J/A+A/566/A118 A comprehensive view of Virgo stellar stream (Duffau+, 2014)
A comprehensive view of the Virgo stellar stream.
Duffau S., Vivas A.K., Zinn R., Mendez R.A., Ruiz M.T.
<Astron. Astrophys. 566, A118 (2014)>
=2014A&A...566A.118D 2014A&A...566A.118D
ADC_Keywords: Stars, halo ; Stars, variable ; Radial velocities;
Abundances, [Fe/H]
Keywords: stars: variables: RR Lyrae - Galaxy: abundances - Galaxy: halo -
Galaxy: kinematics and dynamics - Galaxy: structure
Abstract:
To explore the complex halo substructure that has been reported in the
direction of the Virgo constellation, radial velocities and
metallicities have been measured for 82 RR Lyrae stars (RRLS) that
were identified by the QUEST survey. These stars are distributed over
90 sq. deg. of the sky, and lie from 4 to 23kpc from the Sun. Using
an algorithm for finding groups in phase space and modeling the smooth
halo component in the region, we identified the 5 most significant
RRLS groups, some of which were previously known or suspected. We have
examined the SEKBO and the Catalina catalog of RRLS (with available
spectroscopic measurements), as well as the bright QUEST RRLS sample,
the catalog of Red Giant stars from the Spaghetti survey, and three
recent catalogs of blue horizontal branch (BHB) stars, for stars that
may be related to the QUEST RRLS groups.
Description:
The radial velocities and metallicities as well as the relevant
photometric and light curve parameters of the individual observations
of target stars, in and around the VSS are tabulated here. The final
values of the parameters for each target star are presented as well.
The identified members of each of the main 5 group candidates found in
the region are identified and presented, their radial velocities and
heliocentric distances listed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 9 Telescopes and instruments
table5.dat 57 183 Data on the individual observations of the
target RR Lyrae stars
table6.dat 93 82 Positions, light curve parameters, systemic
velocities and their errors, metallicities for
the target stars
table8.dat 69 8 *Properties of the Groups of RRLs in the Virgo
region detected with ε=0.046
table9.dat 105 61 Data on the individual members of the
kinematical groups
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Note on table8.dat: ε is a measure of clumpiness (smaller values of
ε correspond to tighter groups)
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See also:
J/ApJ/691/306 : Virgo stream RR Lyrae candidates photometry (Prior+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Obs Observatory (CTIO=Cerro Tololo, KPNO=Kitt Peak,
LCO=Las Campanas, La Silla)
10- 13 A4 --- Tel Telescope
15- 20 A6 --- Inst Instrument name
22- 28 A7 --- Code Instrument code
30- 33 I4 mm-1 Grat Grating (lines/mm)
35- 38 I4 0.1nm lam0 Lower value of spectral range λmin
39 A1 --- --- [-]
40- 44 I5 0.1nm lam1 Upper value of spectral range λmax
46- 48 F3.1 0.1nm Res Resolution (Å)
50- 77 A28 --- Dates Observation date(s)
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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 A3 --- Star Star designation (G1)
6- 14 F9.4 d HJD Heliocentric Julian Date of the observation
(HJD-2450000)
17- 20 I4 s Exp Exposure time
25- 31 A7 --- Code Telescope/setup code, following the
definitions of Table 1
34- 38 F5.3 --- Phase [0/1] Mean phase of the observation
42- 45 I4 km/s HRV ? Heliocentric radial velocity
48- 49 I2 km/s e_HRV ? Error on Heliocentric radial velocity
53- 57 F5.2 [Sun] [Fe/H] [-2.6/0]? Metallicity
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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 A3 --- Star Star designation (G1)
6- 15 F10.6 deg RAdeg Right Ascension in degrees (J2000)
18- 26 F9.6 deg DEdeg Declination in degrees (J2000)
29- 33 F5.2 mag Vmag0 Mean extinction-corrected V magnitude
36- 42 F7.5 d Period Period in days
45- 54 F10.5 d HJD0 Heliocentric Julian date at maximum
light in days (HJD-2450000)
57- 58 A2 --- Type RR Lyrae type (Bailey type: ab or c)
61- 64 F4.1 kpc d [4/23] Heliocentric distance
67 I1 --- Nfit ? Number observations used in radial velocity
curve fit
70- 73 I4 km/s Vgamma ? Systemic velocity Vγ
75- 76 I2 km/s sigfit ? rms of the fitting of the radial velocity
curve σfit
79- 80 I2 km/s e_Vgamma ? Final error in the systemic velocity
83- 86 I4 km/s Vgsr ? Radial velocity in the galactic standard of
rest Vgsr
89- 93 F5.2 [Sun] [Fe/H] ? Mean metallicity
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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 A1 --- Group Kinematical group designation (A to H)
3- 23 A21 --- Col Color/symbol in Fig. 11 of the paper
25 I1 --- N Number of members of the indicated group
27- 29 I3 km/s <Vgsr> Mean galactic standard of rest velocity Vgsr
31- 34 F4.1 km/s sigVgsr SGR velocity dispersion σVgsr
36- 39 F4.1 kpc [5/20] Mean distance
41- 44 F4.2 kpc sigd [0.2/1.2] Distance dispersion along the line
of sight σd
46- 49 F4.2 kpc sig3d [0.8/1.6] 3d dispersion σ3d (1)
51- 54 F4.1 --- P(Vgsr) Percentile 95 for that group in Vgsr
56- 59 F4.1 --- P(d) Percentile 95 for that group in
61- 64 F4.1 --- P(sigd) Percentile 95 for that group in σd
66- 69 F4.1 --- P(sig3d) Percentile 95 for that group in σ3d
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Note (1): 3d dispersion, σ3d, of each group calculated by obtaining the
coordinates of the center of the group from the average of the cartesian
coordinates of the members. Then, we estimated the distance separation of
each member to the center of the group. The 3d dispersion, which is given
in kpc, is the average of those distance separations.
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1 A1 --- Group Letter identifying the group, following naming
convention of Table 8 of the paper
3- 11 A9 --- Survey Survey designation (1)
13- 16 A4 --- Tracer Tracer designation (2)
18- 33 A16 --- ID ? Identification name following the
corresponding survey convention
(when available)
36- 45 F10.6 deg RAdeg Right Ascension in degrees (J2000)
47- 56 F10.6 deg DEdeg Declination in degrees (J2000)
58- 61 I4 km/s Vgsr Radial velocity in the galactic standard of
rest
63- 64 I2 kpc d Heliocentric distance
66-105 A40 --- Ref References
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Note (1): Survey identification:
QUEST = Quasar Equatorial Survey Team
CSS = Catalina Sky Survey
SDSS = Sloan Digital Sky Survey
Spaghetti = Spaghetti Survey
SEKBO = Southern Edgeworth-Kuiper Belt Object Survey
HVS = Hypervelocity Star Survey
CHSS = Century Halo Star Survey
Note (2): Tracer designation:
RRLS = RR Lyrae stars
BHB = Blue Horizontal Branch stars
RG = Red Giant stars
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Global notes:
Note (G1): Star Identification:
* QUEST catalog stars are identified by a 3 digit number (Vivas et al.,
2004, Cat. J/AJ/127/1158, <[VZA2004] NNN> in Simbad for numbers 19 to 261).
* Stars observed from the Wu et al. (2005, Cat. J/AJ/130/1640,
<[IGF2000] NN> in Simbad), are identified by their number in their
own catalog and a W prefix.
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Acknowledgements:
Sonia Duffau, LSW, University of Heidelberg, Germany,
sonia.duffau(at)gmail.com
(End) Sonia Duffau [LSW, Univ. Heidelberg], Patricia Vannier [CDS] 09-May-2014