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Ultraviolet Galaxy Counts From STIS Observations of The Hubble Deep FieldsWe present galaxy counts in the near and far ultraviolet (NUV and FUV) obtained from Space Telescope Imaging Spectrograph (STIS) observations of portions of the Hubble Deep Field North, (HDFN), the Hubble Deep Field South, (HDFS) and a parallel field near the HDFN. All three fields have deep (AB>29) optical imaging, and we determine magnitudes by taking the ultraviolet flux detected within the limiting optical isophote. An analysis of the UV-optical colors of detected objects, combined with a visual inspection of the UV images, indicates that there are no detectable objects in the UV images which are not also detected in the optical. We measure the detection area and completeness as a function of magnitude by taking the size-magnitude distribution of galaxies in the entire HDFN WFPC2 V+I image, applying the measured UV-optical colors from the detected galaxies, and determining the total area over which each galaxy would have been detected in the UV images. The average area for the simulated galaxies in each UV magnitude bin, (including galaxies which would not be detected at all), provides the effective area and completeness for the bin. We test this procedure with Monte Carlo simulations. The galaxy counts reach to AB=29 in both the NUV and FUV; 1 magnitude fainter than the HDF F30OW counts, and 7 magnitudes fainter than balloon-based counts. We compare our measured counts to various models.
Document ID
20000110133
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Gardner, J. P.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Brown, T. M.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Ferguson, H. C.
(Space Telescope Science Inst. Baltimore, MD United States)
Fisher, Richard R.
Date Acquired
August 19, 2013
Publication Date
January 1, 2000
Subject Category
Astronomy
Meeting Information
Meeting: Session 6: Cosmology and Large Scale Structure
Location: Rochester, NY
Country: United States
Start Date: June 4, 2000
End Date: June 8, 2000
Sponsors: American Astronautical Society
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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