A long observation of NGC 5548 by BeppoSAX:: The high-energy cutoff, intrinsic spectral variability, and a truly warm absorber

被引：52

作者：

Nicastro, F

Piro, L

De Rosa, A

Feroci, M

Grandi, P

Fiore, F

Elvis, M

Haardt, F

Kaastra, J

Malizia, A

Maraschi, L

Matt, G

Perola, GC

Petrucci, PO

机构：

[1] CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy

[2] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA

[3] Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy

[4] Univ Milan, Dipartimento Fis, Milan, Italy

[5] Space Res Org Netherlands, NL-3584 CA Utrecht, Netherlands

[6] BeppoSAX Sci Data Ctr, Rome, Italy

[7] Osservatorio Astron Brera Merate, Milan, Italy

[8] Univ Roma 3, Dipartimento Fis, I-00146 Rome, Italy

来源：

ASTROPHYSICAL JOURNAL | 2000年 / 536卷 / 02期

关键词：

galaxies : individual (NGC 5548); galaxies : Seyfert; radiation mechanisms : thermal; X-rays : galaxies;

D O I：

10.1086/308950

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

NGC 5548 was observed by BeppoSAX in a single long (8 day) observation from 0.2 to 200 keV. We find (1) spectral variation of the source produced by a change of the intrinsic power-law slope; (2) a high-energy cutoff at E-c = 115(-27)(+39) keV with a hint of change of E-c with flux; and (3) O VII and O VIII absorption K edges and a possible blended O VII-O VIII K alpha,beta emission feature at 0.54(-0.06)(+0.07) keV, inconsistent with a purely photoionized gas in equilibrium. We propose that the temperature of the absorbing and emitting gas is similar to 10(6) K so that both collisional ionization and photoionization contribute.

引用

页码：718 / 728

页数：11

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