Investigations of extragalactic hydroxyl

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5869693

Schmelz, J T

Observations of extragalactic hydroxyl (OH) probe the physical conditions of galactic nuclear regions. The four 18 cm spectral lines of OH are known to respond differently to various conditions, possibly making hydroxyl a better probe then CO and HI in certain galaxies. This survey was used as the basis for a statistical study between OH content and other parameters of the parent galaxy. Statistical methods for samples with upper limits were used to find correlations between tau/sub OH/ and the Hubble Type, IRAS colors, infrared luminosity, and IR-to-blue luminosity ratio of the galaxy. Two galaxies were then studied in detail using the Very Large Array (VLA) interferometer. The first was NGC 3628, an edge-on spiral galaxy in the Leo Triplet. The OH and HI absorption maps reveal a rotating disk which may follow the inner portion of the galaxy's rotation curve. A second structure is expanding with respect to the disk is also revealed and may be similar to the 3-kpc arm in their own Galaxy. The second galaxy studies with the VLA was Mrk 273, a Seyfert with HI absorption and OH Megamaser emission. Although the continuum is resolved at 18 cm (and is a double at six cm), the absorption and emission are associated only with one component and, therefore, not resolved.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 5869693
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELEMENTS
GALAXIES
HYDROGEN
HYDROXYL RADICALS
LUMINOSITY
NONMETALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
RADICALS
RADIOWAVE RADIATION
SHORT WAVE RADIATION