Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-06-25
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication in A&A Letters
Scientific paper
We present high resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M82. Six 12CO lines, 2 13CO lines and 4 fine-structure lines are detected. Besides showing the effects of the overall velocity structure of the nuclear region, the line profiles also indicate the presence of multiple components with different optical depths, temperatures and densities in the observing beam. The data have been interpreted using a grid of PDR models. It is found that the majority of the molecular gas is in low density (n=10^3.5 cm^-3) clouds, with column densities of N_H=10^21.5 cm^-2 and a relatively low UV radiation field (GO = 10^2). The remaining gas is predominantly found in clouds with higher densities (n=10^5 cm^-3) and radiation fields (GO = 10^2.75), but somewhat lower column densities (N_H=10^21.2 cm^-2). The highest J CO lines are dominated by a small (1% relative surface filling) component, with an even higher density (n=10^6 cm^-3) and UV field (GO = 10^3.25). These results show the strength of multi-component modeling for the interpretation of the integrated properties of galaxies.
Caux Emmanuel
Delforge B.
Garcia-Burillo Santiago
Güsten Rolf
Harris Andrew I.
No associations
LandOfFree
Excitation of the molecular gas in the nuclear region of M82 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Excitation of the molecular gas in the nuclear region of M82, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Excitation of the molecular gas in the nuclear region of M82 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-310302