J/A+A/447/173 3D-kinematics of white dwarfs from SPY project. II. (Pauli+, 2006)
3D kinematics of white dwarfs from the SPY project. II.
Pauli E.-M., Napiwotzki R., Heber U.,M.altmann, Odenkirchen M.
<Astron. Astrophys. 447, 173 (2006)>
=2006A&A...447..173P 2006A&A...447..173P
ADC_Keywords: Stars, white dwarf ; Radial velocities ; Space velocities ;
Proper motions ; Stars, distances
Keywords: stars : white dwarfs - stars: kinematic - Galaxy: halo -
Galaxy: kinematics and dynamics - Galaxy: disk
Abstract:
We present the kinematics of a sample of 398 DA white dwarfs from the
SPY project (ESO SN Ia Progenitor surveY) and discuss kinematic
criteria for distinguishing of thin-disk, thick-disk, and halo
populations. This is the largest homogeneous sample of white dwarfs
for which 3D space motions have been determined. Since the percentage
of old stars among white dwarfs is higher than among main-sequence
stars, they are presumably valuable tools in studies of old
populations, such as the halo and the thick disk. Studies of
white-dwarf kinematics can help to determine the fraction of the total
mass of our Galaxy contained in the form of thick-disk and halo white
dwarfs, an issue which is still under discussion. Radial velocities
and spectroscopic distances obtained by the SPY project were combined
with our measurements of proper motions to derive 3D space motions.
Galactic orbits and further kinematic parameters were computed. We
calculated individual errors of kinematic parameters by means of a
Monte Carlo error propagation code. Our kinematic criteria for
assigning population membership were deduced from a sample of F and G
stars taken from the literature, for which chemical criteria can be
used to distinguish between a thin-disk, a thick-disk and a halo star.
Our kinematic population classification scheme is based on the
position in the U-V-velocity diagram, the position in the
Jz-eccentricity diagram, and the Galactic orbit. We combined this
with age information and found seven halo and 23 thick-disk white
dwarfs in this brightness limited sample. Another four rather cool
white dwarfs probably also belong to the thick disk. Correspondingly
2% of the white dwarfs belong to the halo and 7% to the thick disk.
The mass contribution of the thick-disk white dwarfs is found to be
substantial, but is insufficient to account for the missing dark
matter.
Description:
Kinematic parameters for 398 white dwarfs from the ESO
Supernova-Progenitor Survey (SPY) are presented. Proper motions,
spectroscopic distances and high-precision radial velocities
(corrected for gravitational redshift) are measured or compiled. From
these data galactic velocity components U, V, W as well as the
eccentricity and z-component of the angular momentum of the Galactic
orbit are computed and tabulated
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 61 398 Radial velocities (corrected for gravitational
redshift), proper motions, and spectroscopic
distances of the 398 SPY white dwarfs
table8.tex 177 501 LaTeX version of table8
table9.dat 67 398 Kinematic parameters of the 398 SPY white dwarfs
table9.tex 194 498 LaTeX version of table9
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See also:
J/A+A/400/877 : 3D kinematics of white dwarfs from SPY project (Pauli+, 2003)
Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Star name
14- 19 F6.1 km/s RV Radial velocity, corrected for gravitational
redshift
21- 24 F4.1 km/s e_RV rms uncertainty on RV
25 A1 --- n_RV [*] *: stars with only one spectrum
27- 31 I5 mas/yr pmRA Proper motion, mualpha*cos(delta)
33- 35 I3 mas/yr e_pmRA rms uncertainty on pmRA
37- 40 I4 mas/yr pmDE Proper motion, mudelta
42- 43 I2 mas/yr e_pmDE rms uncertainty on pmDE
45- 49 F5.1 pc Dist Spectroscopic distance
51- 55 F5.2 [pc] logDist Log of the distance
58- 61 F4.2 [pc] e_logDist rms uncertainty on logDist
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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- 12 A12 --- Name Star name
14- 17 F4.2 -- ecc Excentricity of Galactic orbit
19- 22 F4.2 --- e_ecc rms uncertainty on ecc
24- 28 I5 kpc.km/s Jz z component of angular momentum of the
Galactic orbit
30- 32 I3 kpc.km/s e_Jz rms uncertainty on Jz
34- 39 F6.1 km/s Uvel U component of Galactic space velocity
41- 44 F4.1 km/s e_Uvel rms uncertainty on Uvel
46- 51 F6.1 km/s Vvel V component of Galactic space velocity
53- 56 F4.1 km/s e_Vvel rms uncertainty on Vvel
58- 62 F5.1 km/s Wvel W component of Galactic space velocity
64- 67 F4.1 km/s e_Wvel rms uncertainty on Wvel
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Acknowledgements: Ulrich Heber, heber(at)sternwarte.uni-erlangen.de
(End) U. Heber [Dr. Remeis-Sternwarte, Germany], P. Vannier [CDS] 20-Oct-2005