Radio observations of the hubble deep field-south region. IV. Optical properties of the faint radio population
The Australia Telescope Hubble Deep Field–South (ATHDF-S) survey of the Hubble Deep Field–South (HDF-S) reaches sensitivities of ~10 µJy at 1.4, 2.5, 5.2, and 8.7 GHz, making the ATHDF-S one of the deepest surveys ever performed with the Australia Telescope Compact Array (ATCA). Here, we present the...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Published: |
Institute of Physics Publishing, Inc
2008
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| Subjects: | |
| Online Access: | http://iopscience.iop.org/1538-3881/135/6/2470/pdf/1538-3881_135_6_2470.pdf http://hdl.handle.net/20.500.11937/11885 |
| Summary: | The Australia Telescope Hubble Deep Field–South (ATHDF-S) survey of the Hubble Deep Field–South (HDF-S) reaches sensitivities of ~10 µJy at 1.4, 2.5, 5.2, and 8.7 GHz, making the ATHDF-S one of the deepest surveys ever performed with the Australia Telescope Compact Array (ATCA). Here, we present the optical identifications of the ATHDF-S radio sources using data from the literature. We find that ~66% of the radio sources have optical counterparts to I = 23.5 mag. Deep Hubble Space Telescope (HST) imaging of the area identifies a further 12% of radio sources. We present new spectroscopic observations for 98 of the radio sources and supplement these spectroscopic redshifts with photometric ones calculated from five-band optical imaging. The host galaxy colors and radio-to-optical ratios indicate that low-luminosity (or “radio-quiet”) active galactic nucleimake up a significantproportion of the sub-mJy radio population, a resultwhich is in accordance with a number of other deep radio studies. The radio-to-optical ratios of the bright (S1.4 GHz > 1 mJy) sources are consistent with a bimodal distribution. |
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