Ultracompact H II Regions: New Challenges

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

12

Scientific paper

The designation ``ultracompact H II region'' first appeared in the astronomical literature over 30 years ago. Since that time, of order 103 actual or candidate ultracompact (UC) H II regions have been identified, and no fewer than seven theoretical models have been proposed to describe them. Recent observational evidence suggests that the conventional ``UC H II'' classification may not be adequate to describe all of the small, dense nebulae surrounding young, massive stars. In particular, it appears that some UC H II regions may be small, high density regions that are integral parts of much larger structures; these we call ``UC H II regions with extended emission''. Other H II regions appear to be an order of magnitude smaller and two orders of magnitude denser than traditional UC H II regions, and hence are deserving of a new classification. We designate these as ``super-ultracompact H II regions'', (though we suspect that ``hypercompact'' will prevail). We provide brief scientific and historical perspectives, present the new observational data and arguments for the new classifications, and briefly discuss possible implications for theoretical models of UC H II regions.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Ultracompact H II Regions: New Challenges 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 Ultracompact H II Regions: New Challenges, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultracompact H II Regions: New Challenges will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1347189

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.