Volume 386, Number 1, April IV 2002
|Page(s)||60 - 68|
|Section||Cosmology (including clusters of galaxies)|
|Published online||15 April 2002|
observations of LINER-2 galaxies
Institute of Astronomy & Astrophysics, National Observatory of Athens, Palaia Penteli, 15236, Athens, Greece
2 Dipartimento di Astronomia, Universita di Bologna, via Ranzani 1, 40127, Bologna, Italy
3 Istituto Technologie e Studio delle Radiazioni Extraterrestri/CNR, via Gobetti 101, 40129, Bologna, Italy
4 Physics Department, University of Athens, Panepistimiopolis, Zografos, 15783, Athens, Greece
5 Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
6 Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna, Italy
Corresponding author: I. Georgantopoulos, email@example.com
Accepted: 15 January 2002
We present BeppoSAX observations of 6 “type-2” LINER and “transition” galaxies (NGC 3379, NGC 3627, NGC 4125, NGC 4374, NGC 5195 and NGC 5879) from the Ho et al. ([CITE]) spectroscopic sample of nearby galaxies. All objects are detected in the 2–10 keV band, having luminosities in the range . The PDS upper limits above 10 keV place constraints on the presence of a heavily obscured AGN in the case of NGC 3379 and NGC 4125. No significant variability is detected in any of the objects. The spectra are described in most cases by a simple power-law model with a spectral slope of while there is evidence neither for a significant absorption above the Galactic nor for an FeKα emission line. Therefore, based on the spectral properties alone, it is difficult to differentiate between a low-luminosity AGN or a star-forming galaxy scenario. However, imaging observations of NGC 3627 and NGC 5195 with Chandra ACIS-S reveal very weak nuclear sources while most of the X-ray flux originates either in off-nuclear point sources or in diffuse emission. The above clearly argue in favour of a star-forming origin for the bulk of the X-ray emission, at least in the above two sources.
Key words: galaxies: active / galaxies: starburst / X-rays: galaxies
© ESO, 2002
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