J/ApJ/960/9 Ultradiffuse galaxies in HFF massive clusters (Zhao+, 2024)
Structure and color gradients of ultradiffuse galaxies in distant massive galaxy
clusters.
Zhao P., Liu F.S., Cui Q., Yesuf H.M., Wu H.
<Astrophys. J., 960, 9 (2024)>
=2024ApJ...960....9Z 2024ApJ...960....9Z
ADC_Keywords: Photometry, HST; Clusters, galaxy; Galaxies, optical; Colors;
Galaxies, radius; Morphology
Keywords: Low surface brightness galaxies
Abstract:
We have measured structural parameters and radial color profiles of
108 ultradiffuse galaxies (UDGs), carefully selected from six distant
massive galaxy clusters in the Hubble Frontier Fields (HFF) in a
redshift range from 0.308 to 0.545. Our best-fitting GALFIT models
show that the HFF UDGs have a median Sersic index of 1.09, which is
close to 0.86 for local UDGs in the Coma cluster. The median
axis-ratio value is 0.68 for HFF UDGs and 0.74 for Coma UDGs,
respectively. The structural similarity between HFF and Coma UDGs
suggests that they are the same kind of galaxies seen at different
times, and that the structures of UDGs do not change at least for
several billion years. By checking the distribution of HFF UDGs in the
rest-frame UVJ and UVI diagrams, we find a large fraction of them are
star forming. Furthermore, a majority of HFF UDGs show small U-V color
gradients within the 1*Re,SMA region, and the fluctuation of the
median radial color profile of HFF UDGs is smaller than 0.1mag, which
is compatible to Coma UDGs. Our results indicate that cluster UDGs may
fade or quench in a self-similar way, irrespective of the radial
distance, in less than ∼4Gyr.
Description:
The Hubble Frontier Fields (HFF) project is a deep-imaging survey,
which observed six massive galaxy clusters --A2744, A370, AS1063,
MACSJ0416, MACSJ0717, and MACSJ1149-- with six central cluster fields
and six coordinated parallel fields by the HST Advanced Camera for
Surveys Wide Field Camera (ACS/WFC) and WFC3/IR camera for over
840 HST orbits.
Shipley+ (2018, J/ApJS/235/14) collected and stacked all existing
image data in HFF fields. They then reduced the stacked images using a
standard procedure, including cosmic-ray detection, background
subtraction, initial source detection, etc. After that, bCGs were
selected and modeled under an iterative process and finally subtracted
from the images. On the bCG-subtracted images, they ran SExtractor
and provided catalogs consisting of total fluxes, flux errors,
flux_radius, semimajor/semiminor axis sizes, etc. Sources in the
catalog are detected in a combination of F814W, F105W, F125W, F140W,
and F160W band images, and the F160W band magnitude limits (90%
completeness) range from 26.9 mag to 27.5 mag for point sources in
deep fields. In addition, their catalogs also provide photometric
redshifts (z_peak) measured using EAZY code. We use all of the above
measurements from these catalogs in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 58 108 Catalog of 108 ultradiffuse galaxies (UDGs)
identified in the Hubble Frontier Fields (HFF)
Program
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See also:
J/A+A/463/503 : Early-type dwarf galaxies in Fornax cluster (Mieske+, 2007)
J/ApJS/191/143 : HST/ACS Coma cluster survey. II. (Hammer+, 2010)
J/ApJ/801/97 : GOODS-S & UDS stellar mass cat. from CANDELS (Santini+, 2015)
J/A+A/590/A31 : ASTRODEEP Frontier Fields Catalogues (Merlin+, 2016)
J/A+A/590/A31 : ASTRODEEP Frontier Fields Catalogues (Merlin+, 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/ApJ/844/157 : Ultradiffuse galaxies in deep HST images of HFF (Lee+, 2017)
J/A+A/608/A142 : Fornax Deep Survey with VST. III. LSB gal. (Venhola+, 2017)
J/ApJS/235/14 : HFF-DeepSpace phot. cat. of 12 HFF fields (Shipley+, 2018)
J/ApJ/894/75 : Ultra-diffuse & LSB dwarf gal. in A370 from HFF (Lee+, 2020)
J/ApJ/923/257 : Ultra-diffuse gal with spectroscopic obs. (Kadowaki+, 2021)
J/ApJS/257/60 : SMUDGes. II. Expanded survey & Stripe 82 (Zaritsky+, 2021)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Cluster identifier as in
Shipley+ 2018, J/ApJS/235/14
(ANNNN-clu or MHHMM-clu)
10- 13 I04 --- Gal [8/8818] Galaxy identifier within the
cluster ID from Shipley's catalog
(2018, J/ApJS/235/14)
15- 22 F8.4 deg RAdeg [3.5/342.3] Right ascension (J2000)
24- 31 F8.4 deg DEdeg [-44.6/37.8] Declination (J2000)
33- 37 F5.2 mag/arcsec2 mu [24/25.3] Absolute surface brightness,
<µ>abs, in the F814W band
39- 42 F4.2 kpc Re [1.5/4.2] Effective radius along the
semimajor axis
44- 47 F4.2 --- n [0.3/3] Sersic index
49- 52 F4.2 --- q [0.26/1] Axis ratio
54- 58 F5.2 mag U-V [-0.5/2.3] Rest-frame U-V color; see
Section 3.1
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Nomenclature note:
Galaxy identifiers in Shipley+ 2018, J/ApJS/235/14 are
<[SLM2018] ANNNN-clu NNNNN> or <[SLM2018] MHHMM-clu NNNNN> in Simbad.
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 30-Jan-2026