J/MNRAS/473/4731 Barred galaxies structural decomposition (Kruk+, 2018)
Galaxy Zoo: secular evolution of barred galaxies from structural decomposition
of multiband images.
Kruk S.J., Lintott C.J., Bamford S.P., Masters K.L., Simmons B.D.,
Haussler B., Cardamone C.N., Hart R.E., Kelvin L., Schawinski K.,
Smethurst R.J., Vika M.
<Mon. Not. R. Astron. Soc., 473, 4731-4753 (2018)>
=2018MNRAS.473.4731K 2018MNRAS.473.4731K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Morphology
Keywords: galaxies: bulges - galaxies: evolution - galaxies: general -
galaxies: star formation - galaxies: stellar content -
galaxies: structure
Abstract:
We present the results of two-component (disc+bar) and three-component
(disc+bar+bulge) multiwavelength 2D photometric decompositions of
barred galaxies in five Sloan Digital Sky Survey (SDSS) bands (ugriz).
This sample of ∼3500 nearby (z<0.06) galaxies with strong bars
selected from the Galaxy Zoo citizen science project is the largest
sample of barred galaxies to be studied using photometric
decompositions that include a bar component. With detailed structural
analysis, we obtain physical quantities such as the bar- and
bulge-to-total luminosity ratios, effective radii, Sersic indices and
colours of the individual components. We observe a clear difference in
the colours of the components, the discs being bluer than the bars and
bulges. An overwhelming fraction of bulge components have Sersic
indices consistent with being pseudo-bulges. By comparing the barred
galaxies with a mass-matched and volume-limited sample of unbarred
galaxies, we examine the connection between the presence of a
large-scale galactic bar and the properties of discs and bulges. We
find that the discs of unbarred galaxies are significantly bluer
compared to the discs of barred galaxies, while there is no
significant difference in the colours of the bulges. We find possible
evidence of secular evolution via bars that leads to the build-up of
pseudo-bulges and to the quenching of star formation in the discs. We
identify a subsample of unbarred galaxies with an inner lens/oval and
find that their properties are similar to barred galaxies, consistent
with an evolutionary scenario in which bars dissolve into lenses. This
scenario deserves further investigation through both theoretical and
observational work.
Description:
We make use of morphological classifications from the Galaxy Zoo
project and 2D photometric decomposition to study the properties of a
local sample of ∼3500 galaxies with strong bars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 175 3461 Structural parameters of discs, bars and bulges
for the 3461 galaxies fitted with disc+bar or
disc+bar+bulge components
table3.dat 198 3461 Properties of the galaxies fitted with disc+bar
or disc+bar+bulge component
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See also:
J/MNRAS/435/2835 : Morphological types from Galaxy Zoo 2 (Willett+, 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SDSS SDSS DR8 objid
21- 34 A14 --- Comp Fit components (disc+bar or disc+bar+bulge)
36- 40 F5.2 mag u-disc Disc integrated SDSS u magnitude (1)
42- 46 F5.2 mag g-disc Disc integrated SDSS g magnitude (1)
48- 52 F5.2 mag r-disc Disc integrated SDSS r magnitude (1)
54- 58 F5.2 mag i-disc Disc integrated SDSS i magnitude (1)
60- 64 F5.2 mag z-disc Disc integrated SDSS z magnitude (1)
66- 69 F4.2 --- n-disc Disc Sersic index
71- 76 F6.2 pix re-disc Disc effective radius
78- 81 F4.2 --- ba-disc Disc axis ratio b/a from the multiband fits
83- 89 F7.2 mag u-bar Bar integrated SDSS u magnitude (1)
91- 95 F5.2 mag g-bar Bar integrated SDSS g magnitude (1)
97-101 F5.2 mag r-bar Bar integrated SDSS r magnitude (1)
103-107 F5.2 mag i-bar Bar integrated SDSS i magnitude (1)
109-113 F5.2 mag z-bar Bar integrated SDSS z magnitude (1)
115-118 F4.2 --- n-bar Bar Sersic index
120-124 F5.2 pix re-bar Bar effective radius
126-129 F4.2 --- ba-bar Bar axis ratio b/a from the multiband fits
131-135 F5.2 mag u-bulge ?=0 Bulge integrated SDSS u magnitude (1)
137-141 F5.2 mag g-bulge ?=0 Bulge integrated SDSS g magnitude (1)
143-147 F5.2 mag r-bulge ?=0 Bulge integrated SDSS g magnitude (1)
149-153 F5.2 mag i-bulge ?=0 Bulge integrated SDSS i magnitude (1)
155-159 F5.2 mag z-bulge ?=0 Bulge integrated SDSS z magnitude (1)
161-164 F4.2 --- n-bulge ?=0 Bulge Sersic index
166-170 F5.2 pix re-bulge ?=0 Bulge effective radius
172-175 F4.2 --- ba-bulge ?=0 Bulge axis ratio b/a from the multiband
fits
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Note (1): from the fits, not corrected for Galactic extinction.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SDSS SDSS DR8 objid
21- 26 F6.4 --- z SDSS DR7 redshift
28- 33 F6.2 --- RMAG SDSS DR7 r-band Petrosian absolute magnitude
35- 39 F5.2 [Msun] logMass Stellar mass (1)
41- 44 F4.2 --- p-bar Debiased bar likelihood (2)
46- 49 F4.2 --- D/Tu Disc-to-total luminosity ratio in SDSS u band
51- 54 F4.2 --- D/Tg Disc-to-total luminosity ratio in SDSS g band
56- 59 F4.2 --- D/Tr Disc-to-total luminosity ratio in SDSS r band
61- 64 F4.2 --- D/Ti Disc-to-total luminosity ratio in SDSS i band
66- 69 F4.2 --- D/Tz Disc-to-total luminosity ratio in SDSS z band
71- 74 F4.2 --- Bar/Tu Bar-tp-total luminosity ratio in SDSS u band
76- 79 F4.2 --- Bar/Tg Bar-tp-total luminosity ratio in SDSS g band
81- 84 F4.2 --- Bar/Tr Bar-tp-total luminosity ratio in SDSS r band
86- 89 F4.2 --- Bar/Ti Bar-tp-total luminosity ratio in SDSS i band
91- 94 F4.2 --- Bar/Tz Bar-tp-total luminosity ratio in SDSS z band
96- 99 F4.2 --- B/Tu ?=0 Bulge-to-total luminosity ratio in
SDSS u band
101-104 F4.2 --- B/Tg ?=0 Bulge-to-total luminosity ratio in
SDSS g band
106-109 F4.2 --- B/Tr ?=0 Bulge-to-total luminosity ratio in
SDSS r band
111-114 F4.2 --- B/Ti ?=0 Bulge-to-total luminosity ratio in
SDSS i band
116-119 F4.2 --- B/Tz ?=0 Bulge-to-total luminosity ratio in
SDSS z band
121-126 F6.2 mag u-r-disc Disc SDSS u-r colour index (3)
128-136 F9.2 mag u-r-bar Bar SDSS u-r colour index (3)
138-146 F9.2 mag u-r-bulge ?=0 Bulge SDSS u-r colour index (3)
148-153 F6.2 mag g-i-disc Disc SDSS g-i colour index (3)
155-164 F10.2 mag g-i-bar Bar SDSS g-i colour index (3)
166-170 F5.2 mag g-i-bulge ?=0 Bulge SDSS g-i colour index (3)
172-176 F5.2 mag r-z-disc Disc SDSS r-z colour index (3)
178-187 F10.2 mag r-z-bar Bar SDSS r-z colour index (3)
189-193 F5.2 mag r-z-bulge ?=0 SDSS Bulge r-z colour index (3)
195-198 F4.2 --- chi2 Reduced chi2 value of the fit
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Note (1): stellar masses are drawn from average values in the MPA-JHU
catalogue (Kauffmann et al., 2003MNRAS.341...33K 2003MNRAS.341...33K).
Note (2): from the GZ2 catalogue (Willett et al., 2013, Cat. J/MNRAS/435/2835),
based on the volunteers' visual inspection.
Note (3): corrected for Galactic reddening and extinction using the maps from
Schlegel, Finkbeiner & Davis (1998ApJ...500..525S 1998ApJ...500..525S) and k-corrected
(Blanton & Roweis, 2007AJ....133..734B 2007AJ....133..734B).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Nov-2020