Información del autor
Autor Gorgas García, Francisco Javier |
Documentos disponibles escritos por este autor (55)
texto impreso
Evolutionary population synthesis models with different metallicities have been computed in order to interpret the observed Mg_2 and H?, line-strength indices in old stellar populations. Both indices are found to be quite insensitive to change[...]texto impreso
Falcón Barroso, J. ; Sánchez Blázquez, P. ; Vazdekis, A. ; Ricciardelli, E. ; Cardiel López, Nicolás ; Cenarro, A. J. ; Gorgas García, Francisco Javier ; Peletier, R. F. | EDP Sciencies | 2011-08We present a number of improvements to the MILES library and stellar population models. We correct some small errors in the radial velocities of the stars, measure the spectral resolution of the library and models more accurately, and give a bet[...]texto impreso
Toloba, E. ; Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Gibson, B. K. | IOP Publishing | 2009-02-01For the first time, we undertake a systematic examination of the nitrogen abundances using the NH3360 feature for a sample of 35 early-type galaxies spanning a range of masses and local environment. The nitrogen-sensitive molecular feature at 33[...]texto impreso
Sánchez Blázquez, Patricia ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Cenarro, J. ; González, J. J. | IOP Publishing | 2003-06-20Central line-strength indices were measured in the blue spectral region for a sample of 98 early-type galaxies in different environments. For most indices (Mg b and [Fe] in particular), elliptical galaxies in rich clusters and in low-density reg[...]texto impreso
Cenarro, A. J. ; Sánchez Blázquez, Patricia ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier | IOP Publishing | 2004-10-20We present measurements of the Ca II triplet and the Ca4227 Lick index for a sample of early-type galaxies in the Coma Cluster, deriving, for the first time, their corresponding relationships with velocity dispersion. Compared with a similar sub[...]texto impreso
Matkovic, A. ; Guzmán, R. ; Sánchez Blázquez, P. ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier | American Institute of Physics | 2009We derive ages, metallicities and [alpha/Fe] ratios for dwarf early-type galaxies (dE/dS0) in the center and a region believed to be infalling into the Coma cluster. We find that a set of metallic indices cannot be described by linear relations [...]texto impreso
Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Pedraz, S. ; González, J. J. | EDP Sciences | 1999-10Empirical fitting functions, describing the behaviour of the ?4000 Å break, D_4000, in terms of effective temperature, metallicity and surface gravity, are presented. For this purpose, the break has been measured in 392 stars from the Lick/IDS L[...]texto impreso
Cenarro, A. J. ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Peletier, R. F. ; Vazdekis, A. ; Prada, F. | Wiley | 2001-09-21A new stellar library at the near-IR spectral region developed for the empirical calibration of the Ca II triplet and stellar population synthesis modelling is presented. The library covers the range lambda lambda 8348-9020 at 1.5-Angstrom (FWHM[...]texto impreso
Cenarro, A. J. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Pedraz, S. ; Peletier, R. F. ; Vazdekis, A. | Wiley | 2001-09-21We present a homogeneous set of stellar atmospheric parameters (T-eff, log g, [Fe/H]) for a sample of about 700 field and cluster stars which constitute a new stellar library in the near-IR developed for stellar population synthesis in this spec[...]texto impreso
Cenarro, A. J. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Vazdekis, A. ; Peletier, R. F. | Wiley | 2002-02-01Using a near-infrared stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the Call triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting function[...]texto impreso
texto impreso
Mármol Queraltó, E. ; Cardiel López, Nicolás ; Sánchez Blázquez, P. ; Trager, S. C. ; Peletier, R. F. ; Kuntschner, H. ; Silva, D. R. ; Cenarro, A. J. ; Vazdekis, A. ; Gorgas García, Francisco Javier | IOP publishing ltd | 2009-11-10The study of stellar populations in early-type galaxies in different environments is a powerful tool for constraining their star formation histories. This study has been traditionally restricted to the optical range, where dwarfs around the turn[...]texto impreso
Pedraz, S. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Sánchez Blázquez, P. ; Guzmán, R. | Wiley | 2002-05In this letter we investigate the kinematical properties of early-type dwarfs by significantly enlarging the scarce observational sample so far available. We present rotation curves and mean velocity dispersions for four bright dwarf ellipticals[...]texto impreso
Vazdekis, A. ; Sánchez Blázquez, P. ; Falcón Barroso, J. ; Cenarro, A. J. ; Beasley, M. A. ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Peletier, R. F. | Wiley | 2010-06-01We present synthetic spectral energy distributions (SEDs) for single-age, single-metallicity stellar populations (SSPs) covering the full optical spectral range at moderately high resolution [full width at half-maximum (FWHM) = 2.3 A]. These SED[...]texto impreso
Toloba, E. ; Boselli, A. ; Cenarro, A. J. ; Peletier, R. F. ; Gorgas García, Francisco Javier ; Gil de Paz, Armando ; Muñoz Mateos, Juan Carlos | EDP Sciencies | 2011-02We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster, obtained with the WHT and INT telescopes at the Roque de los Muchachos Observatory (La Palma, Spain). These data are [...]texto impreso
Toloba, E. ; Boselli, A. ; Peletier, R. F. ; Falcón Barroso, J. ; van de Ven, G. ; Gorgas García, Francisco Javier | EDP Sciencies | 2012-12We place our sample of 18 Virgo dwarf early-type galaxies (dEs) on the (V - K)_e-velocity dispersion, Faber-Jackson, and fundamental plane (FP) scaling relations for massive early-type galaxies (Es). We use a generalized velocity dispersion, whi[...]texto impreso
Toloba, E. ; Boselli, A. ; Peletier, R. F. ; Falcón Barroso, J. ; van de Ven, G. ; Gorgas García, Francisco Javier | EDP Sciencies | 2013-09texto impreso
Cacho, R. ; Sánchez Blázquez, Patricia ; Gorgas García, Francisco Javier ; Pérez, I. | Wiley | 2014-08-11Numerical simulations predict that bars represent a very important agent for triggering gas inflows, which in turn could lead to central star formation. Bars thus are thought to contribute to the formation of the bulge. This process changes both[...]texto impreso
Cacho Martínez, Raúl ; Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Pérez, I. | Oxford Univ. Press | 2014-08-11Numerical simulations predict that bars represent a very important agent for triggering gas inflows, which in turn could lead to central star formation. Bars thus are thought to contribute to the formation of the bulge.This changes both, the gas[...]texto impreso
Cacho Martínez, Raúl ; Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Pérez, I. | Wiley | 2014-08-11Numerical simulations predict that bars represent a very important agent for triggering gas inflows, which in turn could lead to central star formation. Bars thus are thought to contribute to the formation of the bulge. This process changes both[...]texto impreso
Cardiel López, Nicolás ; Gallego Maestro, Jesús ; Pascual Ramírez, Sergio ; Eliche Moral, María del Carmen ; Castillo Morales, África ; Guzmán, R. ; Gil de Paz, Armando ; Pérez González, Pablo Guillermo ; Gorgas García, Francisco Javier ; Zamorano Calvo, Jaime | SPRINGER-VERLAG BERLIN | 2010We present a short summary of the activities developed by GUAIX, the Universidad Complutense de Madrid (UCM) Group of Extragalactic Astrophysics and Astronomical Instrumentation. At present we are focused in the development of data reduction pip[...]texto impreso
Serrano, A. ; Cardiel López, Nicolás ; Gallego Maestro, Jesús ; Balcells, M. ; Prieto, M. ; Cristóbal, D. ; Guzmán, R. ; Pelló, R. ; Gorgas García, Francisco Javier ; Zamorano Calvo, Jaime | Instituto de Astronomía. Universidad Nacional Autónoma de México | 2003As a part of our collaboration in the COSMOS Project, devoted to the characterization of galaxies during the ep o c h of maximum star formation in the history of the Universe, we have carried out a deep photometric survey covering about 380 arcm[...]texto impreso
Matkovic, A. ; Guzmán, R. ; Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Gruel, N. | IOP Publishing | 2009-02-01We present line-strength measurements for 74 early-type galaxies in the core of the Coma cluster reaching down to velocity dispersions, sigma, of 30 km s(-1). The index-sigma relations for our sample, including galaxies with sigmatexto impreso
Toloba, E. ; Boselli, A. ; Gorgas García, Francisco Javier ; Peletier, R. F. ; Cenarro, A. J. ; Gadotti, D. A. ; Gil de Paz, Armando ; Pedraz, S. ; Yildiz, U. | IOP Publishing | 2009-12-10We present new observational results on the kinematical, morphological, and stellar population properties of a sample of 21 dEs located both in the Virgo Cluster and in the field, which show that 52% of the dEs (1) are rotationally supported, (2[...]texto impreso
Gorgas García, Francisco Javier ; Pedraz, Santos ; Guzmán, Rafael ; Cardiel López, Nicolás ; González, J. J. | IOP Publishing | 1997-05-20We present new measurements of central line-strength indices (namely, Mg-2, (Fe), and H beta) and gradients for a sample of six bright spheroidal (Sph) galaxies in the Virgo Cluster. Comparison with similar measurements for elliptical (E) galaxi[...]texto impreso
We present first results of a comprehensive survey of deep long-slit spectra along the minor axis of bulges of edge-on spiral galaxies. Our results indicate that stellar populations in bulges are fairly old and encompass a range of metallicities[...]texto impreso
We have analysed Mg, H? and Fe line-strengths in a sample of elliptical, SO and brightest cluster galaxies. For 15 galaxies, our spectra extend to approximately the half-light radius(r_e), and we are able to measure radial line-strength gradient[...]texto impreso
Sánchez Blázquez, Patricia ; Peletier, R. F. ; Jiménez Vicente, J. ; Cardiel López, Nicolás ; Cenarro, A. J. ; Falcón Barroso, J. ; Gorgas García, Francisco Javier ; Selam, S. ; Vazdekis, A. | Wiley | 2006-09-11A new stellar library developed for stellar population synthesis modelling is presented. The library consists of 985 stars spanning a large range in atmospheric parameters. The spectra were obtained at the 2.5-m Isaac Newton Telescope and cover [...]texto impreso
Cenarro, A. J. ; Peletier, R. F. ; Sánchez Blázquez, P. ; Selam, S. O. ; Toloba, E. ; Cardiel López, Nicolás ; Falcón Barroso, J. ; Gorgas García, Francisco Javier ; Jiménez Vicente, J. ; Vazdekis, A. | Wiley | 2007-01-11We present a homogeneous set of stellar atmospheric parameters (T-eff, log g, [Fe/H]) for MILES, a new spectral stellar library covering the range lambda lambda 3525-7500 angstrom at 2.3 angstrom (FWHM) spectral resolution. The library consists [...]texto impreso
Cenarro, A. J. ; Cardiel López, Nicolás ; Vazdekis, A. ; Gorgas García, Francisco Javier | Wiley | 2009-07-11Using the near-infrared spectral stellar library of Cenarro et al., the behaviour of the Mg i line at 8807 A and nearby TiO bands is analyzed in terms of the effective temperature, surface gravity and metallicity of the library stars. New spectr[...]texto impreso
Vazdekis, A. ; Sánchez Blázquez, P. ; Falcón Barroso, J. ; Cenarro, A. J. ; Beasley, M. A. ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Peletier, R. | Cambridge Univ. Press | 2009-08We present SEDs for single-age, single-metallicity stellar populations (SSPs) covering the full optical spectral range at resolution (FWHM = 2.3Å). These SEDs can be regarded as our base models, as we combine scaled-solar isochrones with an empi[...]texto impreso
Cenarro, A. J. ; Gorgas García, Francisco Javier ; Vazdekis, A. ; Cardiel López, Nicolás ; Peletier, R. F. | Wiley | 2003-02-11We present new relations between recently defined line-strength indices in the near-infrared (CaT*, CaT, PaT, MgI and sTiO) and central velocity dispersion (sigma(0) ) for a sample of 35 early-type galaxies, showing evidence for significant anti[...]texto impreso
Martín Hernández, J.M. ; Mármol Queraltó, E. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; Sánchez Blázquez, P. ; Cenarro, A.J. ; Peletier, R. F. ; Vazdekis, A. ; Falcón Barroso, J. | SPRINGER-VERLAG BERLIN | 2010We are presenting new empirical fitting functions for the Lick/IDS line-strength indices as measured in MILES (Medium-resolution INT Library of Empirical Spectra). Following previous work in the field, these functions describe the empirical beha[...]texto impreso
Mármol Queraltó, E. ; Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Pedraz, S. ; Cenarro, A.J. ; Sánchez Blázquez, P. ; Peletier, R. F. ; Vazdekis, A. | Instituto de Astronomía. Universidad Nacional Autónoma de México | 2005Stellar population synthesis models are crucial for the understanding of the large amount of data which is being gathered for galaxies at low and high redshift, and provide the only way to compare the "real world" with the theoretical framework.[...]texto impreso
Mármol Queraltó, E. ; Cardiel López, Nicolás ; Cenarro, A. J. ; Vazdekis, A. ; Gorgas García, Francisco Javier ; Pedraz, S. ; Peletier, R. F. ; Sánchez Blázquez, P. | EDP Sciencies | 2008-10The analysis of unresolved stellar populations demands evolutionary synthesis models with realistic physical ingredients and extended wavelength coverage. Aims. We quantitatively describe the first CO bandhead at 2.3 mu m to allow stellar popula[...]texto impreso
Old stellar populations .4. Empirical fitting functions for features in the Spectra of G and K stars
Gorgas García, Francisco Javier ; Faber, S. M. ; Burstein, David ; González, J. Jesús ; Courteau, Stéphane ; Prosser, Charles | University Chicago Press | 1993-05Empirical fitting functions are presented that model the behavior of 11 strong atomic and molecular features in the spectra of Galactic G and K stars. The functions express the strength of spectral features as a function of V - K, surface gravit[...]texto impreso
Carretero, C. ; Vazdekis, A. ; Beckman, J. E. ; Sánchez Blázquez, P. ; Gorgas García, Francisco Javier | American Astronomical Society | 2004-07-10We present estimates of CN and Mg overabundances with respect to Fe for early-type galaxies in eight clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey Data Release 1 and from William Hershel T[...]texto impreso
Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Cenarro, J. ; González, J. J. | EDP Sciences | 1998-02We present a new set of accurate formulae for the computation of random errors in the measurement of atomic and molecular line-strength indices. The new expressions are in excellent agreement with numerical simulations. We have found that, in so[...]texto impreso
Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Aragón Salamanca, A. | Wiley | 1998-08-21We have obtained radial gradients in the spectral features of the lambda 4000-Angstrom break (D(4000)) and Mg(2) for a sample of 11 central cluster galaxies (CCGs): eight in clusters with cooling flows and three in clusters without. After carefu[...]texto impreso
Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Aragón Salamanca, A. | Wiley-Blackwell | 1995-11-15Spectroscopic observations of central dominant cluster galaxies, with and without cooling flows, are presented. Through the analysis of absorption spectral features, namely the strength of the magnesium absorption at 5175 Å and the 4000 Å break,[...]texto impreso
Cardiel López, Nicolás ; Gorgas García, Francisco Javier ; Aragón Salamanca, A. | Wiley | 1995-11-15Spectroscopic observations of central dominant cluster galaxies, with and without cooling flows, are presented. Through the analysis of absorption spectral features, namely the strength of the magnesium absorption at lambda 5175 Angstrom and the[...]texto impreso
Toloba, E. ; Guhathakurta, P. ; Peletier, R. F. ; Boselli, A. ; Lisker, T. ; Falcón Barroso, J. ; Simon, J. D. ; van de Ven, G. ; Paudel, S. ; Emsellem, E. ; Janz, J. ; den Brok, M. ; Gorgas García, Francisco Javier ; Hensler, G. ; Laurikainen, E. ; Niemi, S. M. ; Rys, A. ; Salo, H. | University Chicago Press | 2014-12We present spatially resolved kinematics and global stellar populations and mass-to-light ratios for a sample of 39 dwarf early-type (dE) galaxies in the Virgo cluster studied as part of the SMAKCED stellar absorption-line spectroscopy and imagi[...]texto impreso
Toloba, E. ; Guhathakurta, P. ; Boselli, A. ; Peletier, R. F. ; Emsellem, E. ; Lisker, T. ; van de Ven, G. ; Simon, J. D. ; Falcón Barroso, J. ; Adams, J. J. ; Benson, A. J. ; Boissier, S. ; den Brok, M. ; Gorgas García, Francisco Javier ; Hensler, G. ; Janz, J. ; Laurikainen, E. ; Paudel, S. ; Rys, A. ; Salo, H. | IOP Publishing | 2015-02-01We analyze the stellar kinematics of 39 dwarf early-type galaxies (dEs) in the Virgo Cluster. Based on the specific stellar angular momentum lambda(Re) and the ellipticity, we find 11 slow rotators and 28 fast rotators. The fast rotators in the [...]texto impreso
This is the first paper presenting our long-term project aimed at studying the nature of bulges through analyzing their stellar population gradients. We present deep spectroscopic observations along the minor axis and the data reduction for a sa[...]texto impreso
We present the analysis of the radial gradients of stellar absorption lines in a sample of 32 bulges of edge-on spiral galaxies, spanning nearly the full Hubble sequence (from S0 to Sc types), and a large range of velocity dispersion (from about[...]texto impreso
Mármol Queraltó, Esther ; Cardiel López, Nicolás ; Sánchez Blázquez, P. ; Trager, S.C. ; Peletier, R. F. ; Kuntschner, H. ; Silva, D. R. ; Cenarro, A. J. ; Vazdekis, A. ; Gorgas García, Francisco Javier | Cambridge Univ. Press | 2009-08A full understanding of the physical properties of integrated stellar systems demands a multiwavelength approach since each spectral window shows us the contribution of different types of stars. However, most of the observational effort in stell[...]texto impreso
We present a few results of a work in progress tackling the radial spectroscopic properties of bulges of spiral galaxies.texto impreso
Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; González, J. J. | EDP Sciencies | 2006-10This paper commences a series devoted to the study of the stellar content of early-type galaxies. The goal of the series is to set constraints on the evolutionary status of these objects. Methods. In this paper we describe the details of the gal[...]texto impreso
Sánchez Blázquez, P. ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás ; González, J. J. | EDP Sciencies | 2006-10This is the second paper of a series devoted to the study of the stellar content of early-type galaxies. The goal of the series is to set constraints on the evolutionary status of these objects Methods. We use a new set of models that include an[...]texto impreso
Sánchez Blázquez, Patricia ; Gorgas García, Francisco Javier ; Cardiel López, Nicolás | EDP Sciencies | 2006-10Aims. This is the third paper of a series devoted to the study of the stellar content of early-type galaxies. The goal of the series is to set constraints on the evolutionary status of these objects. Methods. We present line-strength gradients f[...]