2006/04/30 by N. Masetti, L. Bassani, A. Bazzano +9 · 50 citations
Physics and Astronomy · #Active galactic nucleus #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Binary number #Context (archaeology) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Observatory #Radio galaxy #Redshift #Spectroscopy #astro-ph
paper · pdf · doi:10.1051/0004-6361:20065111
published in Astronomy and Astrophysics 455(1), 11-19 (EDP Sciences) · 11 pages, 3 figures, 2 tables, accepted for publication on A&A, main journal. The quality of Fig. 1 was degraded to fit the arXiv uploads size limits. Revised version matches the A&A corrected proofs
arxiv created 2006/06/16 · openalex publication_date 2006/07/31 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
We present further results from our onging optical spectrophotometric campaign at the Astronomical Observatory of Bologna in Loiano (Italy) on unidentified hard X-ray sources detected by INTEGRAL. We observed spectroscopically the putative optical counterparts of the INTEGRAL sources IGR J00234+6141, IGR J01583+6713, IGR J06074+2205, IGR J13091+1137 and IGR J20286+2544. We find that the first two are Galactic objects, namely a Cataclysmic Variable at a distance pc and a Be/X transient High-Mass X-ray Binary (HMXB) located at ~6.4 kpc, respectively, whereas the last one is identified with MCG +04-48-002, a Starburst/H ii galaxy at redshift hiding a Seyfert 2 nucleus. We identify IGR J13091+1137 as the (likely Seyfert 2 type) active nucleus of galaxy NGC 4992, which we classify as an X-ray Bright, Optically Normal Galaxy; this is the first example of this type of object to be detected by INTEGRAL, and one of the closest of this class. We moreover confirm the possible Be/X nature of IGR J06074+2205, and we estimate it to be at a distance of ~1 kpc. We also reexamine the spectrum of the elliptical radio galaxy PKS 0352-686, the possible counterpart of the INTEGRAL source IGR J03532-6829, and we find that it is a BL Lac. Physical parameters for these sources are also evaluated by discussing our findings in the context of the available multiwavelength information. These identifications further stress the importance of INTEGRAL in the study of the hard X-ray spectrum of Active Galactic Nuclei, HMXBs and Cataclysmic Variables.