J/ApJ/712/585 Apparent velocity measurements of DA WDs (Falcon+, 2010)
A gravitational redshift determination of the mean mass of white dwarfs. DA
stars.
Falcon R.E., Winget D.E., Montgomery M.H., Williams K.A.
<Astrophys. J., 712, 585-595 (2010)>
=2010ApJ...712..585F 2010ApJ...712..585F
ADC_Keywords: Stars, white dwarf ; Spectroscopy ; Radial velocities
Keywords: stars: kinematics and dynamics - techniques: radial velocities -
techniques: spectroscopic - white dwarfs
Abstract:
We measure apparent velocities (vapp) of the Hα and Hβ
Balmer line cores for 449 non-binary thin disk normal DA white dwarfs
(WDs) using optical spectra taken for the European Southern
Observatory SN Ia progenitor survey (SPY). Assuming these WDs are
nearby and comoving, we correct our velocities to the local standard
of rest so that the remaining stellar motions are random. By averaging
over the sample, we are left with the mean gravitational redshift,
<vg>: we find <vg≥<vapp≥32.57±1.17km/s. Using the
mass-radius relation from evolutionary models, this translates to a
mean mass of 0.647+0.013-0.014M☉. We interpret this as the
mean mass for all DAs.
Description:
We use spectroscopic data from the European Southern Observatory (ESO)
SN Ia progenitor survey (SPY; Napiwotzki et al. 2001AN....322..411N 2001AN....322..411N).
These observations, taken using the UV-Visual Echelle Spectrograph
(UVES) at Kueyen, Unit Telescope 2 of the ESO VLT array, constitute
the largest, homogeneous, high-resolution (0.36Å or ∼16km/s at
Hα) spectroscopic data set for WDs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 847 Apparent velocity measurements for normal DA WDs
table5.dat 98 47 Apparent velocity measurements for thick disk DAs
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See also:
B/wd : Spectroscopically Identified White Dwarfs (McCook+, 2008)
J/A+A/505/441 : UVES/VLT spectra of white dwarfs (Koester+, 2009)
J/A+A/447/173 : 3D-kinematics of white dwarfs from SPY project. II. (Pauli+,
2006)
J/A+A/400/877 : White dwarfs 3D kinematics from SPY project (Pauli+, 2003)
J/A+A/378/556 : UVES/VLT spectra of white dwarfs (Koester+, 2001)
Byte-by-byte Description of file: table[15].dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Target name
15- 21 F7.3 km/s Adp-V Adopted apparent velocity (1)
23- 27 F5.3 km/s e_Adp-V The 1σ error in Adp-V
29- 38 A10 "YYYY/MM/DD" Obs.date UT date of the observation
40- 47 A8 "h:m:s" Obs.time UT time of the observation
49- 55 F7.3 km/s LSR-V Apparent velocity in the LSR (1)
57- 63 F7.3 km/s Ha-V Hα apparent velocity (1)
65- 69 F5.3 km/s e_Ha-V The 1σ error in Ha-V
71- 77 F7.3 km/s Hb-V ? Hβ apparent velocity (1)
79- 83 F5.3 km/s e_Hb-V ? The 1σ error in Hb-V
85- 91 F7.3 km/s Obs-V Apparent velocity for observation (1)
93- 98 F6.3 km/s e_Obs-V The 1σ error in Obs-V
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Note (1): the apparent velocity is the sum of the radial velocity
(Doppler redshift) and the gravitational redshift, which have
comparable values. LSR is the local standard of rest, and it
is assumed that the mean LSR velocity over each population
averaged out -- the mean apparent velocity then equals the mean
gravitational redshift.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 05-Apr-2012