Far-ultraviolet Color Gradients in Early-Type Galaxies
Abstract
We discuss far-UV (FUV) (1500 Å) surface photometry and FUV-B color profiles for eight E/S0 galaxies from images taken with the Ultraviolet Imaging Telescope, primarily during the Astro-2 mission. In three cases, the FUV radial profiles are more consistent with an exponential than a de Vaucouleurs function, but there is no other evidence for the presence of a disk or of young, massive stars. In all cases except M32, the FUV-B color becomes redder at larger radii. There is a wide range of internal radial FUV-B color gradients. However, we find no correlation between the FUV-B color gradients and internal metallicity gradients based on Mg absorption features. We conclude that metallicity is not the sole parameter controlling the ``UV upturn component'' in old populations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1998
- DOI:
- 10.1086/311605
- arXiv:
- arXiv:astro-ph/9808265
- Bibcode:
- 1998ApJ...505L..11O
- Keywords:
-
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M32;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M49;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M60;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M87;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M89;
- GALAXIES: INDIVIDUAL NGC NUMBER: NGC 1399;
- GALAXIES: INDIVIDUAL NGC NUMBER: NGC 3115;
- GALAXIES: INDIVIDUAL NGC NUMBER: NGC 3379;
- GALAXIES: PHOTOMETRY;
- GALAXIES: STELLAR CONTENT;
- ULTRAVIOLET: GALAXIES;
- Galaxies: Individual: Messier Number: M32;
- Galaxies: Individual: Messier Number: M49;
- Galaxies: Individual: Messier Number: M60;
- Galaxies: Individual: Messier Number: M87;
- Galaxies: Individual: Messier Number: M89;
- Galaxies: Individual: NGC Number: NGC 1399;
- Galaxies: Individual: NGC Number: NGC 3115;
- Galaxies: Individual: NGC Number: NGC 3379;
- Galaxies: Photometry;
- Galaxies: Stellar Content;
- Ultraviolet: Galaxies;
- Astrophysics
- E-Print:
- 11 pages