News

This section includes scientific and technological news from the IAC and its Observatories, as well as press releases on scientific and technological results, astronomical events, educational projects, outreach activities and institutional events.

  • Figure caption: Left panels show the i − J vs. g − r diagrams for three different parameters: surface brightness in restframe J (μJ, blue), the logarithm of the stellar mass density (log (ρ), pink), and the radial distance to the most massive galaxies of
    The ultra-deep multiwavelength Hubble Space Telescope Frontier Fields coverage of the Abell Cluster 2744 is used to derive the stellar population properties of its intracluster light (ICL). The restframe colors of the ICL of this intermediate redshift (z = 0.3064) massive cluster are bluer (g – r = 0.68 ± 0.04; i – J = 0.56 ± 0.01) than those found in the stellar populations of its main galaxy members (g – r = 0.83 ± 0.01; i – J = 0.75 ± 0.01). Based on these colors, we derive the following mean metallicity Z = 0.018 ± 0.007 for the ICL. The ICL age is 6 ± 3 Gyr younger than the average age
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  • Our visible and NIR spectropolarimetric measurements of the earthshine compared to literature data. A 10-pixel binning was applied to the NIR spectrum. The uncertainty per wavelength is plotted as vertical gray error bars. Wavelengths of strong telluric a
    Aims. We aim to extend our current observational understanding of the integrated planet Earth spectropolarimetry from the optical to the near-infrared wavelengths. Major biomarkers like O2 and water vapor are strong flux absorbents in the Earth’s atmosphere, and some linear polarization of the reflected stellar light is expected to occur at these wavelengths. Methods. Simultaneous optical (0.4−0.9 μm) and near-infrared (0.9−2.3 μm) linear spectropolarimetric data of the earthshine were acquired by observing the nightside of the waxing Moon. The data have sufficient spectral resolution (2.51
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  • Figure:  GTC/ORISIS Spectroscopy. Upper Panel: 2-D spectral image. Center Panel: Obj1. Lower Panel: Obj2. The Lyα lines, marked with a red line, are clearly seen in both spectra. The blue dashed line, at the bottom of each frame, shows an off-scale sky sp
    We are undertaking a search for high-redshift low-luminosity Lyman Alpha sources in the SHARDS (Survey for High-z Absorption Red and Dead Sources) survey. Among the pre-selected Lyman Alpha sources two candidates were spotted, located 3.19 arcsec apart, and tentatively at the same redshift. Here, we report on the spectroscopic confirmation with Gran Telescopio Canarias of the Lyman Alpha emission from this pair of galaxies at a confirmed spectroscopic redshifts of z=5.07. Furthermore, one of the sources is interacting/merging with another close companion that looks distorted. Based on the
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  • Figure Caption: Teff and log gc estimates for the Galactic (red circles) and LMC (gray triangles) O-type dwarfs as a function of SpT; corresponding linear fits are overplotted with red and black dashed lines.  The figures show the scatter found in effecti
    We are now in an era of large spectroscopic surveys of OB-type stars. Quantitative spectroscopic analysis of these modern datasets is enabling us to review the physical properties of blue massive stars with robust samples, not only revisiting mean properties and general trends, but also incorporating information about the effects of second-order parameters. We investigate the spectral type -- effective temperature (SpT - Teff) calibration for O-type dwarfs, and its claimed dependence on metallicity, using statistically-meaningful samples of stars extracted from the IACOB and VFTS surveys. We
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  • Figure caption: Scenario for the magnetospheric origin of the gamma-rays: A maximally rotating black hole with event horizon rg (black sphere) accretes plasma from the center of the galaxy IC 310. In the apple-shaped ergosphere (blue) extending to 2rg in
    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20%
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  • Figure caption: Data of LMC extreme stars are shown as solid, grey circles in the Spitzer color-magnitude diagram ([3.6]-[8.0] vs. [8.0]). The position of the models during the AGB evolution are also shown (where different colors correspond to different s
    For the first time we use self-consistent evolutionary models of low-and intermediate-mass stars (1-8 solar masses) coupled with theoretical dust formation models to follow the evolution of these stars during the Asymptotic Giant Branch (AGB) in the Spitzer Space Telescope two-color and color-magnitude diagrams. These models are the first able to identify the main regions in the Spitzer diagrams occupied by AGB stars in the Large Magellanic Cloud (LMC). The main diagonal sequences traced by LMC extreme stars in the two-color and color-magnitude Spitzer diagrams are nicely fit by carbon stars
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