J/A+A/659/A92 HydraI galaxy cluster dwarf catalog (HCDC) (La Marca+, 2022)
Galaxy populations in the Hydra I cluster from the VEGAS survey.
I. Optical properties of a large sample of dwarf galaxies.
La Marca A., Peletier R., Iodice E., Paolillo M., Choque Challapa N.,
Venhola A., Forbes D.A., Cantiello M., Hilker M., Rejkuba M., Arnaboldi M.,
Spavone M., D'Ago G., Raj M.A., Ragusa R., Mirabile M., Rampazzo R.,
Spiniello C., Mieske S., Schipani P.
<Astron. Astrophys. 659, A92 (2022)>
=2022A&A...659A..92L 2022A&A...659A..92L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Photometry ; Optical ; Morphology
Keywords: galaxies: dwarf - galaxies: evolution -
galaxy cluster: Hydra I (Abell 1060) - galaxies: photometry
Abstract:
Due to their relatively low stellar mass content and diffuse nature,
the evolution of dwarf galaxies can be strongly affected by their
environment. Analyzing the properties of the dwarf galaxies over a
wide range of luminosities, sizes, morphological types, and
environments, we can obtain insights about their evolution. At
∼50Mpc, the Hydra I cluster of galaxies is among the closest
cluster in the z≃0 Universe, and an ideal environment to study
dwarf galaxy properties in a cluster environment.
We exploit deep imaging data of the Hydra I cluster to construct a new
photometric catalog of dwarf galaxies in the cluster core, which is
then used to derive properties of the Hydra I cluster dwarf galaxy
population as well as to compare it with other clusters. Moreover, we
investigate the dependency of dwarf galaxy properties on their
surrounding environment.
The new wide-field g- and r-band images of the Hydra I cluster
obtained with the OmegaCAM camera on the VLT Survey Telescope (VST) in
the context of the VST Early-type GAlaxy Survey (VEGAS) were used to
study the dwarf galaxy population in the Hydra I cluster core down to
r-band magnitude Mr=-11.5mag. We used an automatic detection tool to
identify dwarf galaxies from a ∼1deg2 field centered on the Hydra I
core, covering almost half of the cluster virial radius. The
photometric pipeline was used to estimate the principal photometric
parameters for all targets. Scaling relations and visual inspection
were used to assess the cluster membership and construct a new dwarf
galaxy catalog. Finally, based on the new catalog, we studied the
structural (Sersic index n, effective radius Re, and axis ratio) and
photometric (colors and surface brightness) properties of the dwarf
galaxies, also investigating how they vary as a function of
clustercentric distance.
The new Hydra I dwarf catalog contains 317 galaxies with a luminosity
between -18.5<Mr←11.5mag, a semi-major axis larger than ∼200pc
(a=0.84"), of which 202 are new detections, and previously unknown
dwarf galaxies in the Hydra I central region. We estimate that our
detection efficiency reaches 50% at the limiting magnitude
Mr=-11.5mag, and at the mean effective surface brightness
<µe,r=26.5mag/arcsec2. We present the standard scaling
relations for dwarf galaxies, which are color-magnitude,
size-luminosity, and Sersic n-magnitude relations, and compare them
with other nearby clusters. We find that there are no observational
differences for dwarfs scaling relations in clusters of different
sizes. We study the spatial distribution of galaxies, finding evidence
for the presence of substructures within half the virial radius. We
also find that mid- and high-luminosity dwarfs (Mr←14.5mag) become,
on average, redder toward the cluster center, and that they have a
mild increase in Re with increasing clustercentric distance, similar
to what is observed for the Fornax cluster. No clear clustercentric
trends are reported for surface brightness and Sersic index.
Considering galaxies in the same magnitude bins, we find that for high
and mid-luminosity dwarfs (Mr←13.5mag), the g-r color is redder for
the brighter surface brightness and higher Sersic n index objects.
This finding is consistent with the effects of harassment and/or
partial gas stripping.
Description:
We derive a new catalog of dwarf galaxies in the central region of the
Hydra I galaxy cluster. It contains 317 galaxies with a luminosity
between -18.5<Mr←11.5mag and a semi-major axis larger than ∼200pc
(a=0.84"), of which 202 are new detections, and previously unknown
dwarfs. For each galaxies we performed a Sersic function fit, and we
derived the main photometric parameters in the g and r bands. All
magnitudes are corrected for Galactic extinction (Schlafly &
Finkbeiner, 2011ApJ...737..103S 2011ApJ...737..103S).
Objects:
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RA (2000) DE Designation(s)
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10 36 36.0 -27 31 04 Hydra I galaxy cluster = Abell 1060
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hcdc.dat 113 317 Catalog of Hydra I cluster members
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See also:
J/ApJS/85/249 : Surface Photometry of Hydra I Galaxies. I. (Hamabe 1993)
J/A+A/486/697 : Hydra I Cluster Catalogue (HCC) (Misgeld+, 2008)
J/A+A/531/A4 : Ultra compact dwarfs and globulars in Hya I (Misgeld+, 2011)
J/ApJ/818/39 : Hydra I wide-field imaging & spectroscopy obs. (Hargis+, 2016)
Byte-by-byte Description of file: hcdc.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Object Id in the HCDC (HCDC_NNN)
10- 18 F9.5 deg RAdeg Right Ascension (J2000)
20- 29 F10.6 deg DEdeg Declination (J2000)
31- 37 F7.3 mag rMAG Absolute magnitude in the r band
39- 43 F5.3 mag e_rMAG Error on the absolute magnitude
in the r band
45- 49 F5.2 arcsec re Effective radius
51- 54 F4.2 arcsec e_re Error on the effective radius
56- 60 F5.2 mag/arcsec+2 muer Mean effective surface brightness
in the r band
62- 66 F5.3 --- b/a Axis ratio
68- 72 F5.3 --- e_b/a Error on the axis ratio
74- 78 F5.1 deg theta Position angle
80- 82 F3.1 deg e_theta Error on the position angle
84- 87 F4.2 --- n Sersic index
89- 92 F4.2 --- e_n Error on the Sersic index
94- 98 F5.2 mag rmag r-band magnitude within 1 effective
radius aperture
100-103 F4.2 mag e_rmag Error on the r-band magnitude
within 1 effective radius aperture
105-108 F4.2 mag g-r g-r Color index within 1 effective
radius aperture
110-113 F4.2 mag e_g-r Error on the g-r Color index
within 1 effective radius aperture
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Acknowledgements:
Antonio La Marca, antoniolamarca46(at)gmail.com
(End) Patricia Vannier [CDS] 13-Dec-2021