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DUST-OBSCURED GALAXIES IN THE LOCAL UNIVERSE

2013/03/31 by Ho Seong Hwang, Margaret J. Geller · 22 citations
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #Brightness #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Infrared #Local Group #Luminous infrared galaxy #Magnitude (astronomy) #Sky #Space Technology and Applications #Universe #astro-ph.CO

paper · pdf · doi:10.1088/0004-637x/769/2/116

published in The Astrophysical Journal 769(2), 116 (IOP Publishing) · 21 pages, 13 figures. To appear in ApJ

arxiv created 2013/04/20 · openalex publication_date 2013/05/13 · arxiv updated 2015/06/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We use Wide-field Infrared Survey Explorer ( WISE ), AKARI , and Galaxy Evolution Explorer ( GALEX ) data to select local analogs of high-redshift ( z ∼ 2) dust obscured galaxies (DOGs). We identify 47 local DOGs with S 12 μm / S 0.22 μm ⩾ 892 and S 12 μm > 20 mJy at 0.05 < z < 0.08 in the Sloan Digital Sky Survey data release 7. The infrared (IR) luminosities of these DOGs are in the range 3.4 × 10 10 ( L ☉ ) ≲ L IR ≲ 7.0 × 10 11 ( L ☉ ) with a median L IR of 2.1 × 10 11 ( L ☉ ). We compare the physical properties of local DOGs with a control sample of galaxies that have lower S 12 μm / S 0.22 μm but have similar redshift, IR luminosity, and stellar mass distributions. Both WISE 12 μm and GALEX near-ultraviolet (NUV) flux densities of DOGs differ from the control sample of galaxies, but the difference is much larger in the NUV. Among the 47 DOGs, 36% ± 7% have small axis ratios in the optical (i.e., b / a < 0.6), larger than the fraction among the control sample (17% ± 3%). There is no obvious sign of interaction for many local DOGs. No local DOGs have companions with comparable optical magnitudes closer than ∼50 kpc. The large- and small-scale environments of DOGs are similar to the control sample. Many physical properties of local DOGs are similar to those of high- z DOGs, even though the IR luminosities of local objects are an order of magnitude lower than for the high- z objects: the presence of two classes (active galactic nuclei- and star formation-dominated) of DOGs, abnormal faintness in the UV rather than extreme brightness in the mid-IR, and diverse optical morphology. These results suggest a common underlying physical origin of local and high- z DOGs. Both seem to represent the high-end tail of the dust obscuration distribution resulting from various physical mechanisms rather than a unique phase of galaxy evolution.

Citations