J/A+A/570/A106      VIPERS. Searching for cosmic voids       (Micheletti+, 2014)
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The VIMOS Public Extragalactic Redshift Survey. Searching for cosmic voids.
    Micheletti D., Hawken A., Iovino A.J., Granett B., Bolzonella M., Cappi A.,
    Abbas U., Adami C., Arnouts S., Bel J., Bottini D., Branchini E., Coupon J.,
    Cucciati O., Davidzon I., De Lucia G., de la Torre S., Fritz A.,
    Franzetti P., Fumana M., Garilli B., Guzzo L., Ilbert O., Krywult J.,
    Le Brun V., Le Fevre O., Maccagni D., Malek K., Marulli F., McCracken H.J.,
    Polletta M., Pollo A., Schimd C., Scodeggio M., Tasca L.A.M., Tojeiro R.,
    Vergani D., Zanichelli A., Burden A., Di Porto C., Marchetti A.,
    Marinoni C., Mellier Y., Moutard T., Moscardini L., Nichol R.C.,
    Peacock J.A., Percival W.J., Zamorani G.
   <Astron. Astrophys. 570, A106 (2014)>
   =2014A&A...570A.106M
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ADC_Keywords: Galaxy catalogs - Redshifts
Keywords: galaxies: general - cosmology: observations -
          large-scale structure of universe

Abstract:
    Characterisation of cosmic voids gives unique information about the
    large-scale distribution of galaxies, their evolution, and
    the cosmological model.

    We identify and characterise cosmic voids in the VIMOS Public
    Extragalactic Redshift Survey (VIPERS) at redshift 0.55 <z< 0.9.

    A new void search method is developed based upon the identification of
    empty spheres that fit between galaxies. The method can be used to
    characterise the cosmic voids despite the presence of complex survey
    boundaries and internal gaps. We investigate the impact of systematic
    observational effects and validate the method against mock catalogues.
    We measure the void size distribution and the void-galaxy correlation
    function.

Description:
    File voidtable.dat lists the catalogue of maximal spheres detected in
    VIPERS samples, divided in groups corresponding to individual voids.
    The spheres have been associated with larger under-densities using the
    percolation method, thus we associate each sphere with a void index
    indicating larger empty regions.

    The identification number (ID) of each maximal sphere is composed of:
    the VIPERS field to which the maximal sphere belongs (W1 or W4); a
    void index indicating to which void the sphere belongs (VVVV); a
    sphere index SSSS indicating the size rank of the sphere relative to
    other maximal spheres within the same void. The complete ID has the
    form Wx.VVVV.SSSS.

    For each maximal sphere of our catalogue we provide: its ID; its
    comoving radius in Mpc ({Omega}_m_=0.27, {Omega}_{Lambda}_=0.73 and
    H_0_=70km/s/Mpc); the right ascension, declination, and redshift of
    the sphere's centre; a p-value giving the detection significance
    with respect to a Poisson distribution. Voids are sorted in ascending
    redshift order, with the redshift associated with each void being that
    of its largest sphere. Spheres inside each void are sorted in
    decreasing radius order.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
void.dat       50      388   List of maximal spheres detected in VIPERS samples
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See also:
   http://vipers.inaf.it : VIPERS database

Byte-by-byte Description of file: void.dat
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   Bytes Format Units   Label     Explanations
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   1- 11  A11   ---     ID        ID of maximal sphere (Wx.VVVV.SSS) (1)
  13- 17  F5.2  Mpc     r         [14/32] Maximal sphere radius
  19- 26  F8.4  deg     RAdeg     Right ascension (J2000.0)
  28- 34  F7.4  deg     DEdeg     Declination (J2000.0)
  36- 41  F6.4  ---     z         [0.54/0.91] Redshift
  43- 50  E8.3  ---     p-value   Detection significance value
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Note (1): The identification number (ID) of each maximal sphere is composed of:
    the VIPERS field to which the maximal sphere belongs (W1 or W4); a
    void index indicating to which void the sphere belongs (VVVV); a
    sphere index SSS indicating the size rank of the sphere relative to
    other maximal spheres within the same void. The complete ID has the
    form Wx.VVVV.SSS.
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Acknowledgements:
     Angela Iovino, angela.iovino(at)brera.inaf.it

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(End)                                        Patricia Vannier [CDS]  08-Sep-2014