DUST EXTINCTION FROM BALMER DECREMENTS OF STAR-FORMING GALAXIES AT 0.75 {<=} z {<=} 1.5 WITH HUBBLE SPACE TELESCOPE/WIDE-FIELD-CAMERA 3 SPECTROSCOPY FROM THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY

Journal Article · Fri Feb 15 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/763/2/145· OSTI ID:22167105

Dominguez, A.; Siana, B.; Masters, D. ^[1]; Henry, A. L.; Martin, C. L. ^[2]; Scarlata, C.; Bedregal, A. G. ^[3]; Malkan, M.; Ross, N. R. ^[4]; Atek, H.; Colbert, J. W. ^[5]; Teplitz, H. I.; Rafelski, M. ^[6]; McCarthy, P.; Hathi, N. P.; Dressler, A. ^[7]

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1. Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States)
2. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
3. Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States)
4. Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States)
5. Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States)
6. Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States)
7. Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States)

Spectroscopic observations of H{alpha} and H{beta} emission lines of 128 star-forming galaxies in the redshift range 0.75 {<=} z {<=} 1.5 are presented. These data were taken with slitless spectroscopy using the G102 and G141 grisms of the Wide-Field-Camera 3 (WFC3) on board the Hubble Space Telescope as part of the WFC3 Infrared Spectroscopic Parallel survey. Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (H{alpha}/H{beta}). We present dust extinction as a function of H{alpha} luminosity (down to 3 Multiplication-Sign 10{sup 41} erg s{sup -1}), galaxy stellar mass (reaching 4 Multiplication-Sign 10{sup 8} M {sub Sun }), and rest-frame H{alpha} equivalent width. The faintest galaxies are two times fainter in H{alpha} luminosity than galaxies previously studied at z {approx} 1.5. An evolution is observed where galaxies of the same H{alpha} luminosity have lower extinction at higher redshifts, whereas no evolution is found within our error bars with stellar mass. The lower H{alpha} luminosity galaxies in our sample are found to be consistent with no dust extinction. We find an anti-correlation of the [O III] {lambda}5007/H{alpha} flux ratio as a function of luminosity where galaxies with L {sub H{alpha}} < 5 Multiplication-Sign 10{sup 41} erg s{sup -1} are brighter in [O III] {lambda}5007 than H{alpha}. This trend is evident even after extinction correction, suggesting that the increased [O III] {lambda}5007/H{alpha} ratio in low-luminosity galaxies is likely due to lower metallicity and/or higher ionization parameters.

• OSTI ID: 22167105
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 763; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CAMERAS
DUSTS
ERRORS
GALAXIES
LUMINOSITY
RED SHIFT
SPECTRA
SPECTROSCOPY
STARS
TELESCOPES