Probing Very Bright End of Galaxy Luminosity Function at z ≳ 7 Using Hubble Space Telescope Pure Parallel Observations
Abstract
We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 arcmin^2 in total area. We have found three bright Y (098)-dropouts, which are candidate galaxies at z ≳ 7.4. One of these objects shows an indication of peculiar variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L > 2L^∗). Such very luminous objects could be the progenitors of the high-mass Lyman break galaxies observed at lower redshifts (up to z ~ 5). While our sample is still limited in size, it is much less subject to the uncertainty caused by "cosmic variance" than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z ≈ 7.4 is not well explained by the current luminosity function (LF) estimates at z ≈ 8. However, its inferred surface density could be explained by the prediction from the LFs at z ≈ 7 if it belongs to the high-redshift tail of the galaxy population at z ≈ 7.
Additional Information
© 2011 The American Astronomical Society. Received 2010 October 11; accepted 2010 December 27; published 2011 January 24. Based on observations made with the NASA/ESA Hubble Space Telescope, 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. These observations are associated with programs 11700 and 11702. We thank the referee for the helpful comments. We acknowledge the support of NASA grant HST-GO-11702.*. H.Y. is supported by the long-term fellowship program of the Center for Cosmology and AstroParticle Physics (CCAPP) at The Ohio State University. B.E.R. is supported by Hubble Fellowship Program number HST-HF-51262.01-A. R.A.W. is supported by NASA JWST Interdisciplinary Scientist grant NAG5-12460 from GSFC. We dedicate this Letter to the memory of John Huchra, who during his life had been a very staunch supporter of the Hubble Space Telescope project.Attached Files
Published - Yan2011p12762Astrophys_J_Lett.pdf
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Additional details
- Eprint ID
- 22650
- Resolver ID
- CaltechAUTHORS:20110303-154338944
- HST-GO-11702
- NASA
- Center for Cosmology and AstroParticle Physics (CCAPP)
- HST-HF-51262.01-A
- NASA Hubble Fellowship
- NAG5-12460
- NASA
- Created
-
2011-03-04Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)