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.

  • Image of Fleming 1 obtained with the VLT.
    Stars are generally spherical, yet their gaseous envelopes oftenappear non-spherical when ejected near the end of their lives. Thisquirk is most notable during the planetary nebula phase when theseenvelopes become ionized. The most popular explanation is that theasymmetry, and in particular the formation of highly collimatedstructures such as the precessing jets observed in a number ofnebulae, is caused by interactions in a binary system. The study ofthe prototypical planetary nebula Fleming 1 with the VLT telescopedemonstrates for the first time that the hypothesis iscorrect. Indeed, it is
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  • Doppler shifts resulting from a two-components Gaussian fit of the He I 10830 triplet intensity profiles. The velocity is saturated at ± 6 km/s. Vertical lines delimit the prominence feet.
    We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the \ion{He}{1}~1083.0~nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent {\it hedgerow} prominence. The data show opposite Doppler shifts, $\pm$~6\kms, at the edges of the prominence feet. We argue
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  • Average star formation rates, (SFR), derived from averaged far-infrared luminosities of 1<z<3 AGNs, as a function of suLX.
    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlation between the mass of the black hole and the mass of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming
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  • Logarithm of the optical depth of the discontonuity between the magnetic and the non magnetic atmosphere (i.e. the base of the canopy). Large positive numbers mean deep in the atmosphere while large negative numbers are higher layers of the atmosphere. Th
    We analyze the spectral asymmetry of Stokes V (circularly polarized) profiles of an individual network patch in the quiet Sun observed by Sunrise/IMaX. At a spatial resolution of 0".15-0".18, the network elements contain substructure which is revealed by the spatial distribution of Stokes V asymmetries. The area asymmetry between the red and blue lobes of Stokes V increases from nearly zero at the core of the structure to values close to unity at its edges (single-lobed profiles). Such a distribution of the area asymmetry is consistent with magnetic fields expanding with height, i.e., an
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  • Image of supercluster Cygnus OB2. Source: IPHAS / Spitzer / Nick Wright (CfA).
    In order to fully understand the gravitational collapse of molecular clouds, the star formation process, and the evolution of circumstellar disks, these phenomena must be studied in different Galactic environments with a range of stellar contents and positions in the Galaxy. The young massive association Cygnus OB2, in the Cygnus-X region, is a unique target to study how star formation and the evolution of circumstellar disks proceed in the presence of a large number of massive stars. We present a catalog obtained with recent optical observations in the r, i, z filters with OSIRIS, mounted
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  • K-band nuclear spectra of LLAGN extracted from our SINFONI data in r = 0.3” apertures. The prominent emission lines are from H2 (marked at the top of the figure), the strongest being 1-0 S(1) at 2.12 μm. Several stellar absorption features (like the 12CO
    We present observations of the molecular gas in the nuclear environment of three prototypical low luminosity AGN (LLAGN), based on VLT/SINFONI AO-assisted integral-field spectroscopy of H 2 1-0 S(1) emission at angular resolutions of ~0.17”. On scales of 50-150 pc the spatial distribution and kinematics of the molecular gas are consistent with a rotating thin disk, where the ratio of rotation ( V) to dispersion (σ) exceeds unity. However, in the central 50 pc, the observations reveal a geometrically and optically thick structure of molecular gas ( V / σ < 1 and N H > 10 23 cm -2) that is
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