J/A+A/590/A92 VCC 2062 CO(1-0) data cubes (Lisenfeld+, 2016)
Molecular gas and star formation in the tidal dwarf galaxy VCC 2062.
Lisenfeld U., Braine J., Duc P.A., Boquien M., Brinks E., Bournaud F.,
Lelli F., Charmandaris V.
<Astron. Astrophys. 590, A92 (2016)>
=2016A&A...590A..92L 2016A&A...590A..92L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Radio lines
Keywords: ISM: molecules - galaxies: interactions - galaxies: ISM -
galaxies: star formation - galaxies: dwarf
Abstract:
The physical mechanisms driving star formation (SF) in galaxies are
still not fully understood. Tidal dwarf galaxies (TDGs), made of gas
ejected during galaxy interactions, seem to be devoid of dark matter
and have a near-solar metallicity. The latter makes it possible to
study molecular gas and its link to SF using standard tracers (CO,
dust) in a peculiar environment. We present a detailed study of a
nearby TDG in the Virgo Cluster, VCC 2062, using new high-resolution
CO(1-0) data from the Plateau de Bure, deep optical imaging from the
Next Generation Virgo Cluster Survey (NGVS), and complementary
multiwavelength data. Until now, there was some doubt whether VCC 2062
was a true TDG, but the new deep optical images from the NGVS reveal a
stellar bridge between VCC 2062 and its parent galaxy, NGC 4694, which
is clear proof of its tidal origin. Several high-resolution tracers
(Hα, UV, 8um, and 24um) of the star formation rate (SFR) are
compared to the molecular gas distribution as traced by the CO(1-0).
Coupled with the SFR tracers, the NGVS data are used with the CIGALE
code to model the stellar populations throughout VCC 2062, yielding a
declining SFR in the recent past, consistent with the low Hα/UV
ratio, and a high burst strength. HI emission covers VCC 2062, whereas
the CO is concentrated near the HI maxima. The CO peaks correspond to
two very distinct regions: one with moderate SF to the NE and one with
only slightly weaker CO emission but with nearly no SF. Even where SF
is clearly present, the SFR is below the value expected from the
surface density of the molecular and the total gas as compared to
spiral galaxies and other TDGs. After discussing different possible
explanations, we conclude that the low surface brightness is a crucial
parameter to understand the low SFR.
Description:
The two fits files contain the data cube of CO(1-0) observed with
Plateau de Bure Interferometer. Both cubes were obtained with natural
weighting and with different taperings. The velocity resolution is
1.8km/s. More details about the data acquisition and reduction are in
the paper.
Objects:
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RA (2000) DE Designation(s)
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12 47 59.92 +10 58 14.9 VCC 2062 = LEDA 43211
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 115 2 List of fits datacubes
fits/* . 2 Individual data cubes
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz Number of slices
32- 38 F7.2 km/s bVRAD Lower value of VRAD interval
40- 45 F6.1 km/s BVRAD Upper value of VRAD interval
47- 53 F7.5 km/s dVRAD Velocity resolution
55- 58 I4 Kibyte size Size of FITS file
60- 69 A10 --- FileName Name of FITS file, in subdirectory fits
71-115 A45 --- Title Title of the FITS file
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Acknowledgements:
Ute Lisenfeld, ute(at)ugr.es
(End) Patricia Vannier [CDS] 01-Apr-2016