X-ray emission from the hot interstellar medium and southwest radio lobe of the nearby radio galaxy Centaurus A

被引:143
作者
Kraft, RP
Vázquez, SE
Forman, WR
Jones, C
Murray, SS
Hardcastle, MJ
Worrall, DM
Churazov, E
机构
[1] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[2] Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England
[3] Moscow Space Res Inst, Moscow 117810, Russia
[4] Max Planck Inst Astrophys, D-85740 Garching, Germany
关键词
galaxies : active; galaxies : individual (Centaurus A; NGC; 5128); galaxies : ISM; galaxies : jets; radio continuum : galaxies; X-rays : galaxies;
D O I
10.1086/375533
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present results from two Chandra/ACIS-I observations and one XMM-Newton observation of X-ray emission from the interstellar medium (ISM) and the inner radio lobes of the nearby radio galaxy Centaurus A. The ISM has an average radial surface brightness pro. le that is well described by a beta-model pro. le with index beta = 0.40 +/- 0.04 and a temperature of k(B)T(ISM) similar to 0.29 keV beyond 2 kpc from the nucleus. We. nd that diffuse X-ray emission is coincident with the outer half of the southwest radio lobe, and a bright X-ray enhancement is detected along the edge of the lobe. On the basis of energetic and lifetime arguments, we reject a nonthermal explanation for this emission. We model this emission as a thin, hot shell or cap of X-ray emitting plasma surrounding the radio lobe that was created by the supersonic inflation of the lobe. This plasma shell is both hotter than (k(B)T(SH) similar to 2.9 keV) and greatly overpressurized relative to the ambient ISM, indicating supersonic expansion. We estimate that the lobe is expanding into the ISM at approximately Mach 8.5, or 2400 km s(-1). We are not directly observing the bow shock, but rather the cooler, denser material that is accumulating ahead of the contact discontinuity. The thermal energy in the shell is a significant fraction of the thermal energy of the hot ISM, demonstrating the possibility that the hot ISM of early galaxies can be reenergized by outflows from nuclear activity. Interestingly, no similarly bright X-ray emission is detected in or along the edge of the northeast lobe, implying that there are differences in the dynamics and evolution of the kiloparsec-scale radio components.
引用
收藏
页码:129 / 146
页数:18
相关论文
共 112 条
  • [1] On the interaction of FR II radio sources with the intracluster medium
    Alexander, P
    [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2002, 335 (03) : 610 - 620
  • [2] PARAMETERS AND PREDICTIONS FOR X-RAY EMITTING GAS OF COMA, PERSEUS, AND VIRGO
    BAHCALL, JN
    SARAZIN, CL
    [J]. ASTROPHYSICAL JOURNAL, 1977, 213 (03) : L99 - L103
  • [3] Diffuse gas and low-mass X-ray binaries in the Chandra observation of the S0 galaxy NGC 1553
    Blanton, EL
    Sarazin, CL
    Irwin, JA
    [J]. ASTROPHYSICAL JOURNAL, 2001, 552 (01) : 106 - 119
  • [4] Chandra observation of the radio source/X-ray gas interaction in the cooling flow cluster Abell 2052
    Blanton, EL
    Sarazin, CL
    McNamara, BR
    Wise, MW
    [J]. ASTROPHYSICAL JOURNAL, 2001, 558 (01) : L15 - L18
  • [5] BOHRINGER H, 1993, MON NOT R ASTRON SOC, V264, pL25
  • [6] The new emerging model for the structure of cooling cores in clusters of galaxies
    Böhringer, H
    Matsushita, K
    Churazov, E
    Ikebe, Y
    Chen, Y
    [J]. ASTRONOMY & ASTROPHYSICS, 2002, 382 (03) : 804 - 820
  • [7] XMM-Newton observations of M 87 and its X-ray halo
    Böhringer, H
    Belsole, E
    Kennea, J
    Matsushita, K
    Molendi, S
    Worrall, DM
    Mushotzky, RF
    Ehle, M
    Guainazzi, M
    Sakelliou, I
    Stewart, G
    Vestrand, WT
    Dos Santos, S
    [J]. ASTRONOMY & ASTROPHYSICS, 2001, 365 (01): : L181 - L187
  • [8] Heated cooling flows
    Brighenti, F
    Mathews, WG
    [J]. ASTROPHYSICAL JOURNAL, 2002, 573 (02) : 542 - 561
  • [9] Emission mechanisms in X-raye-faint galaxies
    Brown, BA
    Bregman, JN
    [J]. ASTROPHYSICAL JOURNAL, 2001, 547 (01) : 154 - 161
  • [10] Hot bubbles from active galactic nuclei as a heat source in cooling-flow clusters
    Brüggen, M
    Kaiser, CR
    [J]. NATURE, 2002, 418 (6895) : 301 - 303