Issue |
Astron. Astrophys. Suppl. Ser.
Volume 128, Number 3, March II 1998
|
|
---|---|---|
Page(s) | 545 - 560 | |
DOI | https://doi.org/10.1051/aas:1998162 | |
Published online | 15 March 1998 |
Physical properties of the ionized gas and brightness distribution in NGC 4736*
1
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: jcn@iac.es; jvm@iac.es
Send offprint request to: I. Rodrigues
Received:
16
September
1996
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