Editing Hubble Deep Field (section)

==Multifrequency followup==
[[File:Hubble Deep Field by Spitzer.jpg|thumb|The HDF imaged by the [[Spitzer Space Telescope]]. The top segment shows the foreground objects in the field; the bottom shows the background with the foreground objects removed.]]

Very-high redshift objects (Lyman-break galaxies) cannot be seen in visible light and generally are detected in [[Infrared astronomy|infrared]] or [[Submillimetre astronomy|submillimetre]] wavelength surveys of the HDF instead.<ref name=Ferguson2/> Observations with the [[Infrared Space Observatory]] (ISO) indicated infrared emission from 13 galaxies visible in the optical images, attributed to large quantities of dust associated with intense star formation.<ref name="RowanRobinson1997">Rowan-Robinson et al. (1997)</ref> Infrared observations have also been made with the [[Spitzer Space Telescope]].<ref>{{cite web |title=GOODS Spitzer and Ancillary Data |url=http://irsa.ipac.caltech.edu/data/SPITZER/GOODS/ |publisher=NASA/IPAC Infrared Science Archive |access-date=January 7, 2009}}</ref> Submillimeter observations of the field have been made with [[James Clerk Maxwell Telescope#Continuum detectors|SCUBA]] on the [[James Clerk Maxwell Telescope]], initially detecting 5 sources, although with very low resolution.<ref name="Ferguson2000b" /> Observations have also been made with the [[Subaru (telescope)|Subaru]] telescope in Hawaii.<ref name="hdf_clearinghouse">{{cite web |last=Ferguson |first=H. |date=2002 |url=http://www.stsci.edu/ftp/science/hdf/clearinghouse/clearinghouse.html |title=HDF Clearinghouse |publisher=Space Telescope Science Institute |access-date=December 27, 2008}}</ref>

X-ray observations by the [[Chandra X-ray Observatory]] revealed six sources in the HDF, which were found to correspond to three elliptical galaxies, one spiral galaxy, one [[active galactic nucleus]] and one extremely red object, thought to be a distant galaxy containing a large amount of [[dust]] absorbing its blue light emissions.<ref name="Hornschemeier2000">Hornschemeier et al. (2000)</ref>

Ground-based radio images taken using the VLA revealed seven radio sources in the HDF, all of which correspond to galaxies visible in the optical images.<ref name="Kellerman1998">Kellerman et al. (1998)</ref> The field has also been surveyed with the [[Westerbork Synthesis Radio Telescope]] and the [[MERLIN]] array of radio telescopes at 1.4&nbsp;GHz;<ref name="wsrt">Garratt et al. (2000)</ref><ref name="merlin">
{{cite web |url=http://www.merlin.ac.uk/topics/deepfield/index.html |title=Preliminary MERLIN Observations of the HST Deep Field |publisher=[[Jodrell Bank Observatory]] |access-date=December 27, 2008}}<!-- DEADLINK --></ref> the combination of VLA and MERLIN maps made at wavelengths of 3.5 and 20&nbsp;cm have located 16 radio sources in the HDF-N field, with many more in the flanking fields.<ref name="Ferguson2000b" /> Radio images of some individual sources in the field have been made with the [[European VLBI Network]] at 1.6&nbsp;GHz with a higher resolution than the Hubble maps.<ref name="evn">Garrett et al. (2001)</ref>