A multiwavelength approach to the star formation rate estimation in galaxies at intermediate redshifts



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Cardiel López, Nicolás and Elbaz, D. and Schiavon, R. P. and Willmer, C. N. A. and Koo, D. C. and Phillips, A. C. and Gallego Maestro, Jesús (2003) A multiwavelength approach to the star formation rate estimation in galaxies at intermediate redshifts. Astrophysical journal, 584 (1). pp. 76-99. ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1086/345594


We use a sample of seven starburst galaxies at intermediate redshifts (z similar to 0.4 and 0.8) with observations ranging from the observed ultraviolet to 1.4 GHz, to compare the star formation rate (SFR) estimators that are used in the different wavelength regimes. We find that extinction-corrected Halpha underestimates the SFR, and the degree of this underestimation increases with the infrared luminosity of the galaxies. Galaxies with very different levels of dust extinction as measured with SFRIR/SFR(Halpha, uncorrected for extinction) present a similar attenuation A [Halpha], as if the Balmer lines probed a different region of the galaxy than the one responsible for the bulk of the IR luminosity for large SFRs. In addition, SFR estimates derived from [O II] lambda3727 match very well those inferred from Halpha after applying the metallicity correction derived from local galaxies. SFRs estimated from the UV luminosities show a dichotomic behavior, similar to that previously reported by other authors in galaxies at z less than or similar to 0.4. Here we extend this result up to z similar to 0.8. Finally, one of the studied objects is a luminous compact galaxy (LCG) that may be suffering similar dust-enshrouded star formation episodes. These results highlight the relevance of quantifying the actual L-IR of LCGs, as well as that of a much larger and generic sample of luminous infrared galaxies, which will be possible after the launch of SIRTF.

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© 2003. The American Astronomical Society. All rights reserved. Valuable discussions with Jaime Zamorano, Pablo Pérez González, and Ranga-Ram Chary are gratefully acknowledged. We thank Hervé Aussel for providing us with the deconvolved ISCOCAM flux for hd2-264.1 and Hector Flores for providing us with his revised ISOCAM fluxes for the GSS galaxies. We are grateful to the staff of the W. M. Keck Observatory for their help during the observations. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. Support for this work has been provided by NSF grants AST 95-29028 and AST 00-71198. N. C. acknowledges financial support from a UCM Fundación del Amo Fellowship, a short contract at the University of California at Santa Cruz, and the Spanish Programa Nacional de Astronomía y Astrofísica under grant AYA 2000-977. D. E. wishes to thank the American Astronomical Society for its support through the Chretien International Research Grant and Joel Primack and David Koo for supporting his research through NASA grants NAG 5-8218 and NAG 5-3507. R. P. S. acknowledges support provided by the National Science Foundation through grant GF-1002-99 and from the Association of Universities for Research in Astronomy, Inc., under NSF cooperative agreement AST 96-13615, and CNPq/Brazil, for financial support through grant 200510/99-1. J. G. acknowledges financial support from the Spanish Programa Nacional de Astronomía y Astrofísica under grant AYA 2000-1790.

Uncontrolled Keywords:Hubble-deep-field; Emission-line galaxies; Ultraluminous infrared galaxies; Ultraviolet luminosity density; Small magellanic cloud; Madrid survey galaxies; Keck-II-telescope; Interstellar extinction; Compact galaxies; Spectroscopic properties
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:29751
Deposited On:24 Apr 2015 08:55
Last Modified:10 Dec 2018 15:05

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