Weak H2 emission from diffuse and translucent clouds

Details Weak H2 emission from diffuse and translucent clouds Weak H2 emission from diffuse and translucent clouds

Mar 1999

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999esasp.427..529t&link_type=abstract

The Universe as Seen by ISO. Eds. P. Cox & M. F. Kessler. ESA-SP 427., p. 529

Physics

6

Diffuse Clouds, Translucent Clouds, Photon-Dominated Regions (Pdrs), Molecules: H2

Scientific paper

We present the first results of a survey for the lowest pure-rotational lines of H2 with the ISO-SWS in a number of well-studied low-density diffuse and translucent clouds. The data are compared with those of the high-density PDR IC 63, for which H2 lines up to S(5) are detected, and of the ``cool'' PDR Cederblad 201. Searches for the S(0) line at 28.218 μm and the S(1) line at 17.035 μm have been performed for the diffuse cloud along the line of sight toward ζ Oph, the translucent clouds toward HD 94413 and HD 154368, the high-latitude cloud MBM 55D, as well as the translucent outskirts of the S 140 molecular cloud. The lines are not detected in diffuse clouds down to ~0.3-0.5 Jy (2σ). They are weakly observed in the peripheral regions of S 140, where their intensities are more than an order of magnitude less than at the peak of the PDR. The observations are compared with available physical models based on optical absorption and/or millimeter emission line data, and, in the case of ζ Oph, with H2 observations in the ultraviolet. The models include both collisional excitation and ultraviolet pumping. The data form tests of the temperature structure and heating mechanisms of these clouds.

Affiliated with

Also associated with

No associations

Rating

Weak H2 emission from diffuse and translucent clouds 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 Weak H2 emission from diffuse and translucent clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Weak H2 emission from diffuse and translucent clouds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1446869