Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-07-26
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
16 pages, 9 figures, Accepted for publication on MNRAS
Scientific paper
We pick out the 35 brightest galaxies from Goto's E+A galaxies catalogue which are selected from the Sloan Digital Sky Survey Data Release 5. The spectra of E+As are prominently characterized by the strong Balmer absorption lines but little [Oii] or H_alpha emission lines. In this work we study the stellar populations of the sample galaxies by fitting their spectra using ULySS, which is a robust full spectrum fitting method. We fit each of the sample with 1-population (a single stellar population-a SSP) and 3-population (3 SSPs) models, separately. By 1-population fits, we obtain SSP-equivalent ages and metallicities which correspond to the `luminosity-weighted' averages. By 3-population fits, we divide components into three groups in age (old stellar population-OSP, intermediate-age stellar population-ISP, and young stellar population-YSP), and then get the optimal age, metallicity and population fractions in both mass and light for OSP, ISP and YSP. During the fits, both Pegase.HR/Elodie3.1 and Vazdekis/Miles are used as two independent population models. The two models result in generally consistent conclusions as follows: for all the sample galaxies, YSPs (< 1Gyr) make important contributions to the light. However, the dominant contributors to mass are OSPs. We also reconstruct the smoothing star formation histories (SFHs) by giving star formation rate (SFR) versus evolutionary age. In addition, we fit the E+A sample and 34 randomly selected elliptical galaxies with 2-population (2 SSPs) model. We obtain the equivalent age of old components for each of the E+A sample and elliptical galaxies. By comparison, the old components of E+As are statistically much younger than those of ellipticals. From the standpoint of the stellar population age, this probably provides an evidence for the proposed evolutionary link from E+As to early-types (E/S0s).
Du Wei
Liang Yan-Chun
Luo A.-Li
Prugniel Philippe
Zhao Yong-Heng
No associations
LandOfFree
Star formation histories and evolution of 35 brightest E+A galaxies from SDSS DR5 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Star formation histories and evolution of 35 brightest E+A galaxies from SDSS DR5, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Star formation histories and evolution of 35 brightest E+A galaxies from SDSS DR5 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-558121