Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 661052.0, MPI für Astronomie / Publikationen_mpia
3D-HST grism spectroscopy of a gravitationally lensed, low-metallicity starburst galaxy at z = 1.847
Authors:Brammer, G. B.; Sánchez-Janssen, R.; Labbé, I.; da Cunha, E.; Erb, D. K.; Franx, M.; Fumagalli, M.; Lundgren, B.; Marchesini, D.; Momcheva, I.; Nelson, E.; Patel, S.; Quadri, R.; Rix, H.-W.; Skelton, R. E.; Schmidt, K. B.; van der Wel, A.; van Dokkum, P. G.; Wake, D. A.; Whitaker, K. E.
Date of Publication (YYYY-MM-DD):2012
Journal Abbrev.:The Astrophysical Journal Letters
Issue / Number:1
Start Page:id. L17
Audience:Not Specified
Abstract / Description:We present Hubble Space Telescope (HST) imaging and spectroscopy of the gravitational lens SL2SJ02176-0513, a cusp arc at z = 1.847. The UV continuum of the lensed galaxy is very blue, which is seemingly at odds with its redder optical colors. The 3D-HST WFC3/G141 near-infrared spectrum of the lens reveals the source of this discrepancy to be extremely strong [O III] λ5007 and Hβ emission lines with rest-frame equivalent widths of 2000 ± 100 and 520 ± 40 Å, respectively. The source has a stellar mass ~108 M &sun;, sSFR ~ 100 Gyr-1, and detection of [O III] λ4363 yields a metallicity of 12 + log (O/H) = 7.5 ± 0.2. We identify local blue compact dwarf analogs to SL2SJ02176-0513, which are among the most metal-poor galaxies in the Sloan Digital Sky Survey. The local analogs resemble the lensed galaxy in many ways, including UV/optical spectral energy distribution, spatial morphology, and emission line equivalent widths and ratios. Common to SL2SJ02176-0513 and its local counterparts is an upturn at mid-IR wavelengths likely arising from hot dust heated by starbursts. The emission lines of SL2SJ02176-0513 are spatially resolved owing to the combination of the lens and the high spatial resolution of HST. The lensed galaxy is composed of two clumps with combined size re ~300 pc, and we resolve significant differences in UV color and emission line equivalent width between them. Though it has characteristics occasionally attributed to active galactic nuclei, we conclude that SL2SJ02176-0513 is a low-metallicity star-bursting dwarf galaxy. Such galaxies will be found in significant numbers in the full 3D-HST grism survey. Based on observations made with the NASA/ESA Hubble Space Telescope, program 12328, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
Free Keywords:galaxies: dwarf; galaxies: formation; galaxies: high-redshift; galaxies: starburst
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.