J/MNRAS/445/630 Early-type galaxies in Ursa Major cluster (Pak+, 2014)
The properties of early-type galaxies in the Ursa Major cluster.
Pak M., Rey S.-C., Lisker T., Lee Y., Kim S., Sung E.-C., Jerjen H.,
Chung J.
<Mon. Not. R. Astron. Soc., 445, 630-647 (2014)>
=2014MNRAS.445..630P 2014MNRAS.445..630P
ADC_Keywords: Clusters, galaxy ; Morphology ; Photometry, SDSS ;
Photometry, ultraviolet
Keywords: galaxies: clusters: individual: Ursa Major - galaxies: dwarf -
galaxies: evolution - galaxies: structure
Abstract:
Using SDSS-DR7 and NASA/IPAC Extragalactic Database spectroscopic
data, we identify 166 galaxies as members of the Ursa Major cluster
with Mr←13.5mag. We morphological classify all
galaxies by means of carefully inspecting g-, r-, i-band colour and
monochromatic images. We show that the Ursa Major cluster is dominated
by late-type galaxies, but also contains a significant number of
early-type galaxies, particularly in the dwarf regime. We present
further evidence for the existence of several subgroups in the
cluster, consistent with previous findings. The early-type fraction is
found to correlate with the mass of the subgroup. We also investigate
environmental effects by comparing the properties of the Ursa Major
early-type dwarf galaxies to those of the Virgo cluster. In contrast
to the Virgo, the red sequence of the Ursa Major cluster is only
sparsely populated in the optical and ultraviolet colour-magnitude
relations. It also shows a statistically significant gap between
-18<Mr←17mag, i.e. the Ursa Major cluster lacks early-type dwarf
galaxies at the bright end of their luminosity function. We discover
that the majority of early-type dwarf galaxies in the Ursa Major
cluster have blue cores with hints of recent or ongoing star
formation. We suggest that gravitational tidal interactions can
trigger central blue star-forming regions in early-type dwarfs. After
that, star formation would only fade completely when the galaxies
experience ram-pressure stripping or harassment, both of which are
nearly absent in the Ursa Major cluster.
Description:
Our sample in the Ursa Major cluster is predominantly based on the
SDSS Data Release 7 (DR7; Abazajian et al., 2009ApJS..182..543A 2009ApJS..182..543A).
In order to investigate the ultraviolet properties of our sample
galaxies in the Ursa Major cluster, we used far-ultraviolet (FUV,
1350-1750Å) and near-ultraviolet (NUV, 1750-2750Å) images from
the GALEX GR6.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 169 166 The Ursa Major cluster catalogue
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See also:
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
II/294 : SDSS Photometric Catalog, DR 7 (Adelman-McCarthy+, 2009)
J/AJ/112/2471 : The Ursa Major cluster. I. (Tully+ 1996)
J/MNRAS/429/2264 : Anatomy of Ursa Majoris (Karachentsev+, 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID ID number, UNNN (1)
6- 18 A13 --- Name Name (2)
20- 27 F8.4 deg RAdeg Right ascension (J2000) from SExtractor
29- 35 F7.4 deg DEdeg Declination (J2000) from SExtractor
37- 43 F7.4 deg SGLON Supergalactic longitude
45- 51 F7.4 deg SGLAT Supergalactic latitude
53- 56 I4 km/s HV [620/1208] Heliocentric radial velocity from SDSS
57 A1 --- n_HV [N] N when HV adopted from NED
59- 62 I4 km/s V0 Radial velocity that adjusted for the frame of
the Local Group by adding 300sinlcosb
64- 68 A5 --- Memb [123, ] Membership from different catalogues (3)
70- 74 A5 --- Group Name of group defined by Karachentsev et al.
(2013) which the galaxy belongs to
76- 83 A8 --- MType Morphology of galaxy classified from this study
85- 86 I2 --- TT1 [-3/10]?=- RC3 T-type from Tully et al.
(1996, Cat. J/AJ/112/2471)
88- 89 I2 --- TT2 [-3/10]?=- RC3 T-type from Karachentsev et al.
(2013, Cat. J/MNRAS/429/2264)
91- 95 F5.2 mag umag SDSS u magnitude
97-100 F4.2 mag e_umag rms uncertainty on umag
102-106 F5.2 mag gmag SDSS g magnitude
108-111 F4.2 mag e_gmag rms uncertainty on gmag
113-117 F5.2 mag rmag SDSS r magnitude
119-122 F4.2 mag e_rmag rms uncertainty on rmag
124-128 F5.2 mag imag SDSS i magnitude
130-133 F4.2 mag e_imag rms uncertainty on imag
135-139 F5.2 mag zmag SDSS z magnitude
141-144 F4.2 mag e_zmag rms uncertainty on zmag
146-150 F5.2 mag NUV ? GALEX NUV magnitude
152-155 F4.2 mag e_NUV ? rms uncertainty on NUV
157-161 F5.2 mag FUV ? GALEX FUV magnitude
163-166 F4.2 mag e_FUV ? rms uncertainty on FUV
168-169 A2 --- Note [bc] bc for blue-cored early-type dwarf galaxies
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Note (1): ID is marked with the R.A. The ID numbers larger than 200 are for
galaxies which are only included in the catalogue of Karachentsev et al.
(2013, Cat. J/MNRAS/429/2264).
Note (2): NGC, UGC or other name of galaxy from
Tully et al. (1996, Cat. J/AJ/112/2471),
Karachentsev et al. (2013, Cat. J/MNRAS/429/2264) and
NED (troncated 2MASX and SDSS names)
Note (3): Membership of galaxy from:
1 = this study
2 = Tully et al. (1996, Cat. J/AJ/112/2471)
3 = Karachentsev et al. (2013, Cat. J/MNRAS/429/2264)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 30-Apr-2015