco EE (2006) Microlensing of the lensed quasar SDSS 0924+0219. Astrophys J 647:874–885. https://doi.org/10.1086/505569 Morgan CW, Kochanek CS, Dai X, Morgan ND, Falco EE, Al MET (2008) X-ray and optical microlensing in the lensed quasar PG 1115 + 080 1. Astrophys J 689:755 Morgan CW, Kochanek CS, Morgan ND, Falco EE (2010) The quasar accretion disk size-black hole mass relation. Astrophys J 712:1129–1136. https://doi.org/10.1088/0004-637X/712/2/1129 Morgan CW, Hainline LJ, Chen B, Tewes M, Kochanek CS, Dai X, Kozlowski S, Blackburne JA, Mosquera AM, Chartas G, Courbin F, Meylan G (2012) Further evidence that quasar X-ray emitting regions are compact: X-ray and optical microlensing in the lensed quasar Q J0158-4325. Astrophys J 756:52. https://doi.org/10.1088/0004-637X/756/1/52 Morgan CW, Hyer GE, Bonvin V, Mosquera AM, Cornachione M, Courbin F, Kochanek CS, Falco EE (2018) Accretion disk size measurement and time delays in the lensed quasar WFI 2033–4723. Astrophys J 869:106. https://doi.org/10.3847/1538-4357/aaed3e Mortonson MJ, Schechter PL, Wambsganss J (2005) Size is everything: universal features of quasar microlensing with extended sources. Astrophys J 628:594–603. https://doi.org/10.1086/431195 Mosquera AM, Kochanek CS (2011) The microlensing properties of a sample of 87 lensed quasars. Astrophys J 738:96. https://doi.org/10.1088/0004-637X/738/1/96 Mosquera AM, Muñoz JA, Mediavilla E (2009) Detection of chromatic microlensing in Q 2237 + 0305 A. Astrophys J 691:1292–1299. https://doi.org/10.1088/0004-637X/691/2/1292 Mosquera AM, Muñoz JA, Mediavilla E, Kochanek CS (2011) A study of gravitational lens chromaticity using ground-based narrowband photometry. Astrophys J 728:145. https://doi.org/10.1088/0004-637X/728/2/145 Mosquera AM, Kochanek CS, Chen B, Dai X, Blackburne JA, Chartas G (2013) The structure of the X-ray and optical emitting regions of the lensed quasar Q 2237+0305. Astrophys J 769:53 Motta V, Mediavilla E, Oz JAM, Falco E, Kochanek CS, Arribas S, García-Lorenzo B, Oscoz A, Serra-Ricart M (2002) Detection of the 2175 a ˚ extinction feature at \(z = 0.83\). Astrophys J 574:719 Motta V, Mediavilla E, Falco E, Munoz JA (2012) Measuring microlensing using spectra of multiply lensed quasars. Astrophys J 755:82. https://doi.org/10.1088/0004-637X/755/1/82 Moustakas L, O’Dowd M, Anguita T, Webster R, Chartas G, Cornachione M, Dai X, Fian C, Hutsemekers D, Jimenez-Vicente J, Labrie K, Lewis G, Macleod C, Mediavilla E, Morgan CW, Motta V, Nierenberg A, Pooley D, Rojas K, Sluse D, Vernardos G, Wambsganss J, Yong SY (2019) Astro2020 science white paper – quasar microlensing: revolutionizing our understanding of quasar structure and dynamics. arXiv e-prints. arXiv:1904.12967. https://doi.org/10.48550/arXiv.1904.12967 Muñoz JA, Mediavilla E, Kochanek CS, Falco EE, Mosquera AM (2011) A study of gravitational lens chromaticity with the Hubble space telescope. Astrophys J 742:67. https://doi.org/10.1088/0004-637X/742/2/67 Muñoz JA, Vives-Arias H, Mosquera AM, Jiménez-Vicente J, Kochanek CS, Mediavilla E (2016) Structure of the accretion disk in the lensed quasar Q2237+0305 from multi-epoch and multi-wavelength narrowband photometry. Astrophys J 817:155. https://doi.org/10.3847/0004-637x/817/2/155 Murray N, Chiang J (1997) Disk winds and disk emission lines. Astrophys J 474:91–103 Murray N, Chiang J, Grossman SA, Voit GM (1995) Accretion disk winds from active galactic nuclei. Astrophys J 451:498 Mushotzky RF (1984) X-ray spectra and time variability of active galactic nuclei. Adv Space Res 3(10–12):157–165. https://doi.org/10.1016/0273-1177(84)90081-4 Nagao T, Marconi A, Maiolino R (2006) The evolution of the broad-line region among sdss quasars. Astron Astrophys 447:157–172. https://doi.org/10.1051/0004-6361:20054024 Narayan R, Yi I (1994) Advection-dominated accretion: a self-similar solution. Astrophys J Lett 428:13–16 Neira F, Anguita T, Vernardos G (2020) A quasar microlensing light-curve generator for LSST. Mon Not R Astron Soc 495:544–553. https://doi.org/10.1093/mnras/staa1208 Neronov A, Vovk I (2016) Test of relativistic gravity using microlensing of relativistically broadened lines in gravitationally lensed quasars. Phys Rev D 93(2):023006. https://doi.org/10.1103/PhysRevD.93.023006 Netzer H (2015) Revisiting the unified model of active galactic nuclei. Annu Rev Astron Astrophys 53:365–408. https://doi.org/10.1146/annurev-astro-082214-122302 Nixon C, King A, Price D, Frank J (2012) Tearing up the disk: how black holes accrete. Astrophys J Lett 757:L24. https://doi.org/10.1088/2041-8205/757/2/L24 Novikov ID, Thorne KS (1973) Astrophysics of black holes, DeWitt C, DeWitt BS (eds). Gordon & Breach, New York, pp 343–450 O’Dowd M, Bate NF, Webster RL, Wayth R, Labrie K (2011) Differential microlensing measurements of quasar broad-line kinematics in Q2237+0305. Mon Not R Astron Soc 415:1985–1998. https://doi.org/10.1111/j.1365-2966.2010.18119.x O’Dowd MJ, Bate NF, Webster RL, Labrie K, Rogers J (2015) Microlensing constraints on broad absorption and emission line flows in the quasar H1413+117. Astrophys J 813:62. https://doi.org/10.1088/0004-637X/813/1/62 Oguri M, Marshall PJ (2010) Gravitationally lensed quasars and supernovae in future wide-field optical imaging surveys. Mon Not R Astron Soc 405:2579. https://doi.org/10.1111/j.1365-2966.2010.16639.x Oguri M, Rusu CE, Falco EE (2014) The stellar and dark matter distributions in elliptical galaxies from the ensemble of strong gravitational lenses. Mon Not R Astron Soc 439:2494–2504. https://doi.org/10.1093/mnras/stu106 Oshima T, Mitsuda K, Fujimoto R, Iyomoto N, Futamoto K, Hattori M, Ota N, Mori K, Ikebe Y, Miralles JM, Kneib J-P (2001) Detection of an iron emission feature from the lensed broad absorption line QSO H1413+117 at \(z = 2.56\). Astrophys J Lett 563(2):103–106. https://doi.org/10.1086/338653 Ostensen R, Refsdal S, Stabell R, Teuber J, Emanuelsen PI, Festin L, Florentin-Nielsen R, Gahm G (1996) Astron Astrophys 309:59. Ota N, Inada N, Oguri M, Mitsuda K, Richards GT, Suto Y, Brandt WN, Castander FJ, Fujimoto R, Hall PB, Keeton CR, Nichol RC, Schneider DP, Eisenstein DE, Frieman JA, Turner EL, Minezaki T, Yoshii Chandra Y (2006) Observations of SDSS J1004+4112: constraints on the lensing cluster and anomalous X-ray flux ratios of the quadruply imaged quasar. Astrophys J 647(1):215–221. https://doi.org/10.1086/505385 Paczynski B (1986) Gravitational microlensing at large optical depth. Astrophys J 301:503 Padovani P, Alexander DM, Assef RJ, Marco BD, Giommi P, Hickox RC, Richards GT, Smolčić V, Hatziminaoglou E, Mainieri V, Salvato M (2017) Active galactic nuclei: what’s in a name? Astron Astrophys Rev 25:2. https://doi.org/10.1007/s00159-017-0102-9 Paic E, Vernardos G, Sluse D, Millon M, Courbin F, Chan JH, Bonvin V (2022) Constraining quasar structure using high-frequency microlensing variations and continuum reverberation. Astron Astrophys 659:A21. https://doi.org/10.1051/0004-6361/202141808 Pancoast A, Brewer BJ, Treu T (2011) Geometric and dynamical models of reverberation mapping data. Astrophys J 730:139. https://doi.org/10.1088/0004-637X/730/2/139 Pancoast A, Brewer BJ, Treu T (2014) Modelling reverberation mapping data – I. Improved geometric and dynamical models and comparison with cross-correlation results. Mon Not R Astron Soc 445:3055–3072. https://doi.org/10.1093/mnras/stu1809 Papadakis IE, DovĆiak M, Kammoun ES (2022) X-ray illuminated accretion discs and quasar microlensing disc sizes. Astron Astrophys 666:A11. https://doi.org/10.1051/0004-6361/202142962 Parker ML, Tomsick JA, Miller JM, Yamaoka K, Lohfink A, Nowak M, Fabian AC, Alston WN, Boggs SE, Christensen FE, Craig WW, Fürst F, Gandhi P, Grefenstette BW, Grinberg V, Hailey CJ, Harrison FA, Kara E, King AL, Stern D, Walton DJ, Wilms J, Zhang WW (2015) NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk. Astrophys J 808(1):9. https://doi.org/10.1088/0004-637X/808/1/9 Pashchenko IN, Plavin AV, Kutkin AM, Kovalev YY (2020) A bias in VLBI measurements of the core shift effect in AGN jets. Mon Not R Astron Soc 499(3):4515–4525. https://doi.org/10.1093/mnras/staa3140 Peterson BM, Wandel A (1999) Keplerian motion of broad-line region gas as evidence for supermassive black holes in active galactic nuclei. Astrophys J 521:95–98 Peterson BM, Crenshaw DM, Meyers KA (1985) Variability of the emission-line spectra and optical continua of seyfert galaxies. III. Results for a homogeneous sample. Astrophys J 298:283–291 Peterson BM, Bentz MC, Desroches L-B, Filippenko AV, Ho LC, Kaspi S, Laor A, Maoz D, Moran EC, Pogge RW, Quillen AC (2005) Multiwavelength monitoring of the dwarf Seyfert 1 galaxy NGC 4395. I. A reverberation-based measurement of the black hole mass. Astrophys J 632(2):799–808. https://doi.org/10.1086/444494 Petters AO (1992) Morse theory and gravitational microlensing. J Math Phys 33:1915–1931. https://doi.org/10.1063/1.529667 Petters AO, Levine H, Wambsganss J (2001) Singularity theory and gravitational lensing. Progress in Mathematical Physics, vol 21. Birkhäuser, Boston, MA. https://doi.org/10.1007/978-1-4612-0145-8 Petters AO, Rider B, Teguia AM (2009a) A mathematical theory of stochastic microlensing. I. Random time-delay functions and lensing maps. J Math Phys 50:072503. https://doi.org/10.1063/1.3158854 Petters AO, Rider B, Teguia AM (2009b) A mathematical theory of stochastic microlensing. II. Random images, shear, and the Kac-Rice formula. J Math Phys 50:122501. https://doi.org/10.1063/1.3267859 Pfuhl O, Davies R, Dexter J, Netzer H, Hönig S, Lutz D, Schartmann M, Sturm E, Amorim A, Brandner W, Clénet Y, Zeeuw PTD, Eckart A, Eisenhauer F, Schreiber NMF, Gao F, Garcia PJV, Genzel R, Gillessen S, Gratadour D, Kishimoto M, Lacour S, Millour F, Ott T, Paumard T, Perraut K, Perrin G, Peterson BM, Petrucci PO, Prieto MA, Rouan D, Shangguan J, Shimizu T, Sternberg A, Straub O, Straubmeier C, Tacconi LJ, Tristram KRW, Vermot P, Waisberg I, Widmann F, Woillez J (GRAVITY Collaboration) (2020) An image of the dust sublimation region in the nucleus of NGC 1068. Astron Astrophys 634:A1. https://doi.org/10.1051/0004-6361/201936255 Poindexter S, Kochanek CS (2010) The transverse peculiar velocity of the Q2237+0305 lens galaxy and the mean mass of its stars. Astrophys J 712:658–667. https://doi.org/10.1088/0004-637X/712/1/658 Poindexter S, Morgan ND, Kochanek CS (2008) The spatial structure of an accretion disk. Astrophys J 673:34–38. https://doi.org/10.1086/524190 Pooley D, Blackburne JA, Rappaport S, Schechter PL (2007) X-ray and optical flux ratio anomalies in quadruply lensed quasars. I. Zooming in on quasar emission regions. Astrophys J 661:19–29 Pooley D, Rappaport S, Blackburne JA, Schechter PL, Wambsganss J (2012) X-ray and optical flux ratio anomalies in quadruply lensed quasars. II. Mapping the dark matter content in elliptical galaxies. Astrophys J 744:111. https://doi.org/10.1088/0004-637X/744/2/111 Popović LĆ, Chartas G (2005) The influence of gravitational lensing on the spectra of lensed quasi-stellar objects. Mon Not R Astron Soc 357:135–144. https://doi.org/10.1111/j.1365-2966.2004.08619.x Popović LČ, Jovanović P, Mediavilla E, Zakharov AF, Abajas C, Muñoz JA, Chartas G (2006) A study of the correlation between the amplification of the Fe K\(\alpha \) line and the X-ray continuum of quasars due to microlensing. Astrophys J 637(2):620–630. https://doi.org/10.1086/498558 Popović LA, Afanasiev VL, Moiseev A, Smirnova A, Simić S, Savić D, Mediavilla EG, Fian C (2020) Spectroscopy and polarimetry of the gravitationally lensed quasar SDSS J1004+4112 with the 6m SAO RAS telescope. Astron Astrophys 634:A27. https://doi.org/10.1051/0004-6361/201936088 Popović LC, Afanasiev VL, Shablovinskaya ES, Ardilanov VI, Savić DJ (2021) Spectroscopy and polarimetry of the gravitationally lensed quasar Q0957+561. Astron Astrophys 647:A98. https://doi.org/10.1051/0004-6361/202039914 Pozdnyakov LA, Sobol IM, Syunyaev RA (1976) Multiple Compton scattering by relativistic electrons – Monte Carlo calculations of the emission spectrum. Sov Astron Lett 2:55–57 Press WH, Gunn JE (1973) Method for detecting a cosmological density of condensed objects. Astrophys J 185:397–412 Rauch KP, Blandford RD (1991) Microlensing and the structure of active galactic nucleus accretion discs. Astrophys J 381:39 Rauch KP, Mao S, Wambsganss J, Paczynski B (1992) Caustic-induced features in microlensing magnification probability distributions. Astrophys J 386:30 Refsdal S, Stabell R (1997) Gravitational microlensing of large sources including shear term effects. Astron Astrophys 325:877–880 Reynolds CS, Nowak MA (2003) Fluorescent iron lines as a probe of astrophysical black hole systems. Phys Rep 377:389 Richards GT, Keeton CR, Pindor B, Hennawi JF, Hall PB, Turner EL, Inada N, Oguri M, Ichikawa S-I, Becker RH, Gregg MD, White RL, Stuart J, Wyithe B, Schneider DP, Johnston DE, Frieman JA, Brinkmann J (2004) Microlensing of the broad emission line region in the quadruple lens SDSS J1004+4112. Astrophys J 610:679 Risaliti G, Lusso E (2019) Cosmological constraints from the Hubble diagram of quasars at high redshifts. Nat Astron 3:272–277. https://doi.org/10.1038/s41550-018-0657-z Rojas K, Motta V, Mediavilla E, Falco E, Jiménez-Vicente J, Muñoz JA (2014) Strong chromatic microlensing in HE0047-1756 and SDSS1155+6346. Astrophys J 797(1):61 Rothschild RE, Mushotzky FR, Baity WA, Gruber DE, Matteson JL, Peterson LE (1983) 2-165 keV observations of active galaxies and the diffuse background. Astrophys J 269:423–437. https://doi.org/10.1086/161053 Rusu CE, Wong KC, Bonvin V, Sluse D, Suyu SH, Fassnacht CD, Chan JHH, Hilbert S, Auger MW, Sonnenfeld A, Birrer S, Courbin F, Treu T, Chen GC-F, Halkola A, Koopmans LVE, Marshall PJ, Shajib AJ (2020) H0LiCOW. XII. Lens mass model of WFI2033-4723 and blind measurement of its time-delay distance and \(H_{0}\). Mon Not R Astron Soc 498:1440–1468. https://doi.org/10.1093/mnras/stz3451 Sądowski A, Abramowicz M, Bursa M, Kluźniak W, Lasota J-P, Różańska A (2011) Relativistic slim disks with vertical structure. Astron Astrophys 527:17. https://doi.org/10.1051/0004-6361/201015256 Saha P (2000) Lensing degeneracies revisited. Astron J 120:1654–1659 Saha P, Williams LLR (2011) Understanding micro-image configurations in quasar microlensing. Mon Not R Astron Soc 411:1671–1677. https://doi.org/10.1111/j.1365-2966.2010.17797.x Saha P, Sluse D, Wagner J, Williams LLR (2024) Essentials of strong gravitational lensing. Space Sci Rev 220:12. https://doi.org/10.1007/s11214-024-01041-w Sarkar A, Ferland GJ, Chatzikos M, Guzmán F, van Hoof PAM, Smyth RT, Ramsbottom CA, Keenan FP, Ballance CP (2021) Improved Fe II emission-line models for AGNs using new atomic data sets. Astrophys J 907:12. https://doi.org/10.3847/1538-4357/abcaa6 Schechter PL, Wambsganss J (2002) Quasar microlensing at high magnification and the role of dark matter: enhanced fluctuations and suppressed saddle points. Astrophys J 580:685–695. https://doi.org/10.1086/343856 Schechter PL, Udalski A, Szymański M, Kubiak M, Pietrzyński G, Soszyński I, Woźniak P, Żebruń K, Szewczyk O, Wyrzykowski Ł (2003) Microlensing of relativistic knots in the quasar HE 1104-1805 AB. Astrophys J 584:657 Schechter PL, Wambsganss J, Lewis GF (2004) Qualitative aspects of quasar microlensing with two mass components: magnification patterns and probability distributions. Astrophys J 613:77–85 Schechter PL, Pooley D, Blackburne JA, Wambsganss J (2014) A calibration of the stellar mass fundamental plane at \(z \sim 0.5\) using the micro-lensing-induced flux ratio anomalies of macro-lensed quasars. Astrophys J 793:96. https://doi.org/10.1088/0004-637X/793/2/96 Schild RE (1996) Microlensing variability of the gravitationally lensed quasar Q0957+561 A, B. Astrophys J 464:125 Schmidt RW, Wambsganss J (2010) Quasar microlensing. Gen Relativ Gravit 42:2127–2150. https://doi.org/10.1007/s10714-010-0956-x Schneider P (1993) Upper bounds on the cosmological density of compact objects with sub-solar masses from the variability of QSOS. Astron Astrophys 279:1–20 Schneider P, Wambsganss J (1990) Are the broad emission lines of quasars affected by gravitational microlensing? Astron Astrophys 237:42–53 Schneider P, Weiss A (1987) A gravitational lens origin for agn-variability? Consequences of micro-lensing. Astron Astrophys 171:49 Schneider P, Ehlers J, Falco EE (1992) Gravitational lenses. Springer, Berlin. https://doi.org/10.1007/978-3-662-03758-4 Schneider P, Kochanek CS, Wambsganss J (2006) Gravitational lensing: strong, weak, micro, Meylan G, Jetzer P, North P (eds). Springer, Berlin. https://doi.org/10.1007/978-3-540-30310-7 Shajib AJ et al (2024) Strong lensing by galaxies. Space Sci Rev 220 Shakura NI, Sunyaev RA (1973) Black holes in binary systems. Observational appearance. Astron Astrophys 24:337 Shalyapin VN, Goicoechea LJ (2014) Deep optical imaging and spectroscopy of the lens system SDSS J1339+1310. Astron Astrophys 568:A116. https://doi.org/10.1051/0004-6361/201323360 Shalyapin VN, Gil-Merino R, Goicoechea LJ (2021) Fast simulations of extragalactic microlensing. Astron Astrophys 653:A121. https://doi.org/10.1051/0004-6361/202140527 Shapiro SL, Lightman AP, Eardley DM (1976) A two-temperature accretion disk model for Cygnus X-1: structure and spectrum. Astrophys J 204:187–199. https://doi.org/10.1086/154162 Shen Y, Ho LC (2014) The diversity of quasars unified by accretion and orientation. Nature 513:210–213. https://doi.org/10.1038/nature13712 Shen Y, Greene JE, Strauss MA, Richards GT, Schneider DP (2008) Biases in virial black hole masses: an SDSS perspective. Astrophys J 680:169 Silpa S, Kharb P, Ho LC, Ishwara-Chandra CH, Jarvis ME, Harrison C (2020) Probing the origin of low-frequency radio emission in PG quasars with the uGMRT – I. Mon Not R Astron Soc 499:5826–5839. https://doi.org/10.1093/mnras/staa2970 Sluse D, Tewes M (2014) Imprints of the quasar structure in time-delay light curves: microlensing-aided reverberation mapping. Astron Astrophys 571:1–10. https://doi.org/10.1051/0004-6361/201424776 Sluse D, Claeskens JF, Hutsemékers D, Surdej J (2007) Multi-wavelength study of the gravitational lens system RXS J1131-1231. III. Long slit spectroscopy: micro-lensing probes the qso structure. Astron Astrophys 468:885–901. https://doi.org/10.1051/0004-6361:20066821 Sluse D, Schmidt R, Courbin F, Hutsemékers D, Meylan G, Eigenbrod A, Anguita T, Agol E, Wambsganss J (2011) Zooming into the broad line region of the gravitationally lensed quasar QSO 2237 + 0305 ≡ the Einstein cross. Astron Astrophys 528:100. https://doi.org/10.1051/0004-6361/201016110 Sluse D, Hutsemékers D, Courbin F, Meylan G, Wambsganss J (2012) Microlensing of the broad line region in 17 lensed quasars. Astron Astrophys 544:62. https://doi.org/10.1051/0004-6361/201219125 Sluse D, Kishimoto M, Anguita T, Wucknitz O, Wambsganss J (2013) Mid-infrared microlensing of accretion disc and dusty torus in quasars: effects on flux ratio anomalies. Astron Astrophys 553:A53. https://doi.org/10.1051/0004-6361/201220843 Sluse D, Hutsemékers D, Anguita T, Braibant L, Riaud P (2015) Evidence for two spatially separated UV continuum emitting regions in the cloverleaf broad absorption line quasar. Astron Astrophys 582:A109. https://doi.org/10.1051/0004-6361/201526832 Smith JE, Robinson A, Young S, Axon DJ, Corbett EA (2005) Equatorial scattering and the structure of the broad-line region in Seyfert nuclei: evidence for a rotating disc. Mon Not R Astron Soc 359:846–864. https://doi.org/10.1111/j.1365-2966.2005.08895.x Speranza G, Balmaverde B, Capetti A, Massaro F, Tremblay G, Marconi A, Venturi G, Chiaberge M, Baldi RD, Baum S, Grandi P, Meyer ET, O’Dea C, Sparks W, Terrazas BA, Torresi E (2021) The MURALES survey. IV. Searching for nuclear outflows in 3C radio galaxies at \(z < 0.3\) with MUSE observations. Astron Astrophys 653:A150. https://doi.org/10.1051/0004-6361/202140686 Stalevski M, Jovanović P, Popović LĆ, Baes M (2012) Gravitational microlensing of active galactic nuclei dusty tori. Mon Not R Astron Soc 425:1576–1584. https://doi.org/10.1111/j.1365-2966.2012.21611.x Suganuma M, Yoshii Y, Kobayashi Y, Minezaki T, Enya K, Tomita H, Aoki T, Koshida S, Peterson BA (2006) Reverberation measurements of the inner radius of the dust torus in nearby Seyfert 1 galaxies. Astrophys J 639:46 Sunyaev RA, Titarchuk LG (1980) Comptonization of X-rays in plasma clouds – typical radiation spectra. Astron Astrophys 86:121 Sunyaev RA, Truemper J (1979) Hard X-ray spectrum of Cyg X-1. Nature 279:506–508. https://doi.org/10.1038/279506a0 Suyu SH et al (2024) Strong gravitational lensing and microlensing of supernovae. Space Sci Rev 220. https://doi.org/10.1007/s11214-024-01044-7 Tewes M, Courbin F, Meylan G (2013) Cosmograil: the cosmological monitoring of gravitational lenses. XI. Techniques for time delay measurement in presence of microlensing. Astron Astrophys 553:120. https://doi.org/10.1051/0004-6361/201220123 Thompson AC, Fluke CJ, Barnes DG, Barsdell BR (2010) Teraflop per second gravitational lensing ray-shooting using graphics processing units. New Astron 15:16 Thompson AC, Vernardos G, Fluke CJ, Barsdell BR (2014) GPU-D: generating cosmological microlensing magnification maps. Astrophysics Source Code Library ascl:1403.001 Thorne KS (1974) Disk-accretion onto a black hole. II. Evolution of the hole. Astrophys J 191:507–519 Tie SS, Kochanek CS (2018) Microlensing makes lensed quasar time delays significantly time variable. Mon Not R Astron Soc 473:80–90. https://doi.org/10.1093/mnras/stx2348 Treyer M, Wambsganss J (2004) Astrometric microlensing of quasars. Dependence on surface mass density and external shear. Astron Astrophys 416:19–34. https://doi.org/10.1051/0004-6361:20034284 Turner TJ, Pounds KA (1989) The EXOSAT spectral survey of AGN. Mon Not R Astron Soc 240:833–880. https://doi.org/10.1093/mnras/240.4.833 Udalski A, Szymanski M, Kubiak M et al. (2006) The Optical Gravitational Lensing Experiment. OGLE-III long term monitoring of the gravitational lens QSO 2237+0305. Acta Astronomica 56:293–305 Urry CM, Padovani P (1995) Unified schemes for radio-loud active galactic nuclei. Publ Astron Soc Pac 107:803–845 Van de Vyvere L, Gomer MR, Sluse D, Xu D, Birrer S, Galan A, Vernardos G (2022) TDCOSMO: VII. Boxyness/discyness in lensing galaxies: detectability and impact on \(H_{0}\). Astron Astrophys 659:A127. https://doi.org/10.1051/0004-6361/202141551 Vegetti S et al (2024) Strong gravitational lensing as a probe of dark matter. Space Sci Rev 220 Venumadhav T, Dai L, Miralda-Escudé J (2017) Microlensing of extremely magnified stars near caustics of galaxy clusters. Astrophys J 850:49. https://doi.org/10.3847/1538-4357/aa9575 Vernardos G (2018) A joint microlensing analysis of lensing mass and accretion disc models. Mon Not R Astron Soc 480:4675 Vernardos G (2019) Microlensing flux ratio predictions for Euclid. Mon Not R Astron Soc 483:5583 Vernardos G (2022) Simualting time-vayring strong lenses. Mon Not R Astron Soc 511:4417 Vernardos G, Fluke CJ (2013) A new parameter space study of cosmological microlensing. Mon Not R Astron Soc 434:832 Vernardos G, Fluke CJ (2014a) Adventures in the microlensing cloud: large datasets, eresearch tools, and GPUs. Astron Comput 6:1 Vernardos G, Fluke CJ (2014b) The effect of macromodel uncertainties on microlensing modelling of lensed quasars. Mon Not R Astron Soc 445:1223 Vernardos G, Tsagkatakis G (2019) Quasar microlensing light-curve analysis using deep machine learning. Mon Not R Astron Soc 486:1944–1952. https://doi.org/10.1093/mnras/stz868 Vernardos G, Fluke CJ, Bate NF, Croton DJ (2014) Gerlumph data release 1: high-resolution cosmological microlensing magnification maps and eresearch tools. Astrophys J Suppl Ser 211:16 Vernardos G, Fluke CJ, Bate NF, Croton DJ, Vohl D (2015) Gerlumph data release 2: 2.5 bilion microlensing light curves. Astrophys J Suppl Ser 217:23 Villafaña L, Williams PR, Treu T, Brewer BJ, Barth AJ, U V, Bennert VN, Vogler HA, Guo H, Bentz MC, Canalizo G, Filippenko AV, Gates E, Hamann F, Joner MD, Malkan MA, Woo J-H, Abolfathi B, Abramson LE, Armen SF, Bae H-J, Bohn T, Boizelle BD, Bostroem A, Brandel A, Brink TG, Channa S, Cooper MC, Cosens M, Donohue E, Fillingham SP, Gonzalez-Buitrago D, Halevi G, Halle A, Hood CE, Horne K, Horst JC, de Kouchkovsky M, Kuhn B, Kumar S, Leonard DC, Loveland D, Manzano-King C, McHardy I, Michel R, Olaes MKB, Park D, Park S, Pei L, Ross TW, Runco JN, Samuel J, Sanchez J, Scott B, Sexton RO, Shin J, Shivvers I, Spencer CL, Stahl BE, Stegman S, Stomberg I, Valenti S, Walsh JL, Yuk H, Zheng W (2022) The Lick AGN monitoring project 2016: dynamical modeling of velocity-resolved H\(\beta \) lags in luminous Seyfert galaxies. Astrophys J 930:52. https://doi.org/10.3847/1538-4357/ac6171 Vives-Arias H, Muñoz JA, Kochanek CS, Mediavilla E, Jiménez-Vicente J (2016) Observations of the lensed quasar Q2237+0305 with CanariCam at GTC. Astrophys J 831:43. https://doi.org/10.3847/0004-637x/831/1/43 Walsh D, Carswell RF, Weymann RJ (1979) 0957+ 561 A, B – twin quasistellar objects or gravitational lens. Nature 279:381 Wambsganss J (1990) Gravitational microlensing. PhD thesis. Ludwig Maximilians University, Munich Wambsganss J (1992) Probability distributions for the magnification of quasars due to microlensing. Astrophys J 386:19 Wambsganss J (1999) Gravitational lensing: numerical simulations with a hierarchical tree code. J Comput Appl Math 109:353 Wambsganss J, Paczynski B, Schneider P (1990) Interpretation of the microlensing event in QSO2237+0305. Astrophys J 358:33 White SV, Jarvis MJ, Häußler B, Maddox N (2015) Radio-quiet quasars in the video survey: evidence for agn-powered radio emission at \(s_{1.4\text{ GHz}} < 1\text{ mJy}\). Mon Not R Astron Soc 448:2665–2686. https://doi.org/10.1093/mnras/stv134 Wielgus M, Lančová D, Straub O, Kluźniak W, Narayan R, Abarca D, Różańska A, Vincent F, Török G, Abramowicz M (2022) Observational properties of puffy discs: radiative GRMHD spectra of mildly sub-Eddington accretion. Mon Not R Astron Soc 514:780–789. https://doi.org/10.1093/mnras/stac1317 Wilkins DR, Gallo LC (2015) Driving extreme variability: the evolving corona and evidence for jet launching in Markarian 335. Mon Not R Astron Soc 449(1):129–146. https://doi.org/10.1093/mnras/stv162 Witt HJ (1990) Investigation of high amplification events in light curves of gravitationally lensed quasars. Astron Astrophys 236:311 Witt HJ (1991) Der Mikrogravitationslinseneffekt – Theorie und Anwendungen. Dissertation. Universität Hamburg Witt HJ (1993) An efficient method to compute microlensed light curves for point sources. Astrophys J 403:530 Witt HJ, Mao S (1994) Interpretation of microlensing events in Q2237+0305. Astrophys J 429:66 Witt HJ, Mao S, Schechter PL (1995) On the universality of microlensing in quadruple gravitational lenses. Astrophys J 443:18 Woźniak PR, Udalski A, Szymański M, Kubiak M, Pietrzyński G, Soszyński I, Żebruń K (2000) The optical gravitational lensing experiment: a hunt for caustic crossings in QSO 2237+0305. Astrophys J 540:65–67 Wyithe JSB, Loeb A (2002) Measuring the size of quasar broad-line clouds through time-delay light-curve anomalies of gravitational lenses. Astrophys J 577:615–625 Wyithe JSB, Turner EL (2001) Determining the microlens mass function from quasar microlensing statistics. Mon Not R Astron Soc 320:21–30. https://doi.org/10.1046/j.1365-8711.2001.03917.x Wyithe JSB, Webster RL, Turner EL (2000a) The distribution of microlensed light-curve derivatives: the relationship between stellar proper motions and transverse velocity. Mon Not R Astron Soc 312:843–852 Wyithe JSB, Webster RL, Turner EL (2000b) Limits on the microlens mass function of Q2237+0305. Mon Not R Astron Soc 315:51–61 Wyithe JSB, Agol E, Turner EL, Schmidt RW (2002) Constraints on the mass profile of the lens galaxy G2237+0305. Mon Not R Astron Soc 330:575 Yang Q, Shen Y, Liu X, Aguena M, Annis J, Avila S, Banerji M, Bertin E, Brooks D, Burke D, Rosell AC, Kind MC, da Costa L, Vicente JD, Desai S, Diehl HT, Doel P, Flaugher B, Fosalba P, Frieman J, Garcia-Bellido J, Gerdes D, Gruen D, Gruendl R, Gschwend J, Gutierrez G, Hinton S, Hollowood DL, Honscheid K, Kuropatkin N, Maia M, March M, Marshall J, Martini P, Melchior P, Menanteau F, Miquel R, Paz-Chinchon F, Malagón AP, Romer K, Sanchez E, Scarpine V, Schubnell M, Serrano S, Sevilla I, Smith M, Suchyta E, Tarle G, Varga TN, Wilkinson R (2020) Dust reverberation mapping in distant quasars from optical and mid-infrared imaging surveys. Astrophys J 900:58. https://doi.org/10.3847/1538-4357/aba59b Yonehara A, Hirashita H, Richter P (2008) Origin of chromatic features in multiple quasars. Variability, dust, or microlensing. Astron Astrophys 478(1):95–109. https://doi.org/10.1051/0004-6361:20067014 Young P (1981) Q0957+561 – effects of random stars on the gravitational lens. Astrophys J 244:756–767 Yu Z, Martini P, Penton A, Davis TM, Kochanek CS, Lewis GF, Lidman C, Malik U, Sharp R, Tucker BE, Aguena M, Annis J, Bertin E, Bocquet S, Brooks D, Rosell AC, Carollo D, Kind MC, Carretero J, Costanzi M, da Costa LN, Pereira MES, Vicente JD, Diehl HT, Doel P, Everett S, Ferrero I, García-Bellido J, Gatti M, Gerdes DW, Gruen D, Gruendl RA, Gschwend J, Gutierrez G, Hinton SR, Hollowood DL, Honscheid K, James DJ, Kuehn K, Mena-Fernández J, Menanteau F, Miquel R, Nichol B, Paz-Chinchón F, Pieres A, Malagón AAP, Raveri M, Romer AK, Sanchez E, Scarpine V, Sevilla-Noarbe I, Smith M, Suchyta E, Swanson MEC, Tarle G, Vincenzi M, Walker AR, Weaverdyck N (2023) OzDES reverberation mapping program: Mg II lags and R-L relation. Mon Not R Astron Soc 522(3):4132–4147. https://doi.org/10.1093/mnras/stad1224 Zackrisson E, Bergvall N, Marquart T, Helbig P (2003) Can microlensing explain the long-term optical variability of quasars? Astron Astrophys 408:17–25. https://doi.org/10.1051/0004-6361:20030895 Zamaninasab M, Clausen-Brown E, Savolainen T, Tchekhovskoy A (2014) Dynamically important magnetic fields near accreting supermassive black holes. Nature 510:126–128. https://doi.org/10.1038/nature13399 Zdziarski AA, You B, Szanecki M (2022) Corrections to estimated accretion disk size due to color correction, disk truncation, and disk wind. Astrophys J Lett 939:2. https://doi.org/10.3847/2041-8213/ac9474 Zheng W, Chen X, Li G, Chen H-Z (2022) An improved GPU-based ray-shooting code for gravitational microlensing. Astrophys J 931:114. https://doi.org/10.3847/1538-4357/ac68ea