J/MNRAS/491/1901 Dwarf galaxies in the MATLAS low-density fields (Habas+, 2020)
Newly discovered dwarf galaxies in the MATLAS low-density fields.
Habas R., Marleau F.R., Duc P.-A., Durrell P.R., Paudel S., Poulain M.,
Sanchez-Janssen R., Sreejith S., Ramasawmy J., Stemock B., Leach C.,
Cuillandre J.-C., Gwyn S., Agnello A., Bilek M., Fensch J., Muller O.,
Peng E.W., van der Burg R.F.J.
<Mon. Not. R. Astron. Soc., 491, 1901-1919 (2020)>
=2020MNRAS.491.1901H 2020MNRAS.491.1901H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, optical ; Galaxies, photometry ; Photometry, SDSS
Keywords: galaxies: dwarf - galaxies: fundamental parameters -
galaxies: photometry - galaxies: structure
Abstract:
We present the photometric properties of 2210 newly identified dwarf
galaxy candidates in the Mass Assembly of early Type gaLAxies with
their fine Structures (MATLAS) fields. The MATLAS deep imaging survey
mapped ∼142deg2 of the sky around nearby isolated early type
galaxies using MegaCam on the Canada-France-Hawaii Telescope, reaching
surface brightnesses of ∼28.5-29 in the g band. The dwarf candidates
were identified through a direct visual inspection of the images and
by visually cleaning a sample selected using a partially automated
approach, and were morphologically classified at the time of
identification. Approximately 75 per cent of our candidates are dEs,
indicating that a large number of early type dwarfs also populate
low-density environments, and 23.2 per cent are nucleated. Distances
were determined for 13.5 per cent of our sample using pre-existing
zspec measurements and HI detections. We confirm the dwarf nature
for 99 per cent of this sub-sample based on a magnitude cut Mg=-18.
Additionally, most of these (∼90 per cent) have relative velocities
suggesting that they form a satellite population around nearby massive
galaxies rather than an isolated field sample. Assuming that the
candidates over the whole survey are satellites of the nearby
galaxies, we demonstrate that the MATLAS dwarfs follow the same
scaling relations as dwarfs in the Local Group as well as the Virgo
and Fornax clusters. We also find that the nucleated fraction
increases with Mg, and evidence of a morphology-density relation for
dwarfs around isolated massive galaxies.
Description:
Observations for the MATLAS project were obtained using MegaCam on the
3.6m CFHT between 2010 and 2015. The observing strategy, data
reduction, and image quality have already been described in detail in
Duc et al. (2015MNRAS.446..120D 2015MNRAS.446..120D, Cat. J/MNRAS/446/120), but key
details are presented below for completeness. Further details of the
MegaCam detector system and data processing can be found in the
introductory paper of the NGVS survey (Ferrarese et al.
2012ApJS..200....4F 2012ApJS..200....4F).
By the end of the observing program, MATLAS imaged 150 fields in the
g-band, which encompass 180 early type galaxies (ETGs) and 59 late
type galaxies (LTGs) from the ATLAS3D parent catalogue. Details of
the observations for each field can be found in Table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 33 389 Catalogue of ETGs with MegaCam observations
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See also:
J/MNRAS/446/120 : ATLAS3D project. XXIX (Duc+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Galaxy name
11 A1 --- Band [ugri] Observed band
13- 14 I2 --- Nexp Number of individual exposures for the given
filter
16- 20 I5 s IntTime Total integration time
22- 25 F4.2 arcsec FWHM Image quality (FWHM of the PSF)
27- 33 F7.2 --- bkg Background level (in ADUs)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 13-Feb-2023