J/ApJ/788/105 XSTPS RR Lyrae in the north Galactic cap (Faccioli+, 2014)
RR Lyrae in XSTPS: the halo density profile in the north Galactic cap.
Faccioli L., Smith M.C., Yuan H.-B., Zhang H.-H., Liu X.-W., Zhao H.-B.,
Yao J.-S.
<Astrophys. J., 788, 105 (2014)>
=2014ApJ...788..105F 2014ApJ...788..105F (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, variable ; Stellar distribution ;
Photometry, SDSS ; Stars, distances ; Surveys
Keywords: Galaxy: halo - Galaxy: stellar content - Galaxy: structure -
stars: variables: RR Lyrae - surveys - techniques: photometric
Abstract:
We present a catalog of RR Lyrae stars (RRLs) observed by the Xuyi
Schmidt Telescope Photometric Survey (XSTPS). The area we consider is
located in the north Galactic cap, covering ∼376.75 deg2 at
RA∼150° and DE∼27° down to a magnitude limit of i∼19. Using
the variability information afforded by the multi-epoch nature of our
XSTPS data, combined with colors from the Sloan Digital Sky Survey, we
are able to identify candidate RRLs. We find 318 candidates, derive
distances to them, and estimate the detection efficiency. The majority
of our candidates have more than 12 observations, and for these we are
able to calculate periods. These also allow us to estimate our
contamination level, which we predict is between 30% and 40%. Finally,
we use the sample to probe the halo density profile in the 9-49 kpc
range and find that it can be well fitted by a double power law. We
find good agreement between this model and the models derived for the
south Galactic cap using the Watkins et al. (2009, J/MNRAS/398/1757) and
Sesar et al. (2010, J/ApJ/708/717) RRL data sets, after accounting for
possible contamination in our data set from Sagittarius stream
members. We consider non-spherical double power-law models of the halo
density profile and again find agreement with literature data sets,
although we have limited power to constrain the flattening due to our
small survey area. Much tighter constraints will be placed by current
and future wide-area surveys, most notably ESA's astrometric Gaia
mission. Our analysis demonstrates that surveys with a limited number
of epochs can effectively be mined for RRLs. Our complete sample is
provided as accompanying online material; as an example the first few
entries of each electronic table are shown in the text.
Description:
XSTPS is a three-band photometric survey of the Milky Way anti-center
carried out with the 1.2 m Schmidt telescope at the Xuyi station of
the Purple Mountain Observatory in China (Zhang et al. 2013RAA....13..490Z 2013RAA....13..490Z)
and completed in 2011 March (see Section 3 of Liu et al.
2014IAUS..298..310L 2014IAUS..298..310L). The survey covers an area of ∼6000 deg2 in a
region of the sky that, for the most part, is not covered by other
large-scale surveys. It is expected to detect ∼100 million stars in i,
and the first data release is due imminently (H.-B. Yuan et al., in
preparation); we used a preliminary version of the catalog for our
study. The three bands employed in the survey are g, r, i, similar,
but not identical, to the corresponding SDSS bands.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 318 Basic data for the RRL candidates
table5.dat 83 318 SDSS matching information for the 318 RRL
in the sample
table6.dat 40 114 VSX catalog matches
table7.dat 9 318 Efficiencies of the 318 RRLs in the sample
table8.dat 51 265 Periods for the 265 RRL candidates in
the sample with at least 12 observations
table9.dat 48 8528 Light curves for the 318 RRLs in the sample
table10.dat 48 318 Heliocentric and galactocentric distances for
the 318 RRLs in the sample
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See also:
B/vsx : AAVSO International Variable Star Index VSX
(Watson+, 2006-2014)
II/294 : The SDSS Photometric Catalog, Release 7
(Adelman-McCarthy+, 2009)
J/AJ/127/1158 : QUEST RR Lyrae Survey first catalog (Vivas+, 2004)
J/AJ/132/1202 : RR Lyrae in Northern Sky Variability Survey
(Kinemuchi+, 2006)
J/ApJ/678/851 : RR Lyrae survey in the Galactic Halo (Keller+, 2008)
J/MNRAS/398/1757 : RR Lyraes in SDSS stripe 82 (Watkins+, 2009)
J/ApJ/708/717 : Light curve templates of RR Lyrae stars (Sesar+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/318] RRL candidate identifier
5- 6 I2 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 16 F6.3 s RAs Second of Right Ascension (J2000)
18- 19 I2 deg DEd Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 28 F5.2 arcsec DEs Arcsecond of Declination (J2000)
30- 31 I2 --- o_ Number of epochs used in
33- 37 F5.2 mag Mean i band magnitude across epochs (1)
39- 42 F4.2 mag e_ Uncertainty in (2)
44- 47 F4.2 mag sd ?=-99 Standard deviation in (3)
49- 51 I3 --- o_ ?=-99 Number of epochs used in (4)
53- 58 F6.2 mag ?=-99 Mean r band magnitude across epochs (1)
60- 65 F6.2 mag e_ ?=-99 Uncertainty in (2)
67- 72 F6.2 mag sd ?=-99 Standard deviation in (3)
74- 76 I3 --- o_ ?=-99 Number of epochs used in (4)
78- 83 F6.2 mag ?=-99 Mean g band magnitude across epochs (1)
85- 90 F6.2 mag e_ ?=-99 Uncertainty in (2)
92- 97 F6.2 mag sd ?=-99 Standard deviation in (3)
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Note (1): All magnitudes are corrected for extincion using the
Schlegel,Finkbeiner,Davis maps (Schlegel,Finkbeiner,Davis,
1998ApJ...500..525S 1998ApJ...500..525S)
Note (2): Quadrature sum of single uncertainties.
Note (3): A value of -99 means 1 epoch.
Note (4): A value of -99 means no (g|r) data.
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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- 3 I3 --- ID [1/318] RRL candidate identifier
5- 6 I2 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 16 F6.3 s RAs Second of Right Ascension (J2000)
18- 19 I2 deg DEd Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 28 F5.2 arcsec DEs Arcsecond of Declination (J2000)
30- 34 F5.2 mag umag SDSS u band PSF magnitude (1)
36- 39 F4.2 mag e_umag Uncertainty in umag
41- 45 F5.2 mag gmag SDSS g band PSF magnitude (1)
47- 50 F4.2 mag e_gmag Uncertainty in gmag
52- 56 F5.2 mag rmag SDSS r band PSF magnitude (1)
58- 61 F4.2 mag e_rmag Uncertainty in rmag
63- 67 F5.2 mag imag SDSS i band PSF magnitude (1)
69- 72 F4.2 mag e_imag Uncertainty in imag
74- 78 F5.2 mag zmag SDSS z band PSF magnitude (1)
80- 83 F4.2 mag e_zmag Uncertainty in zmag
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Note (1): All data in the table come from SDSS "Star" table, Data Release 7
(Cat. II/294)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [2/318] RRL candidate identifier
5- 26 A22 --- VSX VSX catalog identifier (Cat. B/vsx)
28- 31 A4 --- Type VSX catalog type (RRAB, EW, RRC)
33- 40 F8.6 d Period VSX catalog period
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/318] RRL candidate identifier
5- 9 F5.3 --- Eff Detection efficiency
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [13/318] RRL candidate identifier (1)
5- 12 F8.6 d Period Period
14- 19 F6.2 --- Lambda Lambda; see text (2)
21- 51 A31 --- Epochs Epoch excluded plus comments (3)
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Note (1): The list includes objects classified as "Interlopers" upon visual
inspection or "Delta Scuti" if they have a period in the 0.05-0.2d
range more significant than the one quoted here (unless reported as
RRL by either VSX or CDS), or "Double Period" if the folded light
curves shows that the period quoted here is double the true one.
Note (2): Objects with Lambda<4 are not considered truly periodic and
the quoted period is meaningless, unless reported as RRL by VSX/CDS.
Note (3): Epochs are labelled from 0 to N-1 for an object with N observations.
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/318] RRL candidate identifier
5 A1 --- Band [gri] Observational band
7- 15 F9.3 d MJD Modfied Julian Date
17- 21 F5.2 mag mag Observed XSTPS magnitude in Band
23- 26 F4.2 mag e_mag Uncertainty in mag
28- 29 I2 h RAh Hour of Right Ascension (J2000)
31- 32 I2 min RAm Minute of Right Ascension (J2000)
34- 37 F4.1 s RAs Second of Right Ascension (J2000)
39- 40 I2 deg DEd Degree of Declination (J2000)
42- 43 I2 arcmin DEm Arcminute of Declination (J2000)
45- 48 F4.1 arcsec DEs Arcsecond of Declination (J2000)
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/318] RRL candidate identifier
5- 14 F10.7 kpc HDist Heliocentric Distance
16- 25 F10.8 kpc e_HDist Uncertainty in HDist
27- 36 F10.7 kpc GDist Galactocentric Distance
38- 48 F11.9 kpc e_GDist Uncertainty in GDist
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 11-Jul-2017