Densitometry and Thermometry of Starburst Galaxies
Paper i proceeding, 2016

With a goal toward deriving the physical conditions in external galaxies, we have conducted a survey and subsequent high spatial resolution imaging of formaldehyde (H2CO) and ammonia (NH3) emission and absorption in a sample of starburst galaxies. In this article we present the results from a subset of this survey which focuses on high spatial resolution measurements of volume density-and kinetic temperature-sensitive transitions of the H2CO molecule. The volume density structure toward the nuclear region of NGC 253 has been derived from ? ≠4 arcsec NRAO Very Large Array (VLA) measurements of the 110-111 and 211-212 K-doublet transitions of H2CO. The kinetic temperature structure toward NGC 253 and NGC 4945 has been derived from ? ≠0.5-1.0 arcsec measurements of the H2CO 3K-1K+1-2K-1K+1 (near 218 GHz) and 5K-1K+1-4K-1K+1 (near 365 GHz) transitions acquired using the Atacama Large Millimeter/submillimeter Array (ALMA). These measurements have allowed us to characterize the dense gas and kinetic temperature structure within these star forming galaxies, which is a first step toward associating dense star-forming gas and the heating processes at work within galaxies.


J. G. Mangum

National Radio Astronomy Observatory

J. Darling

University of Colorado at Boulder

K. M. Menten

Max Planck-institutet

C. Henkel

Max Planck-institutet

Susanne Aalto

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

M. Spaans

University of Groningen, Kapteyn Astronomical Institute

P. van der Werf

Leiden Observatory Research Institute

A. Ginsburg

European Southern Observatory

E. Fomalont

National Radio Astronomy Observatory

B. Cotton

National Radio Astronomy Observatory

B. Kent

National Radio Astronomy Observatory

EAS Publications Series

1633-4760 (ISSN) 1638-1963 (eISSN)

Vol. 75-76 61-65


Astronomi, astrofysik och kosmologi