Details

Autor(en) / Beteiligte

• TRUMP, Jonathan R
• WEINER, Benjamin J
• RANGEL, Cyprian
• YAN, Renbin
• YESUF, Hassen
• ATEK, Hakim
• DICKINSON, Mark
• DONLEY, Jennifer L
• DUNLOP, James S
• FERGUSON, Henry C
• FINKELSTEIN, Steven L
• GROGIN, Norman A
• SCARLATA, Claudia
• HATHI, Nimish P
• JUNEAU, Stéphanie
• KARTALTEPE, Jeyhan S
• KOEKEMOER, Anton M
• NANDRA, Kirpal
• NEWMAN, Jeffrey A
• RODNEY, Steven A
• STRAUGHN, Amber N
• TEPLITZ, Harry I
• KOCEVSKI, Dale D
• BELL, Eric F
• MCGRATH, Elizabeth J
• KOO, David C
• FABER, S. M
• LAIRD, Elise S
• MOZENA, Mark

Titel

A CANDELS WFC3 GRISM STUDY OF EMISSION-LINE GALAXIES AT z ~ 2: A MIX OF NUCLEAR ACTIVITY AND LOW-METALLICITY STAR FORMATION

Ist Teil von

• The Astrophysical journal, 2011-12, Vol.743 (2), p.144-jQuery1323900401395='48'

Ort / Verlag

Bristol: IOP

Erscheinungsjahr

2011

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We present Hubble Space Telescope Wide Field Camera 3 (WFC3) slitless grism spectroscopy of 28 emission-line galaxies at z ~ 2, in the GOODS-S region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. The high sensitivity of these grism observations, with >1 Delta *s detections of emission lines to f > 2.5 X 10--18 erg s--1 cm--2, means that the galaxies in the sample are typically ~7 times less massive (median M * = 109.5 M ) than previously studied z ~ 2 emission-line galaxies. Despite their lower mass, the galaxies have [O III]/H Delta *b ratios which are very similar to previously studied z ~ 2 galaxies and much higher than the typical emission-line ratios of local galaxies. The WFC3 grism allows for unique studies of spatial gradients in emission lines, and we stack the two-dimensional spectra of the galaxies for this purpose. In the stacked data the [O III] emission line is more spatially concentrated than the H Delta *b emission line with 98.1% confidence. We additionally stack the X-ray data (all sources are individually undetected), and find that the average L [O III]/L 0.5-10 keV ratio is intermediate between typical z ~ 0 obscured active galaxies and star-forming galaxies. Together the compactness of the stacked [O III] spatial profile and the stacked X-ray data suggest that at least some of these low-mass, low-metallicity galaxies harbor weak active galactic nuclei.