Radial Variation of Attenuation and Star Formation in the Largest Late-Type Disks Observed with GALEX
Creators
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Boissier, Samuel1, 2
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Gil de Paz, Armando1, 3
- Boselli, Alessandro2
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Madore, Barry F.1, 4
- Buat, Véronique2
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Cortese, Luca2
- Burgarella, Denis2
- Muńoz-Mateos, Juan Carlos3
- Barlow, Tom A.5
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Forster, Karl5
- Friedman, Peter G.5
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Martin, D. Christopher5
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Morrissey, Patrick5
- Neff, Susan G.6
- Schiminovich, David7
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Seibert, Mark5
- Small, Todd5
- Wyder, Ted K.5
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Bianchi, Luciana8
- Donas, José2
- Heckman, Timothy M.8
- Lee, Young-Wook9
- Milliard, Bruno2
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Rich, R. Michael10
- Szalay, Alex S.8
- Welsh, Barry Y.11
- Yi, Sukyoung K.9
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1.
Carnegie Observatories
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2.
Laboratoire d'Astrophysique de Marseille
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3.
Complutense University of Madrid
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4.
Infrared Processing and Analysis Center
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5.
California Institute of Technology
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6.
Goddard Space Flight Center
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7.
Columbia University
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8.
Johns Hopkins University
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9.
Yonsei University
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10.
University of California, Los Angeles
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11.
University of California, Berkeley
Abstract
For a sample of 43 nearby, late-type galaxies, we have investigated the radial variation of both the current star formation rate and the dust-induced UV light attenuation. To do this we have cross-correlated IRAS images and GALEX observations for each of these galaxies and compiled observations of the gas (CO and H I) and metal-abundance gradients found in the literature. We find that attenuation correlates with metallicity. We then use the UV profiles, corrected for attenuation, to study several variants of the Schmidt law and conclude that our results are compatible with a simple law similar to the one of Kennicutt extending smoothly to lower surface densities, but with considerable scatter. We do not detect an abrupt break in the UV light at the threshold radius derived from Hα data (at which the Hα profile shows a break and beyond which only a few H II regions are usually found). We interpret the Hα sudden break not as a change in the star formation regime (as often suggested), but as the vanishingly small number of ionizing stars corresponding to low levels of star formation.
Additional Information
© 2007 American Astronomical Society. Received 2006 April 20; accepted 2006 July 28. GALEX (Galaxy Evolution Explorer) is a NASA Small Explorer, launched in 2003 April. We gratefully acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d'E´ tudes Spatiales of France and the Korean Ministry of Science and Technology. A. G. d. P. is partially financed by the Spanish Programa Nacional de Astronomı´a y Astrof ı´sica under grant AYA2003-01676. We also thank the MAGPOP network for its support, and the referee for very constructive comments. Facilities: GALEXAttached Files
Published - BOIapjss07.pdf
Files
BOIapjss07.pdf
Additional details
Identifiers
- Eprint ID
- 18044
- Resolver ID
- CaltechAUTHORS:20100421-122451071
Funding
- Programa Nacional de Astronomía y Astrofísica
- AYA2003-01676
Dates
- Created
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2010-04-22Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
Caltech Custom Metadata
- Caltech groups
- Space Radiation Laboratory , Space Astrophysics Laboratory