Open AccessThe clustering of hot and cold IRAS galaxies: the redshift‐space correlation function
Author(s) -
Hawkins E.,
Maddox S.,
Branchini E.,
Saunders W.
Publication year - 2001
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.1365-8711.2001.04431.x
Subject(s) - physics , astrophysics , luminous infrared galaxy , galaxy , luminosity function , luminosity , absolute magnitude , astronomy , redshift , elliptical galaxy , radio galaxy , correlation function (quantum field theory) , optoelectronics , dielectric
We measure the autocorrelation function, ξ , of galaxies in the IRAS Point Source Catalogue galaxy redshift (PSC z ) survey and investigate its dependence on the far‐infrared colour and absolute luminosity of the galaxies. We find that the PSC z survey correlation function can be modelled out to a scale of 10 h −1 Mpc as a power law of slope 1.30±0.04 and correlation length 4.77±0.20 . At a scale of 75 h −1 Mpc we find the value of J 3 to be 1500±400 . We also find that galaxies with higher 100 μm/60 μm flux ratio, corresponding to cooler dust temperatures, are more strongly clustered than warmer galaxies. Splitting the survey into three colour subsamples, we find that, between 1 and 10 h −1 Mpc, the ratio of ξ is a factor of 1.5 higher for the cooler galaxies compared with the hotter galaxies. This is consistent with the suggestion that hotter galaxies have higher star formation rates, and correspond to later‐type galaxies which are less clustered than earlier types. Using volume‐limited subsamples, we find a weak variation of ξ as a function of absolute luminosity, in the sense that more luminous galaxies are less clustered than fainter galaxies. The trend is consistent with the colour dependence of ξ and the observed colour–luminosity correlation, but the large uncertainties mean that it has a low statistical significance.