J/ApJ/911/109 RR Lyrae variable stars in DES Y6 (Stringer+, 2021)
Identifying RR Lyrae variable stars in six years of the Dark Energy Survey.
Stringer K.M., Drlica-Wagner A., Macri L., Martinez-Vazquez C.E.,
Vivas A.K., Ferguson P., Pace A.B., Walker A.R., Neilsen E., Tavangar K.,
Wester W., Abbott T.M.C., Aguena M., Allam S., Bacon D., Bechtol K.,
Bertin E., Brooks D., Burke D.L., Carnero Rosell A., Carrasco Kind M.,
Carretero J., Costanzi M., Crocce M., da Costa L.N., Pereira M.E.S.,
De Vicente J., Desai S., Diehl H.T., Doel P., Ferrero I., Garcia-Bellido J.,
Gaztanaga E., Gerdes D.W., Gruen D., Gruendl R.A., Gschwend J.,
Gutierrez G., Hinton S.R., Hollowood D.L., Honscheid K., Hoyle B.,
James D.J., Kuehn K., Kuropatkin N., Li T.S., Maia M.A.G., Marshall J.L.,
Menanteau F., Miquel R., Morgan R., Ogando R.L.C., Palmese A.,
Paz-Chinchon F., Plazas A.A., Roodman A., Sanchez E., Schubnell M.,
Serrano S., Sevilla-Noarbe I., Smith M., Soares-Santos M., Suchyta E.,
Tarle G., Thomas D., To C., Varga T.N., Wilkinson R.D., Zhang Y.,
The DES Collaboration
<Astrophys. J., 911, 109 (2021)>
=2021ApJ...911..109S 2021ApJ...911..109S
ADC_Keywords: Stars, variable; Photometry, ugriz; Extinction;
Cross identifications
Keywords: RR Lyrae variable stars ; RRab variable stars ;
Milky Way stellar halo ; Milky Way Galaxy
Abstract:
We present a search for RR Lyrae stars using the full six-year data
set from the Dark Energy Survey covering ∼5000deg2 of the southern
sky. Using a multistage multivariate classification and light-curve
template-fitting scheme, we identify RR Lyrae candidates with a median
of 35 observations per candidate. We detect 6971 RR Lyrae candidates
out to ∼335kpc, and we estimate that our sample is >70% complete at
∼150kpc. We find excellent agreement with other wide-area RR Lyrae
catalogs and RR Lyrae studies targeting the Magellanic Clouds and
other Milky Way satellite galaxies. We fit the smooth stellar halo
density profile using a broken-power-law model with fixed halo
flattening (q=0.7), and we find strong evidence for a break at
R0=32.1-0.9+1.1kpc with an inner slope of
n1=-2.54-0.09+0.09 and an outer slope of
n2=-5.42-0.14+0.13. We use our catalog to perform a search for
Milky Way satellite galaxies with large sizes and low luminosities.
Using a set of simulated satellite galaxies, we find that our RR
Lyrae-based search is more sensitive than those using resolved stellar
populations in the regime of large (rh≥500pc), low-surface-brightness
dwarf galaxies. A blind search for large, diffuse satellites yields
three candidate substructures. The first can be confidently associated
with the dwarf galaxy Eridanus II. The second has a distance and
proper motion similar to the ultrafaint dwarf galaxy Tucana II but is
separated by ∼5 deg. The third is close in projection to the globular
cluster NGC 1851 but is ∼10 kpc more distant and appears to differ in
proper motion.
Description:
The Dark Energy Survey (DES, see II/371) was a six-year
optical/near-infrared imaging survey covering ∼5000deg2 of the
southern Galactic cap using the Dark Energy Camera (DECam) mounted at
the prime focus of the 4m Blanco telescope at the Cerro Tololo
Inter-American Observatory (CTIO). Observations were completed in
2019-January. DES obtained ∼10x90s exposures in five broadband filters,
grizY.
As in Stringer+ 2019, J/AJ/158/16, the light curves for this work were
assembled using the internal DES "Quick" release pipeline.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 256 6971 The Dark Energy Survey (DES) Y6 RRab candidates
lcs/* . 6971 The light curves in CSV format for
each RRab candidate
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See also:
II/347 : KiDS-ESO-DR3 multi-band source catalog (de Jong+, 2017)
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
J/AcA/51/221 : OGLE-II. Cepheids in IC 1613 (Udalski+, 2001)
J/AJ/123/840 : VI photometry of variable stars in Fornax (Bersier+, 2002)
J/AJ/127/1158 : QUEST RR Lyrae Survey first catalog (Vivas+, 2004)
J/AJ/132/714 : QUEST RR Lyrae survey. II. Halo overdensities (Vivas+, 2006)
J/MNRAS/398/1757 : RR Lyraes in SDSS stripe 82 (Watkins+, 2009)
J/ApJ/712/1259 : LCID project. II. Variables in IC1613 (Bernard+, 2010)
J/ApJ/708/717 : Light curve templates of RR Lyrae stars (Sesar+, 2010)
J/ApJ/731/4 : Galactic halo as seen by the CFHTLS (Sesar+, 2011)
J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)
J/ApJ/753/106 : Quasar variability with SDSS & POSS imaging (MacLeod+, 2012)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)
J/ApJ/765/154 : RR Lyrae stars in the Catalina Sky Survey (Drake+, 2013)
J/AJ/145/160 : Variables in LMC GCs. III. Reticulum (Kuehn+, 2013)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/ApJ/788/105 : XSTPS RR Lyrae in the north Galactic cap (Faccioli+, 2014)
J/ApJ/793/135 : Positions and distances of RR Lyrae stars (Sesar+, 2014)
J/ApJ/793/62 : Triangulum-Andromeda stellar properties (Sheffield+, 2014)
J/PASP/126/616 : Variable stars in Leo I dSph (Stetson+, 2014)
J/ApJ/781/22 : Region I of La Silla QUEST RR Lyrae stars (Zinn+, 2014)
J/A+A/584/A106 : Catalogues of variable AGNs (Simm+, 2015)
J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)
J/ApJ/817/73 : QSOs & RR Lyrae in PS1 3π Data (Hernitschek+ 2016)
J/MNRAS/462/4349 : Variable stars in Sculptor dSph (Martinez-Vazquez+, 2016)
J/MNRAS/469/3688 : CSS Periodic Variable Star Catalogue (Drake+, 2017)
J/AJ/154/263 : NIR photometry of 77 RR Lyrae stars (Karczmarek+, 2017)
J/ApJ/850/137 : ISLAndS project. III. Var. stars (Martinez-Vazquez+, 2017)
J/AJ/153/204 : RR Lyrae stars from the PS1 3π survey (Sesar+, 2017)
J/AJ/153/107 : Australian Dark Energy Survey (OzDES) QSO cat. (Tie+, 2017)
J/AJ/154/85 : CTIO/DECam photometry of RR Lyrae stars in M5 (Vivas+, 2017)
J/MNRAS/474/4112 : Candidate RR Lyr star streams in inner Galaxy (Mateu+, 2018)
J/ApJ/855/43 : Distant RR Lyrae stars discovered with HiTS (Medina+, 2018)
J/MNRAS/480/669 : Variable stars in the SMCNOD (Prudil+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/A+A/624/A13 : KiDS DR3 QSO catalog (Nakoneczny+, 2019)
J/ApJ/875/77 : PMs of MW satellites with Gaia & DES (Pace+, 2019)
J/AJ/158/223 : RR Lyrae members of Pal 5 stream (Price-Whelan+, 2019)
J/AJ/158/16 : Identification of RR Lyrae stars from DES (Stringer+, 2019)
J/ApJ/893/47 : MW satellite census. I. DES & PS1 (Drlica-Wagner+, 2020)
J/A+A/638/A104 : GaiaDR2 cand. RR Lyrae of Sgr stream & dwarf (Ramos+, 2020)
J/ApJ/892/137 : Spectroscopy of Grus II, Tuc IV and Tuc V (Simon+, 2020)
http://www.sdss.org/ : SDSS home page
http://des.ncsa.illinois.edu/releases/other/y6-rrl : DES Y6 RR Lyrae home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- ID [871765223/1700521769] DES Y6A1 Coadd Object ID
12- 21 F10.6 deg RAdeg Right Ascension, decimal degrees (J2000)
23- 32 F10.6 deg DEdeg [-67/5] Decination, decimal degrees (J2000)
34- 38 F5.3 mag Ag [0.01/0.55] Extinction, g band (1)
40- 44 F5.3 mag Ar [0.008/0.4] Extinction, r band (1)
46- 50 F5.3 mag Ai [0.006/0.3] Extinction, i band (1)
52- 56 F5.3 mag Az [0.004/0.21] Extinction, z band (1)
58- 62 F5.3 mag AY [0.004/0.18] Extinction, Y band (1)
64- 69 F6.3 mag gmag0 [14.15/23.44]? Mean g-band magnitude with
extinction correction
71- 76 F6.3 mag rmag0 [14.38/23.3]? Mean r-band magnitude with
extinction correction
78- 83 F6.3 mag imag0 [14.43/23.2]? Mean i-band magnitude with
extinction correction
85- 90 F6.3 mag zmag0 [14.19/23.01]? Mean z-band magnitude with
extinction correction
92- 97 F6.3 mag Ymag0 [13.87/22.34]? Mean Y-band magnitude with
extinction correction
99- 100 I2 --- Nobs [10/73] Number of Observations
102- 107 F6.4 d Per [0.3/1] Best fit period
109- 113 F5.3 mag Amp [0.14/1.93] Best-fit model amplitude
115- 119 F5.2 mag mu [13.26/22.61] Best-fit distance modulus
121- 125 F5.3 --- RF1 [0.75/1] Score from first random forest
classifier (variability)
127- 131 F5.3 --- RF2 [0.34/1] Score from second random forest
classifier (variability)
133- 137 F5.3 --- RF3 [0.6/1] Score from third random forest
classifier (template fit)
139- 157 I19 --- GaiaDR2 ?=-99 Gaia DR2 source_id for cross-matched
RRab in Clementini+ (2019, J/A+A/622/A60)
159- 164 I6 --- PS1 ?=-99 Pan-Starrs PS1 identifier from
Sesar+ (2017, J/AJ/153/204) RRab catalog
166- 178 I13 --- CSDR2 ?=-99 Catalina Surveys DR2 RRab catalog
identifier (2)
180- 193 I14 --- DESY3Q2 ?=-99 DES Y3Q2 identifier from
Stringer+ (2019, J/AJ/158/16)
195- 209 A15 --- Sys Association with resolved stellar system
211- 230 A20 --- SysID Star identifier in System from previous study
232- 250 A19 --- r_Sys Reference for star in System (3)
252- 256 A5 --- ACc Anomalous Cepheid candidate
("True"=11 occurrences or "False")
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Note (1): Extinction derived from Schlegel+ (1998ApJ...500..525S 1998ApJ...500..525S) converted
to extinction in DES filters:
Ag=3.6830*EBV;
Ar=2.6048*EBV;
Ai=1.9401*EBV;
Az=1.4505*EBV;
AY=1.2774*EBV;
Note (2): The Catalina Sky Surveys DR2 include Drake+ 2013, J/ApJ/763/32 ;
2013, J/ApJ/765/154 and 2014, J/ApJS/213/9 ;
Torrealba+ 2015, J/MNRAS/446/2251 and Drake+ 2017, J/MNRAS/469/3688).
Note (3): Reference as follows:
Bersier+02 = Bersier & Wood 2002, J/AJ/123/840 (275 occurrences;
in Simbad)
Clement+01 = Clement C.M. 2001, V/150 (1 occurrence)
Kuehn+13 = Kuehn+ 2013, J/AJ/145/160 (14 occurrences)
Martinez-Vazquez+16 = Martinez-Vazquez+ 2016, J/MNRAS/462/4349
(112 occurrences; <[MSM2016] scl-CEMVNNN> in Simbad)
Martinez-Vazquez+19 = Martinez-Vazquez+ 2019MNRAS.490.2183M 2019MNRAS.490.2183M (3 occurrences)
Soszynski+16 = Soszynski+ 2016, J/AcA/66/131 (635 occurrences;
in Simbad)
Soszynski+17 = Soszynski+ 2017AcA....67..103S 2017AcA....67..103S (1 occurrence)
Vivas+20 = Vivas+, 2020ApJS..247...35V 2020ApJS..247...35V (1 occurrence)
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History:
From electronic version of the journal for Table 1
Light curves (rrablcv4.tar.gz) downloaded at:
http://des.ncsa.illinois.edu/releases/other/y6-rrl
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Oct-2022