J/A+A/620/A165 Fornax Deep Survey with VST. IV. dwarf galaxies (Venhola+, 2018)
The Fornax Deep Survey (FDS) with the VST.
IV. A size and magnitude limited catalog of dwarf galaxies in the area of the
Fornax cluster.
Venhola A., Peletier R., Laurikainen E., Salo H., Iodice E., Mieske S.,
Hilker M., Wittmann C., Lisker T., Paolillo M., Cantiello M., Janz J.,
Spavone M., D'Abrusco R., van de Ven G., Napolitano N., Verdoes Kleijn G.,
Maddox N., Capaccioli M., Grado A., Valentijn E., Falcon-Barroso J.,
Limatola L.
<Astron. Astrophys. 620, A165 (2018)>
=2018A&A...620A.165V 2018A&A...620A.165V (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Morphology
Keywords: galaxies: clusters: individual: Fornax - galaxies: dwarf -
galaxy: photometry - galaxies: structure
Abstract:
The Fornax Deep Survey (FDS), an imaging survey in the u', g',
r', and i'-bands, has a supreme resolution and image depth
compared to the previous spatially complete Fornax Cluster Catalog
(FCC). Our new data allows us to study the galaxies down to r'- band
magnitude mr~=21mag (Mr'~=-10.5mag), which opens a new parameter
regime to investigate the evolution of dwarf galaxies in the cluster
environment. After the Virgo cluster, Fornax is the second nearest
galaxy cluster to us, and with its different mass and evolutionary
state, it provides a valuable comparison that makes it possible to
understand the various evolutionary effects on galaxies and galaxy
clusters. These data provide an important legacy dataset to study the
Fornax cluster.
We aim to present the Fornax Deep Survey (FDS) dwarf galaxy catalog,
focusing on explaining the data reduction and calibrations, assessing
the quality of the data, and describing the methods used for defining
the cluster memberships and first order morphological classifications
for the catalog objects. We also describe the main scientific
questions that will be addressed based on the catalog. This catalog
will also be invaluable for future follow-up studies of the Fornax
cluster dwarf galaxies.
As a first step we used the SExtractor fine-tuned for dwarf galaxy
detection, to find galaxies from the FDS data, covering a 26deg2 area
of the main cluster up to its virial radius, and the area around the
Fornax A substructure. We made 2D-decompositions of the identified
galaxies using GALFIT, measure the aperture colors, and the basic
morphological parameters like concentration and residual flux
fraction. We used color-magnitude, luminosity-radius and
luminosity-concentration relations to separate the cluster galaxies
from the background galaxies. We then divided the cluster galaxies
into early- and late-type galaxies according to their morphology and
gave first order morphological classifications using a combination of
visual and parametric classifications.
Our final catalog includes 14,095 galaxies. We classify 590 galaxies
as being likely Fornax cluster galaxies, of which 564 are dwarfs
(Mr'>-18.5mag) consisting our Fornax dwarf catalog. Of the cluster
dwarfs we classify 470 as early-types, and 94 as late-type galaxies.
Our final catalog reaches its 50% completeness limit at magnitude
Mr'=-10.5mag and surface brightness <µe,r'=26mag/arcsec2, which
is approximately three magnitudes deeper than the FCC. Based on
previous works and comparison with a spectroscopically confirmed
subsample, we estimate that our final Fornax dwarf galaxy catalog has
≲10% contamination from the background objects.
Description:
The Fornax Deep Survey is a collaboration of the two guaranteed
observing time surveys Focus (PI: R. Peletier) and VEGAS (PI: E.
Iodice, see also Capaccioli et al. 2015, Cat. J/A+A/581/A10) that
covers the area of the Fornax cluster and Fornax A subgroup with deep
multiband imaging
The observations of the FDS were performed between November 2013 and
November 2017.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
dwarf.dat 340 564 Fornax dwarf galaxies catalog
dwarfbck.dat 340 13505 Background galaxies catalog
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See also:
J/A+A/581/A10 : VEGAS: A VST Early-type GAlaxy Survey (Capaccioli+, 2015)
J/A+A/608/A142 : Fornax Deep Survey with VST III. LSB galaxies (Venhola+, 2017)
Byte-by-byte Description of file: dwarf.dat dwarfbck.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Target Name of the object (FDSNN_DWARFNNNa)
17- 23 F7.4 deg RAdeg Right Ascension in degrees (ICRS)
25- 32 F8.4 deg DEdeg Declination in degrees (ICRS)
34- 43 F10.6 deg PA [] Major Axis position angle
45- 53 F9.6 deg e_PA Uncertainty of position angle
55- 62 F8.6 --- arat Axis ratio from the r'-band GALFIT model
64- 71 F8.6 --- e_arat Uncertainty of axis ratio
73- 79 F7.4 mag rmag r'-band total apparent magnitude from Sersic fit
81- 88 F8.6 mag e_rmag Uncertainty of r'-band total magnitude
90- 96 F7.4 mag gmag g'-band total apparent magnitude from Sersic fit
98-105 F8.6 mag e_gmag Uncertainty of g'-band total magnitude
107-115 F9.4 mag rnuc ?=-1 r'-band apparent magnitude of nucleus
117-125 F9.4 mag gnuc ?=-1 g'-band apparent magnitude of nucleus
127-135 F9.6 arcsec reff Effective radius from the r'-band GALFIT model
137-145 F9.6 arcsec e_reff Uncertainty of effective radius in arcsec
147-153 F7.4 --- n Sersic index from the r'-band GALFIT model
155-162 F8.6 --- e_n Uncertainty of Sersic index
164-171 F8.4 mag umag1 ?=-1 u'-band apparent aperture magnitude
within reff
173-182 F10.6 mag e_umag1 ?=-1 Uncertainty of u'-band apparent aperture
magnitude within reff
184-190 F7.4 mag gmag1 g'-band apparent aperture magnitude within reff
192-199 F8.6 mag e_gmag1 Uncertainty of g'-band apparent aperture
magnitude within reff
201-207 F7.4 mag rmag1 r'-band apparent aperture magnitude within reff
209-216 F8.6 mag e_rmag1 Uncertainty of r'-band apparent aperture
magnitude within reff
218-224 F7.4 mag imag1 i'-band apparent aperture magnitude within reff
226-233 F8.6 mag e_imag1 Uncertainty of i'-band apparent aperture
magnitude within reff
235-243 F9.6 --- C Concentration parameter in r'-band
(see Section 7.5)
245-253 F9.6 --- RFF Residual Flux Fraction in r'-band
(see Section 7.4)
255-259 A5 --- Class Morphological classification (1)
261-340 A80 --- Ref Cross-matched names within 8 arcsec (2)
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Note (1): Morphological classification as follows:
e = smooth early-type
e* = smooth early-type, object has a nucleus
e(s) = early-types with structure
e(s)* = early-types with structure, object has a nucleus
l = late-type
l* = late-type, object has a nucleus
back = background
Note (2): Cross-matched names within 8 arcsec from SIMBAD,
Ferguson (1989AJ.....98..367F 1989AJ.....98..367F, Cat. VII/180),
Eigenthaler et al. (2018ApJ...855..142E 2018ApJ...855..142E), and
Mieske et al. (2007, Cat. J/A+A/463/503).
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Acknowledgements:
Aku Venhola, Aku.Venhola(at)student.oulu.fi
References:
Iodice et al., Paper I 2016ApJ...820...42I 2016ApJ...820...42I
Iodice et al., Paper II 2017ApJ...839...21I 2017ApJ...839...21I
Venhola et al., Paper III 2017A&A...608A.142V 2017A&A...608A.142V, Cat. J/A+A/608/A142
(End) Patricia Vannier [CDS] 04-Oct-2018