2007A&A...471..795L


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.20CEST15:04:40

2007A&A...471..795L - Astronomy and Astrophysics, volume 471, 795-804 (2007/9-1)

How young stellar populations affect the ages and metallicities of galaxies.

LI Z. and HAN Z.

Abstract (from CDS):

Two important stellar-population parameters (age and metallicity) of the dominant stellar populations (DSPs) of galaxies are usually estimated by comparing the observed absorption line indices or colors to predictions of some simple stellar population models. However, some studies show that there is actually recent star formation in galaxies, including early type ones. This suggests that we may not be obtaining accurate the two stellar-population parameters for the DSPs of galaxies. This is obvious when we estimate the two parameters by colors, because the youngest populations dominate the light and make the fitted stellar populations younger and richer in metal. We plan to study how young populations (YSPs) in composite stellar populations (CSPs) affect the colors of star systems and to analyze how the stellar ages and metallicities derived from colors possibly deviate from those of the DSPs. The techniques of stellar population synthesis and Monte Carlo process are used in this analysis. It is found that the age and mass fraction of a YSP affect colors of a mixed star system significantly, but the former is stronger. In addition, our results show that the stellar ages and metallicities derived directly from a pair of colors are about 2.14Gyr younger, while 0.0027 more metal rich on average than those of the DSPs of composite stellar systems. Some possible distributions of the differences between stellar-population parameters determined by colors and those of DSPs of CSPs are presented. The possible distributions of the differences between colors of CSPs and those of their DSPs are also shown. Stellar ages and metallicities measured by colors and line-strength indices are compared in the work, with a sample of 18 galaxies. Furthermore, the YSPs may affect the fundamental plane and Kormendy relation of early type galaxies.

Abstract Copyright:

Journal keyword(s): galaxies: stellar content - galaxies: photometry - galaxies: elliptical and lenticular, cD

VizieR on-line data: <Available at CDS (J/A+A/471/795): dev.dat comp.dat>

Simbad objects: 23

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Number of rows : 23

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 NGC 80 GiG 00 21 10.865 +22 21 26.11   13.7       ~ 85 1
2 NGC 596 GiG 01 32 51.906 -07 01 53.54   11.5       ~ 225 0
3 2E 0150.5-1358 ClG 01 53 00.40 -13 44 18.0           ~ 385 0
4 NGC 720 GiG 01 53 00.523 -13 44 19.25   12.4   10.36   ~ 481 0
5 NGC 2681 LIN 08 53 32.739 +51 18 49.35 11.40 11.09 10.29     ~ 295 1
6 NGC 2950 G 09 42 35.116 +58 51 04.39   11.8       ~ 181 0
7 NGC 3166 GiP 10 13 45.674 +03 25 28.81   11.2       ~ 205 0
8 NGC 3377 GiP 10 47 42.400 +13 59 08.30 11.55 11.24 10.38     ~ 716 1
9 NGC 3384 GiG 10 48 16.897 +12 37 45.48   10.0       ~ 543 1
10 NGC 3941 Sy2 11 52 55.360 +36 59 10.96   11.45 11.62 9.97   ~ 214 0
11 NGC 4026 GiP 11 59 25.0903700828 +50 57 41.935297936   12.17       ~ 231 0
12 NGC 4150 GiG 12 10 33.655 +30 24 05.35 12.72 12.44 11.64     ~ 281 2
13 NGC 4179 GiG 12 12 52.1114216001 +01 17 58.952313083   12.8       ~ 153 0
14 NGC 4261 LIN 12 19 23.21607184 +05 49 29.7000920   13.92 12.87     ~ 1089 0
15 NGC 4350 GiP 12 23 57.814 +16 41 36.08   11.5 11.08     ~ 288 0
16 M 86 GiG 12 26 11.814 +12 56 45.49 10.32 9.83 8.90   7.50 ~ 994 1
17 NGC 4570 GiG 12 36 53.401 +07 14 47.99   11.8       ~ 306 0
18 NGC 5308 GiP 13 47 00.4356033187 +60 58 23.332964486   12.5       ~ 187 0
19 NGC 5574 GiP 14 20 55.9683239893 +03 14 16.790076636 13.54 13.23 12.39     ~ 127 1
20 NGC 7013 G 21 03 33.611 +29 53 50.45   12.9       ~ 125 0
21 NGC 7280 GiP 22 26 27.5777963451 +16 08 53.429262697   13.6       ~ 143 0
22 NGC 7457 G 23 00 59.9274269967 +30 08 41.794468187   11.04 11.87     ~ 397 0
23 NGC 7743 Sy2 23 44 21.1586928811 +09 56 02.970129689   14.19 13.28     ~ 283 0

    Equat.    Gal    SGal    Ecl

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2019.10.20-15:04:40

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