Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:astro-ph/0402519)
· On-line Data
· References in the article
· Citations to the Article (2) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (9)
· NED Objects (1)
· Also-Read Articles (Reads History)
· HEP/Spires Information
·
· Translate This Page
Title:
The Counterarc to MS 1512-cB58 and a Companion Galaxy
Authors:
Teplitz, Harry I.; Malkan, Matthew A.; McLean, Ian S.
Affiliation:
AA(Spitzer Science Center, MS 220-6, California Institute of Technology, Pasadena, CA 91125; .), AB(Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095.), AC(Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095.)
Publication:
The Astrophysical Journal, Volume 608, Issue 1, pp. 36-41. (ApJ Homepage)
Publication Date:
06/2004
Origin:
UCP
ApJ Keywords:
Cosmology: Observations, Galaxies: Evolution, Galaxies: High-Redshift, Galaxies: Individual: Alphanumeric: MS 1512-cB58, Cosmology: Gravitational Lensing
DOI:
10.1086/420689
Bibliographic Code:
2004ApJ...608...36T

Abstract

We present near-infrared spectra of ``A2,'' the primary counterarc to the gravitationally lensed galaxy MS 1512-cB58. The spectra show redshifted Hα, [N II], [O III], and Hβ at z=2.729+/-0.001. We observe the same Hα/[O III] ratio as cB58, which together with the redshift confirms that A2 is indeed another image of a single background galaxy. Published lensing reconstruction reports that A2 is a magnification of the entire source, while cB58 is an image of only a part. At marginal significance, A2 shows higher line-to-continuum ratios than cB58 (by a factor of ~2), suggesting a nonuniform ratio of young to old stars across the galaxy. We observe a second emission-line source in the slit. This object, ``W5,'' is predicted to be a lensed image of another galaxy at a redshift similar to cB58. W5 is blueshifted from cB58 by ~400 km s-1 and has a significantly lower Hα/[O III] ratio, confirming that it is an image of a different background galaxy in a group with cB58. The Hα emission line in W5 implies a star formation rate of 6 Msolar yr-1 (H0=70 km s-1 Mpc-1, ΩM=0.3,ΩΛ=0.7), after correcting for lensing magnification.

Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints