Study of the Central Region of M 31. I. Spectrophotometric Observational Results
Abstract
Summary. In the present investigation, we try to obtain some information about the stellar content of M 31's central bulge. In this first paper, we describe the spectrophotometric observational results obtained for a region of 3 kpc diameter, centered on the nucleus and divided into sections 250 pc long. It appears that the line intensities of Na I ( 5890 -5896), Mgi ( 5167-5173-5184), Fei (24383, 23746 23734, 2 3647\ Ca ii (2 3933.68) and Cn (2241004200) weaken as the distance from the centre increases. There are also strong arguments in favour of variations of the intensities of the H (Hy, H and H and Ca I (24226.74) lines and the CH band (G band at 224283 -4318). Among the studied elements, only Ni I (23462, 23524.53) does not seem to suffer any variation throughout the nuclear bulge. Key words: M 31 - nuclear region - spectrophotometry - stellar population
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1973
- Bibcode:
- 1973A&A....26...95J