Expanding shells of shocked neutral hydrogen around compact HII regions
arXiv:astro-ph/0205032 · doi:10.1051/0004-6361:20020671
Abstract
By comparing radial velocities of radio bright compact HII regions with their HI absorption profiles, we discovered expanding shells of neutral hydrogen around them. These shells are revealed by absorption of the radio continuum emission from the HII regions at velocities indicating greater distances than the observed radial velocity. We believe that these shells are shock zones at the outer edge of the expanding ionized region. Additionally we found evidence for a velocity inversion inside the Perseus arm caused by a spiral shock, which results in a deep absorption line in the spectra of compact HII regions behind it.
8 pages, 11 figures. accepted for publication in Astronomy and Astrophysics
References in corpus (1)
Cited by in corpus (13)
- A Self-Absorption Census of Cold HI Clouds in the Canadian Galactic Plane Survey
- A Thorough Investigation of Distance and Age of the Pulsar Wind Nebula 3C58
- A CGPS Look at the Spiral Structure of the Outer Milky Way I: Distances and Velocities to Star Forming Regions
- Singly-Peaked P-Cygni type Ly from starburst galaxies
- Surveys of Clumps, Cores, and Condensations in Cygnus X: I. a New Catalog of ~0.1 pc Massive Dense Cores
- The JCMT 12CO(3-2) Survey of the Cygnus X Region: I. A Pathfinder
- Unveiling the birth and evolution of the HII region Sh2-173
- A Relation Between the Warm Neutral and Ionized Media Observed in the Canadian Galactic Plane Survey
- A Sino-German 6cm polarisation survey of the Galactic plane - VIII. Small-diameter sources
- A New Distance to the Supernova Remnant DA 530 Based on HI Absorption of Polarized Emission
- Observations of Ly Emitters at High Redshift
- Type-Ia Supernova Remnant Shell At Seen In The Three Sightlines Toward The Gravitationally Lensed Qso B1422+231
- A global view on star formation: The GLOSTAR Galactic plane survey XII. Effelsberg's continuum view and data release