J/A+A/695/A131 Mass-radius relation of white dwarfs (Raddi+, 2025)
Testing the mass-radius relation of white dwarfs in common proper-motion pairs.
I. Hydrogen-dominated atmospheres.
Raddi R., Rebassa-Mansergas A., Torres S., Camisassa M.E., Napiwotzki R.,
Koester D., Tremblay P.-E., Heber U., Althaus L.
<Astron. Astrophys. 695, A131 (2025)>
=2025A&A...695A.131R 2025A&A...695A.131R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, white dwarf ;
Stars, masses ; Stars, diameters ; Proper motions ; Optical
Keywords: techniques: radial velocities - binaries: visual - white dwarfs
Abstract:
White dwarf masses are among the most important properties used to
constrain their past and future evolution. Direct estimates of white
dwarf masses are crucial for assessing the validity of theoretical
evolutionary models and methods of analysis.
The main goal of this work was to measure the masses and radii of
white dwarfs that belong to widely separated, common proper-motion
binaries with non-degenerate companions. These can be assessed,
independently from theoretical mass-radius relations, through
measurements of gravitational redshifts and photometric radii.
We studied 50 white dwarfs with hydrogen-dominated atmospheres,
performing a detailed analysis of high-resolution (R∼18500) spectra
via state-of-the-art grids of synthetic models and specialized
software. We measured accurate radial velocities from the Hα and
Hβ line cores to obtain the white dwarf gravitational redshifts.
Jointly with a photometric analysis, formalized by a Bayesian
inference method, we measured precise radii for the white dwarfs in
our sample, which allowed us to directly measure the white dwarf
masses from their gravitational redshifts.
The distributions of measured masses and radii agree within 6% (at the
1-σ level) from the theoretical mass-radius relation, thus
delivering a much smaller scatter in comparison with previous analyses
that used gravitational redshift measurements from low-resolution
spectra. Our comparison against model-dependent spectroscopic
estimates produces a larger scatter of 15% on the mass determinations.
We find an agreement within ∼10% from previous model-based,
photometric mass estimates from the literature.
Combining gravitational redshift measurements and photometric analysis
of white dwarfs delivers precise and accurate empirical estimates of
their masses and radii. This work confirms the reliability of the
theoretical mass-radius relation from the lightest to the heaviest
white dwarfs in our sample (∼0.38-1.3M☉).
Description:
In this work, we have presented the high-resolution spectroscopic
follow-up of 48 white dwarfs with VLT/UVES. The observed objects
belong to widely separated, common proper motion pairs with
non-degenerate stars. We focused our analysis on the 33 objects
classified as DA white dwarfs, to which we added 17 more objects of
the same spectral class that are drawn from the SPY survey (Napiwotzki
et al., 2020A&A...638A.131N 2020A&A...638A.131N, Cat. J/A+A/638/A131), also observed with
VLT/UVES and belonging to common proper motion pairs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 90 65 Relevant Gaia parameters of the studied
white dwarfs
tableb2.dat 116 66 Relevant Gaia parameters of the
wide binary companions
tabled1.dat 157 51 Spectroscopic parameters
tableg1.dat 116 52 Photometric parameters of the studied
white dwarfs
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- SName Short Name (G1)
13- 31 I19 --- GaiaDR3 Gaia DR3 source_id
33- 35 A3 --- Type White dwarf type assigned upon visual
inspection of the spectra.
37- 41 F5.2 arcsec plx Parallax
43- 46 F4.2 arcsec e_plx Parallax error
48- 54 F7.2 mas/yr pmRAcosDE Proper motion along RA, pmRA*cosDE
56- 59 F4.2 mas/yr e_pmRAcosDE Proper motion along RA, pmRA*cosDE, error
61- 67 F7.2 mas/yr pmDE Proper motion along DE
69- 72 F4.2 mas/yr e_pmDE Proper motion along DE error
74- 78 F5.2 mag Gmag Gaia G magnitude
80- 84 F5.2 mag BPmag Gaia BP magnitude
86- 90 F5.2 mag RPmag Gaia RP magnitude
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- SName Short Name of the corresponding white dwarf
companions (G1)
12 A1 --- n_SName [n] n = no deblended transits
14- 32 I19 --- GaiaDR3 Gaia DR3 source_id
34- 38 F5.2 arcsec plx Parallax
40- 43 F4.2 arcsec e_plx Parallax error
45- 51 F7.2 mas/yr pmRAcosDE Proper motion along RA, pmRA*cosDE
53- 56 F4.2 mas/yr e_pmRAcosDE Proper motion along RA, pmRA*cosDE, error
58- 64 F7.2 mas/yr pmDE Proper motion along DE
66- 69 F4.2 mas/yr e_pmDE Proper motion along DE error
71- 75 F5.2 mag Gmag Gaia G magnitude
77- 81 F5.2 mag BPmag Gaia BP magnitude
83- 87 F5.2 mag RPmag Gaia RP magnitude
89- 93 F5.1 arcsec Sep Separation
95- 99 I5 au a Semi-major axis
101-104 F4.2 km/s DeltaV Velocity difference
106-111 F6.2 km/s RV Radial velocity
113-116 F4.2 km/s e_RV Radial velocity error
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- SName Short Name (G1)
12 A1 --- n_SName [cd] Note on SName (1)
14- 18 I5 K Teff1 ?=- Koester 1D Models effective temperature
20- 22 I3 K e_Teff1 ? Koester 1D Models effective temperature
error
24- 27 F4.2 [cm/s2] logg1 ?=- Koester 1D Models surface gravity
29- 32 F4.2 [cm/s2] e_logg1 ? Koester 1D Models surface gravity error
34- 37 I4 K DTeff3D1 ? Koester 1D Models effective temperature
difference
39- 43 F5.2 [cm/s2] Dlogg1 ? Koester 1D Models surface gravity
difference
45- 49 F5.3 Msun Mass1 ?=- Koester 1D Models mass (5)
51- 55 F5.3 Msun e_Mass1 ? Koester 1D Models mass error
57- 61 F5.1 km/s v(Ha+Hb)1 ?=- Koester 1D Models Halpha+Hbeta
velocity (2)
63- 65 F3.1 km/s e_v(Ha+Hb)1 ? Koester 1D Models Halpha+Hbeta
velocity error
66- 67 A2 --- n_v(Ha+Hb)1 [gl ] Note on v(Ha+Hb)1 (4)
69- 73 F5.1 km/s vHa1 ?=- Koester 1D Models Halpha velocity (2)
75- 78 F4.1 km/s e_vHa1 ? Koester 1D Models Halpha velocity error
79- 80 A2 --- n_vHa1 [gl ] Note on vHa1 (4)
82- 86 I5 K Teff2 ?=- Tremblay 3D Models effective temperature
88- 90 I3 K e_Teff2 ? Tremblay 3D Models effective temperature
error
92- 95 F4.2 [cm/s2] logg2 ?=- Tremblay 3D Models surface gravity
97-100 F4.2 [cm/s2] e_logg2 ? Tremblay 3D Models surface gravity error
102-106 F5.3 Msun Mass2 ?=- Tremblay 3D Models mass (5)
108-112 F5.3 Msun e_Mass2 ? Tremblay 3D Models mass error
114-118 F5.1 km/s v(Ha+Hb)2 ?=- Tremblay 3D Models Halpha+Hbeta
velocity (3)
120-122 F3.1 km/s e_v(Ha+Hb)2 ? Tremblay 3D Models Halpha+Hbeta
velocity error
123 A1 --- n_v(Ha+Hb)2 [gl] Note on v(Ha+Hb)2 (4)
126-130 F5.1 km/s vHa2 ?=- Tremblay 3D Models Halpha velocity (3)
132-135 F4.1 km/s e_vHa2 ? Tremblay 3D Models Halpha velocity error
136 A1 --- n_vHa2 [gl] Note on vHa2 (4)
139-143 F5.1 km/s v(Ha+Hb)3 ?=- Gaussian fit Halpha+Hbeta velocity (2)
145-147 F3.1 km/s e_v(Ha+Hb)3 ? Gaussian fit Halpha+Hbeta velocity error
149-153 F5.1 km/s vHa3 ?=- Gaussian fit Halpha velocity (2)
155-157 F3.1 km/s e_vHa3 ? Gaussian fit Halpha velocity error
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Note (1): Note as follows:
c = vWD measured from the Zeeman lπ component
d = using the spectra from the SPY project
Note (2): measured via model fit of both the Hα and Hβ lines.
Note (3): measured via model ift of the H[alpha line only.
Note (4): g and l indicate whether the radial-velocity fit using the model
spectra also required additional Gaussian and Lorentzian functions to
reproduce the line cores.
Note (5): Spectroscopic masses are estimated via interpolation of evolutionary
tracks (Althaus et al., 2013A&A...557A..19A 2013A&A...557A..19A, Cat. J/A+A/557/A19;
Camisassa et al., 2016ApJ...823..158C 2016ApJ...823..158C and
2019A&A...625A..87C 2019A&A...625A..87C, Cat. J/A+A/625/A87).
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Byte-by-byte Description of file: tableg1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- SName Short Name (G1)
12 A1 --- n_SName [ab] Note on Name
14- 18 I5 K Teff Effective temperature
20- 23 I4 K e_Teff Effective temperature error
25- 30 F6.4 Rsun R Radius
32- 34 I3 pc d Distance
36- 40 F5.3 mag A(55) Extinction at 5500Å
42- 45 F4.2 Msun Mass1 Mass averaged over the radial estimates
of v(Hα+Hβ)WD
47- 50 F4.2 Msun e_Mass1 Mass error over the radial estimates
of v(Hα+Hβ)WD
52- 56 F5.2 --- rho(M-R)1 Correlation among mass and radius over the
radial estimates of v(Hα+Hβ)WD
58- 62 F5.1 km/s Vgr1 Gravitational-redshift factor over the
radial estimates of v(Hα+Hβ)WD
64- 66 F3.1 km/s e_Vgr1 Gravitational-redshift factor error over the
radial estimates of v(Hα+Hβ)WD
68- 72 F5.1 % DeltaR1 Difference in Radius with respect to the
theoretical evolutionary tracks over the
radial estimates of v(Hα+Hβ)WD
74- 78 F5.1 % DeltaM1 Difference in Mass with respect to the
theoretical evolutionary tracks over the
radial estimates of v(Hα+Hβ)WD
80- 83 F4.2 Msun Mass2 ? Mass over the radial estimates
of v(Hα)WD
85- 88 F4.2 Msun e_Mass2 ? Mass error over the radial estimates
of v(Hα)WD
90- 94 F5.2 --- rho(M-R)2 ? Correlation among mass and radius over the
radial estimates of v(Hα)WD
96-100 F5.1 km/s Vgr2 ? Gravitational-redshift factor over the
radial estimates of v(Hα)WD
102-104 F3.1 km/s e_Vgr2 ? Gravitational-redshift factor error over
the radial estimates of v(Hα)WD
106-110 F5.1 % DeltaR2 ? Difference in Radius with respect to the
theoretical evolutionary tracks over the
radial estimates of v(Hα)WD
112-116 F5.1 % DeltaM2 ? Difference in Mass with respect to the
theoretical evolutionary tracks over the
radial estimates of v(Hα)WD
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Global notes:
Note (G1): The short name of the new targets is based on the Gaia DR3
coordinates in the HHMM+DDMM format (else HEHHMM+DDMM, HSHHMM+DDMM or
WDHHMM+DDd for the SPY sample).
WD1544-377 was re-observed for comparison purposes.
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History:
Copied at https://zenodo.org/records/14793626
(End) Patricia Vannier [CDS] 23-May-2025