C-GOALS Article (Web of Science)

abstract

  • 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 mid-infrared (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 MIR 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 LFIR > 8 × 1010 L⊙.

authors

  • Torres-Albà, N.
  • Iwasawa, K.
  • Díaz-Santos, T.
  • Charmandaris, V.
  • Ricci, C.
  • Chu, J. K.
  • Sanders, D. B.
  • Armus, L.
  • Barcos-Muñoz, L.
  • Evans, A. S.
  • Howell, J. H.
  • Inami, H.
  • Linden, S. T.
  • Medling, Anne M
  • Privon, G. C.
  • U, V.
  • Yoon, I.

publication date

  • 2018

webpage

published in

start page

  • A140

volume

  • 620