J/ApJ/864/11 The VVV Variables (V4) catalog (Medina+, 2018)
An automated tool to detect variable sources in the Vista Variables in the Via
Lactea Survey: The VVV Variables (V4) catalog of tiles d001 and d002.
Medina N., Borissova J., Bayo A., Kurtev R., Navarro Molina C., Kuhn M.,
Kumar N., Lucas P.W., Catelan M., Minniti D., Smith L.C.
<Astrophys. J., 864, 11 (2018)>
=2018ApJ...864...11M 2018ApJ...864...11M
ADC_Keywords: YSOs; Stars, variable; Photometry, infrared; Photometry, H-alpha;
Stars, distances
Keywords: catalogs; open clusters and associations: general;
stars: pre-main sequence; techniques: photometric
Abstract:
Time-varying phenomena are one of the most substantial sources of
astrophysical information, and their study has led to many fundamental
discoveries in modern astronomy. We have developed an automated tool
to search for and analyze variable sources in the near-infrared Ks
band using the data from the VISTA Variables in the Via Lactea (VVV)
ESO Public Large Survey. This process relies on the characterization
of variable sources using different variability indices calculated
from time series generated with point-spread function (PSF) photometry
of sources under analysis. In particular, we used two main indices,
the total amplitude ΔKs and the eta index η, to identify
variable sources. Once the variable objects are identified, periods
are determined with generalized Lomb-Scargle periodograms and the
information potential metric. Variability classes are assigned
according to a compromise between comparisons with VVV templates and
the period of the variability. The automated tool is applied on VVV
tiles d001 and d002 and led to the discovery of 200 variable sources.
We detected 70 irregular variable sources and 130 periodic ones. In
addition, nine open-cluster candidates projected in the region are
analyzed, and the infrared variable candidates found around these
clusters are further scrutinized by cross-matching their locations
against emission star candidates from VPHAS+ survey Hα color
cuts.
Description:
The VISTA Variables in the Via Lactea (VVV) survey is an ESO Infrared
Large Public survey (Minniti+ 2010NewA...15..433M 2010NewA...15..433M &
Saito+ 2012A&A...537A.107S 2012A&A...537A.107S) that uses the 4m VISTA telescope located
at Cerro Paranal Observatory, Chile. The survey was designed for
mapping 562deg2 in the Galactic bulge and the southern disk in five
near-infrared broadband filters --Z(λeff=0.8um),
Y (λeff=1.02um), H (λeff=1.25um),
J (λeff=1.64um), and Ks (λeff=2.14um-- with a time
coverage spanning 5yr between 2010 and 2015 in the Ks band).
To test our method, we choose the first two VVV disk tiles, namely
d001 and d002, due to their low crowding and interstellar reddening
when compared to the rest of the VVV disk area.
The preliminary reduced images were retrieved from the VISTA Science
Archive (VSA) database (Cross+ 2012A&A...548A.119C 2012A&A...548A.119C).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 79 9 Basic information on the star cluster candidates
in the region
table4.dat 62 73 VPHAS+ r, (r-i) and (r-Hα) magnitudes and
colors of the YSO candidates
table5.dat 285 201 The VVV Variables (V4) catalog of the first
two VVV disk tiles, namely d001 and d002
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See also:
II/337 : VISTA Variables in the Via Lactea Survey DR1 (Saito+, 2012)
II/341 : VPHAS+ DR2 survey (Drew+, 2016)
II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)
J/ApJS/112/557 : Classification of IRAS Sources (Kwok+ 1997)
J/A+AS/132/211 : Interstellar SiO sources (Harju+ 1998)
J/AcA/48/35 : All Sky Automated Survey variable stars (Pojmamski 1998)
J/AJ/121/3160 : JHK photom. near the Trapezium region (Carpenter+, 2001)
J/ApJS/161/118 : byHα photometry in open clusters (McSwain+, 2005)
J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/A+A/532/A131 : Galactic star clusters in VVV survey (Borissova+, 2011)
J/A+A/525/A149 : Red MSX Survey (RMS): bol. fluxes of YSOs (Mottram+, 2011)
J/MNRAS/416/817 : RV cat. of O-type stars in IC 2944 & Cen OB2 (Sana+, 2011)
J/AJ/143/70 : Differential reddening in MW GCs (Alonso-Garcia+, 2012)
J/A+A/545/A54 : Danks 1, Danks 2, and RCW 79 variables (Chene+, 2012)
J/ApJS/208/11 : Red MSX Source Survey: massive protostars (Lumsden+, 2013)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/MNRAS/440/2036 : VPHAS+ survey synthetic colours (Drew+, 2014)
J/MNRAS/441/715 : Mid-infrared study of RR Lyrae stars (Gavrilchenko+, 2014)
J/AJ/149/99 : VVV GCs. I. 2MASS-GC 02, Terzan 10 (Alonso-Garcia+, 2015)
J/MNRAS/453/1026 : Lagoon Nebula M8 T tauri accretion rates (Kalari+, 2015)
J/ApJ/810/L20 : VISTA KS photometry of EWS 2012-BLG-548 (Minniti+, 2015)
J/MNRAS/450/4364 : H2 emission from massive YSOs survey (Navarete+, 2015)
J/A+A/591/A145 : VVV Survey outer bulge RRab stars (Gran+, 2016)
J/other/NewA/49.50 : New Variables in 3 Galactic open clusters (Palma+, 2016)
J/MNRAS/465/3039 : Eruptive var. protostars from VVV EW (Contreras+, 2017)
J/MNRAS/465/3011 : VVV high amp. NIR variable stars (Contreras Pena+, 2017)
J/AJ/153/179 : VVV Survey RRLyrae in Southern Gal. plane (Minniti+, 2017)
http://horus.roe.ac.uk/vsa/ : VISTA Science Archive home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Tile Tile identifier (d001 or d002)
6- 18 A13 --- Name Cluster name
20- 21 I2 h RAh Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 27 I2 s RAs Second of right ascension (J2000)
29 A1 --- DE- Sign of declination (J2000)
30- 31 I2 deg DEd Degree of declination (J2000)
33- 34 I2 arcmin DEm Arcminute of declination (J2000)
36- 37 I2 arcsec DEs Arcsecond of declination (J2000)
39- 46 F8.4 deg GLON Galactic longitude
48- 54 F7.4 deg GLAT Galactic latitude
56- 59 F4.2 arcmin Rad [0.3/0.8] Radius
61- 64 F4.2 arcmin e_Rad [0.07/0.2] Radius uncertainty
66- 68 F3.1 mag E(J-K) [1/3.2] Color excess
70- 72 F3.1 mag e_E(J-K) [0.1/0.6] E(J-K) uncertainty
73 A1 --- f_E(J-K) a= Chene et al. (2013A&A...549A..98C 2013A&A...549A..98C)
75- 79 A5 --- AName Abbreviated cluster name as in Table 4;
column added by CDS
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- AName Abbreviated cluster name
6 A1 --- --- [_]
7- 9 A3 --- ID YSO candidate identifier within AName
11- 19 F9.5 deg RAdeg [174.7/178.9] Right Ascension (J2000)
21- 29 F9.5 deg DEdeg [-64.4/-63.2] Declination (J2000)
31- 35 F5.2 mag rmag [15.68/21.78] Photometric r band magnitude
37- 40 F4.2 mag e_rmag [0.01/0.27] Uncertainty in rmag
42- 45 F4.2 mag r-i [0.67/2.18] The (r-i) color index
47- 51 F5.3 mag e_r-i [0.007/0.138] Uncertainty in r-i
53- 56 F4.2 mag r-Ha [0.7/1.89] The (r-Hα) color index
58- 62 F5.3 mag e_r-Ha [0.007/0.159] Uncertainty in r-Ha
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Variable source identifier
10- 21 F12.8 deg RAdeg [174.1/180.9] Right Ascension (J2000)
23- 34 F12.8 deg DEdeg [-64.6/-62.8] Declination (J2000)
36- 48 F13.9 deg GLON [294.7/297.7] Galactic longitude
50- 63 F14.11 deg GLAT [-2.3/-1] Galactic latitude
65- 70 F6.3 mag KsmagAvg [11.2/16.4] Average Ks magnitude of time-series
72- 76 F5.3 mag e_KsmagAvg [0.01/0.3] Uncertainty in <Ksmag>
78- 79 I2 --- Epochs [25/55] Number of observations
81- 85 F5.3 mag DelKs [0.2/3.3] Total photometric amplitude in Ks band
87- 92 F6.3 mag Jmag [13.6/19.1]? Photometric J band magnitude
94- 98 F5.3 mag e_Jmag [0.004/0.1]? Uncertainty in Jmag
100-105 F6.3 mag Hmag [13.4/17.4]? Photometric H band magnitude
107-111 F5.3 mag e_Hmag [0.003/0.07]? Uncertainty in Hmag
113-119 F7.4 mag umag [12.8/21.2]? Photometric u band magnitude
121-128 F8.6 mag e_umag [0.0005/0.2]? Uncertainty in umag
130-136 F7.4 mag gmag [12/21.7]? Photometric g band magnitude
138-145 F8.6 mag e_gmag [0.0003/0.2]? Uncertainty in gmag
147-153 F7.4 mag r2mag [11.9/21.6]? Photometric r2 band magnitude
155-162 F8.6 mag e_r2mag [0.0003/0.2]? Uncertainty in r2mag
164-170 F7.4 mag rmag [11.9/21.4]? Photometric r band magnitude
172-179 F8.6 mag e_rmag [0.0003/0.2]? Uncertainty in rmag
181-187 F7.4 mag imag [11.9/21.3]? Photometric i band magnitude
189-196 F8.6 mag e_imag [0.0004/0.3]? Uncertainty in imag
198-204 F7.4 mag Hamag [11.9/20.8]? Photometric Hα band magnitude
206-213 F8.6 mag e_Hamag [0.0005/0.3]? Uncertainty in Hamag
215-219 F5.3 --- eta [0.1/3.2] The η variability index
221-228 A8 --- Class Preliminary classification (1)
230-233 A4 --- Tile Name of VVV tile where source is found
235-246 F12.7 d Per [0.2/1423.2]? Period
248-255 F8.6 mag AKs [0.1/0.4]? Ks band extinction using
Nishiyama (2009ApJ...696.1407N 2009ApJ...696.1407N)
257-263 F7.4 kpc Dist [3.6/14.8]? Distance from PL relations of
RRab sources
265 A1 --- CCD Position in (H-Ks,J-H) color-color diagram (2)
267-285 A19 --- BibCode Catalog reference of documented source
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Note (1): Class as follows:
Binary = Binary --33 occurrences.
ClCeph = Classical Cepheid --13 occurrences.
Dipper = Sources that show fading events and then return to their normal
magnitude --5 occurrences.
Eruptive = Sources that show outbursts with amplitude >1mag and duration
longer than a few days and typically at least a year
--12 occurrences.
Fader = Sources that show a continuous decrease in brightness (t>1yr), or a
big decrease in brightness in a source with relatively constant
luminosity --7 occurrences.
LAE = "low-amplitude eruptive": sources that present outbursts with
amplitude lower than 1mag and duration typically longer than a
year --8 occurrences.
LPV = long-period variables --7 occurrences.
LPV-YSO = Sources with a measured period but short-timescale scatter in the
time series --7 occurrences.
Pmotion = 1 occurrence
RRab = RR Lyrae of ab type --25 occurrences.
RRc = RR Lyrae of c type --42 occurrences.
STV = short-timescale variable: Sources with fast and constant scatter in
their time series. They can also show brief rises in magnitude in
timescales of weeks --20 occurrences.
Unclass = Unclassified --21 occurrences.
Note (2): The "F" region is located between the reddening vectors of the giant
and dwarf stars. The "T" region is between the reddening vector of the
giant stars and the classical T Tauri star (CTT) locus, where Class II
YSOs and Herbig Ae/Be stars (Hillenbrand+ 1992ApJ...397..613H 1992ApJ...397..613H) can be
identified. In the so-called "P" region, located below the reddening
vector of the CTTs, the likely protostellar objects are situated.
See section 4.3.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Aug-2019