| Name | SDP_pvanderw_3 |
| Title | A Herschel survey of molecular lines in (U)LIRGs: physical conditions, the nature of the power source, and a benchmark for high-z observations |
| URL | |
| DOI | https://doi.org/10.5270/esa-ntsgtkr |
| Author | European Space Agency |
| Description | The key diagnostic of the warm star-forming molecular clouds in galaxies is provided by their cooling radiation: [CII] and [OI] lines, but also lines of CO, the main tracer of molecular gas. While in our Galaxy cooling by CO lines is unimportant, this situation is totally different in local ULIRGs, where the CO is an important coolant, and the thermal balance is totally different from that in our Galaxy. These results demonstrate the enormous, as yet almost unexplored, diagnostic power of these lines for probing physical conditions. Since these lines are very luminous, they can be used to probe galaxies out to very high redshifts. Here we propose a systematic study with the SPIRE-FTS and PACS of the principal neutral gas cooling lines ([CII], [OI] and the CO ladder from 5-4 to 13-12) in a 60 micron flux-limited sample of 32 galaxies: 24 LIRGs and 8 ULIRGs. Aims of this key project are: - analysis of the neutral gas cooling budget, in particular the relative importance of CO and [CII] emission; - analysis of the CO rotational ladder to derive the mass of molecular gas as a function of temperature and density; - modeling of the data using advanced PDR/XDR models with the goal of separating UV-excited (starburst) and X-ray excited (AGN) components; - analysis of the implications for molecular mass measurements based on CO lines, both at low and high redshift; - achieving statistical robustness, so that inferences can be made on the infrared galaxy population in general, and trends with other galaxy characteristics (IR luminosity, type of power source,.) can be traced. Only Herschel can provide the necessary high-J CO and cooling line data. Combined with our extensive ground-based data (low-J CO, HCN lines) this dataset will elucidate the energy source and physical conditions in local ULIRGs, and establish the critical lin...k necessary for the interpretation of observations of high-z galaxies in mid-J CO lines and other luminous lines, which will become routine in the ALMA era. |
| Publication | On the far-infrared metallicity diagnostics: applications to high-redshift galaxies . Rigopoulou D. et al. . Monthly Notices of the Royal Astronomical Society, Volume 473, Issue 1, p.20-29 . 473 . 10.1093\/mnras\/stx2311 . 2018MNRAS.473...20R , HIFI Spectroscopy of H2O Submillimeter Lines in Nuclei of Actively Star-forming Galaxies . Liu L. et al. . The Astrophysical Journal, Volume 846, Issue 1, article id. 5, 35 pp. (2017). . 846 . 10.3847\/1538-4357\/aa81b4 . 2017ApJ...846....5L , Neutral Carbon Emission in Luminous Infrared Galaxies: The [C I] Lines as Total Molecular Gas Tracers . Jiao Qian et al. . The Astrophysical Journal Letters, Volume 840, Issue 2, article id. L18, 7 pp. (2017). . 840 . 10.3847\/2041-8213\/aa6f0f . 2017ApJ...840L..18J , HERUS: A CO Atlas from SPIRE Spectroscopy of Local ULIRGs . Pearson Chris et al. . The Astrophysical Journal Supplement Series, Volume 227, Issue 1, article id. 9, 25 pp. (2016). . 227 . 10.3847\/0067-0049\/227\/1\/9 . 2016ApJS..227....9P , Herschel observations of water vapour in Markarian 231 . González-Alfonso E. et al. . Astronomy and Astrophysics, Volume 518, id.L43, 5 pp. . 518 . 10.1051\/0004-6361\/201014664 . 2010A&A...518L..43G , Black hole accretion and star formation as drivers of gas excitation and chemistry in Markarian 231 . van der Werf P. P. et al. . Astronomy and Astrophysics, Volume 518, id.L42, 5 pp. . 518 . 10.1051\/0004-6361\/201014682 . 2010A&A...518L..42V , Stacked Average Far-infrared Spectrum of Dusty Star-for... |
| Instrument | SPIRE_SpireSpectrometer_ |
| Temporal Coverage | 2009-12-09T07:17:14Z/2009-12-09T09:16:15Z |
| 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 | 2010-01-18T07:17:14Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, 2010, A Herschel Survey Of Molecular Lines In Openparucloseparlirgs: Physical Conditions Comma The Nature Of The Power Source Comma And A Benchmark For High-Z Observations, SPG v14.1.0, European Space Agency, https://doi.org/10.5270/esa-ntsgtkr |