HOW COMPLEX IS THE OBSCURATION IN ACTIVE GALACTIC NUCLEI? NEW CLUES FROM THE SUZAKU MONITORING OF THE X-RAY ABSORBERS IN NGC 7582

被引:116
作者
Bianchi, Stefano [1 ]
Piconcelli, Enrico [2 ]
Chiaberge, Marco [3 ]
Jimenez Bailon, Elena [4 ,5 ]
Matt, Giorgio [1 ]
Fiore, Fabrizio [2 ]
机构
[1] Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy
[2] Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy
[3] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[4] Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico
[5] LAEFF, Madrid 28691, Spain
关键词
galaxies: active; galaxies: Seyfert; X-rays: individual (NGC 7582); XMM-NEWTON; SEYFERT-2; GALAXIES; CIRCINUS GALAXY; COMPTON-THIN; OBSCURED AGN; QUASARS; LINE; ABSORPTION; NGC-7582; REGIONS;
D O I
10.1088/0004-637X/695/1/781
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of a Suzaku monitoring campaign of the Seyfert 2 galaxy, NGC 7582. The source is characterized by very rapid (on timescales even lower than a day) changes of the column density of an inner absorber, together with the presence of constant components arising as reprocessing from a Compton-thick material. The best-fitting scenario implies important modifications to the zeroth-order view of Unified Models. While the existence of a pc-scale torus is needed in order to produce a constant Compton reflection component and an iron Ka-emission line, in this Seyfert 2 galaxy this is not viewed along the line of sight. On the other hand, the absorption of the primary continuum is due to another material, much closer to the black hole, roughly at the distance of the broad-line region, which can produce the observed rapid spectral variability. On top of that, the constant presence of a 10(22) cm(-2) column density can be ascribed to the presence of a dust lane, extended on a galactic scale, as previously confirmed by Chandra. There is now mounting evidence that complexity in the obscuration of active galactic nuclei (AGNs) may be the rule rather than the exception. We therefore propose to modify the Unification Model, adding to the torus the presence of two further absorbers/emitters. Their combination along the line of sight can reproduce all the observed phenomenology.
引用
收藏
页码:781 / 787
页数:7
相关论文
共 50 条
[1]   UNIFIED MODELS FOR ACTIVE GALACTIC NUCLEI AND QUASARS [J].
ANTONUCCI, R .
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, 1993, 31 :473-521
[2]  
Arnaud KA, 1996, ASTR SOC P, V101, P17
[4]   On the Iwasawa-Taniguchi effect of radio-quiet AGN [J].
Bianchi, S. ;
Guainazzi, M. ;
Matt, G. ;
Bonilla, N. Fonseca .
ASTRONOMY & ASTROPHYSICS, 2007, 467 (01) :L19-L22
[5]   The soft X-ray/NLR connection: a single photoionized medium? [J].
Bianchi, S ;
Guainazzi, M ;
Chiaberge, M .
ASTRONOMY & ASTROPHYSICS, 2006, 448 (02) :499-511
[6]   X-ray reprocessing in Seyfert galaxies:: Simultaneous XMM-Newton/BeppoSAX observations [J].
Bianchi, S ;
Matt, G ;
Balestra, I ;
Guainazzi, M ;
Perola, GC .
ASTRONOMY & ASTROPHYSICS, 2004, 422 (01) :65-76
[7]   A search for changing-look AGN in the Grossan catalog [J].
Bianchi, S ;
Guainazzi, M ;
Matt, G ;
Chiaberge, M ;
Iwasawa, K ;
Fiore, F ;
Maiolino, R .
ASTRONOMY & ASTROPHYSICS, 2005, 442 (01) :185-194
[8]   The circumnuclear X-ray reflectors in NGC 1068 and the Circinus galaxy [J].
Bianchi, S ;
Matt, G ;
Iwasawa, K .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2001, 322 (03) :669-680
[9]  
Bianchi S, 2007, AIP CONF PROC, V924, P822, DOI 10.1063/1.2774948
[10]   A multiwavelength map of the nuclear region of NGC 7582 [J].
Bianchi, Stefano ;
Chiaberge, Marco ;
Piconcelli, Enrico ;
Guainazzi, Matteo .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2007, 374 (02) :697-702