Nonthermal Phenomena in Clusters of Galaxies
Tóm tắt
Recent observations of high energy (>20 keV) X-ray emission in a few clusters of galaxies broaden our knowledge of physical phenomena in the intracluster space. This emission is likely to be nonthermal, probably resulting from Compton scattering of relativistic electrons by the cosmic microwave background (CMB) radiation. Direct evidence for the presence of relativistic electrons in some 50 clusters comes from measurements of extended radio emission in their central regions. We briefly review the main results from observations of extended regions of radio emission, and Faraday rotation measurements of background and cluster radio sources. The main focus of the review are searches for nonthermal X-ray emission conducted with past and currently operating satellites, which yielded appreciable evidence for nonthermal emission components in the spectra of a few clusters. This evidence is clearly not unequivocal, due to substantial observational and systematic uncertainties, in addition to virtually complete lack of spatial information. If indeed the emission has its origin in Compton scattering of relativistic electrons by the CMB, then the mean magnetic field strength and density of relativistic electrons in the cluster can be directly determined. Knowledge of these basic nonthermal quantities is valuable for the detailed description of processes in intracluster gas and for the origin of magnetic fields.
Tài liệu tham khảo
M. Arnaud, N. Aghanim, R. Gastaud et al., Astron. Astrophys. 365, L67 (2001)
P. Blasi, S. Colafrancesco, Astropar. Phys. 122, 169 (1999)
A.M. Bykov, H. Bloemen, Yu.A. Uvarov, Astron. Astrophys. 362, 886 (2000)
C.L. Carilli, G.B. Taylor, Annu. Rev. Astron. Astrophys. 40, 319 (2002)
T.E. Clarke, J. Korean Astron. Soc. 37, 337 (2004)
T.E. Clarke, P.P. Kronberg, H. Böhringer, Astrophys. J. 547, L111 (2001)
L.P. David, A. Slyz, C. Jones et al., Astrophys. J. 412, 479 (1993)
B. Dennison, Astrophys. J. 239, L93 (1980)
C.D. Dermer, Y. Rephaeli, Astrophys. J. 329, 687 (1988)
K. Dolag, S. Schindler, F. Govoni, L. Feretti, Astron. Astrophys. 378, 777 (1999)
J.W. Dreher, C.L. Carilli, R.A. Perley, Astrophys. J. 316, 611 (1987)
F. Durret, J. Kaastra, J. Nevalainen, T. Ohashi, N. Werner, Space Sci. Rev. (2008). doi:10.1007/s11214-008-9313-8
D. Eckert, A. Neronov, T.J.-L. Courvoisier, N. Produit, Astron. Astrophys. 470, 835 (2007)
T.A. Enßlin, C. Vogt, T.E. Clarke, G.B. Taylor, Astrophys. J. 597, 870 (2003)
C. Ferrari, F. Govoni, S. Schindler, A.M. Bykov, Y. Rephaeli, Space Sci. Rev. (2008). doi:10.1007/s11214-008-9311-x
L. Feretti, D. Dallacasa, F. Govoni et al., Astron. Astrophys. 344, 472 (1999)
Y. Fukazawa, K. Nakazawa, N. Isobe et al., Astrophys. J. 546, L87 (2001)
R. Fusco-Femiano, D. Dal Fiume, L. Feretti et al., Astrophys. J. 513, L21 (1999)
R. Fusco-Femiano, D. Dal Fiume, S. De Grandi et al., Astrophys. J. 534, L7 (2000)
R. Fusco-Femiano, D. Dal Fiume, M. Orlandini et al., Astrophys. J. 552, L97 (2001)
R. Fusco-Femiano, M. Orlandini, S. de Grandi et al., Astron. Astrophys. 398, 441 (2003)
R. Fusco-Femiano, M. Orlandini, G. Brunetti et al., Astrophys. J. 602, L73 (2004)
R. Fusco-Femiano, R. Landi, M. Orlandini, Astrophys. J. 624, L69 (2005)
R. Fusco-Femiano, R. Landi, M. Orlandini, Astrophys. J. 654, L9 (2007)
R. Gilli, G. Risaliti, M. Salvati, Astron. Astrophys. 347, 424 (1999)
G. Giovannini, L. Feretti, New Astron. 5, 335 (2000)
G. Giovannini, L. Feretti, T. Venturi, K.-T. Kim, P.P. Kronberg, Astrophys. J. 406, 399 (1993)
G. Giovannini, M. Tordi, L. Feretti, New Astron. 4, 141 (1999)
G. Giovannini, L. Feretti, F. Govoni, M. Murgia, R. Pizzo, Astron. Nachr. 327, 563 (2006)
O. Goldshmidt, Y. Rephaeli, Astrophys. J. 411, 518 (1993)
D.E. Gruber, Y. Rephaeli, Astrophys. J. 565, 877 (2002)
F. Govoni, L. Feretti, Int. J. Mod. Phys. D 13, 1549 (2004)
G. Hasinger, B. Altieri, M. Arnaud et al., Astron. Astrophys. 365, L45 (2001)
M. Henriksen, Astrophys. J. 511, 666 (1999)
M. Henriksen, R. Mushotzky, Astrophys. J. 553, 84 (2001)
J.S. Kaastra, J.A.M. Bleeker, R. Mewe, Nucl. Phys. B 69, 567 (1998)
J.S. Kaastra, R. Lieu, J. Mittaz et al., Astrophys. J. 519, L119 (1999)
N. Kawano, K. Nakazawa, Y. Fukazawa et al., in Proc. of ‘The Extreme Universe in the Suzaku Era’ (2007 in press), conf. CD
K.-T. Kim, P.P. Kronberg, P.C. Tribble, Astrophys. J. 379, 80 (1991)
T. Kitaguchi, K. Makishima, K. Nakazawa et al., in Proc. of ‘The Extreme Universe in the Suzaku Era’ (2007 in press), conf. CD
M. Kokubun, K. Makishima, T. Takahashi et al., Publ. Astron. Soc. Jpn. 59, 53 (2007)
R. Landi, Ph.D. thesis, Bologna University, 2005
F. Lebrun, J.P. Leray, P. Lavocat et al., Astron. Astrophys. 411, L141 (2003)
J.J. Mohr, B. Mathiesen, A.E. Evrard, Astrophys. J. 517, 627 (1999)
S. Molendi, S. de Grandi, R. Fusco-Femiano et al., Astrophys. J. 525, L73 (1999)
S. Molendi, S. De Grandi, M. Guainazzi, Astron. Astrophys. 392, 13 (2002)
M. Murgia, F. Govoni, L. Feretti et al., Astron. Astrophys. 424, 429 (2004)
K. Nakazawa, K. Makishima, Y. Fukazawa, Publ. Astron. Soc. Jpn. 59, 167 (2007)
D.M. Neumann, D.H. Lumb, G.W. Pratt, U.G. Briel, Astron. Astrophys. 400, 811 (2003)
J. Nevalainen, T. Oosterbroek, M. Bonamente, S. Colafrancesco, Astrophys. J. 608, 166 (2004)
W.I. Newman, A.L. Newman, Y. Rephaeli, Astrophys. J. 575, 755 (2002)
V. Petrosian, Astrophys. J. 557, 560 (2001)
V. Petrosian, A.M. Bykov, Space Sci. Rev. (2008). doi:10.1007/s11214-008-9315-6
V. Petrosian, G. Madejski, K. Luli, Astrophys. J. 652, 948 (2006)
V. Petrosian, A.M. Bykov, Y. Rephaeli, Space Sci. Rev. (2008). doi:10.1007/s11214-008-9327-2
O. Reimer, M. Pohl, P. Sreekumar, J.R. Mattox, Astrophys. J. 588, 155 (2003)
M. Renaud, G. Belanger, J. Paul, F. Lebrun, R. Terrier, Astron. Astrophys. 453, L5 (2006)
Y. Rephaeli, Astrophys. J. 212, 608 (1977)
Y. Rephaeli, Astrophys. J. 227, 364 (1979)
Y. Rephaeli, Mon. Not. R. Astron. Soc. 225, 851 (1987)
Y. Rephaeli, in Proc. of Heidelberg Int. Symp. AIP Conf. Ser., vol. 558 (2001), p. 427
Y. Rephaeli, D.E. Gruber, Astrophys. J. 333, 133 (1988)
Y. Rephaeli, D.E. Gruber, Astrophys. J. 579, 587 (2002)
Y. Rephaeli, D.E. Gruber, Astrophys. J. 595, 137 (2003)
Y. Rephaeli, D.E. Gruber, Astrophys. J. 606, 825 (2004)
Y. Rephaeli, J. Silk, Astrophys. J. 442, 91 (1995)
Y. Rephaeli, D. Gruber, R. Rothschild, Astrophys. J. 320, 139 (1987)
Y. Rephaeli, D. Gruber, M. Ulmer, Astrophys. J. 429, 554 (1994)
Y. Rephaeli, D. Gruber, P. Blanco, Astrophys. J. 511, L21 (1999)
Y. Rephaeli, D.E. Gruber, Y. Arieli, Astrophys. J. 649, 673 (2006)
M. Rossetti, S. Molendi, Astron. Astrophys. 414, 41 (2004)
M. Rossetti, S. Molendi, astro-ph/0702417 (2007), electronic preprint only
G. Risaliti, R. Maiolino, M. Salvati, Astrophys. J. 522, 157 (1999)
L. Rudnick, K. Blundell, Astrophys. J. 588, 143 (2003)
J.S. Sanders, A.C. Fabian, Mon. Not. R. Astron. Soc. 381, 1381 (2007)
C.L. Sarazin, Astrophys. J. 520, 529 (1999)
C.L. Seeger, G. Westerhout, R.G. Conway, Astrophys. J. 126, 585 (1957)
A. Simionescu, N. Werner, A. Finoguenov, H. Böhringer, M. Brüggen, Astron. Astrophys. (2007 submitted) (astro-ph/0709.4499)
T. Takahashi, K. Abe, M. Endo et al., Publ. Astron. Soc. Jpn. 59, 35 (2007)
G.B. Taylor, R.A. Perley, Astrophys. J. 416, 554 (1993)
M. Thierbach, U. Klein, R. Wielebinski, Astron. Astrophys. 397, 53 (2003)
K. Tokoi, K. Sato, Y. Ishisaki et al., Publ. Astron. Soc. Jpn. 60 (2007 in press) (astro-ph/0711.1454)
P. Ubertini, F. Lebrun, G. Di Cocco et al., Astron. Astrophys. 411, L131 (2003)
A. Valinia, M. Henriksen, M. Loewenstein et al., Astrophys. J. 515, 42 (1999)
C. Vogt, T.A. Enßlin, Astron. Astrophys. 412, 373 (2003)
M.A.G. Willson, Mon. Not. R. Astron. Soc. 151, 1 (1970)
C. Winkler, T. Courvoisier, G. Di Cocco et al., Astron. Astrophys. 411, L1 (2003)