Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d

Details Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d

Nov 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998apj...507..263w&link_type=abstract

The Astrophysical Journal, Volume 507, Issue 1, pp. 263-269.

Astronomy and Astrophysics

Astronomy

10

Ism: H Ii Regions, Infrared: Ism: Lines And Bands, Ism: Abundances, Ism: Individual: Alphanumeric: G29.96-0.02, Ism: Individual: Alphanumeric: W51D

Scientific paper

We have observed [Ne II] 12.814 μm line emission from two well-studied ultracompact H II regions, G29.96-0.02 and W51d, and obtained its spatially resolved line images. Spatial distributions of the line emission were compared with the VLA 15 GHz continuum maps to derive the Ne^+ abundance, which puts strong constraint on the effective temperature or the spectral type of the ionizing star(s). We show that the total neon abundance of G29.96-0.02 is close to the local interstellar abundance of neon, and the dominant species of neon is Ne^+ over the whole H II region. When the ionic ratio derived from observed fluxes of [Ne III] 36.0 μm and [Ne II] 12.8 μm is compared with a theoretical calculation based on the recent model of non-LTE stellar atmosphere, it implies that the ionizing star(s) have an effective temperature of ~34,000 K or spectral type of O9.5 in the main sequence. On the other hand, the derived Ne^+ abundance of W51d is significantly lower than the local interstellar abundance of neon. In addition, we found the Ne^+ abundance decreases remarkably toward the center of W51d. These results suggest that the dominant species of neon would be Ne^++ in W51d, and the ionizing star(s) has significantly high effective temperature (~39,000 K). Alternatively, the [Ne II] line could suffer from enormous extinction due to dust associated with this ultracompact H II region.

Affiliated with

Also associated with

No associations

Rating

Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d 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 Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations of the [Ne II] 12.8 Micron Emission from Two UltracompactH II Regions, G29.96-0.02 and W51d will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1074638