Stellar population gradient in lenticular galaxies: NGC 1023, NGC 3115 and NGC 4203
Universidade Federal do Rio Grande do Sul, Instituto de Física, CP 15051, Porto Alegre CEP 91501-970, RS, Brazil
Corresponding author: Ch. Bonatto, firstname.lastname@example.org
Accepted: 2 July 2003
We investigate the stellar population content in the lenticular galaxies NGC 1023, NGC 3115 and NGC 4203 applying a population synthesis method based on a seven component spectral basis with different ages – , , , , , and older than 1010 years, and metallicity in the range . This study employs two-dimensional STIS spectra in the range 2900–5700 Å, obtained from the Hubble Space Telescope public archives. We extracted one-dimensional spectra in adjacent windows 100 pc wide (projected distance) from the nuclear regions up to 300–400 pc. The largest contribution, both in λ5870 Å flux and mass fraction, comes from old stars (age years). We verified the possible existence of circumnuclear bursts (CNBs) in NGC 3115 and NGC 4203.
Key words: galaxies: elliptical and lenticular, cD / galaxies: stellar content / galaxies: nuclei
© ESO, 2003