相关论文: Spectral detection of multiple stellar populations…
We analyse publicly available, individual spectra of four, massive ($M>10^{11}M_{\odot}$) early-type galaxies with redshifts in the range 1.4 < z < 2 to determine their stellar content, extending our previous work up to z~2. The wide…
Drawing from the LEGA-C dataset, we present the spectroscopic view of the stellar population across a large volume- and mass-selected sample of galaxies at large lookback time. We measure the 4000\AA\ break (D$_n$4000) and Balmer absorption…
(Abridged) We apply Principal Component Analysis (PCA) to a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS) in order to infer differences in their star formation histories. Out of the first few principal components…
We use a purely data-driven rectified factor analysis to identify early-type galaxies with recent star formation in DR4 of the SDSS Spectroscopic Catalogue. We compare the spectra and environment of these galaxies with `normal' early-types,…
Stellar population studies of early-type galaxies (ETGs) based on their optical stellar continuum suggest that these are quiescent systems. However, emission lines and ultraviolet photometry reveal a diverse population. We use a new version…
The stellar populations of galaxies hold vital clues to their formation histories. In this paper we present results based on modeling stacked spectra of early-type galaxies drawn from the Sloan Digital Sky Survey (SDSS) as a function of…
We present stellar population parameters of twelve early-type galaxies (ETGs) in the Coma Cluster based on spectra obtained using the Low Resolution Imaging Spectrograph on the Keck II Telescope. Our data allow us to examine in detail the…
It has long been shown that the extreme ultraviolet spectrum of the ionizing stars of H II regions can be estimated by comparing the observed line emission to detailed models. In the Galactic Center (GC), however, previous observations have…
We present a detailed stellar population analysis of 11 bright ($H<26.6$) galaxies at $z=9-11$ (three spectroscopically confirmed) to constrain the chemical enrichment and growth of stellar mass of early galaxies. We use the flexible…
We present the analysis of 10 massive early-type galaxies at $z\sim1.5$. They have been identified by means of a near-IR low resolution spectroscopic follow-up of a complete sample of 36 bright (K' $<$ 18.5) Extremely Red Objects (EROs,…
We combine the exceptional depth of the Hubble Ultra Deep Field (HUDF) images and the deep GRism ACS Program for Extragalactic Science (GRAPES) grism spectroscopy to explore the stellar populations of 34 bulges belonging to late-type…
Determining the properties of old stellar populations (those with age >1 Gyr) has long involved the comparison of their integrated light, either in the form of photometry or spectroscopic indexes, with empirical or synthetic templates. Here…
We present F850LP-F160W color gradients for 11 early-type galaxies (ETGs) at 1.0<z_spec<1.9. Significant negative F850LP-F160W color gradients have been detected in ~70% of our sample within the effective radius R_e, the remaining 30%…
We study the stellar population of galaxies with active star formation, determining ages of the stellar components by means of spectral population synthesis of their absorption spectra. The data consist of optical spectra of 185 nearby ($z…
In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…
We have fit the far-ultraviolet (FUV) to mid-infrared (MIR) spectral energy distributions (SEDs) for several nearby galaxies ($<$ 20 Mpc). Global, radial, and local photometric measurements are explored to better understand how SED-derived…
We derive new spectral H_gamma index definitions which are robust age indicators for old and relatively old stellar populations and thus have great potential for solving the age-metallicity degeneracy of galaxy spectra. To study H_gamma as…
We present a detailed spatial analysis of stellar populations based on long-slit optical spectra in a sample of eight luminous early-type galaxies selected from nearby sparse groups and pairs, three of them may be interacting with a galaxy…
[Abridged]We present the morphological analysis based on HST-NICMOS observations in the F160W filter of a sample of 32 early-type galaxies (ETGs) at 1<z<2 with spectroscopic confirmation of their redshift and spectral type. We find that…
Major progress has been achieved in recent years in mapping the properties of passively-evolving, early-type galaxies (ETG) from the local universe all the way to redshift ~2. Here, age and metallicity estimates for local cluster and field…