Kinematics and composition of H II regions in spiral galaxies. II. M51, M101 and NGC 2403

Journal Article · Sun Apr 01 00:00:00 EST 1990 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115400· OSTI ID:6806412

Zaritsky, D; Hill, J M; Elston, R ^[1]

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1. Steward Observatory, Tucson, AZ (USA) Kitt Peak National Observatory, Tucson, AZ (USA)

The velocities of H II regions in M101 and NGC 2403 and the excitations, log(forbidden O III/H-beta), in regions in M101, M51, and NGC 2043 were measured using the MX multiobject spectrometer. The velocity data are used to determine position angles, inclinations, rotation curves, line-of-sight velocity dispersion, and mass-to-light ratios for the optical disks of NGC 2403 and M101. The excitation data are used to examine the differences between galaxies. It is shown that late-type spiral galaxies may be divided into two distinct groups on the basis of excitation of their H II regions at a particular fractional radius. It is found that the excitation gradients of M33 and M101 steepen significantly toward the center of the galaxy. The excitation measurements are used to estimate the magnitude of the abundance gradients in M33, M101, NGC 2403, and NGC 2997. 46 refs.

• OSTI ID: 6806412
• Journal Information: Astronomical Journal; (USA), Vol. 99; ISSN 0004-6256
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXIES
SPIRAL CONFIGURATION
H2 REGIONS
CHEMICAL COMPOSITION
PARTICLE KINEMATICS
BALMER LINES
BRIGHTNESS
COORDINATES
ELEMENT ABUNDANCE
ERRORS
EXCITATION
MASS
VELOCITY
ABUNDANCE
CONFIGURATION
COSMIC RADIO SOURCES
ENERGY-LEVEL TRANSITIONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
640105* - Astrophysics & Cosmology- Galaxies