Related papers: A Robust Age Indicator for Old Stellar Populations
We examine the stellar population radial gradients (age, metallicity and [$\alpha/$Fe]) of $\sim$ 100 passive central galaxies up to $\sim 2 R_e$. The targeted groups have a halo mass range spanning from $11 < \log(M_{200}/M_{\odot}) < 15$,…
Galactic astrophysics is now in the process of building a multi-dimensional map of the Galaxy. For such a map, stellar ages are the essential ingredient. Ages are however measured only indirectly by comparing observational data with models.…
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…
We present a new technique for the determination of the low-mass slope ($\alpha_1$; $M_* < 0.5 M_{\odot}$) of the present day stellar mass function (PDMF) using the pixel space fitting of integrated light spectra. It can be used to…
We present some results of an observational and theoretical study on unresolved stellar systems based on the Surface Brightness Fluctuations (SBF) technique. It is shown that SBF magnitudes are a valuable tracer of stellar population…
Context. Stochasticity and physical parameter degeneracy problems complicate the derivation of the parameters (age, mass, and extinction) of unresolved star clusters when using broad-band photometry. Aims. We develop a method to simulate…
We report preliminary results of the characterization of bulge and inner disk stellar populations for 8 nearby spiral galaxies using Gemini/GMOS. The long-slit spectra extend out to 1-2 disk scale lengths with S/N/Ang > 50. Two different…
Using data from the WISE mission, we have measured near infra-red (NIR) photometry of a diverse sample of dust-free stellar systems (globular clusters, dwarf and giant early-type galaxies) which have metallicities that span the range -2.2 <…
We present deep optical and near-infrared imaging of the rich cluster A2218 at z=0.17. Our optical imaging comes from new multicolour Hubble Space Telescope WFPC2 observations in the F450W (B), F606W (V) and F814W (I) passbands. These…
Although the spectrum of a prototypical early-type galaxy is assumed to lack emission lines, a substantial fraction (likely as high as 30%) of nearby red sequence galaxy spectra contain emission lines with line ratios characteristic of low…
The stellar metallicity is a direct measure of the amount of metals present in a galaxy, as a large part of the metals lie in its stars. In this paper we investigate new stellar metallicity indicators suitable for high-z galaxies studying…
Masking the horizontal branch and giant stars allows unambiguous measurements of mean age and metallicity in simple old stellar populations from metal and hydrogen line strengths. Billion year resolution is possible in the luminous halos of…
The age and chemical composition of the stars in present-day galaxies carry important clues about their star formation processes. The latest generation of population synthesis models have allowed to derive age and stellar metallicity…
We explore whether the rest-frame near-UV spectral region, observable in high-redshift galaxies via optical spectroscopy, contains sufficient information to allow the degeneracy between age and metallicity to be lifted. We do this by…
Current stellar population models have arguably the largest uncertainties in the near-IR wavelength range, partly due to a lack of large and well calibrated empirical spectral libraries. In this paper we present a project, which aim it is…
A new metallicity distribution and an age-metallicity relation are presented for 437 nearby F and G turn-off and sub-giant stars selected from radial velocity data of Nidever et al. Photometric metallicities are derived from uvby-H\beta…
Photometry and long-slit spectroscopy are presented for 14 S0 and spiral galaxies of the Fornax, Eridanus and Pegasus cluster, and NGC 7582 group. The structural parameters of the galaxies are derived from the R-band images by performing a…
We present selected results from integral-field spectroscopy of 48 early-type galaxies observed as part of the SAURON survey. Maps of the Hbeta, Fe5015, Mgb and Fe5270 indices in the Lick/IDS system were derived for each of the survey…
Stellar masses play a crucial role in the exploration of galaxy properties and the evolution of the galaxy population. In this paper, we explore the minimum possible uncertainties in stellar mass-to-light (M/L) ratios from the assumed star…
MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-year SDSS-IV survey that will obtain resolved spectroscopy from 3600 $\AA$ to 10300 $\AA$ for a representative sample of over 10,000 nearby galaxies. In this paper, we…