J/other/Sci/348.418 Isolated compact elliptical galaxies (Chilingarian+, 2015)
Isolated compact elliptical galaxies: Stellar systems that ran away.
Chilingarian I., Zolotukhin I.
<Science, 348, 418-421 (2015)>
=2015Sci...348..418C 2015Sci...348..418C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Redshifts ; Photometry, SDSS ;
Photometry, ultraviolet ; Photometry, infrared
Abstract:
Compact elliptical galaxies form a rare class of stellar system (∼30
presently known) characterized by high stellar densities and small
sizes and often harboring metal-rich stars. They were thought to form
through tidal stripping of massive progenitors, until two isolated
objects were discovered where massive galaxies performing the
stripping could not be identified. By mining astronomical survey data,
we have now found 195 compact elliptical galaxies in all types of
environment. They all share similar dynamical and stellar population
properties. Dynamical analysis for nonisolated galaxies demonstrates
the feasibility of their ejection from host clusters and groups by
three-body encounters, which is in agreement with numerical
simulations. Hence, isolated compact elliptical and isolated quiescent
dwarf galaxies are tidally stripped systems that ran away from their
hosts.
Description:
We constructed a sample of 195 galaxies. We then cross-matched this
list against the SDSS Galaxy Groups catalog (Tempel et al., 2012, Cat.
J/A+A/540/A106) and established their group/cluster membership. For
seven objects without counterparts in the Galaxy Groups catalog, we
identified possible host galaxies (in most cases, group centers)
located between 750kpc and 3.3Mpc in projection. Because some bright
and extended galaxies were missing from the SDSS spectroscopic sample,
and therefore also from the Galaxy Groups catalog, we used
NASA/Infrared Processing and Analysis Center (IPAC) Extragalactic
Database (NED) for the identification of host galaxies for 45 cEs. Our
final sample contains 56 galaxies in clusters, 128 in groups, and 11
isolated or field cE galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables1.dat 236 195 Properties of 195 cEs and their host galaxies
found in this study
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See also:
J/A+A/540/A106 : SDSS-DR8 groups and clusters of galaxies (Tempel+, 2012)
Byte-by-byte Description of file: tables1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- objId Unique SDSS object identifier of cE galaxy
20- 28 F9.5 deg RAdeg Right ascension (J2000)
30- 37 F8.5 deg DEdeg Declination (J2000)
39- 42 I4 --- Plate SDSS plane number
44- 48 I5 --- MJD SDSS MJD number
50- 52 I3 --- Fiber SDSS Fiber number
55- 59 F5.2 mag FUV ? Extinction k-corrected GALEX FUV magnitude
61- 65 F5.2 mag NUV ? Extinction k-corrected GALEX NUV magnitude
67- 71 F5.2 mag umag ? Extinction k-corrected SDSS u magnitude (AB)
73- 77 F5.2 mag gmag ? Extinction k-corrected SDSS g magnitude (AB)
79- 83 F5.2 mag rmag ? Extinction k-corrected SDSS r magnitude (AB)
85- 89 F5.2 mag imag ? Extinction k-corrected SDSS i magnitude (AB)
92- 96 F5.2 mag zmag ? Extinction k-corrected SDSS z magnitude (AB)
98-102 F5.2 mag Ymag ? Extinction k-corrected UKIDSS Y magnitude (AB)
104-108 F5.2 mag Jmag ? Extinction k-corrected UKIDSS J magnitude (AB)
110-114 F5.2 mag Hmag ? Extinction k-corrected UKIDSS H magnitude (AB)
116-120 F5.2 mag Kmag ? Extinction k-corrected UKIDSS K magnitude (AB)
123-127 I5 km/s RV Radial velocity derived from the SSP fitting
129-130 I2 km/s e_RV rms uncertainty on RV
132-134 I3 km/s sigma Velocity dispersion derived from the SSP fitting
136-137 I2 km/s e_sigma rms uncertainty on sigma
139-142 F4.1 Gyr Age Age derived from the SSP fitting
144-146 F3.1 Gyr e_Age rms uncertainty on Age
148-152 F5.2 --- [Fe/H] Metallicity derived from the SSP fitting
154-157 F4.2 --- e_[Fe/H] rms uncertainty on [Fe/H]
159-164 F6.4 --- z SDSS redshift
166-171 F6.4 --- e_z rms uncertainty on z
173-178 F6.2 mag rMAG Extinction k-corrected absolute r magnitude
of cE galaxy
180-197 I18 --- Host ? objID of cE host galaxy (1)
199-207 F9.5 deg RAHd ? Host galaxy right ascension (J2000)
209-216 F8.5 deg DEHd ? Host galaxy declination (J2000)
218-223 F6.4 --- zH ? Redshift of host galaxy from SDSS or NED
225-230 F6.2 mag rMAGH ? Extinction k-corrected absolute r magnitude
of host galaxy
232-236 I5 kpc dproj ? Projected distance between cE and its host
galaxy
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Note (1): Missing value means there is no host galaxy and this row corresponds
to an isolated cE.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Nov-2015