J/A+A/400/877 White dwarfs 3D kinematics from SPY project (Pauli+, 2003)
3D kinematics of white dwarfs from the SPY project.
Pauli E.-M., Napiwotzki R., Altmann M., Heber U., Odenkirchen M., Kerber F.
<Astron. Astrophys. 400, 877 (2003)>
=2003A&A...400..877P 2003A&A...400..877P
ADC_Keywords: Stars, white dwarf ; Radial velocities ; Space velocities ;
Proper motions ; Stars, distances
Keywords: stars, white dwarfs - stars, kinematics - Galaxy: halo -
Galaxy: thick disk - Galaxy: kinematics and dynamics
Abstract:
We present kinematics of a sample of 107 DA white dwarfs from the SPY
project (ESO SN Ia Progenitor surveY) and discuss kinematic criteria
for a distinction of thin disk, thick disk, and halo populations. This
is the first 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 are combined with our measurements of
proper motions to derive 3D space motions. Galactic orbits and further
kinematic parameters are computed. We calculate individual errors of
kinematic parameters by means of a Monte Carlo error propagation code.
Our kinematic criteria for assigning population membership are deduced
from a sample of F and G stars taken from the literature for which
chemical criteria can be used to distinguish between thin disk, thick
disk and halo. Candidates for thick disk and halo members are selected
in a first step from the classical U-V-velocity diagram. Our final
assignment of population membership is based on orbits and position in
the Jz-eccentricity diagram. We find four halo and twelve thick disk
white dwarfs. We also present a systematic study of the effects of
ignoring the radial velocity in kinematic investigations.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 62 107 Radial velocities, proper motions and spectral
distributions
table2.dat 66 107 Kinematic parameters of the white dwarfs
--------------------------------------------------------------------------------
See also:
J/A+A/378/556 : UVES/VLT spectra of white dwarfs (Koester+, 2001)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Object name
13 I1 --- Nspectra Number of spectra
15- 20 F6.1 km/s RV Radial velocity
22- 25 F4.1 km/s e_RV Error of radial velocity
27- 30 I4 mas/yr pmRA Proper motion mualpha*cos(delta)
32- 35 I4 mas/yr e_pmRA Error of mualpha
37- 40 I4 mas/yr pmDE Proper motion mudelta
42- 45 I4 mas/yr e_pmDE Error of mudelta
47- 52 F6.1 pc DistSp Spectroscopic distance
54- 57 F4.2 [pc] log(Dist) log of distance
59- 62 F4.2 [pc] e_log(Dist) Error of log of distance
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Object name
13- 16 F4.2 --- ecc Eccentricity of galactic orbit
18- 21 F4.2 --- e_ecc Error of eccentricity
23- 27 I5 kpc.km/s Jz z-component of angular momentum
29- 31 I3 kpc.km/s e_Jz Error of z-component of angular momentum
33- 38 F6.1 km/s Uvel U velocity
40- 43 F4.1 km/s e_Uvel Error of Uvel
45- 50 F6.1 km/s Vvel V velocity
52- 55 F4.1 km/s e_Vvel Error of Vvel
57- 61 F5.1 km/s Wvel W velocity
63- 66 F4.1 km/s e_Wvel Error of Wvel
--------------------------------------------------------------------------------
Acknowledgements: Eva-Maria Pauli
References:
Napiwotzki et al., 2001A&A...378L..17N 2001A&A...378L..17N
Binaries discovered by the SPY project. I.
Napiwotzki et al., 2002A&A...386..957N 2002A&A...386..957N
Binaries discovered by the SPY project. II.
(End) Patricia Bauer [CDS] 20-Feb-2003