Location of Population I-type objects with respect to the Galactic plane

Journal Article · Wed Jun 01 04:00:00 EDT 1977 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/112064· OSTI ID:7313231

Lockman, F J

Galactic radio H II regions and supernova remnants, like the molecular clouds and neutral H I gas, do not lie in a simple plane but instead show broad systematic variations in with Galactocentric radius R. These features seem to persist over azimuthal distances approx.5 kpc. The most striking example occurs in the region 6 of all species is significantly less than zero. It is probable that the Galactic potential is also not planar but rather has a z (R) form like that of the molecular clouds. The layer of luminous H II regions is extremely narrow (sigma/sub z/=30 pc) implying that the mechanism which induces large-scale star formation operates most efficiently over a very small range in z. The H II regions have a z (R) distribution and dispersion much more like that of the molecular clouds than the H I gas, and furthermore, at one R the of H I appears to lie some 70 pc above the molecular clouds and H II regions. Thus the rate of star formation in the z direction is not simply dependent on the neutral atomic gas density, but does seem closely linked to the number of molecular clouds.

• Research Organization: Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015
• OSTI ID: 7313231
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 82:6; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
DISTRIBUTION
ELECTROMAGNETIC RADIATION
GALAXIES
H2 REGIONS
MILKY WAY
MOLECULES
NEBULAE
RADIATIONS
RADIOWAVE RADIATION
SPATIAL DISTRIBUTION
SUPERNOVA REMNANTS