Kinematics and composition of H II regions in spiral galaxies. I - M33

Abstract

view Abstract Citations (93) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Kinematics and Composition of H II Regions in Spiral Galaxies. I. M33 Zaritsky, Dennis ; Elston, Richard ; Hill, J. M. Abstract We present the results from a study of moderate-dispersion spectra of 55 H II regions in M33 observed with the MX multiobject spectrometer. From the velocity data we derive the systemic velocity (-172 +/- 6 km s^-1^), the inclination (56^deg^ +/- 1^deg^), the position angle of the major axis (23^deg^ + 1^deg^), the line-of-sight velocity dispersion (9 +/- 4 km s^-1^), the rotation curve for the system of H II regions, and the M/L inner disk (~2 in solar units). From measurements of the line-intensity ratio of [O III] λ 5007 + λ 4959 to Hβ we derive the O/H abundance gradient, -0.09 +/- 0.02 dex/kpc, and show that the dispersion of excitation values decreases with radius. When overlapping previous work, our results are in excellent agreement. Publication: The Astronomical Journal Pub Date: January 1989 DOI: 10.1086/114960 Bibcode: 1989AJ.....97...97Z Keywords: Astronomical Spectroscopy; Galactic Structure; H Ii Regions; Mass To Light Ratios; Spiral Galaxies; Forbidden Transitions; Gratings (Spectra); H Beta Line; Metallicity; Oxygen Spectra; Astrophysics; GALAXIES: LOCAL GROUP; GALAXIES: INDIVIDUAL; GALAXIES: STRUCTURE; GALAXIES: STELLAR CONTENT; GALAXIES: INTERNAL MOTIONS; NEBULAE: H II REGIONS full text sources ADS | data products SIMBAD (61) NED (56) Related Materials (1) Part 2: 1990AJ.....99.1108Z