J/ApJ/923/257 Ultra-diffuse galaxies with spectroscopic obs. (Kadowaki+, 2021)
On the properties of spectroscopically confirmed ultra-diffuse galaxies across
environments.
Kadowaki J., Zaritsky D., Donnerstein R.L., RS P., Karunakaran A.,
Spekkens K.
<Astrophys. J., 923, 257 (2021)>
=2021ApJ...923..257K 2021ApJ...923..257K
ADC_Keywords: Galaxies, spectra; Redshifts; Magnitudes, absolute; Morphology;
Spectra, optical; Ultraviolet; Clusters, galaxy
Keywords: Low surface brightness galaxies ; Spectroscopy ;
Galaxy environments ; Galaxy stellar content ; Galaxy evolution ;
Galaxy distances ; Galaxy colors ; Galaxy properties
Abstract:
We present new redshift measurements for 19 candidate ultra-diffuse
galaxies (UDGs) from the Systematically Measuring Ultra-Diffuse
Galaxies (SMUDGes) survey after conducting a long-slit spectroscopic
follow-up campaign on 23 candidates with the Large Binocular
Telescope. We combine these results with redshift measurements from
other sources for 29 SMUDGes and 20 non-SMUDGes candidate UDGs.
Together, this sample yields 44 spectroscopically confirmed UDGs
(re≥1.5kpc and µg(0)≥24mag/arcsec2 within uncertainties)
and spans cluster and field environments, with all but one projected
on the Coma cluster and environs. We find no statistically significant
differences in the structural parameters of cluster and noncluster
confirmed UDGs, although there are hints of differences among the axis
ratio distributions. Similarly, we find no significant structural
differences among those in locally dense or sparse environments.
However, we observe a significant difference in color with respect to
projected clustercentric radius, confirming trends observed previously
in statistical UDG samples. This trend strengthens further when
considering whether UDGs reside in either cluster or locally dense
environments, suggesting starkly different star formation histories
for UDGs residing in high- and low-density environments. Of the
16 large (re≥3.5kpc) UDGs in our sample, only one is a field galaxy
that falls near the early-type galaxy red sequence. No other field
UDGs found in low-density environments fall near the red sequence.
This finding, in combination with our detection of Galaxy Evolution
Explorer NUV flux in nearly half of the UDGs in sparse environments,
suggests that field UDGs are a population of slowly evolving galaxies.
Description:
Our sample of low surface brightness candidate ultra-diffuse galaxies
(UDGs) comes primarily from the first Systematically Measuring
Ultra-Diffuse Galaxies (SMUDGes) catalog (Zaritsky+ 2019, J/ApJS/240/1).
We augment the published SMUDGes catalog by similarly processing a few
small regions of the Legacy Survey that lie far from the Coma cluster.
We observed our selected sample of UDG candidates with the
Multi-Object Double Spectrograph (MODS) in binocular mode on the Large
Binocular Telescope (LBT) on three separate observing runs occurring
on the nights of 2017 February 25-26, 2018 January 17-18, and
2019 April 4-5 (UTC). We observed each target for 40 to 100 minutes in
a series of dithered 20 or 30 minute exposures. We used the G400L
grating (R∼1850) in the blue channel (3200-5800Å) and the G670L
grating (R∼2300) in the red channel (5800-10000Å). We only use the
blue channel data to measure redshifts.
To calculate physical quantities, we adopt a ΛCDM cosmology
with ΩM=0.31, ΩΛ=0.69, and H0=67km/s/Mpc
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 99 19 LBT SMUDGes redshift sample
table3.dat 103 29 Non-LBT SMUDGes redshift sample
table4.dat 103 20 Non-LBT non-SMUDGes redshift sample
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See also:
J/MNRAS/357/819 : Colours and HI line observations in Virgo (Sabatini+, 2005)
J/ApJ/638/725 : Fundamental manifold of spheroids (Zaritsky+, 2006)
J/ApJ/681/197 : ACS Virgo Cluster Survey. XV (Peng+, 2008)
J/A+A/506/677 : HI in Local Supercluster dwarf galaxies (Huchtmeier+, 2009)
J/ApJ/772/82 : A catalog of globular cluster systems (Harris+, 2013)
J/ApJS/215/22 : The Extended Virgo Cluster Catalog (EVCC) (Kim+, 2014)
J/ApJ/833/167 : PAndAS view of Andromeda satellites. II. (Martin+, 2016)
J/ApJS/225/11 : Subaru-UDGs in the Coma cluster (Yagi+, 2016)
J/ApJ/842/133 : HI-bearing ultra-diffuse ALFALFA galaxies (Leisman+, 2017)
J/MNRAS/468/703 : Abell 168 ultra-diffuse galaxies distribution (Roman+, 2017)
J/A+A/608/A142 : Fornax Deep Survey with VST. III. LSB gal. (Venhola+, 2017)
J/ApJ/857/104 : Low surface brightness galaxies from HSC-SSP (Greco+, 2018)
J/AJ/157/212 : Ultra-diffuse galaxies at UV wavelengths (Singh+, 2019)
J/ApJS/240/1 : SMUDGes. I. First results in Coma Cluster (Zaritsky+, 2019)
J/ApJ/893/47 : MW satellite census. I. DES & PS1 (Drlica-Wagner+, 2020)
J/MNRAS/491/5317 : The SDSS extended PSFs (Infante-Sainz+, 2020)
J/ApJ/902/39 : GBT HI obs. of ultradiffuse galaxies (Karunakaran+, 2020)
J/ApJ/894/75 : Ultra-diffuse & LSB dwarf gal. in A370 from HFF (Lee+, 2020)
Byte-by-byte Description of file: table[234].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Set [SMDG ] SMUDGes ("SMDG") or non-SMDG
(blank) sample
5- 18 A14 --- Name SMUDGes name for SMDG or name based
on coordinates (HHMMSSs+DDMMSS; J2000)
20- 22 A3 --- f_Name Flag(s) on Name (1)
24- 36 A13 --- AName Alternate name (2)
38- 41 F4.1 mag/arcsec2 mu0g [22.5/25.8] g-band central surface
brightness, µg(0)
43 A1 --- l_NUVMag Limit flag on NUVMag
45- 49 F5.1 mag NUVMag [-15.5/-6]? Absolute GALEX NUV magnitude
51- 55 F5.1 mag gMag [-16.9/-9.7] Absolute g-band magnitude
57- 61 F5.1 mag rMag [-17.3/-10.2] Absolute r-band magnitude
63- 67 F5.1 mag zMag [-17.6/-10.6] Absolute z-band magnitude
69- 71 F3.1 kpc re [0.3/9.9] Effective radius
73- 76 F4.2 --- b/a [0.37/0.97] Axial ratio
78- 81 F4.2 --- n [0.33/1.8] Sersic index
83- 87 I5 km/s czCMB [553/12269] Recessional velocity in the
cosmic microwave background rest frame
89- 93 F5.1 km/s e_czCMB [0.2/192]? czCMB uncertainty
95 A1 --- Env [DSU] Environmental classification (3)
97- 99 A3 --- Cl? Cluster?
101-103 A3 --- Ref Reference(s) (not for Table 2) (4)
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Note (1): Flag as follows:
d = Redshift identification is somewhat uncertain.
e = Observer-frame redshift was previously reported in
Kadowaki+ (2017ApJ...838L..21K 2017ApJ...838L..21K).
f = Heliocentric redshift was previously reported in Gu+ (2018ApJ...859...37G 2018ApJ...859...37G).
We report the CMB rest-frame corrected, variance-weighted, mean velocity
and standard error taken from measurements for our LBT measurements and
those reported in Gu+ (2018ApJ...859...37G 2018ApJ...859...37G).
g = This object is too faint to be modeled in the Legacy Survey data.
h = Galaxy is brighter than our pipeline threshold and was masked during
processing.
Note (2): Alternate names sourced from van Dokkum+ (2015ApJ...798L..45V 2015ApJ...798L..45V ;
<[VAM2015] DFNN> in Simbad) and Yagi+ (2016, J/ApJS/225/11 ;
<[YKK2016] NNN> in Simbad), with the exception of DFX2 (in Table 4) which
is sourced from Alabi+ (2018MNRAS.479.3308A 2018MNRAS.479.3308A ; <[YKK2016] 12> in Simbad).
Yagi objects are also denoted as "Subaru-UDG" in NASA's Extragalactic
Database.
Note (3): The local environment designations are as follows:
D = dense,
S = sparse,
U = unconstrained.
Note (4): Reference as follows:
1 = Huchtmeier et al. (2003A&A...401..483H 2003A&A...401..483H)
2 = Karunakaran et al. (2020, J/ApJ/902/39)
3 = Huchtmeier et al. (2009, J/A+A/506/677)
4 = Kim et al. (2014, J/ApJS/215/22)
5 = van Dokkum et al. (2015ApJ...804L..26V 2015ApJ...804L..26V)
6 = Gu et al. (2018ApJ...859...37G 2018ApJ...859...37G)
7 = Chilingarian et al. (2019ApJ...884...79C 2019ApJ...884...79C)
8 = Alabi et al. (2018MNRAS.479.3308A 2018MNRAS.479.3308A)
9 = Ruiz-Lara et al. (2018MNRAS.478.2034R 2018MNRAS.478.2034R)
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 09-Mar-2022