J/MNRAS/409/1455 Stellar populations of early-type galaxies (Harrison+, 2010)
The stellar populations of early-type galaxies.
I. Observations, line strengths and stellar population parameters.
Harrison C.D., Colless M., Kuntschner H., Couch W.J., De Propris R.,
Pracy M.B.
<Mon. Not. R. Astron. Soc., 409, 1455-1469 (2010)>
=2010MNRAS.409.1455H 2010MNRAS.409.1455H
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Spectroscopy
Keywords: methods: data analysis - galaxies: clusters: general -
galaxies: elliptical and lenticular, cD - galaxies: stellar content
Abstract:
The influence of environment on the formation and evolution of
early-type galaxies is, as yet, an unresolved issue. Constraints can
be placed on models of early-type galaxy formation and evolution by
examining their stellar populations as a function of environment. We
present a catalogue of galaxies well suited to such an investigation.
The magnitude-limited (bJ≤19.45) sample was drawn from four
clusters (Coma, A1139, A3558 and A930 at =0.04) and their
surrounds. The catalogue contains luminosities, redshifts, velocity
dispersions and Lick line strengths for 416 galaxies, of which 245 are
classified as early types. Luminosity-weighted ages, metallicities and
α-element abundance ratios have been estimated for 219 of these
early types. We also outline the steps necessary for measuring fully
calibrated Lick indices and estimating the associated stellar
population parameters using up-to-date methods and stellar population
models. In a subsequent paper we perform a detailed study of the
stellar populations of early-type galaxies in clusters and investigate
the effects of environment.
Description:
Galaxies in the four clusters and three standard stars (HR6159, HR6770
and HR7317) were observed with 2dF during the nights of 2002 April
19-21 using the 300B and 1200V gratings.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 90 416 Details of the low-redshift galaxies
tablea2.dat 189 416 Line-strengths of the galaxies
tablea3.dat 52 416 Stellar population parameters of the galaxies
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Cluster Cluster name
7- 21 A15 --- Name Galaxy name
23- 24 I2 h RAh Right ascension (J2000)
26- 27 I2 min RAm Right ascension (J2000)
29- 33 F5.2 s RAs Right ascension (J2000)
35 A1 --- DE- Declination sign (J2000)
36- 37 I2 deg DEd Declination (J2000)
39- 40 I2 arcmin DEm Declination (J2000)
42- 45 F4.1 arcsec DEs Declination (J2000)
47 A1 --- ET [y/n-] Early-type galaxy ?
49- 53 F5.2 mag bJmag bJ (blue) magnitude
55- 60 F6.2 mag bJMAG Absolute bJ magnitude
62- 66 F5.2 mag rFmag ?=- rF (red) magnitude
68- 73 F6.2 mag rFMAG ?=- Absolute rF magnitude
75- 79 I5 km/s cz Heliocentric spectroscopic redshift
81- 82 I2 km/s e_cz rms uncertainty on cz
84- 86 I3 km/s sigma Velocity dispersion
88- 90 I3 km/s e_sigma rms uncertainty on sigma
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Galaxy name
17- 23 F7.4 0.1nm C2 ?=- C2(4668Å) index line strength
25- 31 F7.4 0.1nm Hb ?=- Hβ index line strength
33- 39 F7.4 0.1nm HbG ?=- HβG index (1)
41- 47 F7.4 0.1nm [OIII]1 ?=- [OIII]1 index line strength (1)
49- 55 F7.4 0.1nm [OIII]2 ?=- [OIII]2 index line strength (1)
57- 62 F6.4 0.1nm Fe5015 ?=- Fe5015 index line strength
64- 70 F7.4 mag Mg1 ?=- Mg1 index line strength
72- 77 F6.4 mag Mg2 ?=- Mg2 index line strength
79- 84 F6.4 0.1nm Mgb ?=- Mgb index line strength
86- 91 F6.4 0.1nm Fe5270 ?=- Fe5270 index line strength
93- 98 F6.4 0.1nm Fe5335 ?=- Fe5335 index line strength
100-105 F6.4 0.1nm Fe5406 ?=- Fe5406 index line strength
107-112 F6.4 0.1nm e_C2 ?=- rms uncertainty on C2 (4668Å)
114-119 F6.4 0.1nm e_Hb ?=- rms uncertainty on Hb
121-126 F6.4 0.1nm e_HbG ?=- rms uncertainty on HbaG
128-133 F6.4 0.1nm e_[OIII]1 ?=- rms uncertainty on [OIII]1
135-140 F6.4 0.1nm e_[OIII]2 ?=- rms uncertainty on [OIII]2
142-147 F6.4 0.1nm e_Fe5015 ?=- rms uncertainty on Fe5015
149-154 F6.4 mag e_Mg1 ?=- rms uncertainty on Mg1
156-161 F6.4 mag e_Mg2 ?=- rms uncertainty on Mg2
163-168 F6.4 0.1nm e_Mgb ?=- rms uncertainty on Mgb
170-175 F6.4 0.1nm e_Fe5270 ?=- rms uncertainty on Fe5270
177-182 F6.4 0.1nm e_Fe5335 ?=- rms uncertainty on Fe5335
184-189 F6.4 0.1nm e_Fe5406 ?=- rms uncertainty on Fe5406
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Note (1): index defined in Gonzales J.J. 1993, PhD thesis,
Univ. California , Santa Cruz (USA)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Galaxy name
17- 20 F4.1 Gyr Age ?=- Age of stellar population
22- 24 F3.1 Gyr E_Age ?=- Error on Age, upper limit
26- 28 F3.1 Gyr e_Age ?=- Error on Age, lower limit
30- 34 F5.2 [Sun] [Z/H] ?=- Metallicity
36- 39 F4.2 [Sun] e_[Z/H] ?=- rms uncertainty on Metallicity
41- 45 F5.2 [Sun] [a/Fe] ?=- [α/Fe] abundance
47- 50 F4.2 [Sun] e_[a/Fe] ?=- rms uncertainty on [a/Fe]
52 I1 --- N ? Number of indices used to estimate
the parameters
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-May-2011