Herschel/HerMES: the X-ray-infrared correlation for star-forming galaxies at z∼1
Pérez-Fournon, I.; Rodighiero, G.; Ivison, R. J.; Clements, D. L.; Georgakakis, A.; Buat, V.; Burgarella, D.; Wang, L.; Hatziminaoglou, E.; Franceschini, A.; Bock, J.; Cooray, A.; Farrah, D.; Ibar, E.; Oliver, S. J.; Page, M. J.; Roseboom, I. G.; Symeonidis, M.; Vaccari, M.; Auld, R.; Eales, S.; Chanial, P.; Glenn, J.; Griffin, M.; Mortier, A. M. J.; Papageorgiou, A.; Pearson, C. P.; Pohlen, M.; Rawlings, J. I.; Raymond, G.; Rowan-Robinson, M.; Seymour, N.; Smith, A. J.; Tugwell, K. E.; Vigroux, L.; Wright, G.; Vieira, J. D.; Scott, Douglas; Brisbin, D.
United Kingdom, Greece, United States, France, Italy, Germany, Canada, Spain
Abstract
For the first time, we investigate the X-ray/infrared (IR) correlation for star-forming galaxies (SFGs) at z∼ 1, using SPIRE submm data from the recently launched Herschel Space Observatory and deep X-ray data from the 2-Ms Chandra Deep Field-North survey. We examine the X-ray/IR correlation in the soft X-ray (SX; 0.5-2 keV) and hard X-ray (HX; 2-10 keV) bands by comparing our z∼ 1 SPIRE-detected SFGs to equivalently IR-luminous (LIR > 1010 L⊙) samples in the local/low-redshift Universe. Our results suggest that the X-ray/IR properties of the SPIRE SFGs are on average similar to those of their local counterparts, as we find no evidence for evolution in the LSX/LIR and LHX/LIR ratios with redshift. We note, however, that at all redshifts, both LSX/LIR and LHX/LIR are strongly dependent on IR luminosity, with luminous and ultraluminous IR galaxies (LIRGs and ULIRGs; LIR > 1011 L⊙) having up to an order of magnitude lower values than normal IR galaxies (LIR < 1011 L⊙). We derive a LSX-LIR relation and confirm the applicability of an existing LHX-LIR relation for both local and distant LIRGs and ULIRGs, consistent with a scenario where X-ray luminosity is correlated with the star formation rate.