Name | OT2_pmaloney_1 |
Title | Water, Molecular Ions, and a Massive Molecular Outflow in Arp 220 |
URL | http://archives.esac.esa.int/hsa/whsa-tap-server/data?retrieval_type=OBSERVATION&observation_id=1342257854&instrument_name=HIFI&product_level=LEVEL0&compress=true |
DOI | https://doi.org/10.5270/esa-6p3jsp1 |
Author | maloney, p. |
Description | The archetypal ultraluminous infrared galaxy Arp 220 revealed a remarkably rich spectrum in Herschel SPIRE FTS observations, including luminous emission from warm CO and water. The spectrum also revealed the presence of a massive molecular outflow, traced by P Cygni line profiles in the molecular ions OH+ and H2O+, and possibly H2O. Comparison of the column densities of these ions relative to water (and the absence of the ion H3O+) indicated that only an XDR powered by an X-ray-luminous AGN is capable of explaining the relative abundances; that these molecular ions are the same species that are participating in the outflow suggests there may be a connection between the AGN and the outflow. Because the FTS did not resolve the lines, only limited information regarding the outflow and the column densities could be derived from the saturated lines. To much more accurately characterize both the physical and chemical state of the gas (in particular the water chemistry) and the mass and energetics of the outflow, we propose to obtain HIFI observations of a number of H2O, H2O+, and OH+ emission and absorption lines (including those exhibiting P Cygni profiles). In addition, we propose to observe two fairly strong unidentified emission lines, which fall quite close to the expected frequencies of the HCN and HCO+ J=6-5 rotation lines. Lower-lying transitions of both species have been measured from the ground; the apparent velocity offsets from the expected positions may be the consequence of complex emission and-or absorption profiles. In the case of HCN, the FTS data have established that the J=13-12 line and above are seen in absorption. |
Publication | |
Instrument | HIFI_HifiPoint_dbs |
Temporal Coverage | 2012-12-26T18:22:38Z/2013-02-02T11:41:40Z |
Version | SPG v14.1.0 |
Mission Description | Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities. |
Creator Contact | https://support.cosmos.esa.int/h®erschel/ |
Date Published | 2013-08-02T10:08:11Z |
Publisher And Registrant | European Space Agency |
Credit Guidelines | European Space Agency, 2013-08-02T10:08:11Z, OT2_pmaloney_1, SPG v14.1.0. https://doi.org/10.5270/esa-6p3jsp1 |