2009/12/30 by Tomotsugu Goto, Yusei Koyama, T. Wada +39 · 1 citation
Environmental Science · Physics and Astronomy · #Astronomy #Astrophysics #Cluster (spacecraft) #Cosmology and Gravitation Theories #Extrapolation #Field (mathematics) #Field galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Hubble Deep Field #Luminosity #Photometric redshift #Physics #Population #Redshift #Redshift survey #Remote Sensing in Agriculture #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1051/0004-6361/200913473
Accepted for publication in A&A AKARI special issue
arxiv created 2009/12/30 · openalex publication_date 2010/05/01 · arxiv updated 2015/05/14 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/28
Aims. We aim to reveal environmental dependence of infrared luminosity functions (IR LFs) of galaxies at z ~ 0.8 using the AKARI \nsatellite. AKARI’s wide field of view and unique mid-IR filters help us to construct restframe 8 μm LFs directly without relying on \nSED models. \nMethods. We construct restframe 8 μm IR LFs in the cluster region RXJ1716.4+6708 at z = 0.81, and compare them with a blank \nfield using the AKARI north ecliptic pole deep field data at the same redshift. AKARI’s wide field of view (10' × 10') is suitable to \ninvestigate wide range of galaxy environments. AKARI’s 15 μm filter is advantageous here since it directly probes restframe 8 μm at \nz ~ 0.8, without relying on a large extrapolation based on a SED fit, which was the largest uncertainty in previous work. \nResults. We have found that cluster IR LFs at restframe 8 μm have a factor of 2.4 smaller L^∗ and a steeper faint-end slope than that \nof the field. Confirming this trend, we also found that faint-end slopes of the cluster LFs becomes flatter and flatter with decreasing \nlocal galaxy density. These changes in LFs cannot be explained by a simple infall of field galaxy population into a cluster. Physics \nthat can preferentially suppress IR luminous galaxies in high density regions is required to explain the observed results.