Astrophys. J., Suppl. Ser., 234, 33-33 (2018/February-0)
A Green Bank Telescope Survey of large Galactic H II regions.
ANDERSON L.D., ARMENTROUT W.P., LUISI M., BANIA T.M., BALSER D.S. and WENGER T.V.
Abstract (from CDS):
As part of our ongoing H II Region Discovery Survey (HRDS), we report the Green Bank Telescope detection of 148 new angularly large Galactic H II regions in radio recombination line (RRL) emission. Our targets are located at a declination of δ> -45○, which corresponds to 266○>^ℓ^> -20○ at b=0○. All sources were selected from the Wide-field Infrared Survey Explorer Catalog of Galactic H II Regions, and have infrared angular diameters ≥ 260′′ . The Galactic distribution of these "large" H II regions is similar to that of the previously known sample of Galactic H II regions. The large H II region RRL line width and peak line intensity distributions are skewed toward lower values, compared with that of previous HRDS surveys. We discover seven sources with extremely narrow RRLs < 10kms–1. If half the line width is due to turbulence, these seven sources have thermal plasma temperatures < 1100K. These temperatures are lower than any measured for Galactic H II regions, and the narrow-line components may arise instead from partially ionized zones in the H II region photodissociation regions. We discover G039.515+00.511, one of the most luminous H II regions in the Galaxy. We also detect the RRL emission from three H II regions with diameters > 100pc, making them some of the physically largest known H II regions in the Galaxy. This survey completes the HRDS H II region census in the Northern sky, where we have discovered 887 H II regions and more than doubled the size of the previously known census of Galactic H II regions.
© 2018. The American Astronomical Society. All rights reserved.
Galaxy: structure - H II regions - radio lines: ISM - surveys
VizieR on-line data:
<Available at CDS (J/ApJS/234/33): table1.dat table2.dat table3.dat table4.dat>
Status in Simbad:
could be processed
View the reference in ADS
To bookmark this query, right click on this link: simbad:2018ApJS..234...33A and select 'bookmark this link' or equivalent in the popup menu