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Decoding the spectra of SDSS early-type galaxies : New indicators of age and recent star formation
(2007-12-01)
We apply principal component analysis (PCA) to a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS) in order to infer differences in their star formation histories from their unresolved stellar populations. ...
UV-optical colors as probes of early-type galaxy evolution
(2007-12-01)
We have studied ∼2100 early-type galaxies in the SDSS DR3 which have been detected by the GALEX Medium Imaging Survey (MIS), in the redshift range O <z <0.1.1. Combining GALEXUV photometry with corollary optical data from ...
The UV properties of E+A galaxies : Constraints on feedback-driven quenching of star formation
(2007-12-01)
We present the first large-scale study of E+A galaxies that incorporates photometry in the ultraviolet (UV) wavelengths. E+A galaxies are 'post-starburst' systems, with strong Balmer absorption lines indicating significant ...
The effect of environment on the ultraviolet color-magnitude relation of early-type galaxies
(2007-12-01)
We use GALEX near-UV (NUV ) photometry of a sample of early-type galaxies selected in the SDSS (Sloan Digital Sky Survey) to study the UV color-magnitude relation (CMR). NUV - r color is an excellent tracer of even small ...
The look-back time evolution of far-ultraviolet flux from the brightest cluster elliptical galaxies at z <0.2
(2007-12-01)
We present the GALEXUV photometry of the elliptical galaxies in Abell clusters at moderate redshifts (z <0.2) for the study of the look-back time evolution of the UV upturn phenomenon. The brightest elliptical galaxies (M ...
Better age estimation using ultraviolet-optical colours : Breaking the age-metallicity degeneracy
(2007-10-01)
We demonstrate that the combination of GALEX ultraviolet (UV) photometry in the far-UV (FUV; ~1530 Å) and near-UV (NUV; ~2310 Å) passbands with optical photometry in the standard U, B, V, R, I filters can efficiently break ...
Recent star formation in high-redshift early-type galaxies : Insights from the rest-frame UV
(2007-06)
We combine deep UBV RIzJK photometry from the MUSYC survey with redshifts from the COMBO-17 survey to study the rest-frame ultraviolet (UV) properties of 674 high-redshift (0.5 <z <1) early-type galaxies, drawn from the ...
UV bright globular clusters in M87 : More evidence for super-He-rich stellar populations?
(2007-05-01)
We study the ultraviolet (UV) and optical properties of 38 massive globular clusters (GCs) in the Virgo elliptical, M87, imaged using the STIS and WFPC2 instruments onboard the Hubble Space Telescope. The majority of these ...
Observational evidence for AGN feedback in early-type galaxies
(2007)
A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called active galactic nucleus (AGN) feedback. The energy input from an active central massive black hole is invoked to suppress ...
Galex-derived residual star formation history of elliptical galaxies
(EDP Sciences, 2007)
Bright early-type galaxies are still forming stars at low-level residual star formation (RSF) mode. The GALEX UV satellite has detected excessive UV flux in > 30% of our volume-limited sample of ∼10 galaxies. The RSF galaxy ...