XMM-Newton observations of the two X-ray weak quasars PG 1411+442 and Mrk 304

被引:14
作者
Brinkmann, W
Papadakis, IE
Ferrero, E
机构
[1] Max Planck Inst Extraterr Phys, Ctr Interdisciplinary Plasma Sci, D-85741 Garching, Germany
[2] Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece
[3] FORTH Hellas, IESL, Iraklion 71110, Crete, Greece
来源
ASTRONOMY & ASTROPHYSICS | 2004年 / 414卷 / 01期
关键词
galaxies : active; quasars : general; quasars; individual; PG; 1411+442; Mrk; 304;
D O I
10.1051/0004-6361:20031617
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of XMM-Newton observations of two X-ray weak quasars, PG 1411+442 and Mrk 304. In both cases the spectra can basically be represented by hard power laws with photon indices typical for radio-quiet quasars, heavily intrinsically absorbed by column densities of similar to2x10(23) cm(-2) in PG 1411+442 and similar to4x10(22) cm(-2) in Mrk 304. The data require in both cases an additional steep (Gammasimilar to3) soft power law component, absorbed only by the galactic column density towards the quasars. The soft parts of the spectra exhibit additional complex structures like emission line features around similar to0.59 keV, and absorption edges around 0.7 keV and similar to1 keV. These features strongly suggest the presence of "warm" (i.e. ionized) material in the central region of the two sources. Due to the insufficient photon statistics and to the lack of more advanced models for the spectral fitting, we are unable to determine accurately the geometry and physical state of the absorbing material. The physical implications of various viable spectral absorption or scattering scenarios for the nature of these objects and of the X-ray weak quasars in general, are discussed.
引用
收藏
页码:107 / 116
页数:10
相关论文
共 40 条
[1]   A two-component ionized reflection model of MCG-6-30-15 [J].
Ballantyne, DR ;
Vaughan, S ;
Fabian, AC .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2003, 342 (01) :239-248
[2]   THE EMISSION-LINE PROPERTIES OF LOW-REDSHIFT QUASI-STELLAR OBJECTS [J].
BOROSON, TA ;
GREEN, RF .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1992, 80 (01) :109-135
[3]   On the nature of soft X-ray weak quasi-stellar objects [J].
Brandt, WN ;
Laor, A ;
Wills, BJ .
ASTROPHYSICAL JOURNAL, 2000, 528 (02) :637-649
[4]   XMM-Newton observation of PG 0844+349 [J].
Brinkmann, W ;
Grupe, D ;
Branduardi-Raymont, G ;
Ferrero, E .
ASTRONOMY & ASTROPHYSICS, 2003, 398 (01) :81-87
[5]  
Brinkmann W, 1997, ASTRON ASTROPHYS, V319, P413
[6]  
Brinkmann W, 1999, ASTRON ASTROPHYS, V345, P43
[7]   A CATALOG OF X-RAY MEASUREMENTS OF SELECTED SAMPLES OF ACTIVE GALAXIES AND NUCLEI [J].
DELLACECA, R ;
PALUMBO, GGC ;
PERSIC, M ;
BOLDT, EA ;
DEZOTTI, G ;
MARSHALL, EE .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1990, 72 (03) :471-&
[8]   AN IONIZED ACCRETION DISK IN CYGNUS X-1 [J].
DONE, C ;
MULCHAEY, JS ;
MUSHOTZKY, RF ;
ARNAUD, KA .
ASTROPHYSICAL JOURNAL, 1992, 395 (01) :275-288
[9]  
EHLE M, 2001, XMM NEWTON USERS HDB
[10]   ACCURATE GALACTIC NH VALUES TOWARDS QUASARS AND AGN [J].
ELVIS, M ;
LOCKMAN, FJ ;
WILKES, BJ .
ASTRONOMICAL JOURNAL, 1989, 97 (03) :777-782