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The morphological diversities among star-forming galaxies at high redshifts in the great observatories origins deep survey
ASTROPHYSICAL JOURNAL
  • S Ravindranath
  • M Giavalisco
  • HC Ferguson
  • C Conselice
  • N Katz, University of Massachusetts - Amherst
  • M Weinberg, University of Massachusetts - Amherst
  • J Lotz
  • M Dickinson
  • SM Fall
  • B Mobasher
  • C Papovich
Publication Date
2006
Abstract
We used the deep, multiwavelength images obtained by the Great Observatories Origins Deep Survey (GOODS) to identify ~4700 Lyman break galaxies (LBGs) at z > 2.5, and 292 starburst galaxies at z ~ 1.2. We present the results from morphological analysis based on light profile shape and ellipticity for ~1333 of the most luminous LBGs. About 40% of LBGs at z ~ 3 have exponential profiles, ~30% of the galaxies have steep (r1/4-like) profiles, and ~30% of LBGs have multiple cores of disturbed morphologies suggestive of close pairs or mergers. The fraction of spheriod-like LBGs decrease by about 15% from z ~ 5 to 3. A comparison of LBGs with the starburst galaxies at z ~ 1.2 shows that disklike and merger morphologies are dominant, but the fraction of spheroid-like profiles is about 20% higher among LBGs. The ellipticity distribution for LBGs exhibits a pronounced skew toward high ellipticities (epsilon > 0.5), which cannot be explained by morphologies similar to the local disks and spheroids viewed at random orientations. The peak of the distribution evolves toward lower epsilon, from 0.7 at z = 4 to ~0.5 at z = 3. The ellipticity distribution for the z ~ 1.2 galaxies is relatively flat, similar to that seen for present-day galaxies. The dominance of elongated morphologies suggests that in a significant fraction of LBGs we may be witnessing star formation in clumps along gas-rich filaments, or the earliest gas-rich bars that encompass essentially the entire visible galaxy.
Comments

This is a pre-published version which is collected from arXiv link. The published version is at http://iopscience.iop.org/0004-637X/652/2/963?fromSearchPage=true

Pages
963-980
Citation Information
S Ravindranath, M Giavalisco, HC Ferguson, C Conselice, et al.. "The morphological diversities among star-forming galaxies at high redshifts in the great observatories origins deep survey" ASTROPHYSICAL JOURNAL Vol. 652 Iss. 2 (2006)
Available at: http://works.bepress.com/martin_weinberg/35/