J/ApJ/765/28 CFHTLS galaxies with faint tidal features (Atkinson+, 2013)
Faint tidal features in galaxies within the Canada-France-Hawaii Telescope
Legacy Survey wide fields.
Atkinson A.M., Abraham R.G., Ferguson A.M.N.
<Astrophys. J., 765, 28 (2013)>
=2013ApJ...765...28A 2013ApJ...765...28A
ADC_Keywords: Galaxies, photometry ; Photometry, ugriz ; Surveys ; Redshifts
Keywords: astronomical databases: miscellaneous; catalogs; galaxies: general;
galaxies: interactions; galaxies: peculiar; galaxies: statistics
Abstract:
We present an analysis of the detectability of faint tidal features in
galaxies from the wide-field component of the Canada-France-Hawaii
Telescope Legacy Survey. Our sample consists of 1781 luminous
(Mr'←19.3mag) galaxies in the magnitude range 15.5mag<r'<17mag and
in the redshift range 0.04<z<0.2. Although we have classified tidal
features according to their morphology (e.g., streams, shells, and
tails), we do not attempt to interpret them in terms of their physical
origin (e.g., major versus minor merger debris). Instead, we provide a
catalog that is intended to provide raw material for future
investigations which will probe the nature of low surface brightness
substructure around galaxies. We find that around 12% of the galaxies
in our sample show clear tidal features at the highest confidence
level. This fraction rises to about 18% if we include systems with
convincing, albeit weaker tidal features, and to 26% if we include
systems with more marginal features that may or may not be tidal in
origin. These proportions are a strong function of rest-frame color
and of stellar mass. Linear features, shells, and fans are much more
likely to occur in massive galaxies with stellar masses
>1010.5M☉, and red galaxies are twice as likely to show tidal
features than are blue galaxies.
Description:
The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) is the
product of 450 nights of observations on CFHT from 2003 to 2009 using
the MegaCam. In this paper, we focus solely on the intermediate-depth
data from the wide component of the survey (hereafter referred to as
CFHTLS-W). This survey covers approximately 170deg2 of the sky in
four separate patches ranging in size from 25 to 72deg2.
The CFHTLS-W survey is based on data obtained through five filters
(u*, g', r', i', z') with the wide survey total exposure time being
approximately one hour per filter per field. The four wide fields were
centered at the following J2000 coordinates:
RA=02:18:00, DE=-07:00:00 (W1); RA=08:54:00, DE=-04:15:00 (W2);
RA=14:17:54, DE=+54:30:31 (W3); and RA=22:13:18, DE+01:19:00 (W4).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 63 1780 Master data table of selected galaxies
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See also:
B/cfht : Log of CFHT Exposures (CADC, 1979-)
II/317 : The CFHTLS Survey (T0007 release) (Hudelot+ 2012)
J/ApJ/736/24 : VI photometry of sources in the halo of NGC253 (Bailin+, 2011)
J/ApJS/186/427 : Detailed morphology of SDSS galaxies (Nair+, 2010)
J/AJ/130/2647 : Tidal features of 126 nearby red galaxies (van Dokkum+, 2005)
J/ApJ/588/218 : i*g* photometry of SDSS EDR galaxies (Abraham+, 2003)
J/ApJS/107/1 : Morphologies of distant galaxies II (Abraham+ 1996)
J/MNRAS/274/1107 : Morphological classifications of APM galaxies (Naim+ 1995)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- CFHTLS Identifier (W{1-4}-NNN)
8 I1 --- Conf [0/4]? Confidence tidal class, 4=certain (1)
10- 14 A5 --- Feat Feature classification (2)
16- 25 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
27- 36 F10.6 deg DEdeg Declination in decimal degrees (J2000)
38- 42 F5.3 --- zph [0.04/0.2] Photometric redshift estimate
44- 49 F6.2 --- r'Mag [-25/-19.3] Absolute rest-frame r' band magnitude
51- 55 F5.2 [Msun] M* [9/12] Log of the stellar mass
57- 61 F5.3 mag g'-r' Rest-frame (g'-r') color index
63 A1 --- R/B Blue cloud (B) or red sequence (R) flag
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Note (1): Confidence class (see text for details):
4 = certain detection of a tidal feature;
3 = probable detection of a tidal feature (over 75% certain);
2 = possible detection of a tidal feature (around 50% certain);
1 = hint of a potential tidal feature. Very uncertain;
0 = none.
Note (2): Feature classification as follows (thumbnail of Fig.6):
H = shell surrounding the galaxy (a)
S = stream (b)
M = miscellaneous/diffuse structure (c)
A = one arm (d)
L = linear feature (e)
F = fans of diffuse light (f)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 29-Oct-2014