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arXiv · astro-ph/0202189

BeppoSAX observations of LINER-2 galaxies

I. Georgantopoulos·F. Panessa·A. Akylas·A. Zezas·M. Cappi·A. Comastri
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Abstract

We present BeppoSAX observations of 6 ``type-2'' LINER and ``transition'' galaxies (NGC3379, NGC3627, NGC4125, NGC4374, NGC5195 and NGC5879)from the Ho et al. (1997) spectroscopic sample of nearby galaxies. All objects are detected in the 2-10 keV band, having luminosities in the range L(2-10 keV) ~ 1x10^{39}- 1x10^{40} erg s-1. The PDS upper limits above 10 keV place constraints on the presence of a heavily obscured AGN in the case of NGC3379 and NGC4125. 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 1.7-2.5 while there is evidence neither for a significant absorption above the Galactic nor for an FeK 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 NGC3627 and NGC5195 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.

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I. Georgantopoulos, F. Panessa, A. Akylas, A. Zezas, M. Cappi, A. Comastri. 2002-02-08. BeppoSAX observations of LINER-2 galaxies. https://doi.org/10.1051/0004-6361%3A20020078

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