MORPHOLOGY AND SIZE DIFFERENCES BETWEEN LOCAL AND HIGH-REDSHIFT LUMINOUS INFRARED GALAXIES

Journal Article · Mon Jan 10 04:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/726/2/93· OSTI ID:21567650

Rujopakarn, Wiphu; Rieke, George H; Eisenstein, Daniel J; Juneau, Stephanie ^[1]

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1. Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)

We show that the star-forming regions in high-redshift luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) and submillimeter galaxies (SMGs) have similar physical scales to those in local normal star-forming galaxies. To first order, their higher infrared (IR) luminosities result from higher luminosity surface density. We also find a good correlation between the IR luminosity and IR luminosity surface density in starburst galaxies across over five orders of magnitude of IR luminosity from local normal galaxies to z {approx} 2 SMGs. The intensely star-forming regions of local ULIRGs are significantly smaller than those in their high-redshift counterparts and hence diverge significantly from this correlation, indicating that the ULIRGs found locally are a different population from the high-redshift ULIRGs and SMGs. Based on this relationship, we suggest that luminosity surface density should serve as a more accurate indicator for the IR emitting environment, and hence the observable properties, of star-forming galaxies than their IR luminosity. We demonstrate this approach by showing that ULIRGs at z {approx} 1 and a lensed galaxy at z {approx} 2.5 exhibit aromatic features agreeing with local LIRGs that are an order of magnitude less luminous, but have similar IR luminosity surface density. A consequence of this relationship is that the aromatic emission strength in star-forming galaxies will appear to increase at z>1 for a given IR luminosity compared to their local counterparts.

• OSTI ID: 21567650
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 726; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ELECTROMAGNETIC RADIATION
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
INFRARED RADIATION
MORPHOLOGY
RADIATIONS
RED SHIFT
SIZE
STAR EVOLUTION