J/MNRAS/440/1690 Bulge and disc colours of ETG in Coma (Head+, 2014)
Dissecting the red sequence: the bulge and disc colours of early-type galaxies
in the Coma cluster.
Head J.T.C.G., Lucey J.R., Hudson M.J., Smith R.J.
<Mon. Not. R. Astron. Soc., 440, 1690-1711 (2014)>
=2014MNRAS.440.1690H 2014MNRAS.440.1690H (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Photometry, SDSS ;
Morphology
Keywords: galaxies: clusters: individual: Abell 1656 -
galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: formation; galaxies: structure
Abstract:
We explore the internal structure of red-sequence galaxies in the Coma
cluster across a wide range of luminosities (-17>Mg>-22) and
cluster-centric radii (0<rcluster<1.3r200). We present the 2D
bulge-disc decomposition of galaxies in deep Canada-France-Hawaii
Telescope u, g, i imaging using GALFIT. Rigorous filtering is applied
to identify an analysis sample of 200 galaxies which are well
described by an 'archetypal' S0 structure (central bulge + outer
disc).
Description:
We consider internal bulge and/or disc colour gradients by allowing
component sizes to vary between bands. Gradients are required for 30
percent of analysis sample galaxies. Bulge half-light radii are found
to be uncorrelated with galaxy luminosity (Re∼1kpc, n∼2) for all but
the brightest galaxies (Mg←20.5). The S0 discs are brighter (at
fixed size, or smaller at fixed luminosity) than those of star-forming
spirals. A similar colour-magnitude relation is found for both bulges
and discs. The global red sequence for S0s in Coma hence results from
a combination of both component trends. We measure an average bulge -
disc colour difference of 0.09±0.01mag in g-i, and 0.16±0.01mag in
u-g. Using simple stellar population models, bulges are either ∼2-3
times older, or ∼2 times more metal rich than discs. The trend towards
bluer global S0 colours observed further from Coma's core is driven by
a significant correlation in disc colour with cluster-centric radius.
An equivalent trend is detected in bulge colours at a marginal
significance level. Our results therefore favour environment-mediated
mechanisms of disc fading as the dominant factor in S0 formation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled1.dat 307 567 Fitting results are presented for Sersic-only
and bulge + disc (B+D) models in the g-band
tabled3.dat 298 567 Results are presented for bulge + disc models
in the u- and i-bands
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See also:
VII/240 : Millennium Galaxy Catalogue (Liske+, 2003)
V/139 : SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+ 2012)
J/MNRAS/453/3729 : Sersic + exponential disc morphologies in Coma (Head+, 2015)
Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- ObjID SDSS DR8 Object ID
25- 32 F8.4 deg RAdeg Right ascension (J2000)
40- 47 F8.4 deg DEdeg Declination (J2000)
49- 54 F6.2 arcmin Rproj Projected distance from Coma
57- 61 F5.3 --- z Redshift
65- 71 F7.3 mag MgS ? Rest-frame Sersic magnitude
(g-band Sersic model)
73- 77 F5.3 mag e_MgS ?=9.999 rms uncertainty on MgS
81- 87 F7.3 mag MgB ?=999 Rest-frame bulge magnitude
(g-band B+D model)
89- 94 F6.3 mag e_MgB ?=9.999 rms uncertainty on MgB
97-103 F7.3 mag MgD ?=999 Rest-frame disc magnitude
(g-band B+D model)
105-109 F5.3 mag e_MgD ?=9.999 rms uncertainty on MgD
113-119 F7.3 mag MgT ?=999 Rest-frame total magnitude
(g-band B+D model)
121-125 F5.3 mag e_MgT ?=9.999 rms uncertainty on MgT
129-133 F5.3 mag B/Tg g-band bulge fraction (B+D model)
137-141 F5.3 mag e_B/Tg ?=9.999 rms uncertainty on B/Tg
145-150 F6.3 arcsec ReSg Effective Sersic half-light radius
(g-band Sersic model)
153-157 F5.3 arcsec e_ReSg ?=9.999 rms uncertainty on ReSg
160-165 F6.3 --- nSg Sersic index (g-band Sersic model)
169-173 F5.3 --- e_nSg ?=9.999 rms uncertainty on nSg
177-181 F5.3 --- qSg Sersic axis ratio (b/a,g-band Sersic model)
185-189 F5.3 --- e_qSg ?=9.999 rms uncertainty on qSg
193-198 F6.3 arcsec ReBg Effective bulge half-light radius
(g-band B+D model)
200-205 F6.3 arcsec e_ReBg ?=9.999 rms uncertainty on ReBg
209-214 F6.3 arcsec ReDg ?=9.999 Effective disc half-light radius
(g-band B+D model)
216-221 F6.3 arcsec e_ReDg ?=9.999 rms uncertainty on ReDg
224-229 F6.3 --- nB Bulge Sersic index (B+D model)
233-237 F5.3 --- e_nB ?=9.999 rms uncertainty on nB
241-245 F5.3 --- qB Bulge Sersic axis ratio (b/a, B+D model)
249-253 F5.3 --- e_qB ?=9.999 rms uncertainty on qB
257-261 F5.3 --- qD Disc Sersic axis ratio (b/a, B+D model)
265-269 F5.3 --- e_qD ?=9.999 rms uncertainty on qD
273-277 F5.1 deg DPA Absolute position angle difference between
components, ΔPA
279-284 F6.2 --- chi2nusg ?=999 Reduced χ2 (g-band, Sersic model)
287-292 F6.2 -- chi2nug ?=999 Reduced χ2 (g-band, B+D model)
297 I1 --- ProfType [1/6] Major axis surface brightness profile
type (1)
305-307 A3 --- FiltSamp Filtering sample (2)
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Note (1): Profile type (see Allen et al., 2006MNRAS.371....2A 2006MNRAS.371....2A) as follows:
1 = Classic profile
2 = Disc-dominated system
3 = Sersic profile
4 = Inverted profile
5 = Bulge or disc dominated
6 = Disc with perturbation
Note (2): Filtering sample code as follows:
U1 = Unsuitable, masking fraction
U2 = Unsuitable, asymmetry
U3 = Unsuitable, high χ2ν
U4 = Unsuitable, SB profile type
U5 = Unsuitable, blue core
S6 = Sersic, BIC
S7 = Sersic, B/C
A8 = Analysis, flagged (χ2)
A9 = Analysis, flagged (bar-like structure)
A10 = Analysis, flagged (force swap)
A11 = Analysis, regular fit
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Byte-by-byte Description of file: tabled3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- ObjID SDSS DR8 Object ID
25- 31 F7.3 mag MuB ?=999 Rest-frame bulge magnitude (u-band)
33- 37 F5.3 mag e_MuB ?=9.999 rms uncertainty on MuB
41- 47 F7.3 mag MuD ?=999 Rest frame disc magnitude (u-band)
49- 53 F5.3 mag e_MuD ?=9.999 rms uncertainty on MuD
57- 63 F7.3 mag MuT ?=999 Rest frame total magnitude (u-band
65- 69 F5.3 mag e_MuT ?=9.999 rms uncertainty on MuT
73- 77 F5.3 --- B/Tu u-band bulge fraction
81- 85 F5.3 --- e_B/Tu ?=9.999 rms uncertainty on B/Tu
89- 94 F6.3 arcsec ReBu Effective bulge half-light radius (u-band)
96-101 F6.3 arcsec e_ReBu ?=9.999 rms uncertainty on ReBU
104-110 F7.3 arcsec ReDu Effective disc half-light radius (u-band)
112-117 F6.3 arcsec e_ReDu ?=9.999 rms uncertainty on ReDU
121-125 F5.3 --- chi2nuu Reduced χ2 (u-band)
129-135 F7.3 mag MiB ?=999 Rest frame bulge magnitude (i-band)
137-142 F6.3 mag e_MiB ?=9.999 rms uncertainty on MiB
145-151 F7.3 mag MiD ?=999 Rest frame disc magnitude (i-band)
153-157 F5.3 mag e_MiD ?=9.999 rms uncertainty on MiD
161-167 F7.3 mag MiT ?=999 Rest frame total magnitude (i-band)
169-173 F5.3 mag e_MiT ?=9.999 rms uncertainty on MiT
177-181 F5.3 --- B/Ti i-band bulge fraction
185-189 F5.3 --- e_B/Ti ?=9.999 rms uncertainty on B/Ti
193-198 F6.3 arcsec ReBi ?=999 Effective bulge half-light radius
(i-band)
200-205 F6.3 arcsec e_ReBi ?=9.999 rms uncertainty on ReBi
209-214 F6.3 arcsec ReDi Effective disc half-light radius (i-band)
216-221 F6.3 arcsec e_ReDi ?=9.999 rms uncertainty on ReDi
223-229 F7.3 --- chi2nui ?=999 reduced χ2 (i-band)
233-238 F6.3 mag D(u-g) ?=9.999 Radial gradient in galaxy (u-g)
241-245 F5.3 mag e_D(u-g) ?=0 rms uncertainty on D(u-g)
249-254 F6.3 mag D(u-g)m Radial gradient in model (u-g)
257-261 F5.3 mag e_D(u-g)m rms uncertainty on D(u-g)m
265-270 F6.3 mag D(g-i) ?=9.999 Radial gradient in galaxy (g-i)
273-277 F5.3 mag e_D(g-i) ?=0 rms uncertainty on D(g-i)
281-286 F6.3 mag D(g-i)m ?=9.999 Radial gradient in model (g-i)
289-293 F5.3 mag e_D(g-i)m rms uncertainty on D(g-i)m
297-298 A2 --- MultiType Best-fit multi-band model
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History:
From electronic version of the journal
References:
Head de tal., Paper II 2015MNRAS.453.3729H 2015MNRAS.453.3729H, Cat. J/MNRAS/453/3729
(End) Patricia Vannier [CDS] 03-Jul-2015