A Hubble Space Telescope study of two HII regions in NGC 6822

Citation
Cr. O'Dell et al., A Hubble Space Telescope study of two HII regions in NGC 6822, PUB AST S P, 111(765), 1999, pp. 1382-1391
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
ISSN journal
0004-6280 → ACNP
Volume
111
Issue
765
Year of publication
1999
Pages
1382 - 1391
Database
ISI
SICI code
0004-6280(199911)111:765<1382:AHSTSO>2.0.ZU;2-O
Abstract
We report on the study of the Hubble V and Hubble X H II regions in NGC 682 2 with the Hubble Space Telescope employing emission-line and stellar filte rs. Calibration was made for both data sets, providing magnitudes for the s tars and surface brightnesses for the nebulae. The forms of these H II regi ons are shown to be decidedly more complex than revealed by ground-based im ages, both having bright cores within more extended emission. The four OB a ssociations within the images are shown to have ages of 5-10 million years. We conclude that the H II regions are sufficiently optically thick to be u sed as ultraviolet photon counters and hence indicators of the star formati on rate.