2006/04/21 by Asantha Cooray, Masami Ouchi · 1 citation
Engineering · Environmental Science · Physics and Astronomy · #Astronomy #Astrophysics #CCD and CMOS Imaging Sensors #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy group #Halo #Luminosity #Luminosity function #Luminous infrared galaxy #Mass-to-light ratio #Physics #Remote Sensing in Agriculture #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10437.x
published as Mon.Not.Roy.Astron.Soc.369:1869-1879,2006 · 13 pages, 9 figures; accepted for publication in Mon. Not. Roy. Astron. Soc.; low resolution figures submitted here. A pdf file with high resolution figures available at http://www.cooray.org/Cooray-Ouchi.pdf
arxiv created 2006/04/21 · openalex publication_date 2006/05/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using the conditional luminosity function (CLF) – the luminosity distribution of galaxies in a dark matter halo – as a way to model galaxy statistics, we study how z= 4 Lyman Break Galaxies (LBGs) are distributed in dark matter haloes. For this purpose, we measure luminosity-dependent clustering of LBGs in the Subaru/XMM–Newton Deep Field by separating a sample of 16 920 galaxies to three magnitude bins in i′ band between 24.5 and 27.5. Our model fits to data show a possible trend for more-luminous galaxies to appear as satellites in more-massive haloes; the minimum halo mass in which satellites appear is 3.9+4.1−3.5× 1012, 6.2+3.8−4.9× 1012 and 9.6+7.0−4.6× 1012 M⊙ (1σ errors) for galaxies with 26.5 < i′ < 27.5, 25.5 < i′ < 26.5 and 24.5 < i′ < 25.5 mag, respectively. The satellite fraction of galaxies at z= 4 in these magnitude bins is 0.13–0.3, 0.09–0.22 and 0.03–0.14, respectively, where the 1σ ranges account for differences coming from two different estimates of the z= 4 LF from the literature. To jointly explain the LF and the large-scale linear bias factor of z= 4 LBGs as a function of rest UV luminosity requires central galaxies to be brighter in UV at z= 4 than present-day galaxies in same dark matter mass haloes. Moreover, UV luminosity of central galaxies in haloes with total mass greater than roughly 1012 M⊙ must decrease from z= 4 to today by an amount more than the luminosity change for galaxies in haloes below this mass. This mass-dependent luminosity evolution is preferred at more than 3σ confidence level compared to a pure-luminosity evolution scenario where all galaxies decrease in luminosity by the same amount from z= 4 to today. The scenario preferred by the data is consistent with the ‘downsizing’ picture of galaxy evolution.