RXTE observation of NGC 6240:: a search for the obscured active nucleus

被引:30
作者
Ikebe, Y
Leighly, K
Tanaka, Y
Nakagawa, T
Terashima, Y
Komossa, S
机构
[1] Max Planck Inst Extraterr Phys, D-85741 Garching, Germany
[2] Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA
[3] Inst Space & Astronaut Sci, Kanagawa 2298510, Japan
[4] NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
关键词
galaxies : active; galaxies : individual : NGC 6240; galaxies : nuclei; galaxies : starburst; infrared : galaxies; X-rays : galaxies;
D O I
10.1046/j.1365-8711.2000.03514.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The wide-band energy spectrum of NGC 6240 over the range 0.5-200 keV is investigated using the RXTE and ASCA data. The RXTE data provide the spectrum beyond the ASCA range (0.5-10 keV) with significant detection of signals up to 30 keV and upper limits above 20 keV. The spectrum above 10 keV is found to be very flat. A strong iron K emission line discovered in the previous ASCA observation is also confirmed with the RXTE Proportional Counter Array (PCA), These results provide further evidence for the dominance of a reflection component, i.e, emission from cool material illuminated by an active galactic nucleus (AGN). By fitting the spectra obtained with RXTE and ASCA simultaneously, we satisfactorily modelled the AGN spectrum with a Compton reflection component and probably a transmitted AGN component penetrating through a thick absorber. The X-ray luminosity of the AGN is estimated to be in the range 4 x 10(43) to 6 x 10(44) erg s(-1) in the range 2-10 keV, which categorizes NGC 6240 among the most luminous Seyfert nuclei. The ratio of the 2-10 keV X-ray luminosity to the infrared luminosity, L-x(2-10 keV)/L-IR, is 0.01-0.1, which implies a quite substantial, if not dominant, contribution of AGN to the infrared luminosity.
引用
收藏
页码:433 / 441
页数:9
相关论文
共 53 条
[41]   10(12)L. STARBURSTS AND SHOCKED MOLECULAR-HYDROGEN IN THE COLLIDING GALAXIES-ARP 220 (=IC-4553) AND NGC-6240 [J].
RIEKE, GH ;
CUTRI, RM ;
BLACK, JH ;
KAILEY, WF ;
MCALARY, CW ;
LEBOFSKY, MJ ;
ELSTON, R .
ASTROPHYSICAL JOURNAL, 1985, 290 (01) :116-124
[42]   In-flight performance of the High Energy X-ray Timing Experiment on the Rossi X-ray Timing Explorer [J].
Rothschild, RE ;
Blanco, PR ;
Gruber, DE ;
Heindl, WA ;
MacDonald, DR ;
Marsden, DC ;
Pelling, MR ;
Wayne, LR ;
Hink, PL .
ASTROPHYSICAL JOURNAL, 1998, 496 (01) :538-549
[43]  
Schulz H, 1998, ASTRON ASTROPHYS, V330, P823
[44]  
SERLEMITSOS PJ, 1995, PUBL ASTRON SOC JPN, V47, P105
[45]  
Shier LM, 1997, ASTR SOC P, V116, P502
[46]   ROSAT survey diffuse X-ray background maps .2. [J].
Snowden, SL ;
Egger, R ;
Freyberg, MJ ;
McCammon, D ;
Plucinsky, PP ;
Sanders, WT ;
Schmitt, JHMM ;
Trumper, J ;
Voges, W .
ASTROPHYSICAL JOURNAL, 1997, 485 (01) :125-&
[47]  
TANAKA Y, 1994, PUBL ASTRON SOC JPN, V46, pL37
[48]  
Trumper J., 1990, Physikalische Blaetter, V46, P137
[49]   ASCA observations of type 2 Seyfert galaxies .1. Data analysis results [J].
Turner, TJ ;
George, IM ;
Nandra, K ;
Mushotzky, RF .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1997, 113 (01) :23-67
[50]   NEAR-INFRARED LINE IMAGING OF NGC 6240 - COLLISION SHOCK AND NUCLEAR STARBURST [J].
VANDERWERF, PP ;
GENZEL, R ;
KRABBE, A ;
BLIETZ, M ;
LUTZ, D ;
DRAPATZ, S ;
WARD, MJ ;
FORBES, DA .
ASTROPHYSICAL JOURNAL, 1993, 405 (02) :522-537