Open AccessX‐ray background synthesis: the infrared connection
Author(s) -
Gandhi P.,
Fabian A. C.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06259.x
Subject(s) - physics , infrared , connection (principal bundle) , astronomy , astrophysics , x ray background , quasar , galaxy , structural engineering , engineering
We present a synthesis model of the X‐ray background based on the cross‐correlation between mid‐infrared and X‐ray surveys, where the distribution of type 2 sources is assumed to follow that of luminous infrared galaxies while type 1 sources are traced by the observed ROSAT distribution. The best fits to both the X‐ray number counts and background spectrum require at least some density evolution. We explore a limited range of parameter space for the evolutionary variables of the type 2 luminosity function. Matching the redshift distribution to that observed in deep Chandra and XMM–Newton fields, we find weak residuals as a signature of Fe emission from sources in a relatively peaked range of redshift. This extends the recent work of Franceschini et al. and emphasizes the possible correlation between obscured active galactic nuclei and star‐forming activity.