Galaxy Zoo Talk

Merging galaxies in the distant Universe through a gravitational magnifying glass

  • c_cld by c_cld

    The galaxyzoo logo published by ESO 😃

    H-ATLAS J142935.3-002836 H-ATLAS J142935.3-002836

    Credit:

    ESO/NASA/ESA/W. M. Keck Observatory

    In this picture you can see the foreground galaxy that is doing the
    lensing, which resembles how our home galaxy, the Milky Way, would
    appear if seen edge-on. But around this galaxy there is an almost
    complete ring — the smeared out image of a star-forming galaxy merger
    far beyond.

    Colours & filters Band Telescope

    blue Infrared f110w Hubble Space Telescope WFC3

    green Infrared H Keck

    red Infrared K Keck

    Posted

  • c_cld by c_cld

    H-ATLAS J142935.3-002836 in SDSS:

    1237648720710206422

    1237648720710206422 1237648720710206422

    SDSS J142935.23-002835.6 -- sub-millimetric source / z(spectroscopic) 1.026

    Posted

  • ElisabethB by ElisabethB moderator

    Oh wow ! Just amazing ! 😄

    Posted

  • c_cld by c_cld

    arXiv:1406.4859 Hugo Messias, Simon Dye, Neil Nagar, et all

    Herschel-ATLAS and ALMA: HATLAS J142935.3-002836, a lensed major merger at redshift 1.027

    (Submitted on 18 Jun 2014)

    [Abridged]

    Aims: This work focuses on one lensed system, HATLAS J142935.3-002836 (H1429-0028), selected in the Herschel-ATLAS field. Gathering a rich, multi-wavelength dataset, we aim to confirm the lensing hypothesis and model the background source's morphology and dynamics, as well as to provide a full physical characterisation.

    Methods: Multi-wavelength high-resolution data is utilised to assess the nature of the system. A lensing-analysis algorithm which simultaneously fits different wavebands is adopted to characterise the lens. The background galaxy dynamical information is studied by reconstructing the 3-D source-plane of the ALMA CO(J:4-3) transition. Near-IR imaging from HST and Keck-AO allows to constrain rest-frame optical photometry independently for the foreground and background systems. Physical parameters (such as stellar and dust masses) are estimated via modelling of the spectral energy distribution taking into account source blending, foreground obscuration, and differential magnification.

    Results: The system comprises a foreground edge-on disk galaxy (at z_sp=0.218) with an almost complete Einstein ring around it. The background source (at z_sp=1.027) is magnified by a factor of ~8-10 depending on wavelength. It is comprised of two components and a tens of kpc long tidal tail resembling the Antennae merger. As a whole, the system is a massive stellar system (1.32[-0.41,+0.63] x1E11 Mo) forming stars at a rate of 394+-90 Mo/yr, and has a significant gas reservoir M_ISM = 4.6+-1.7 x1E10 Mo. Its depletion time due to star formation alone is thus expected to be tau_SF=M_ISM/SFR=117+-51 Myr. The dynamical mass of one of the components is estimated to be 5.8+-1.7 x1E10 Mo, and, together with the photometric total mass estimate, it implies that H1429-0028 is a major merger system (1:2.8[-1.5,+1.8]).

    Posted