J/ApJ/776/80 PAndAS view of Andromeda satellites. I. (Martin+, 2013)
The PAndAS view of the Andromeda satellite system.
I. A bayesian search for dwarf galaxies using spatial and color-magnitude
information.
Martin N.F., Ibata R.A., McConnachie A.W., Mackey A.D., Ferguson A.M.N.,
Irwin M.J., Lewis G.F., Fardal M.A.
<Astrophys. J., 776, 80 (2013)>
=2013ApJ...776...80M 2013ApJ...776...80M
ADC_Keywords: Galaxies, optical
Keywords: galaxies: dwarf; Local Group; methods: data analysis;
methods: statistical
Abstract:
We present a generic algorithm to search for dwarf galaxies in
photometric catalogs and apply it to the Pan-Andromeda Archaeological
Survey (PAndAS). The algorithm is developed in a Bayesian framework
and, contrary to most dwarf galaxy search codes, makes use of both the
spatial and color-magnitude information of sources in a probabilistic
approach. Accounting for the significant contamination from the Milky
Way foreground and from the structured stellar halo of the Andromeda
galaxy, we recover all known dwarf galaxies in the PAndAS footprint
with high significance, even for the least luminous ones. Some
Andromeda globular clusters are also recovered and, in one case,
discovered. We publish a list of the 143 most significant detections
yielded by the algorithm. The combined properties of the 39 most
significant isolated detections show hints that at least some of these
trace genuine dwarf galaxies, too faint to be individually detected.
Follow-up observations by the community are mandatory to establish
which are real members of the Andromeda satellite system. The search
technique presented here will be used in an upcoming contribution to
determine the PAndAS completeness limits for dwarf galaxies. Although
here tuned to the search of dwarf galaxies in the PAndAS data, the
algorithm can easily be adapted to the search for any localized
overdensity whose properties can be modeled reliably in the parameter
space of any catalog.
Description:
The PAndAS survey is a Large Programme of the Canada-France-Hawaii
Telescope (CFHT) conducted with the MegaPrime/MegaCam wide-field
camera (g and i bands) over the period 2008-2011 (McConnachie et al.
2009Natur.461...66M 2009Natur.461...66M; A. W. McConnachie et al., in preparation). It
builds on a pilot survey of the Andromeda surroundings observed with
the same instrument and set up from 2003 until 2008 (Ibata et al.
2007ApJ...671.1591I 2007ApJ...671.1591I; McConnachie et al. 2008ApJ...688.1009M 2008ApJ...688.1009M). In
total, it has a coverage of ∼390deg2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 182 143 List of significant detections returned by the
algorithm
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See also:
V/143 : Revised Bologna Catalog of M31 clusters, V.5 (Galleti+ 2012)
J/ApJ/768/172 : Kinematic analysis of red giant in M31 dSphs (Collins+, 2013)
J/ApJ/758/11 : Bayesian distances to M31 satellites (Conn+, 2012)
J/ApJ/756/79 : Opt. photometry in 3 Local Group dwarf galaxies (Sand+, 2012)
J/ApJ/752/45 : SPLASH: Stellar spectro. of M31 satellites (Tollerud+, 2012)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/AJ/133/715 : Dwarf galaxies of the Local Group (Whiting+, 2007)
J/A+A/416/917 : Revised Bologna Catalog of M31 GCs (Galleti+, 2004)
J/A+AS/127/409 : New nearby dwarf galaxy candidates list (Karachentseva+ 1998)
J/AJ/106/986 : CMD for And III (Armandroff+, 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- --- [Detection]
11- 13 I3 --- Seq [1/143] Detection number
15- 16 I2 h RAh Hour of right ascension (J2000)
18- 19 I2 min RAm Minute of right ascension (J2000)
21- 22 I2 s RAs Second of right ascension (J2000)
24 A1 --- DE- Sign of declination (J2000)
25- 26 I2 deg DEd Degree of declination (J2000)
28- 29 I2 arcmin DEm Arcminute of declination (J2000)
31- 32 I2 arcsec DEs Arcsecond of declination (J2000)
34- 38 F5.1 deg X0 [-9/11] Dwarf galaxy center along X (X0)
40- 44 F5.1 deg Y0 [-13/8.4] Dwarf galaxy center along Y (Y0)
46 A1 --- l_S Limit flag on S
47- 49 F3.1 --- S [3/8.5] Signal value
51- 53 F3.1 --- Sth [3/4.6] Detection threshold Sth
55-182 A128 --- Notes Remarks (nature; location when overlap with
known structures)
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History:
From electronic version of the journal
References:
Martin et al. Paper I. 2013ApJ...776...80M 2013ApJ...776...80M This catalog
Martin et al. Paper II. 2016ApJ...833..167M 2016ApJ...833..167M Cat. J/ApJ/833/167
(End) Emmanuelle Perret [CDS] 23-Mar-2015