A5103127033- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Chalcogenide Semiconductor Thin Films
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Phase-change materials and chalcogenides
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Glass properties and applications
- Isotope Analysis in Ecology
- Diamond and Carbon-based Materials Research
- Quantum Dots Synthesis And Properties
- Astrophysical Phenomena and Observations
- Advanced Semiconductor Detectors and Materials
- Metal and Thin Film Mechanics
- SAS software applications and methods
- Semiconductor Quantum Structures and Devices
- Thermography and Photoacoustic Techniques
- Nuclear Physics and Applications
- Semiconductor materials and devices
- Silicon Nanostructures and Photoluminescence
- Calibration and Measurement Techniques
- Semiconductor materials and interfaces
- Astrophysics and Star Formation Studies
Universidad Nacional Autónoma de México
2015-2024
University of Almería
2024
Yebes Observatory
2023
Center for Research and Advanced Studies of the National Polytechnic Institute
1999-2022
Center for Engineering and Industrial Development
2016-2021
Max Planck Institute for Extraterrestrial Physics
2021
University of Zulia
2019
University of Oxford
2018
University of Havana
2016
Arizona State University
2015
view Abstract Citations (947) References (97) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Old Stellar Populations. V. Absorption Feature Indices for the Complete Lick/IDS Sample of Stars Worthey, Guy ; Faber, S. M. Gonzalez, J. Jesus Burstein, D. Twenty-one optical absorption features, 11 which have been previously defined, are automatically measured in a sample 460 stars. Following Gorgas et al., indices summarized fitting functions that give index...
We present absorption-line strengths on the Lick/IDS line-strength system of 381 galaxies and 38 globular clusters in 4000--6400 Åregion. All were observed at Lick Observatory between 1972 1984 with Cassegrain Image Dissector Scanner spectrograph, making this study one largest homogeneous collections galaxy spectral line data to date. also a catalogue nuclear velocity dispersions used correct onto stellar system. Extensive discussion both random systematic errors is provided. Indices are...
We present single stellar population (SSP) equivalent ages, metallicities, and abundance ratios for local elliptical galaxies derived from Hbeta, Mgb, <Fe> absorption line strengths. use an extension of the Worthey (1994) models that incorporates non-solar line-strength "response functions" by Tripicco & Bell (1995), allowing us to correct enhancements Mg other alpha-like elements relative Fe-peak elements. SSP-equivalent ages ellipticals Gonzalez (1993) are found vary widely, 1.5 < t 18...
This paper analyzes single stellar population (SSP)–equivalent parameters for 50 local elliptical galaxies as a function of their structural parameters. The galaxy sample is drawn from the high-quality spectroscopic surveys González (1993) and Kuntschner (1998). basic data are central values SSP-equivalent ages, t, metallicities, [Z/H], "enhancement" ratios, [E/Fe], derived in Paper I, together with global including velocity dispersions, radii, surface brightnesses, masses, luminosities....
view Abstract Citations (596) References (33) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS MG and Fe Absorption Features in Elliptical Galaxies Worthey, Guy ; Faber, S. M. Gonzalez, J. Mg indices from two homogenous collections of nuclear elliptical galaxy spectra are compared with model indices. In the average giant elliptical, [Mg/Fe] ratio exceeds that most metal-rich stars solar neighborhood by ~0.2-0.3 dex, a large spread about this mean. This result...
Wide-field optical surveys have begun to uncover large samples of fast (trise ≲ 5 d), luminous (Mpeak < −18), blue transients. While commonly attributed the breakout a supernova shock into dense wind, great distances transients this class found so far hampered detailed investigation their properties. We present photometry and spectroscopy from comprehensive worldwide campaign observe AT 2018cow (ATLAS 18qqn), first fast-luminous transient be in real time at low redshift. Our spectra (<2 days...
Aims.This is the second paper of a series devoted to study stellar content early-type galaxies. The goal set constraints on evolutionary status these objects
By means of the fossil record method implemented through Pipe3D, we reconstruct global and radial stellar mass growth histories (MGHs) an unprecedentedly large sample galaxies, ranging from dwarf to giant objects, "Mapping Nearby Galaxies at Apache Point Observatory" survey. We confirm that main driver MGHs is mass, with more massive galaxies assembling their masses earlier (downsizing), though for a given segregate by color, specific star formation rate (sSFR), morphological type. From...
Infrared spectroscopy has been used to analyze the structural changes in samples prepared by sol-gel method. Silica gels were from alcoholic solutions of tetraethylorthosilicate (TEOS) with different H2O/TEOS molar ratios. The IR spectra these gels, Si–O bond stretching region, shows that their structure strongly depends on ratio. relative change intensity modes, using ratios, are interpreted terms degrees disorder. According our infrared absorption data, a decrease ratio about 7, SiO2...
view Abstract Citations (206) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Old Stellar Populations. IV. Empirical Fitting Functions for Features in the Spectra of G and K Stars Gorgas, Javier ; Faber, S. M. Burstein, David Gonzalez, J. Courteau, Stephane Prosser, Charles fitting functions are derived 11 atomic molecular features prominent spectra stars. The behavior closely mimics that expected from physics stellar atmospheres, except index...
The Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) will be a Day-One instrument of the Spanish 10.4 m telescope Gran Telescopio Canarias, whose first light is planned 2002. GTC installed at Observatorio del Roque de los Muchachos in La Palma, Spain. OSIRIS three primary modes are imaging resolution long slit multiple object spectroscopy. designed to operate from 365 1000 nm with field view 7 by arcminutes maximum spectral 5000. Among main features use tunable...
We present a detailed study of the stellar populations (SPs) and kinematics bulge inner disk regions eight nearby spiral galaxies (Sa-Sd) based on deep Gemini/GMOS data. The long-slit spectra extend to 1-2 scale lengths with S/N/Ang>=50. Several different model fitting techniques involving absorption-line indices full spectrum are explored found weigh age, metallicity, abundance ratios differently. SPs not well matched by single episodes star formation; representative must involve average...
The structure of molecular beam deposited microcrystalline silicon and germanium films prepared under different growth conditions has been analyzed by conventional transmission electron microscope (TEM) Raman scattering (RS) compared to electrical conductivity experiments. TEM measurements yield an average grain size L0 ranging from 200 Å 1.5 μm. On the other hand, line shape RS is determined a mean free path related separation l between defects (or impurities), where l≤150 Å. We find in...
view Abstract Citations (180) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Correlations between Line Strengths and Fine Structure in Elliptical Galaxies Schweizer, Francois ; Seitzer, Patrick Faber, S. M. Burstein, David Dalle Ore, Cristina Gonzalez, J. Jesus For 36 giant elliptical galaxies located mostly the field groups, strength of nuclear Hβ absorption line at any given absolute magnitude increases systematically with amount fine...
We present optical and near-infrared (NIR) photometry for three gamma-ray burst supernovae (GRB-SNe): GRB 120729A, 130215A / SN 2013ez 130831A 2013fu. In the case of 2013ez, we also spectroscopy at t-t0=16.1 d, which covers rest-frame 3000-6250 Angstroms. Based on Fe II (5169) Si (II) (6355), our spectrum indicates an unusually low expansion velocity 4000-6350 km/s, lowest ever measured a GRB-SN. Additionally, determined brightness shape each accompanying relative to template supernova (SN...
Abstract Gamma-ray bursts (GRBs) are fascinating events due to their panchromatic nature. We study optical plateaus in GRB afterglows via an extended search into archival data. comprehensively analyze all published GRBs with known redshifts and observed by many ground-based telescopes (e.g., Subaru Telescope, RATIR) around the world several space-based observatories such as Neil Gehrels Swift Observatory. fit 500 light curves, showing existence of plateau 179 cases. This sample is 75% larger...