Astron. Astrophys. Suppl. Ser.
Volume 128, Number 3, March II 1998
|Page(s)||545 - 560|
|Published online||15 March 1998|
Physical properties of the ionized gas and brightness distribution in NGC 4736*
Dep. de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul, CP. 15051, Porto Alegre, 91501-970, RS, Brazil
2 Departamento de Astrofísica, Facultad de Física, Universidad de La Laguna, E-38071 La Laguna, Tenerife, Spain
3 Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain e-mail: email@example.com; firstname.lastname@example.org
Send offprint request to: I. Rodrigues
Accepted: 27 August 1997
In this work we study the galaxy NGC 4736, using narrow band interference filters imaging centered at the emission lines , , , , and and nearby continua. We have obtained sizes, positions, emission line absolute fluxes, and continua intensities for 90 regions, mainly distributed in a ring-like structure of 3.2 kpc in diameter. The luminosities are in the range . The regions size distribution presents a characteristic diameter and verifies the relation . The temperature of the ionizing sources and the metallicity of the regions are respectively in the ranges K and . The masses of the ionizing clusters are in the range . The continua radial surface brightness distribution is better fitted by the superposition of a de Vaucouleurs', a thin and a thick exponential disk laws. The monochromatic colors show that outside the star forming ring the disk presents a younger stellar population than inside it.
Key words: galaxies: individual: NGC 4736 / galaxies: abundances / galaxies: ISM / galaxies: spiral / galaxies: structure
© European Southern Observatory (ESO), 1998