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.

  • HST image of the Butterfly nebula obtained by the authors on 1997. Red is Halpha+[NII], green is [OIII].
    The Butterfly Nebula (Minkowski 2-9) is an outstanding example of a highly collimated outflow from an evolved star. The formation of these extreme nebular geometries -i.e. how the (quasi)spherical symmetry that characterizes all the evolution of a solar-like star is broken when its envelope is ejected-  is one of the most debated and controversial topics in the study of the late stages of stellar evolution. Minkowski 2-9 gives us clear hints of what it might going on. This hourglass-shaped nebula is extraordinary in several aspects, but its  outstanding characteristic is undoubtedly its
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  • Ratio between total infrared and NUV luminosities against total  infrared luminosity for star-forming GALEX-LAEs. Right vertical axis  (dust attenuation) was built by using the calibration of  Buat et al. (2005). Yellow dots are data of nearby galaxies ta
    One remaining open question regarding the physical properties of  Lyaemitters (LAEs) is their dust content and its evolution  with redshift. The variety of results is large and with those reported  by now is difficult to establish clear relations between dust, other  fundamental parameters of galaxies (star-formation rate, metallicity  or age) and redshift. In this Letter, we report Herschel  PACS-100mm, PACS-160mm and Spitzer MIPS-24mm  detections of a sample of spectroscopically GALEX-selected LAEs at  z~0.3 and~1.0. Five out of ten and one out of two LAEs are detected in, at least, one
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  • 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
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  • 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
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  • 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
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  • 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
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