ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies
Observations using the 7 mm receiver system on the Australia Telescope Compact Array have revealed large reservoirs of molecular gas in two high-redshift radio galaxies: HATLAS J090426.9+015448 (zz = 2.37) and HATLAS J140930.4+003803 (zz = 2.04). Optically the targets are very faint, and spectroscop...
| Asıl Yazarlar: | , , , , , , , , , , , |
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| Materyal Türü: | Journal article |
| Baskı/Yayın Bilgisi: |
Oxford University Press
2016
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| _version_ | 1826296327558922240 |
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| author | Heywood, I Contreras, Y Smith, D Cooray, A Dunne, L Gómez, L Ibar, E Ivison, R Jarvis, M Michałowski, M Riechers, D van der Werf, P |
| author_facet | Heywood, I Contreras, Y Smith, D Cooray, A Dunne, L Gómez, L Ibar, E Ivison, R Jarvis, M Michałowski, M Riechers, D van der Werf, P |
| author_sort | Heywood, I |
| collection | OXFORD |
| description | Observations using the 7 mm receiver system on the Australia Telescope Compact Array have revealed large reservoirs of molecular gas in two high-redshift radio galaxies: HATLAS J090426.9+015448 (zz = 2.37) and HATLAS J140930.4+003803 (zz = 2.04). Optically the targets are very faint, and spectroscopy classifies them as narrow-line radio galaxies. In addition to harbouring an active galactic nucleus the targets share many characteristics of sub-mm galaxies. Far-infrared data from Herschel-ATLAS suggest high levels of dust (>109 M⊙) and a correspondingly large amount of obscured star formation (∼1000 M⊙ / yr). The molecular gas is traced via the J = 1 → 0 transition of 12CO, its luminosity implying total H2 masses of (1.7 ± 0.3) × 1011 and (9.5 ± 2.4) × 1010 (αCO/0.8) M⊙ in HATLAS J090426.9+015448 and HATLAS J140930.4+003803 respectively. Both galaxies exhibit molecular line emission over a broad (∼1000 km/s) velocity range, and feature double-peaked profiles. We interpret this as evidence of either a large rotating disk or an on-going merger. Gas depletion timescales are ∼100 Myr. The 1.4 GHz radio luminosities of our targets place them close to the break in the luminosity function. As such they represent ‘typical’ zz > 2 radio sources, responsible for the bulk of the energy emitted at radio wavelengths from accretion-powered sources at high redshift, and yet they rank amongst the most massive systems in terms of molecular gas and dust content. We also detect 115 GHz rest-frame continuum emission, indicating a very steep high-radio-frequency spectrum, possibly classifying the targets as compact steep spectrum objects. |
| first_indexed | 2024-03-07T04:14:38Z |
| format | Journal article |
| id | oxford-uuid:c9026d3d-4214-403f-928e-28e7f376e01c |
| institution | University of Oxford |
| last_indexed | 2024-03-07T04:14:38Z |
| publishDate | 2016 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:c9026d3d-4214-403f-928e-28e7f376e01c2022-03-27T06:55:59ZATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxiesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c9026d3d-4214-403f-928e-28e7f376e01cSymplectic Elements at OxfordOxford University Press2016Heywood, IContreras, YSmith, DCooray, ADunne, LGómez, LIbar, EIvison, RJarvis, MMichałowski, MRiechers, Dvan der Werf, PObservations using the 7 mm receiver system on the Australia Telescope Compact Array have revealed large reservoirs of molecular gas in two high-redshift radio galaxies: HATLAS J090426.9+015448 (zz = 2.37) and HATLAS J140930.4+003803 (zz = 2.04). Optically the targets are very faint, and spectroscopy classifies them as narrow-line radio galaxies. In addition to harbouring an active galactic nucleus the targets share many characteristics of sub-mm galaxies. Far-infrared data from Herschel-ATLAS suggest high levels of dust (>109 M⊙) and a correspondingly large amount of obscured star formation (∼1000 M⊙ / yr). The molecular gas is traced via the J = 1 → 0 transition of 12CO, its luminosity implying total H2 masses of (1.7 ± 0.3) × 1011 and (9.5 ± 2.4) × 1010 (αCO/0.8) M⊙ in HATLAS J090426.9+015448 and HATLAS J140930.4+003803 respectively. Both galaxies exhibit molecular line emission over a broad (∼1000 km/s) velocity range, and feature double-peaked profiles. We interpret this as evidence of either a large rotating disk or an on-going merger. Gas depletion timescales are ∼100 Myr. The 1.4 GHz radio luminosities of our targets place them close to the break in the luminosity function. As such they represent ‘typical’ zz > 2 radio sources, responsible for the bulk of the energy emitted at radio wavelengths from accretion-powered sources at high redshift, and yet they rank amongst the most massive systems in terms of molecular gas and dust content. We also detect 115 GHz rest-frame continuum emission, indicating a very steep high-radio-frequency spectrum, possibly classifying the targets as compact steep spectrum objects. |
| spellingShingle | Heywood, I Contreras, Y Smith, D Cooray, A Dunne, L Gómez, L Ibar, E Ivison, R Jarvis, M Michałowski, M Riechers, D van der Werf, P ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title | ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title_full | ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title_fullStr | ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title_full_unstemmed | ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title_short | ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
| title_sort | atca detections of massive molecular gas reservoirs in dusty high z radio galaxies |
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