M. T. Costado
A5081698921- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Higher Education Teaching and Evaluation
- History and Developments in Astronomy
- Particle Detector Development and Performance
- Neutrino Physics Research
- Educational theories and practices
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Solar and Space Plasma Dynamics
- Atomic and Subatomic Physics Research
- Educational Innovations and Technology
- Historical Astronomy and Related Studies
- Spectroscopy and Laser Applications
- Teaching and Learning Programming
Universidad de Cádiz
2018-2024
Contextual Change (United States)
2020
Ação Educativa
2020
Instituto de Astrofísica de Andalucía
2013-2018
Arcetri Astrophysical Observatory
2017
Consejo Superior de Investigaciones Científicas
2007-2015
Unidades Centrales Científico-Técnicas
2007-2014
Instituto de Astrofísica de Canarias
2005-2013
Universidad de La Laguna
2005-2011
MAGIC Telescopes
2009
A precision measurement by the Alpha Magnetic Spectrometer on International Space Station of positron fraction in primary cosmic rays energy range from 0.5 to 350 GeV based $6.8\ifmmode\times\else\texttimes\fi{}{10}^{6}$ and electron events is presented. The very accurate data show that steadily increasing 10 $\ensuremath{\sim}250\text{ }\text{ }\mathrm{GeV}$, but, 20 250 GeV, slope decreases an order magnitude. spectrum shows no fine structure, ratio observable anisotropy. Together, these...
The blazar Mrk 501 was observed at energies above 0.10 TeV with the MAGIC Telescope from 2005 May through July. high sensitivity of instrument enabled determination flux and spectrum source on a night-by-night basis. Throughout our observational campaign, found to vary by an order magnitude. Intranight variability flux-doubling times down 2 minutes during two most active nights, namely, June 30 July 9. These are fastest variations ever in 501. ~20 minute long flare 9 showed indication 4 ± 1...
The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at distance more than 5 billion light-years (a redshift 0.536). No quasar been observed previously in radiation, and this is also most object emitting above 50 gigaelectron volts. Because high-energy may be stopped by interacting with diffuse background light universe,...
We report about very high energy (VHE) γ-ray observations of the Crab Nebula with MAGIC telescope. The flux from nebula was measured between 60 GeV and 9 TeV. spectrum can be described by a curved power law dF/dE = f0(E/300 GeV)[a+blog10(E/300 GeV)] normalization f0 (6.0 ± 0.2stat) × 10−10 cm−2 s−1 TeV−1, − 2.31 0.06stat, b 0.26 0.07stat. peak in spectral distribution is estimated at 77 35 GeV. Within observation time experimental resolution telescope, emission steady pointlike. emission's...
We report the results of a three-year-long dedicated monitoring campaign restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically optical near-infrared domains. monitored number erupting episodes past few years, increased density our observations during eruptive episodes. In this paper, we present full historical data set from 2009 to 2012 with multi-wavelength dense coverage two high-luminosity events between August...
(Abridged) We have used the atmospheric parameters, [alpha/Fe] abundances and radial velocities, determined from Gaia-ESO Survey GIRAFFE spectra of FGK-type stars (iDR1), to provide a chemo-kinematical characterisation disc stellar populations. focuss on subsample 1016 with high quality covering volume |Z|<4.5kpc R in range 2-13kpc. identified thin thick separation vs [M/H] plane, thanks presence low-density region number density distribution. The seem lie progressively thinner layers...
The Gaia-ESO Survey is obtaining high-quality spectroscopic data for about 10^5 stars using FLAMES at the VLT. UVES high-resolution spectra are being collected 5000 FGK-type stars. These analyzed in parallel by several state-of-the-art methodologies. Our aim to present how these analyses were implemented, discuss their results, and describe a final recommended parameter scale defined. We also precision (method-to-method dispersion) accuracy (biases with respect reference values) of...
We analyze the timing of photons observed by MAGIC telescope during a flare active galactic nucleus Mkn 501 for possible correlation with energy, as suggested some models quantum gravity (QG), which predict vacuum refractive index ≃1+(E/MQGn)n, n=1,2. Parametrizing delay between γ-rays different energies Δt=±τlE or Δt=±τqE2, we find τl=(0.030±0.012) s/GeV at 2.5-σ level, and τq=(3.71±2.57)×10−6 s/GeV2, respectively. use these results to establish lower limits MQG1>0.21×1018 GeV...
We report on the results from observations in very high energy band (VHE; Eγ ≥ 100 GeV) of black hole X-ray binary (BHXB) Cygnus X-1. The were performed with MAGIC telescope, for a total 40 hr during 26 nights, spanning period between 2006 June and November. Searches steady γ-ray signals yielded no positive result, upper limits to integral flux ranging 1% 2% Crab Nebula flux, depending energy, have been established. also analyzed each observation night independently, obtaining evidence at...
One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring high-end region a pulsar's spectrum would shed light on this question. By developing new electronic trigger, we lowered threshold Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 GeV. In configuration, detected gamma-rays from Crab pulsar that were greater than GeV, revealing relatively high cutoff energy in phase-averaged spectrum. This indicates emission...
We report the detection of a new source very high energy (VHE; Eγ ≥ 100 GeV) γ-ray emission located close to Galactic plane, MAGIC J0616+225, which is spatially coincident with supernova remnant IC 443. The observations were carried out telescope in periods 2005 December-2006 January and 2006 December-2007 January. Here we present results from this source, leading VHE signal statistical significance 5.7 σ 2006/2007 data measured differential flux consistent power law, described as dNγ/(dA dt...
We study the relationship between age, metallicity, and alpha-enhancement of FGK stars in Galactic disk. The results are based upon analysis high-resolution UVES spectra from Gaia-ESO large stellar survey. explore limitations observed dataset, i.e. accuracy parameters selection effects that caused by photometric target preselection. find colour magnitude cuts survey suppress old metal-rich young metal-poor stars. This suppression may be as high 97% some regions age-metallicity relationship....
The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. resulting upper limits on gamma-ray emission above 100 GeV are in range 4.6 to 7.5 x 10^{-12} cm^{-2} s^{-1} spectral indices from -1.5 -2.5, thereby constraining produced cosmic rays, dark matter annihilations, central radio NGC1275. Results compatible with cosmological simulations cosmic-ray-induced emission, average ray-to-thermal pressure <4%...
(Abridged) We analyzed the stellar parameters and radial velocities of ~1200 stars in five bulge fields as determined from Gaia-ESO survey data (iDR1). use VISTA Variables The Via Lactea (VVV) photometry to obtain reddening values by using a semi-empirical T_eff-color calibration. From Gaussian decomposition metallicity distribution functions, we unveil clear bimodality all fields, with relative size components depending specific position on sky. In agreement some previous studies, find mild...
Context. A key science goal of the Gaia-ESO survey (GES) at VLT is to use kinematics low-mass stars in young clusters and star forming regions probe their dynamical histories how they populate field as become unbound. The clustering around massive Wolf-Rayet binary system γ2 Velorum was one first GES targets.
Aims. Until recently, most high-resolution spectroscopic studies of the Galactic thin and thick discs were mostly confined to objects in solar vicinity. Here we aim at enlarging volume which individual chemical abundances are used characterise discs, using first internal data release Gaia-ESO survey (GES iDR1).
The spatial distribution of elemental abundances in the disc our Galaxy gives insights both on its assembly process and subsequent evolution, stellar nucleogenesis different elements. Gradients can be traced using several types objects as, for instance, (young old) stars, open clusters, HII regions, planetary nebulae. We aim at tracing radial distributions elements produced through nucleosynthetic channels -the alpha-elements O, Mg, Si, Ca Ti, iron-peak Fe, Cr, Ni Sc - by Gaia-ESO idr4...
We use Gaia-ESO Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters, that were observed as calibrators, a demonstration of quality and analysis. The results compare well with available literature, within 0.1 dex or less, after small (compared internal spreads) offset between UVES GIRAFFE 0.10-0.15 was taken into account. In particular, we present for first time NGC 5927, one most metal-rich clusters studied literature so far [Fe/H]=-0.49 dex, included connect open...
Photometry alone is not sufficient to unambiguously distinguish between ultra-faint star clusters and dwarf galaxies because of their overlap in morphological properties. Here we report on VLT/GIRAFFE spectra candidate member stars two recently discovered satellites Reticulum 2 Horologium 1, obtained as part the ongoing Gaia-ESO Survey. We identify 18 members 5 1. find have a velocity dispersion ~3.22 km/s, implying M/L ratio ~ 500. inferred stellar parameters for all candidates mean...
The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling formation and evolution. Open clusters allow us to derive both its evolution over time. In this paper we perform first investigation of present-day based on [Fe/H] determinations late type members pre-main-sequence clusters. Because their youth, these are therefore essential tracing current inter-stellar medium metallicity. We used products Gaia-ESO Survey analysis 12 young regions...
The MAGIC collaboration observed BL Lacertae for 22.2 hr during 2005 August to December and 26 2006 July September. source is the historical prototype eponym of a class low-frequency-peaked (LBL) objects. A very high energy (VHE) γ-ray signal was discovered with 5.1 σ excess in data. Above 200 GeV, an integral flux (0.6 ± 0.2) × 10-11 cm-2 s-1 measured, corresponding approximately 3% Crab flux. differential spectrum between 150 900 GeV rather steep photon index -3.6 0.5. light curve shows no...
We searched for very high energy (VHE) gamma-ray emission from the supernova remnant Cassiopeia A. The shell-type A was observed with 17 meter MAGIC telescope between July 2006 and January 2007 a total time of 47 hours. source detected above an 250 GeV significance 5.2sigma photon flux 1 TeV (7.3+-0.7_stat+-2.2_sys)10^-13 cm^-2s^-1. spectrum is compatible power law dN/dE = E^-Gamma index Gamma=2.3+-0.2_stat+-0.2_sys. point-like within angular resolution telescope.
We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 June 23. A $\gamma$-ray signal was detected by AGILE with \sqrt{TS}=4.5 on 9--15, $F(E>100 \mathrm{MeV})= 42^{+14}_{-12}\times 10^{-8}$ photons cm$^{-2}$ s$^{-1}$. This flaring state is brighter than average flux observed EGRET a factor $\sim$3, but still consistent highest flux. In hard X-rays (20-60 keV)...