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.

  • Caption of the figure: Herschel PACS 70, 100, and 160 μm images (top) and SPIRE 250, 350, and 500 μm maps (bottom). North is up and East is to the left. The 11 kpc diameter ring is resolved up to 250 μm.
    We report far-infrared (FIR) imaging of the Seyfert 2 galaxy NGC 3081 in the range 70- 500 μm, obtained with an unprecedented angular resolution, using the Herschel Space Observatory instruments PACS and SPIRE. The 11 kpc (∼70′′) diameter star-forming ring of the galaxy appears resolved up to 250 μm. We extracted infrared (1.6-500 μm) nuclear fluxes, that is active nucleus-dominated fluxes, and fitted them with clumpy torus models, which successfully reproduce the FIR emission with small torus sizes. Adding the FIR data to the near- and mid-infrared spectral energy distribution (SED) results
    Advertised on
  • Variation of the star formation history with respect to dynamical mass (each panel representing a mass bin as given in Table 2). Sketchy (theoretical) SFHs, plotted as grey Gaussian curves, are superimposed over the detailed (empirical) SFH histograms (bl
    The abundance ratios between key elements such as iron and α-process elements carry a wealth of information on the star formation history (SFH) of galaxies. So far, simple chemical evolution models have linked [α/Fe ] with the SFH time-scale, correlating large abundance ratios with short-lived SFH. The incorporation of full spectral fitting to the analysis of stellar populations allows for a more quantitative constraint between [α/Fe ] and the SFH. In this letter, we provide, for the first time, an empirical correlation between [α/Fe ] (measured from spectral indices) and the SFH (determined
    Advertised on
  • The authors show that the surface structure of the primitive asteroid (65) Cybele is covered by a layer of fine anhydrous silicate grains, mixed with smaller quantities of water ice and complex organics, similar to the nonequilibrium phases coexisting on comet surfaces. The co-existence of water ice and anhydrous silicates on the surface indicates that silicate hydration did not occurred, suggesting that the surface temperatures remained low. The team of researchers is the same that published last April two papers in Nature showing the first evidence of water ice and organic molecules on an
    Advertised on
  • Central starbursts in galaxies are an extreme example of ongoing galaxy evolution. The outer parts of galaxies contain a fossil record ofgalaxy formation and evolution processes in the more distant past. The characterization of resolved stellar populations allows one a detailed study of these topics.In our study we used the Hubble Space Telescope to observe the outerparts (up to 8 scale radii) of NGC 1569 and NGC 4449, two of the closest and strongest dwarf starburst galaxies in the local universe, to characterize their stellar density and populations, and obtain new insights into the
    Advertised on
  • Left: Chromospheric image of a chromospheric active region at -161 mÅ from the core of the Ca II 8542 line, where fibrils are covering almost the entire field-of-view. Right: Circular polarization image (Stokes V) at the same wavelength, quantifies the st
    Fibrils are thin elongated features visible in the solar chromosphere in and around magnetized regions. Because of their visual appearance they have been traditionally considered a tracer of the magnetic field lines. To our best knowledge, this common conception has never been actually put to test, probably because a proper empirical determination of the chromospheric magnetic field is very challenging, requiring high-resolution spectro-polarimetry in chromospheric lines. In this work we challenge that notion for the first time by comparing their orientation to that of the magnetic field
    Advertised on
  • NGC 4013 is a nearby Sb edge-on galaxy known for its “prodigious” HI warp and its “giant” tidal stream. Previous work on this unusual object shows that it cannot be fitted satisfactorily by a canonical thin+thick disk structure. We have produced a new decomposition of NGC 4013, considering three stellar flattened components (thin+thick disk plus an extra and more extended component) and one gaseous disk. All four components are considered to be gravitationally coupled and isothermal. To do so, we have used the 3.6µm images from the Spitzer Survey of Stellar Structure in Galaxies (S4G).We
    Advertised on