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Astron. Astrophys. 346, 407-414 (1999)
The complex 0.1-200 keV spectrum of the Seyfert 1 Galaxy NGC 4593
M. Guainazzi 1,
G.C. Perola 2,
G. Matt 2,
F. Nicastro 3,2,
L. Bassani 4,
F. Fiore 3,5,
D. DalFiume 4 and
L. Piro 6
1 Astrophysics Division, Space Science Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
2 Dipartimento di Fisica "E.Amaldi", Università di Roma 3, Via della Vasca Navale 84, I-00146 Roma, Italy
3 Osservatorio Astronomico di Roma, Via dell'Osservatorio 5, I-00040 Monteporzio Catone, Italy
4 Istituto Tecnologie e Studio Radiazioni Extraterrestri, CNR, Via Gobetti 101, I-40129 Bologna, Italy
5 BeppoSAX Science Data Center, Via Corcolle 19, I-00131 Roma, Italy
6 Istituto di Astrofisica Spaziale, CNR, Via Fosso del Cavaliere, I-00133 Roma, Italy
Received 28 September 1998 / Accepted 17 March 1999
Abstract
We report on the first observation of the Seyfert 1 galaxy
NGC 4593 in the 0.1-200 keV band, performed with the
BeppoSAX observatory. Its spectral components are for the first time
simultaneously measured: a power-law with photon spectral index
![[FORMULA]](img1.gif)
1.9; the Compton-reflection of
the primary power-law; a moderately broad
(![[FORMULA]](img2.gif)
eV)
![[FORMULA]](img3.gif)
fluorescent line from neutral iron;
and an absorption edge, whose threshold energy is consistent with
K-shell photoionization from OVII . The amount of
reflection and the iron line properties are consistent with both being
produced in a plane-parallel, X-ray illuminated relativistic accretion
disc surrounding the nuclear black hole, seen at an inclination of
![[FORMULA]](img4.gif)
. Any cutoff of the intrinsic
continuum is constrained to lay above 150 keV. The claim for a
strongly variable soft excess is dismissed by our data and by a
reanalysis of archival ASCA and ROSAT data.
Key words: galaxies: individual:
NGC 4593 
galaxies:
nuclei
galaxies:
Seyfert
X-rays: galaxies
Send offprint requests to: M. Guainazzi (mguainaz@astro.estec.esa.nl)
Contents
- 1. Introduction
- 2. Data reduction
- 3. Timing analysis
- 4. Spectral analysis
- 4.1. Continuum shape
- 4.2. On the iron line
- 4.3. The warm absorber
- 5. Comparison with ASCA and ROSAT results
- 6. Discussion
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999
Online publication: May 21, 1999
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