2018/10/04 by N. Torres-Albà, K. Iwasawa, T. Díaz-Santos +14 · 1 citation
Physics and Astronomy · #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201834105
published as A&A 620, A140 (2018) · 24 pages, 13 figures, 11 tables, accepted for publication in A&A
arxiv created 2018/10/04 · arxiv updated 2018/12/12
We analyze Chandra X-ray observatory data for a sample of 63 luminous infrared galaxies (LIRGs), sampling the lower-infrared luminosity range of the Great Observatories All-Sky LIRG survey (GOALS), which includes the most luminous infrared selected galaxies in the local universe. X-rays are detected for 84 individual galaxies within the 63 systems, for which arcsecond resolution X-ray images, fluxes, infrared and X-ray luminosities, spectra and radial profiles are presented. Using X-ray and MIR selection criteria, we find AGN in (31±5)% of the galaxy sample, compared to the (38±6)% previously found for GOALS galaxies with higher infrared luminosities (C-GOALS I). Using mid-infrared data, we find that (59±9)% of the X-ray selected AGN in the full C-GOALS sample do not contribute significantly to the bolometric luminosity of the host galaxy. Dual AGN are detected in two systems, implying a dual AGN fraction in systems that contain at least one AGN of (29±14)%, compared to the (11±10)% found for the C-GOALS I sample. Through analysis of radial profiles, we derive that most sources, and almost all AGN, in the sample are compact, with half of the soft X-ray emission generated within the inner ∼ 1 kpc. For most galaxies, the soft X-ray sizes of the sources are comparable to those of the MIR emission. We also find that the hard X-ray faintness previously reported for the bright C-GOALS I sources is also observed in the brightest LIRGs within the sample, with L\rm FIR>8×1010 L\odot.