Access to Astronomical Catalogues

J/ApJ/710/1664      BV photometry in Leo IV and Leo V dSphs     (de Jong+, 2010)
The enigmatic pair of dwarf galaxies Leo IV and Leo V: coincidence or common
origin?
    de Jong J.T.A., Martin N.F., Rix H.-W., Smith K.W., Jin S., Maccio A.V.
   <Astrophys. J., 710, 1664-1671 (2010)>
   =2010ApJ...710.1664D
ADC_Keywords: Galaxies, photometry ; Photometry, UBV ; Galaxies, nearby

Keywords: galaxies: individual (Leo IV dSph, Leo V dSph) - Local Group


Abstract:
    We have obtained deep photometry in two 1°x1° fields covering
    the close pair of dwarf spheroidal galaxies Leo IV and Leo V and part
    of the area in between. From the distribution of likely red giant
    branch (RGB) and horizontal-branch (HB) stars in the data set, we find
    that both Leo IV and Leo V are significantly larger than indicated by
    previous measurements based on shallower data. With a half-light
    radius of rh=4.6'±0.8' (206±36pc) and rh=2.6'±0.6'
    (133±31pc), respectively, both systems are now well within the
    physical size bracket of typical dwarf spheroidal Milky Way
    satellites. Both are also found to be significantly elongated with an
    ellipticity of ε∼0.5, a characteristic shared by many of the
    fainter (MV>-8) Milky Way dwarf spheroidals. The large spatial
    extent of our survey allows us to search for extra-tidal features in
    the area between the two dwarf galaxies with unprecedented
    sensitivity. The spatial distribution of candidate RGB and HB stars in
    this region is found to be non-uniform at the ∼3σ level. We
    investigate different scenarios to explain the close proximity of Leo
    IV and Leo V, and the possible tidal bridge between them.

Description:
    Deep, wide-field photometry in the Johnson B and V filters was
    obtained for two 1°x1° fields, using the LAICA imager on the
    3.5m telescope at the Calar Alto observatory. Observations were
    carried out during the nights of 2009 February 24 and 25.
Objects:
    ----------------------------------------------------------------
       RA   (2000)   DE       Designation(s)
    ----------------------------------------------------------------
    11 32 58.6   -00 33 06    NAME LEO IV = NAME LEO IV DWARF GALAXY
    11 31 08.4   +02 12 57    NAME LEO V  = NAME LEO V
    ----------------------------------------------------------------

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        55    24738   Photometric data


See also:
   J/ApJS/191/352 : Abundances in stars of Milky Way dwarf satellites (Kirby+,
                    2010)
   J/ApJ/694/L144 : Spectroscopic study of Leo V dSph (Walker+, 2009)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ID        Chip identification number (1)
   6- 14  F9.5  deg     RAdeg     Right Ascension in decimal degrees (J2000)
  16- 23  F8.5  deg     DEdeg     Declination in decimal degrees (J2000)
  25- 30  F6.3  mag     Bmag      The Johnson B band magnitude
  32- 36  F5.3  mag     e_Bmag    The 1σ error in Bmag
  38- 43  F6.3  mag     Vmag      The Johnson V band magnitude
  45- 49  F5.3  mag     e_Vmag    The 1σ error in Vmag
  51- 55  F5.3  mag     E(B-V)    The E(B-V) color excess

Note (1): The first digit of the chip ID indicates the field, where a
     "0" stands for the Northern field containing Leo V and a 
     "1" for the Southern field containing Leo IV; 
     the integers following the underscore signify the exposure and the
     chip number, respectively, both running from 1 to 4.


History:
    From electronic version of the journal
(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    29-Mar-2012