Morganti, R., Oosterloo, T., Raymond Oonk, J.B. et al. (2 more authors) (2016) The missing link: Tracing molecular gas in the outer filament of Centaurus A. Astronomy & Astrophysics, 592. L9. ISSN 0004-6361
Abstract
We report the detection, using observations of the CO(2−1) line performed with the Atacama Pathfinder EXperiment (APEX), of molecular gas in the region of the outer filament of Centaurus A, a complex region known to show various signatures of an interaction between the radio jet, an H i cloud, and ionised gas filaments. We detect CO(2−1) at all observed locations, which were selected to represent regions with very different physical conditions. The H2 masses of the detections range between 0.2 × 106 and 1.1 × 106M⊙, for conservative choices of the CO to H2 conversion factor. Surprisingly, the stronger detections are not coincident with the H i cloud, but instead are in the region of the ionised filaments. We also find variations in the widths of the CO(2−1) lines throughout the region, with broader lines in the region of the ionised gas, i.e. where the jet-cloud interaction is strongest, and with narrow profiles in the H i cloud. This may indicate that the molecular gas in the region of the ionised gas has the momentum of the jet-cloud interaction encoded in it, in the same way as the ionised gas does. These molecular clouds may therefore be the result of very efficient cooling of the down-stream gas photo- or shock-ionised by the interaction. On the other hand, the molecular clouds with narrower profiles, which are closer to or inside the H i cloud, could be pre-existing cold H2 cores which manage to survive the effects of the passing jet.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © ESO, 2016. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | galaxies: active ; galaxies: individual: Centaurus A ; ISM: jets and outflows ; radio lines: galaxies |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 03 Nov 2017 11:16 |
Last Modified: | 03 Nov 2017 11:22 |
Published Version: | https://doi.org/10.1051/0004-6361/201628950 |
Status: | Published |
Publisher: | EDP Sciences |
Refereed: | Yes |
Identification Number: | 10.1051/0004-6361/201628950 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123344 |