J/ApJS/269/3 Siena Galaxy Atlas 2020 (SGA-2020) (Moustakas+, 2023)
Siena Galaxy Atlas 2020.
Moustakas J., Lang D., Dey A., Juneau S., Meisner A., Myers A.D.,
Schlafly E.F., Schlegel D.J., Valdes F., Weaver B.A., Zhou R.
<Astrophys. J. Suppl. Ser., 269, 3 (2023)>
=2023ApJS..269....3M 2023ApJS..269....3M
ADC_Keywords: Galaxy catalogs; Photometry, ugriz; Morphology; Galaxies, radius;
Redshifts
Keywords: Galaxy photometry ; Celestial objects catalogs
Abstract:
We present the 2020 version of the Siena Galaxy Atlas (SGA-2020), a
multiwavelength optical and infrared imaging atlas of 383620 nearby
galaxies. The SGA-2020 uses optical grz imaging over ∼20000deg2 from
the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys
Data Release 9 and infrared imaging in four bands (spanning
3.4-22µm) from the 6 year unWISE coadds; it is more than 95%
complete for galaxies larger than R(26)∼25" and r<18 measured at the
26mag/arcsec2 isophote in the r band. The atlas delivers precise
coordinates, multiwavelength mosaics, azimuthally averaged optical
surface-brightness profiles, model images and photometry, and
additional ancillary metadata for the full sample. Coupled with
existing and forthcoming optical spectroscopy from the DESI, the
SGA-2020 will facilitate new detailed studies of the star formation
and mass assembly histories of nearby galaxies; enable precise
measurements of the local velocity field via the Tully-Fisher and
fundamental plane relations; serve as a reference sample of lasting
legacy value for time-domain and multimessenger astronomical events;
and more.
Description:
We opt to construct the initial SGA-2020 parent sample using the
HyperLeda extragalactic database. We supplement the initial HyperLeda
catalog selection with sources drawn from additional catalogs
including the Legacy Surveys Data Release 8 (DR8) photometric
catalogs. See Section 2.
We build the SGA-2020 from the same optical and infrared imaging data
used to produce the Legacy Surveys DR9. Briefly, the optical data
consist of grz imaging over ∼20000deg2 from a number of different
surveys. In the North Galactic Cap, we use data from the
Beijing-Arizona Sky Survey (BASS), which provides ∼5000deg2 of gr
imaging using the 90Prime Camera on the Steward Observatory Bok 2.3m
telescope at KPNO; and data from the Mayall z-band Legacy Survey
(MzLS), which provides z-band imaging over the same ∼5000deg2
footprint as BASS using the Mosaic-3 camera at the KPNO Mayall 4m
telescope.
In the South Galactic Cap (SGC) and in the North Galactic Cap up to a
decl. of approximately +32°, we use grz imaging over ∼15000deg2
from roughly 50 distinct (but uniformly processed) data sets obtained
with the Dark Energy Camera (DECam) at the Cerro Tololo Inter-American
Observatory 4m Blanco telescope. Note that the majority of this DECam
imaging comes from the DECam Legacy Survey (DECaLS) and the Dark
Energy Survey (DES).
We supplement the optical data with all-sky infrared imaging at
3.4-22um from WISE. Specifically, we use the
6yr WISE plus NEOWISE-Reactivation (NEOWISE-R;
Mainzer+ 2014, J/ApJ/792/30) image stacks in W1 (3.4um) and W2
(4.6um) from Meisner+ (2021RNAAS...5..168M 2021RNAAS...5..168M), and the W3 (12um) and W4
(22um) unblurred image stacks from Lang (2014AJ....147..108L 2014AJ....147..108L);
collectively, we refer to these custom image stacks as the unWISE
coadds.
Acknowledging the SGA-2020 data products in publications:
Use of the SGA-2020 data products must acknowledge the Scientific
Publication Acknowledgment for the DESI Legacy Imaging Surveys, as
well as the specific SGA acknowledgment.
If you are already using the standard DESI Acknowledgments in your
paper, you can use this short Acknowledgment:
The DESI Legacy Imaging Surveys consist of three individual and
complementary projects: the Dark Energy Camera Legacy Survey (DECaLS),
the Beijing-Arizona Sky Survey (BASS), and the Mayall z-band Legacy
Survey (MzLS). DECaLS, BASS and MzLS together include data obtained,
respectively, at the Blanco telescope, Cerro Tololo Inter-American
Observatory, NSF's NOIRLab; the Bok telescope, Steward Observatory,
University of Arizona; and the Mayall telescope, Kitt Peak National
Observatory, NOIRLab. NOIRLab is operated by the Association of
Universities for Research in Astronomy (AURA) under a cooperative
agreement with the National Science Foundation. Pipeline processing
and analyses of the data were supported by NOIRLab and the Lawrence
Berkeley National Laboratory (LBNL). Legacy Surveys also uses data
products from the Near-Earth Object Wide-field Infrared Survey
Explorer (NEOWISE), a project of the Jet Propulsion
Laboratory/California Institute of Technology, funded by the National
Aeronautics and Space Administration. Legacy Surveys was supported by:
the Director, Office of Science, Office of High Energy Physics of the
U.S. Department of Energy; the National Energy Research Scientific
Computing Center, a DOE Office of Science User Facility; the U.S.
National Science Foundation, Division of Astronomical Sciences; the
National Astronomical Observatories of China, the Chinese Academy of
Sciences and the Chinese National Natural Science Foundation. LBNL is
managed by the Regents of the University of California under contract
to the U.S. Department of Energy.
The complete acknowledgments can be found at
http://www.legacysurvey.org/acknowledgment/
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sga2020.dat 1136 383620 Ellipse-fitting results
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Description of file:
SGA-2020.fits is the original catalog in FITS format downloaded at:
http://sga.legacysurvey.org/
See also:
VII/119 : Catalogue of Principal Galaxies (PGC) (Paturel+ 1989)
VII/155 : Third Reference Cat. of Bright Galaxies (RC3) (de Vaucouleurs+ 1991)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
VII/239 : History and Accurate Positions for the NGC/IC Objects (Corwin, 2004)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
J/AJ/108/2128 : RC3 corrections and additions (Corwin+ 1994)
J/ApJS/173/185 : GALEX UV atlas of nearby galaxies (Gil de Paz+, 2007)
J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Gal. (Sheth+, 2010)
J/ApJS/196/11 : Bulge+disk decompositions of SDSS galaxies (Simard+, 2011)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/MNRAS/446/3943 : galaxies 2D phot. decompositions in SDSS-DR7 (Meert+, 2015)
J/AJ/154/86 : MaNGA catalog, DR15 (Wake+, 2017)
J/ApJS/245/25 : WISE Extended Source Catalog (WXSC). I. (Jarrett+, 2019)
J/ApJS/244/24 : z=0 Multiwavelength Galaxy Synthesis (z0MGS) (Leroy+, 2019)
J/ApJS/267/27 : SMUDGes V. Complete cat. of UDGs from DR9 (Zaritsky+, 2023)
http://sga.legacysurvey.org/ : Siena Galaxy Atlas 2020 home page
Byte-by-byte Description of file: sga2020.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID [2/5005247] SGA unique
identification number (SGA_ID)
9- 24 A16 --- SGA2020 SGA-2020 name (SGA-2020 @{ID})
(SGA_GALAXY)
26- 54 A29 --- Name Unique galaxy name (GALAXY)
56- 62 I7 --- PGC [1/6740716]? Unique identifier from
the Principal Catalogue of Galaxies
(Paturel+ 1989, VII/119 ;
obsoleted by VII/237) (PGC)
64- 74 F11.7 deg RALdeg Right ascension (J2000) from the
reference indicated in Ref (RA_LEDA)
76- 86 F11.7 deg DELdeg Declination (J2000) from the
reference indicated in Ref
(DEC_LEDA)
88- 96 A9 --- MType Visual morphological type from
HyperLeda (if available) (MORPHTYPE)
98- 103 F6.2 deg PA-LEDA Galaxy position angle (measured
east of north); taken from the
reference indicated in Ref (PA_LEDA)
105- 111 F7.4 arcmin D25-LEDA [0.16/63] Major-axis diameter at
the 25mag/arcsec2 (optical)
surface-brightness isophote; taken
from the reference indicated in Ref
(D25_LEDA)
113- 118 F6.4 --- b/a-LEDA [0.03/1] Ratio of the semiminor
axis to the semimajor axis; taken
from the reference indicated in Ref
(BA_LEDA)
120- 128 F9.5 --- z-LEDA [-0.003/4.4]? Heliocentric redshift
from HyperLeda; a NULL value does
not imply that no redshift exists
(Z_LEDA)
130- 136 F7.4 mag/arcsec2 SBD25-LEDA [14.5/31.7] Mean surface brightness
based on D25-LEDA and mag-LEDA
(SBD25LEDA)
138- 144 F7.4 mag mag-LEDA [6.3/25] Apparent bt-band Vega
magnitude (MAG_LEDA) (1)
146 I1 --- ByHand [0/1] Boolean flag indicating
whether one or more of RALdeg,
DELdeg, D25-LEDA, PA-LEDA,
b/a-LEDA, or mag-LEDA were changed
from their published values
(usually via visual inspection)
while building the parent sample
(BYHAND)
148- 160 A13 --- Ref Reference indicating the origin of
the object (REF) (2)
162- 167 I6 --- GroupID [0/531676] Unique group
identification number (GROUP_ID)
169- 197 A29 --- Group Group name, constructed from the
name of its largest member (see
Section 2.2). For isolated
galaxies, identical to Name
(GROUP_NAME)
199- 200 I2 --- Nm [1/13] Number of group members
(i.e., group multiplicity)
(GROUP_MULT)
202 I1 --- Prim [0/1] Boolean flag indicating the
primary (i.e., largest) group
member (GROUP_PRIMARY)
204- 214 F11.7 deg RAGdeg Mean R.A. of the group weighted by
D25-LEDA (GROUP_RA)
216- 226 F11.7 deg DEGdeg Mean decl. of the group weighted by
D25-LEDA (GROUP_DEC)
228- 234 F7.4 arcmin GrDiam [0.16/63] Approximate group
diameter (see Section 2.2)
(GROUP_DIAMETER)
236- 243 A8 --- BrickName Name of custom Tractor "brick,"
encoding the sky position (e.g.,
"1126p222" is centered on
RA=112.6,DE=+22.2) (BRICKNAME)
245- 255 F11.7 deg RAdeg Right ascension (J2000) based on
The Tractor model fit (RA)
257- 267 F11.7 deg DEdeg Declination (J2000) based on The
Tractor model fit (DEC)
269- 275 F7.4 arcmin D26 [0.06/78] Major axis diameter at
the µ=26mag/arcsec2 r-band
isophote (D26)
277- 280 A4 --- r_D26 Reference indicating the origin of
the DIAM measurement: SB26, SB25,
or LEDA (D26_REF) (3)
282- 287 F6.2 deg PA Galaxy position angle (measured
east of north), as measured from
the ellipse moments (see Section
3.2.3); equivalent to PA-LEDA if
the ellipse moments could not be
measured (PA)
289- 294 F6.4 --- b/a [0.06/1] Minor-to-major axis ratio,
as measured from the ellipse
moments; equivalent to b/a-LEDA if
the ellipse moments could not be
measured (BA)
296- 306 F11.7 deg RAMdeg Light-weighted R.A. (J2000), as
measured from the ellipse moments
(RA_MOMENT) (4)
308- 318 F11.7 deg DEMdeg Light-weighted decl. (J2000), as
measured from the ellipse moments
(DEC_MOMENT) (4)
320- 328 F9.4 arcsec SMA-Moment [0.3/1084]? Second moment of the
light distribution along the major
axis based on the measured ellipse
moments (SMA_MOMENT) (5)
330- 340 E11.6 arcsec gSMA50 [0/93493]? Half-light semimajor
axis length based on Equation-2 in
g-band (G_SMA50)
342- 352 E11.6 arcsec rSMA50 [0/62331]? Half-light semimajor
axis length based on Equation-2 in
r-band (R_SMA50)
354- 364 E11.6 arcsec zSMA50 [0/7e+9]? Half-light semimajor
axis length based on Equation-2 in
z-band (Z_SMA50)
366- 374 F9.4 arcsec SMASB22 [0.03/1901]? Semimajor axis length
at the r-band 22mag/arcsec2
isophote (SMA_SB22)
376- 386 F11.4 arcsec SMASB22.5 [0.003/104140]? Semimajor axis
length at the r-band
22.5mag/arcsec2 isophote
(SMA_SB22.5)
388- 398 F11.4 arcsec SMASB23 [0.005/147363]? Semimajor axis
length at the r-band
23mag/arcsec2 isophote (SMA_SB23)
400- 410 F11.4 arcsec SMASB23.5 [0.003/245391]? Semimajor axis
length at the r-band
23.5mag/arcsec2 isophote
(SMA_SB23.5)
412- 419 F8.4 arcsec SMASB24 [0.1/733]? Semimajor axis length at
the r-band 24mag/arcsec2 isophote
(SMA_SB24)
421- 428 F8.4 arcsec SMASB24.5 [0.2/867]? Semimajor axis length at
the r-band 24.5mag/arcsec2
isophote (SMA_SB24.5)
430- 437 F8.4 arcsec SMASB25 [0.19/702]? Semimajor axis length
at the r-band 25mag/arcsec2
isophote (SMA_SB25)
439- 446 F8.4 arcsec SMASB25.5 [0.9/774]? Semimajor axis length at
the r-band 25.5mag/arcsec2
isophote (SMA_SB25.5)
448- 455 F8.4 arcsec SMASB26 [1.9/828]? Semimajor axis length at
the r-band 26mag/arcsec2 isophote
(SMA_SB26)
457- 463 F7.4 mag gmagSB22 [8.8/51]? Cumulative g-band
brightness measured within SMASB22
(GMAGSB22)
465- 471 F7.4 mag rmagSB22 [8/28.4]? Cumulative r-band
brightness measured within SMASB22
(RMAGSB22)
473- 479 F7.4 mag zmagSB22 [7.6/43.4]? Cumulative z-band
brightness measured within SMASB22
(ZMAGSB22)
481- 487 F7.4 mag gmagSB22.5 [8.8/49.1]? Cumulative g-band
brightness measured within
SMASB22.5 (GMAGSB22.5)
489- 495 F7.4 mag rmagSB22.5 [8/36]? Cumulative r-band
brightness measured within
SMASB22.5 (RMAGSB22.5)
497- 503 F7.4 mag zmagSB22.5 [7.5/46.3]? Cumulative z-band
brightness measured within
SMASB22.5 (ZMAGSB22.5)
505- 511 F7.4 mag gmagSB23 [8.8/47]? Cumulative g-band
brightness measured within SMASB23
(GMAGSB23)
513- 519 F7.4 mag rmagSB23 [8/34.7]? Cumulative r-band
brightness measured within SMASB23
(RMAGSB23)
521- 527 F7.4 mag zmagSB23 [7.5/51.6]? Cumulative z-band
brightness measured within SMASB23
(ZMAGSB23)
529- 535 F7.4 mag gmagSB23.5 [8.7/48.1]? Cumulative g-band
brightness measured within
SMASB23.5 (GMAGSB23.5)
537- 543 F7.4 mag rmagSB23.5 [8/35]? Cumulative r-band
brightness measured within
SMASB23.5 (RMAGSB23.5)
545- 551 F7.4 mag zmagSB23.5 [7.5/43.4]? Cumulative z-band
brightness measured within
SMASB23.5 (ZMAGSB23.5)
553- 559 F7.4 mag gmagSB24 [8.7/46]? Cumulative g-band
brightness measured within SMASB24
(GMAGSB24)
561- 567 F7.4 mag rmagSB24 [8/28.5]? Cumulative r-band
brightness measured within SMASB24
(RMAGSB24)
569- 575 F7.4 mag zmagSB24 [7.4/43.4]? Cumulative z-band
brightness measured within SMASB24
(ZMAGSB24)
577- 583 F7.4 mag gmagSB24.5 [8.7/45.3]? Cumulative g-band
brightness measured within
SMASB24.5 (GMAGSB24.5)
585- 591 F7.4 mag rmagSB24.5 [8/27]? Cumulative r-band
brightness measured within
SMASB24.5 (RMAGSB24.5)
593- 599 F7.4 mag zmagSB24.5 [7.4/44.3]? Cumulative z-band
brightness measured within
SMASB24.5 (ZMAGSB24.5)
601- 607 F7.4 mag gmagSB25 [8.7/51.2]? Cumulative g-band
brightness measured within SMASB25
(GMAGSB25)
609- 615 F7.4 mag rmagSB25 [8/27.3]? Cumulative r-band
brightness measured within SMASB25
(RMAGSB25)
617- 623 F7.4 mag zmagSB25 [7.6/49]? Cumulative z-band
brightness measured within SMASB25
(ZMAGSB25)
625- 631 F7.4 mag gmagSB25.5 [8.7/46]? Cumulative g-band
brightness measured within
SMASB25.5 (GMAGSB25.5)
633- 639 F7.4 mag rmagSB25.5 [8/23.1]? Cumulative r-band
brightness measured within
SMASB25.5 (RMAGSB25.5)
641- 647 F7.4 mag zmagSB25.5 [7.6/42.3]? Cumulative z-band
brightness measured within
SMASB25.5 (ZMAGSB25.5)
649- 655 F7.4 mag gmagSB26 [8.6/47.1]? Cumulative g-band
brightness measured within SMASB26
(GMAGSB26)
657- 663 F7.4 mag rmagSB26 [8/24.5]? Cumulative r-band
brightness measured within SMASB26
(RMAGSB26)
665- 671 F7.4 mag zmagSB26 [7.6/23]? Cumulative z-band
brightness measured within SMASB26
(ZMAGSB26)
673- 681 F9.4 arcsec e_SMASB22 [0.001/3763]? SMASB22 1σ
uncertainty (SMASB22ERR)
683- 693 F11.4 arcsec e_SMASB22.5 [0.002/349384]? SMASB22.5 1σ
uncertainty (SMASB22.5ERR)
695- 705 F11.4 arcsec e_SMASB23 [0.002/318385]? SMASB23 1σ
uncertainty (SMASB23ERR)
707- 717 F11.4 arcsec e_SMASB23.5 [0.003/380471]? SMASB23.5 1σ
uncertainty (SMASB23.5ERR)
719- 725 F7.4 arcsec e_SMASB24 [0.004/6]? SMASB24 1σ
uncertainty (SMASB24ERR)
727- 733 F7.4 arcsec e_SMASB24.5 [0.006/8]? SMASB24.5 1σ
uncertainty (SMASB24.5ERR)
735- 741 F7.4 arcsec e_SMASB25 [0.009/7]? SMASB25 1σ
uncertainty (SMASB25ERR)
743- 749 F7.4 arcsec e_SMASB25.5 [0.01/13]? SMASB25.5 1σ
uncertainty (SMASB25.5ERR)
751- 757 F7.4 arcsec e_SMASB26 [0.01/12]? SMASB26 1σ
uncertainty (SMASB26ERR)
759- 765 F7.4 mag e_gmagSB22 [0.0002/27]? gmagSB22 1σ
uncertainty (GMAGSB22_ERR)
767- 773 F7.4 mag e_rmagSB22 [0.0002/3]? rmagSB22 1σ
uncertainty (RMAGSB22_ERR)
775- 781 F7.4 mag e_zmagSB22 [0/4]? zmagSB22 1σ
uncertainty (ZMAGSB22_ERR)
783- 789 F7.4 mag e_gmagSB22.5 [0.0002/1]? gmagSB22.5 1σ
uncertainty (GMAGSB22.5_ERR)
791- 797 F7.4 mag e_rmagSB22.5 [0.0002/12]? rmagSB22.5 1σ
uncertainty (RMAGSB22.5_ERR)
799- 805 F7.4 mag e_zmagSB22.5 [0.0002/8]? zmagSB22.5 1σ
uncertainty (ZMAGSB22.5_ERR)
807- 813 F7.4 mag e_gmagSB23 [0.0002/10]? gmagSB23 1σ
uncertainty (GMAGSB23_ERR)
815- 821 F7.4 mag e_rmagSB23 [0.0002/7]? rmagSB23 1σ
uncertainty (RMAGSB23_ERR)
823- 829 F7.4 mag e_zmagSB23 [0.0002/64]? zmagSB23 1σ
uncertainty (ZMAGSB23_ERR)
831- 837 F7.4 mag e_gmagSB23.5 [0.0002/7]? gmagSB23.5 1σ
uncertainty (GMAGSB23.5_ERR)
839- 845 F7.4 mag e_rmagSB23.5 [0.0001/9]? rmagSB23.5 1σ
uncertainty (RMAGSB23.5_ERR)
847- 853 F7.4 mag e_zmagSB23.5 [0.0002/9]? zmagSB23.5 1σ
uncertainty (ZMAGSB23.5_ERR)
855- 861 F7.4 mag e_gmagSB24 [0.0002/2]? gmagSB24 1σ
uncertainty (GMAGSB24_ERR)
863- 869 F7.4 mag e_rmagSB24 [0.0001/3]? rmagSB24 1σ
uncertainty (RMAGSB24_ERR)
871- 877 F7.4 mag e_zmagSB24 [0.0002/74]? zmagSB24 1σ
uncertainty (ZMAGSB24_ERR)
879- 885 F7.4 mag e_gmagSB24.5 [0.0002/18]? gmagSB24.5 1σ
uncertainty (GMAGSB24.5_ERR)
887- 893 F7.4 mag e_rmagSB24.5 [0.0001/3]? rmagSB24.5 1σ
uncertainty (RMAGSB24.5_ERR)
895- 901 F7.4 mag e_zmagSB24.5 [0.0001/54]? zmagSB24.5 1σ
uncertainty (ZMAGSB24.5_ERR)
903- 909 F7.4 mag e_gmagSB25 [0.0002/16]? gmagSB25 1σ
uncertainty (GMAGSB25_ERR)
911- 917 F7.4 mag e_rmagSB25 [0.0001/5]? rmagSB25 1σ
uncertainty (RMAGSB25_ERR)
919- 925 F7.4 mag e_zmagSB25 [0.0001/9]? zmagSB25 1σ
uncertainty (ZMAGSB25_ERR)
927- 933 F7.4 mag e_gmagSB25.5 [0.0002/23]? gmagSB25.5 1σ
uncertainty (GMAGSB25.5_ERR)
935- 941 F7.4 mag e_rmagSB25.5 [0.0001/1]? rmagSB25.5 1σ
uncertainty (RMAGSB25.5_ERR)
943- 949 F7.4 mag e_zmagSB25.5 [0.0001/12]? zmagSB25.5 1σ
uncertainty (ZMAGSB25.5_ERR)
951- 957 F7.4 mag e_gmagSB26 [0.0002/28]? gmagSB26 1σ
uncertainty (GMAGSB26_ERR)
959- 965 F7.4 mag e_rmagSB26 [0.0001/7]? rmagSB26 1σ
uncertainty (RMAGSB26_ERR)
967- 974 F8.4 mag e_zmagSB26 [0.0001/133]? zmagSB26 1σ
uncertainty (ZMAGSB26_ERR)
976- 982 F7.4 mag gCOG-m1 [7.6/45.1]? Best-fitting
curve-of-growth parameter mtot
from Equation-1 in g-band
(GCOGPARAMS_MTOT) (6)
984- 994 E11.6 mag gCOG-m0 [1.5e-07/4.3e+11]? Best-fitting
curve-of-growth parameter m0 from
Equation-1 in g-band
(GCOGPARAMS_M0) (6)
996- 1006 E11.6 --- gCOG-alp1 [3.5e-10/6.2e+15]? Best-fitting
curve-of-growth parameter α1
from Equation-1 in g-band
(GCOGPARAMS_ALPHA1) (6)
1008- 1015 F8.4 --- gCOG-alp2 [0/169]? Best-fitting
curve-of-growth parameter α2
from Equation-1 in g-band
(GCOGPARAMS_ALPHA2) (6)
1017- 1027 F11.4 --- gCOG-Chi2 [0/463626]? Χ2 of the fit to
the curve of growth in g-band
(see Section 3.2.3)
(GCOGPARAMS_CHI2)
1029- 1035 F7.4 mag rCOG-m1 [7.5/23.5]? Best-fitting
curve-of-growth parameter mtot
from Equation-1 in r-band
(RCOGPARAMS_MTOT) (6)
1037- 1047 E11.6 mag rCOG-m0 [5.6e-7/2.1e+13]? Best-fitting
curve-of-growth parameter m0 from
Equation-1 in r-band
(RCOGPARAMS_M0) (6)
1049- 1059 E11.6 --- rCOG-alp1 [7.5e-9/1.5e+16]? Best-fitting
curve-of-growth parameter α1
from Equation-1 in r-band
(RCOGPARAMS_ALPHA1) (6)
1061- 1068 F8.4 --- rCOG-alp2 [0/183]? Best-fitting
curve-of-growth parameter α2
from Equation-1 in r-band
(RCOGPARAMS_ALPHA2) (6)
1070- 1080 F11.4 --- rCOG-Chi2 [0/572291]? Χ2 of the fit to
the curve of growth in r-band
(see Section 3.2.3)
(RCOGPARAMS_CHI2)
1082- 1088 F7.4 mag zCOG-m1 [6.9/40.4]? Best-fitting
curve-of-growth parameter mtot
from Equation-1 in z-band
(ZCOGPARAMS_MTOT) (6)
1090- 1100 E11.6 mag zCOG-m0 [7.6e-8/4e+12]? Best-fitting
curve-of-growth parameter m0 from
Equation-1 in z-band
(ZCOGPARAMS_M0) (6)
1102- 1112 E11.6 --- zCOG-alp1 [2.7e-10/6e+15]? Best-fitting
curve-of-growth parameter α1
from Equation-1 in z-band
(ZCOGPARAMS_ALPHA1) (6)
1114- 1121 F8.4 --- zCOG-alp2 [0/197]? Best-fitting
curve-of-growth parameter α2
from Equation-1 in z-band
(ZCOGPARAMS_ALPHA2) (6)
1123- 1133 F11.4 --- zCOG-Chi2 [0/405272]? Χ2 of the fit to
the curve of growth in z-band
(see Section 3.2.3)
(ZCOGPARAMS_CHI2)
1135- 1136 I2 --- Fit [0/32] Ellipse-fitting Bitmasks
described in Table 3 (ELLIPSEBIT)
(7)
--------------------------------------------------------------------------------
Note (1): This magnitude estimate is heterogeneous in both bandpass and
aperture but, for most galaxies, it is measured in the B band; use
with care.
Note (2): References as follows:
LEDA-20181114 = the HyperLeda extragalactic database;
http://leda.univ-lyon1.fr/ (380532 occurrences)
DR8 = the Legacy Surveys Data Release 8;
http://legacysurvey.org/dr8 (2889 occurrences)
OpenNGC = OpenNGC catalog; http://github.com/mattiaverga/OpenNGC
(142 occurrences)
LGDWARFS = Local Group dwarf galaxies from McConnachie (2012, J/AJ/144/4);
(29 occurrences)
RC3 = The third Reference Cat. of Bright Galaxies; see VII/155
(28 occurrences)
See Section 2.1.
Note (3): By default, we infer D26 from SMASB26. However, if the r-band
surface-brightness profile could not be measured at this level, we
estimate D26 as 2.5xSMASB25 or 1.5xD25-LEDA, in that order of priority.
Note (4): Light-weighted R.A. and decl. (J2000), as measured from the ellipse
moments. Equivalent to RA_X0 in Table 5 but set to RALdeg if ellipse
fitting failed or was not carried out.
Note (5): Second moment of the light distribution along the major axis based
on the measured ellipse moments. Equivalent to MAJORAXIS in Table 5
but converted to arcseconds. If ellipse-fitting or curve-of-growth
modeling failed or was not attempted, then the column value is NULL.
Note (6): We fit the curve of growth, m(r), using the following empirical model:
m(r)=mtot+m0loge[1+α1(r/r0)-α2]; Equation-1
where mtot, m0, α1, α2, and r0 are constant
parameters of the model, and r is the semimajor axis in arcseconds.
See Section 3.2.3.
Note (7): Ellipse-fitting Bitmasks as in Table 3:
---------------------------------------------------------------------------
Bit Bit name Definition
Number
---------------------------------------------------------------------------
0 --- Not used; ignore
1 REX_TOOSMALL Ellipse fit skipped; galaxy classified as
too-small type REX
2 NOTREX_TOOSMALL Ellipse fit skipped; galaxy classified as
too-small type EXP, DEV, or SER
3 FAILED Ellipse fitting was attempted but failed
4 NOTFIT Ellipse fitting was not attempted
5 REJECTED Ellipse-fitting results were rejected based
on visual inspection
---------------------------------------------------------------------------
Bitmask encoding various reasons why ellipse fitting failed or was not
attempted; see Section 3.2.3 for additional details.
See also: http://portal.nersc.gov/project/cosmo/temp/ioannis/sga-dr9/sga/
sga2020/#bitmasks
--------------------------------------------------------------------------------
History:
Downloaded from: http://sga.legacysurvey.org/
(End) Emmanuelle Perret [CDS] 25-Jan-2024