A5018012426- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- E-Learning and Knowledge Management
- Nanocluster Synthesis and Applications
- GNSS positioning and interference
- Impact of Light on Environment and Health
- Crystal Structures and Properties
- Astro and Planetary Science
- Photocathodes and Microchannel Plates
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Educational Innovations and Technology
- Magnetism in coordination complexes
- CCD and CMOS Imaging Sensors
- Digital literacy in education
National Institute of Astrophysics, Optics and Electronics
2010-2024
University of Cambridge
2011
Universidad de La Laguna
2011
Johns Hopkins University
2007
Universidad Nacional Autónoma de México
2005
We present an extended ultraviolet-blue (850-4700 Å) library of theoretical stellar spectral energy distributions computed at high resolution, λ/Δλ = 50,000. The UVBLUE grid, as we named the library, is based on LTE calculations carried out with ATLAS9 and SYNTHE codes developed by R. L. Kurucz consists nearly 1800 entries that cover a large volume parameter space. It spans range in Teff from 3000 to 50,000 K, surface gravity ranges log g 0.0 5.0 Δ 0.5 dex, while seven chemical compositions...
Aims. The fast improvement of spectroscopic observations makes mandatory a strong effort on the theoretical side to better reproduce spectral energy distribution (SED) stars at high resolution. In this regard, relying Kurucz Atlas/Synthe original codes we computed Bluered library, consisting 832 synthetic SED stars, that cover large parameter space very resolution () along 3500-7000 Å wavelength range.
We use the Galaxy Evolution Explorer (GALEX) Medium and All-Sky Imaging Survey (MIS AIS) data from first public release (GR1), matched to Sloan Digital Sky (SDSS) DR3 catalog, perform source classification. The GALEX surveys provide photometry in far- near-UV bands SDSS five optical (u, g, r, i, z). GR1/DR3 overlapping areas are 363 (86) deg2 for AIS (MIS), sources within 0.5° central area of fields. Our sample covers mostly |b| > 30° Galactic latitudes. present statistical properties...
We carried out a critical appraisal of the two theoretical models, Kurucz' ATLAS9 and PHOENIX/NextGen, for stellar atmosphere synthesis. Our tests relied on fit spectral energy distributions (SEDs) sample 334 target stars along whole spectral-type sequence, from classical optical catalogs Gunn & Stryker Jacoby et al. The best-fitting physical parameters (Teff, log g) allowed an independent calibration temperature bolometric scale versus empirical classification (i.e., type MK luminosity...
We here present the luminosity function (LF) of globular clusters (GCs) in five nearby spiral galaxies using samples GC candidates selected Hubble Space Telescope mosaic images F435W, F555W and F814W filters. Our search, which surpasses fractional area covered by all previous searches these galaxies, has resulted detection 158 M81, 1123 M101, 226 NGC4258, 293 M51 173 NGC628. The LFs constructed from this dataset, after correcting for relatively small contamination reddened young clusters,...
Using the UVBLUE library of synthetic stellar spectra we have computed a set mid-UV line and continuum spectroscopic indices. We explore their behavior in terms leading parameters [T_eff,log(g)]. The overall result is that indices follow general trends depicted by those from empirical databases. Separately also examine index sensitivity to changes chemical composition, an analysis only feasible under theoretical approach. In this respect, lines FeI3000, BL3096 MgI2852 2828/2921 are least...
MEGARA (<i>Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía</i>) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the 10.4m telescope in La Palma. offers two IFU fiber bundles, one covering 12.5x11.3 arcsec<sup>2</sup> with a spaxel size of 0.62 arcsec (Large Compact Bundle; LCB) another 8.5x6.7 0.42 (Small SCB). The MOS mode will allow observing up to 100 objects region 3.5x3.5 arcmin<sup>2</sup> around bundles. Both LCB capabilities...
MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the 10.4m telescope in La Palma that being built by a Consortium led UCM (Spain) also includes INAOE (Mexico), IAA-CSIC (Spain), UPM (Spain). The instrument currently finishing AIV will be sent to on November 2016 its on-sky commissioning April 2017. IFU fiber bundle (LCB) covers 12.5x11.3 arcsec2 with spaxel size of 0.62 arcsec while...
In these proceedings we give a summary of the characteristics and current status MEGARA instrument, future optical IFU MOS for 10.4-m Gran Telescopio Canarias (GTC). is being built by Consortium public research institutions led Universidad Complutense de Madrid (UCM, Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) UPM (Spain). The two different fiber bundles, one called LCB (Large Compact Bundle) with field-of-view 12.5×11.3 arcsec<sup>2</sup> spaxel size 0.62 arcsec yielding...
We present the results obtained from an objective search for stellar clusters, both in currently active nuclear starburst region, and poststarburst disk of M82. Images with Advanced Camera Surveys (ACS) on board Hubble Space Telescope (HST) F435W (B), F555W (V), F814W (I) filters were used clusters. detected 653 which 393 are located outside central 450 pc The luminosity function clusters shows apparent turnover at B = 22 mag (MB − 5.8), we interpret Monte Carlo simulations as due to...
We analyse the photometric, chemical, star formation history and structural properties of brightest globular cluster (GC) in M81, referred to as GC1 this work, with intention establishing its nature origin. find that it is a metal-rich ([Fe/H] = −0.60 ± 0.10), alpha-enhanced ([α/Fe] ∼ 0.20 0.05), core-collapsed (core radius rc 1.2 pc, tidal rt 76rc), old (>13 Gyr) cluster. It has an ultraviolet excess equivalent ∼2500 blue horizontal branch stars. detected X-rays indicative presence low-mass...
We here report the detection of extended HeII4686 nebular emission in central region NGC1569 using integral field spectrograph MEGARA at 10.4-m Gran Telescopio Canarias. The observations cover a Field View (FoV) 12.5 arcsec x 11.3 seeing-limited spatial resolution ~15 pc and spectral R=6000 wavelength range 4330--5200 Angstrom. extends over semi-circular arc ~40 width ~150 diameter around super star cluster A (SSC-A). Av derived Balmer decrement varies from Galactic value 1.6 mag to maximum...
ABSTRACT We here present the results of an analysis optical spectroscopy 42 globular cluster (GC) candidates in nearby spiral galaxy M81 (3.61 Mpc). The spectra were obtained using long-slit and multi-object spectroscopic modes OSIRIS instrument at 10.4-m Gran Telescopio Canarias a spectral resolution ∼1000. used classical H β versus [MgFe]′ index diagram to separate genuine old GCs from clusters younger than 3 Gyr. Of 30 with continuum signal-to-noise ratio &gt;10, we confirm 17 objects...
La rápida evolución de la Inteligencia Artificial (IA) está transformando diversos sectores, incluida educación superior. integración efectiva IA en los procesos enseñanza-aprendizaje ofrece oportunidades sin precedentes, como personalización del aprendizaje, generación recursos multimedia enriquecidos y automatización tareas administrativas. Sin embargo, a pesar su potencial, adopción estas tecnologías emergentes se ve obstaculizada por falta competencias digitales el cuerpo docente. Este...
MEGARA is the new generation IFU and MOS optical spectrograph built for 10.4m Gran Telescopio CANARIAS (GTC). The project was developed by a consortium led UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC UPM (Spain). instrument arrived to GTC on March 28th 2017 successfully integrated commissioned at telescope from May August 2017. During on-sky commissioning we demonstrated powerful robust provides intermediate-to-high spectral resolutions RFWHM ~ 6,000, 12,000 20,000 an...
We present results on the star formation history and extinction in disk of M82 over spatial scales 10'' (∼180 pc). Multi-band photometric data covering far-ultraviolet to near-infrared bands were fitted a grid synthetic spectral energy distributions. obtained distribution functions age for each 117 apertures analyzed, taking into account observational errors through Monte Carlo simulations. These with Gaussian obtain mean ages extinctions together their errors. The zones analyzed include...
Synthetic Lick indices computed with solar scaled abundances and α-element enhancement are presented compared predictions from both theoretical computations (Tripicco & Bell; Thomas, Maraston, Bender; Barbuy et al.) empirical fitting functions (de Freitas Pacheco). We propose selected combinations of capable singling out α-enhanced stars without requiring previous knowledge their main atmospheric parameters. By applying this approach to the 460 in Worthey al. catalog, we detected a list 82...
We report the detection of 7 new Wolf-Rayet (WR) star locations in M81 using Multi-Object Spectrograph OSIRIS instrument at Gran Telescopio Canarias. These detections are result a follow-up an earlier study same instrumental set-up that resulted 14 WR locations. analyse entire sample 21 spectra to classify them one known sub-types template stars Large Magellanic Cloud (LMC), with similar metallicity M81. Taking into consideration dispersion strengths bumps for given sub-type, we found 19...
We present an analysis of 402 F, G, and K solar neighborhood stars, with accurate estimates [Fe/H] in the range -1.0 to +0.5 dex, aimed at detection α-enhanced stars investigation their kinematical properties. The is based on comparison 571 sets spectral indices Lick/IDS system, coming from four different observational data sets, synthetic computed solar-scaled abundances α-element enhancement. use selected combinations single out without requiring previous knowledge main atmospheric...
OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the first light instrument of Gran Telescopio Canarias (GTC). It provides a flexible competitive tunable filter (TF). Since it based on Fabry-Perot interferometer working in collimated beam, TF transmission wavelength depends position target with respect to optical axis. This effect non-negligible must be accounted data reduction. Our paper establishes calibration accuracy required spectrophotometric...
We here present the results of an analysis optical spectroscopy 42 globular cluster (GC) candidates in nearby spiral galaxy M81 (3.61~Mpc). The spectra were obtained using long-slit and MOS modes OSIRIS instrument at 10.4~m Gran Telescopio Canarias (GTC) a spectral resolution $\sim$1000. used classical H$\beta$ vs [MgFe]$'$ index diagram to separate genuine old GCs from clusters younger than 3 Gyr. Of 30 with continuum signal-to-noise ratio $>10$, we confirm 17 objects be (age $>10$~Gyr,...
We present the results from spectroscopic and photometric analysis of 17 globular cluster (GC) candidates in Irr II galaxy NGC 3077. The GC were selected on Hubble Space Telescope (HST) images cleaned foreground Galactic stars using GAIA parameters. carried out aperture photometry multi-band archival SDSS, 2MASS all candidates, low resolution (R= 1000) observations 12 three suspected OSIRIS/MOS mode at Gran Telescopio Canarias (GTC). Age, metallicity extinction values determined both data,...
Abstract We present the results from spectroscopic and photometric analysis of 17 globular cluster (GC) candidates in Irr II galaxy NGC 3077. The GC were selected on Hubble Space Telescope images cleaned foreground Galatic stars using GAIA parameters. carried out aperture photometry multiband archival Sloan Digital Sky Survey, Two Micron All Survey all candidates, low resolution ( R = 1000) observations 12 three suspected Optical System for Imaging Low-Intermediate-Resolution Integrated...
Abstract The well-known age–metallicity-attenuation degeneracy does not permit unique and good estimates of basic parameters stars stellar populations. effects dust can be avoided using spectral line indices, but current methods have been able to break the age–metallicity degeneracy. Here we show that at least two new indices defined measured on high-resolution ( R = 6000) spectra a signal-to-noise ratio (S/N) ≥ 10, one gets unambiguous age metallicity intermediate old Spectroscopic data...