Tracing Galaxy Assembly: Tadpole Galaxies in the Hubble Ultra Deep Field
Open Access
- 10 March 2006
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 639 (2), 724-730
- https://doi.org/10.1086/499576
Abstract
In the Hubble Ultra Deep Field (HUDF) an abundance of galaxies is seen with a knot at one end plus an extended tail, resembling a tadpole. These "tadpole galaxies" appear dynamically unrelaxed--presumably in an early merging state--where tidal interactions likely created the distorted knot-plus-tail morphology. Here we systematically select tadpole galaxies from the HUDF and study their properties as a function of their photometric redshifts. In a companion HUDF variability study, Cohen et al. (2005) revealed a total of 45 variable objects believed to be Active Galactic Nuclei (AGN). Here we show that this faint AGN sample has no overlap with the tadpole galaxy sample, as predicted by theoretical work. The tadpole morphology--combined with the lack of overlap with the variable objects--supports the idea that these galaxies are in the process of an early-stage merger event, i.e., at a stage that likely precedes the "turn-on" of any AGN component and the onset of any point-source variability.Comment: 7 pages, 4 figures. Accepted for publication by Astrophysical JournaThis publication has 25 references indexed in Scilit:
- Clues to Active Galactic Nucleus Growth from Optically Variable Objects in the Hubble Ultra Deep FieldThe Astrophysical Journal, 2006
- Galaxy Morphologies in the Hubble Ultra Deep Field: Dominance of Linear Structures at the Detection LimitThe Astrophysical Journal, 2005
- Energy input from quasars regulates the growth and activity of black holes and their host galaxiesNature, 2005
- Discovery of Face-on Counterparts of Chain Galaxies in the Tadpole Advanced Camera for Surveys FieldThe Astrophysical Journal, 2004
- Observing the Formation of the Hubble Sequence in the Great Observatories Origins Deep SurveyThe Astrophysical Journal, 2004
- The Chandra Deep Field North Survey. XIII. 2 Ms Point-Source CatalogsThe Astronomical Journal, 2003
- New Insight on Galaxy Formation and Evolution From Keck Spectroscopy of the Hawaii Deep FieldsThe Astronomical Journal, 1996
- SExtractor: Software for source extractionAstronomy and Astrophysics Supplement Series, 1996
- The Contribution of Late-Type/Irregulars to the Faint Galaxy Counts from Hubble Space Telescope Medium-Deep Survey ImagesThe Astrophysical Journal, 1995
- Faintest Galaxy Morphologies From HST WFPC2 Imaging of the Hawaii Survey FieldsThe Astronomical Journal, 1995