Near-infrared and star-forming properties of local luminous infrared galaxies

Almudena Alonso-Herrero, George H. Rieke, Marcia J. Rieke, Luis Colina, Pablo G. Pérez-González, Stuart D. Ryder

Research output: Contribution to journalArticle

132 Scopus citations

Abstract

We use Hubble Space Telescope (HST) NICMOS continuum and Paα observations to study the near-infrared and star formation properties of a representative sample of 30 local (d ∼ 35-75 Mpc) luminous infrared galaxies (LIRGs, infrared [8-1000 μm] luminosities of log LIR = 11-11.9 L). The data provide spatial resolutions of 25-50 pc and cover the central ∼3.3-7.1 kpc regions of these galaxies. About half of the LIRGs show compact (∼1-2 kpc) Paα emission with a high surface brightness in the form of nuclear emission, rings, and minispirals. The rest of the sample show Paα emission along the disk and the spiral arms extending over scales of 3-7 kpc and larger. About half of the sample contains H II regions with Ha luminosities significantly higher than those observed in normal galaxies. There is a linear empirical relationship between the mid-IR 24 μm and hydrogen recombination (extinction-corrected Paα) luminosity for these LIRGs, and the H II regions in the central part of M51. This relation holds over more than four decades in luminosity, suggesting that the mid-IR emission is a good tracer of the star formation rate (SFR). Analogous to the widely used relation between the SFR and total IR luminosity of R. Kennicutt, we derive an empirical calibration of the SFR in terms of the monochromatic 24 μm luminosity that can be used for luminous, dusty galaxies.

Original languageEnglish (US)
Pages (from-to)835-849
Number of pages15
JournalAstrophysical Journal
Volume650
Issue number2 I
DOIs
StatePublished - Oct 20 2006

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Keywords

  • Galaxies: ISM
  • Galaxies: interactions
  • Galaxies: spiral
  • Galaxies: star clusters
  • H II regions
  • Infrared: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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