J/ApJ/862/13 The Carnegie-Irvine Galaxy Survey. VI. Spirals (Yu+, 2018)
The Carnegie-Irvine Galaxy Survey. VI. Quantifying spiral structure.
Yu S.-Y., Ho L.C., Barth A.J., Li Z.-Y.
<Astrophys. J., 862, 13 (2018)>
=2018ApJ...862...13Y 2018ApJ...862...13Y
ADC_Keywords: Galaxies, photometry; Morphology; Surveys
Keywords: galaxies: photometry ; galaxies: spiral ; galaxies: structure
Abstract:
The Carnegie-Irvine Galaxy Survey provides high-quality broadband
optical images of a large sample of nearby galaxies for detailed study
of their structure. To probe the physical nature and possible
cosmological evolution of spiral arms, a common feature of many disk
galaxies, it is important to quantify their main characteristics. We
describe robust methods to measure the number of arms and their mean
strength, length, and pitch angle. The arm strength depends only
weakly on the adopted radii over which it is measured, and it is
stronger in bluer bands than redder bands. The vast majority of
clearly two-armed ("grand-design") spiral galaxies have a
systematically higher relative amplitude of the m=2 Fourier mode in
the main spiral region. We use both one-dimensional and
two-dimensional Fourier decomposition to measure the pitch angle,
finding reasonable agreement between these two techniques with a
scatter of ∼2°. To understand the applicability and limitations of
our methodology to imaging surveys of local and distant galaxies, we
create mock images with properties resembling observations of local
(z≲0.1) galaxies by the Sloan Digital Sky Survey and distant galaxies
(0.1≲z≲1.1) observed with the Hubble Space Telescope. These
simulations lay the foundation for forthcoming quantitative
statistical studies of spiral structure to understand its formation
mechanism, dependence on galaxy properties, and cosmological
evolution.
Description:
The Carnegie-Irvine Galaxy Survey (CGS) is an optical imaging survey
of a statistically complete sample of 605 bright (BT≤12.9mag),
nearby (median DL=24.9Mpc) galaxies in the southern sky (δ≤0°).
The observations were made using the 100 inch du Pont telescope at Las
Campanas Observatory in Chile. The broadband BVRI images have a field
of view of 8.9'x8.9'.
Our final sample of 211 spiral galaxies spans the full range of Hubble
types.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 178 211 Properties of spiral arms
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/ApJ/542/673 : Morphological types of galaxies in clusters (Fasano+, 2000)
J/ApJS/147/1 : Classification of nearby galaxies (Conselice+, 2003)
J/A+A/423/849 : Spiral galaxies observed in the K band (Grosbol, 2004)
J/A+A/438/507 : Degree of lopsidedness for galaxies (Bournaud+, 2005)
J/MNRAS/397/1756 : Fourier-derived param. of the CIG sample (Durbala+, 2009)
J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Gal. (Sheth+, 2010)
J/ApJS/197/21 : The Carnegie-Irvine Galaxy Survey (CGS). I. (Ho+, 2011)
J/ApJS/197/22 : The Carnegie-Irvine Galaxy Survey (GGS). II. (Li+, 2011)
J/ApJS/219/4 : S4G pipeline 4: multi-component decompositions (Salo+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Galaxy identifier
14- 17 A4 --- TType Hubble morphology type
19- 20 A2 --- AC Arm class from this work (1)
22- 23 I2 --- ElmAC [1/12]? Elmegreen & Elmegreen
(1987ApJ...314....3E 1987ApJ...314....3E & 1995ApJ...445..591E 1995ApJ...445..591E)
arm class (2)
25- 28 F4.2 --- ell [0.03/0.6] Ellipticity (3)
30- 34 F5.1 deg PA Position angle (3)
36 I1 --- M1D [1/4]? The 1D method Fourier mode
chosen for further analysis
38 I1 --- M2D [2/4]? The 2D method Fourier mode
chosen for further analysis
40- 42 I3 arcsec RR1Dlo [4/152]? Lower 1D method radial range
44- 46 I3 arcsec RR1Dup [19/245]? Upper 1D method radial range
48- 50 I3 arcsec RR2Dlo [4/140]? Lower 2D method radial range
52- 54 I3 arcsec RR2up [29/236]? Upper 2D method radial range
56- 58 I3 arcsec Larm [27/668]? Spiral arm length
60- 61 I2 arcsec e_Larm [0/57]? Uncertainty in Larm
63- 66 F4.2 --- SB [0.06/0.96]? Mean strength for B image
68- 71 F4.2 --- e_SB [0.01/0.09]? Uncertainty in SB
73- 76 F4.2 --- SV [0.05/0.94] Mean strength for V image
78- 81 F4.2 --- e_SV [0.01/0.08] Uncertainty in SV
83- 86 F4.2 --- SR [0.06/0.95] Mean strength for R image
88- 91 F4.2 --- e_SR [0.01/0.08] Uncertainty in SR
93- 96 F4.2 --- SI [0.06/0.92] Mean strength for I image
98-101 F4.2 --- e_SI [0.0/0.08] Uncertainty in SI
103-106 F4.2 --- S2 [0.03/0.8]? Mean relative amplitude of m=2
Fourier mode for R image
108-111 F4.1 deg Pitch2DB [6.3/43]? Pitch angle using 2DDFT for B image
113-115 F3.1 deg e_Pitch2DB [0.4/7.3]? Uncertainty in Pitch2DB
117-120 F4.1 deg Pitch2DV [6.3/43]? Pitch angle using 2DDFT for V image
122-124 F3.1 deg e_Pitch2DV [0.4/8.7]? Uncertainty in Pitch2DV
126-129 F4.1 deg Pitch2DR [6/46.7]? Pitch angle using 2DDFT for R image
131-133 F3.1 deg e_Pitch2DR [0.5/9.2]? Uncertainty in Pitch2DR
135-138 F4.1 deg Pitch2DI [6/44.4]? Pitch angle using 2DDFT for I image
140-142 F3.1 deg e_Pitch2DI [0.4/9.2]? Uncertainty in Pitch2DI
144-147 F4.1 deg Pitch1DB [3.8/43.2]? Pitch angle using 1DDFT
for B image
149-151 F3.1 deg e_Pitch1DB [0.2/4.6]? Uncertainty in Pitch1DB
153-156 F4.1 deg Pitch1DV [4.7/46]? Pitch angle using 1DDFT for V image
158-160 F3.1 deg e_Pitch1DV [0.2/4]? Uncertainty in Pitch1DV
162-165 F4.1 deg Pitch1DR [4.2/46]? Pitch angle using 1DDFT for R image
167-169 F3.1 deg e_Pitch1DR [0.2/4]? Uncertainty in Pitch1DR
171-174 F4.1 deg Pitch1DI [4.4/48.4]? Pitch angle using 1DDFT
for I image
176-178 F3.1 deg e_Pitch1DI [0.2/4]? Uncertainty in Pitch1DI
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Note (1): Arm class as follows:
G = grand-design galaxy (23 occurrences);
NG = non-grand-design galaxy (188 occurrences).
Note (2): Arm class from Elmegreen & Elmegreen (1987ApJ...314....3E 1987ApJ...314....3E) as follows:
1 = Chaotic, fragmented, unsymmetric arms
2 = Fragmented spiral arm pieces with no regular pattern
3 = Fragmented arms uniformly distributed around the galactic center
4 = Only one prominent arm; otherwise fragmented arms
5 = Two symmetric, short arms in the inner regions; irregular outer arms
6 = Two symmetric inner arms; feathery ringlike outer structure
7 = Two symmetric, long outer arms; feathery or irregular inner arms
8 = Tiqghtly wrapped ringlike arms
9 = Two symmetric inner arms; multiple long and continuous outer arms
12 = Two long symmetric arms dominating the optical disk
Note (3): The ellipticities and position angles (PAs) used in this work are
mainly taken from Li+ (2011, J/ApJS/197/22).
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History:
From electronic version of the journal
References:
Ho et al. Paper I. 2011ApJS..197...21H 2011ApJS..197...21H Cat. J/ApJS/197/21
Li et al. Paper II. 2011ApJS..197...22L 2011ApJS..197...22L Cat. J/ApJS/197/22
Huang et al. Paper III. 2013ApJ...766...47H 2013ApJ...766...47H
Huang et al. Paper IV. 2016ApJ...821..114H 2016ApJ...821..114H Cat. J/ApJ/821/114
Li et al. Paper V. 2017ApJ...845...87L 2017ApJ...845...87L Cat. J/ApJ/845/87
Yu et al. Paper VI. 2018ApJ...862...13Y 2018ApJ...862...13Y This catalog
Gao et al. Paper VII. 2018ApJ...862..100G 2018ApJ...862..100G Cat. J/ApJ/862/100
Gao et al. Paper VIII. 2019ApJS..244...34G 2019ApJS..244...34G Cat. J/ApJS/244/34
Gao et al. Paper IX. 2020ApJS..247...20G 2020ApJS..247...20G Cat. J/ApJS/247/20
Gao et al. Paper X. 2022ApJS..262...54G 2022ApJS..262...54G Cat. J/ApJS/262/54
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Jul-2019