Probing the molecular interstellar medium of M82 with Herschel-SPIRE spectroscopy

Panuzzo, P.; Rangwala, N.; Rykala, A.; Isaak, K. G.; Glenn, J.; Wilson, C. D.; Auld, R.; Baes, M.; Barlow, M. J.; Bendo, G. J.; Bock, J. J.; Boselli, A.; Bradford, M.; Buat, V.; Castro-Rodríguez, N.; Chanial, P.; Charlot, S.; Ciesla, L.; Clements, D. L.; Cooray, A.; Cormier, D.; Cortese, L.; Davies, J. I.; Dwek, E.; Eales, S. A.; Elbaz, D.; Fulton, T.; Galametz, M.; Galliano, F.; Gear, W. K.; Gomez, H. L.; Griffin, M.; Hony, S.; Levenson, L. R.; Lu, N.; Madden, S.; O'Halloran, B.; Okumura, K.; Oliver, S.; Page, M. J.; Papageorgiou, A.; Parkin, T. J.; Pérez-Fournon, I.; Pohlen, M.; Polehampton, E. T.; Rigby, E. E.; Roussel, H.; Sacchi, N.; Sauvage, M.; Schulz, B.; Schirm, M. R. P.; Smith, M. W. L.; Spinoglio, L.; Stevens, J. A.; Srinivasan, S.; Symeonidis, M.; Swinyard, B.; Trichas, M.; Vaccari, M.; Vigroux, L.; Wozniak, H.; Wright, G. S.; Zeilinger, W. W.
Bibliographical reference

Astronomy and Astrophysics, Volume 518, id.L37

Advertised on:
7
2010
Number of authors
63
IAC number of authors
2
Citations
84
Refereed citations
77
Description
We present the observations of the starburst galaxy M82 taken with the Herschel SPIRE Fourier-transform spectrometer. The spectrum (194-671 μm) shows a prominent CO rotational ladder from J = 4-3 to 13-12 emitted by the central region of M82. The fundamental properties of the gas are well constrained by the high J lines observed for the first time. Radiative transfer modeling of these high-S/N 12CO and 13CO lines strongly indicates a very warm molecular gas component at ~500 K and pressure of ~3×106 K cm-3, in good agreement with the H2 rotational lines measurements from Spitzer and ISO. We suggest that this warm gas is heated by dissipation of turbulence in the interstellar medium (ISM) rather than X-rays or UV flux from the straburst. This paper illustrates the promise of the SPIRE FTS for the study of the ISM of nearby galaxies. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Related projects
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Formation and Evolution of Galaxies: Observations in Infrared and other Wavelengths
This IAC research group carries out several extragalactic projects in different spectral ranges, using space as well as ground-based telescopes, to study the cosmological evolution of galaxies and the origin of nuclear activity in active galaxies. The group is a member of the international consortium which built the SPIRE instrument for the
Ismael
Pérez Fournon