CLASH

• Verfasst von: Zitrin, Adi [VerfasserIn]
• Titel: CLASH
• Titelzusatz: discovery of a bright z[simeq]6.2 dwarf galaxy quadruply lensed by MACS J0329.6-0211
• Verf.angabe: A. Zitrin, J. Moustakas, L. Bradley, D. Coe, L.A. Moustakas, M. Postman, X. Shu, W. Zheng, N. Benítez, R. Bouwens, T. Broadhurst, H. Ford, O. Host, S. Jouvel, A. Koekemoer, M. Meneghetti, P. Rosati, M. Donahue, C. Grillo, D. Kelson, D. Lemze, E. Medezinski, A. Molino, M. Nonino, and S. Ogaz
• E-Jahr: 2012
• Jahr: 2012 February 10
• Umfang: 6 S.
• Fussnoten: Im Titel steht nach "z" "tilde" über "Unterstrich" ; Gesehen am 18.10.2018
• Titel Quelle: Enthalten in: The astrophysical journal / 2
• Ort Quelle: London : Institute of Physics Publ., 1995
• Jahr Quelle: 2012
• Band/Heft Quelle: 747(2012,1) Artikel-Nummer L9, 6 Seiten
• ISSN Quelle: 2041-8213
• DOI: doi:10.1088/2041-8205/747/1/L9
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1580238831

Abstract

We report the discovery of a z phot = 6.18 +0.05 - 0.07 (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 ( z l = 0.45). The galaxy is observed as a high-redshift dropout in HST /ACS/WFC3 CLASH and Spitzer /IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman break in the 18-band photometry, making this galaxy one of the highest-redshift multiply lensed objects known to date with an observed magnitude of F125W =24.00 ± 0.04 AB mag for its most magnified image. We also present the first strong-lensing analysis of this cluster uncovering 15 additional multiply imaged candidates of five lower-redshift sources spanning the range z s ##IMG## [http://ej.iop.org/icons/Entities/sime.gif] sime 2-4. The mass model independently supports the high photometric redshift and reveals magnifications of 11.6 +8.9 - 4.1 , 17.6 +6.2 - 3.9 , 3.9 +3.0 - 1.7 , and 3.7 +1.3 - 0.2 , respectively, for the four images of the high-redshift galaxy. By delensing the most magnified image we construct an image of the source with a physical resolution of 200 pc when the universe was 0.9 Gyr old, where the z ##IMG## [http://ej.iop.org/icons/Entities/sime.gif] sime 6.2 galaxy occupies a source-plane area of approximately 2.2 kpc 2 . Modeling the observed spectral energy distribution using population synthesis models, we find a demagnified stellar mass of ##IMG## [http://ej.iop.org/images/2041-8205/747/1/L9/apjl421305ieqn1.gif] $\sim10^9 \,\mathcal M_ødot $ , subsolar metallicity ( Z / Z ☉ 0.5), low dust content ( A V 0.1 mag), a demagnified star formation rate (SFR) of ##IMG## [http://ej.iop.org/images/2041-8205/747/1/L9/apjl421305ieqn2.gif] $\sim3.2 \,\mathcal M_ødot $ yr -1 , and a specific SFR of 3.4 Gyr -1 , all consistent with the properties of local dwarf galaxies.