J/ApJ/972/151 Doppler beaming factors in binary stars (Zheng+, 2024)
Direct Method to Compute Doppler Beaming Factors in Binary Stars.
Zheng C., Huang Y., Liu J., Lu Y., Han H., Tan Y., Beers T.C.
<Astrophys. J., 972, 151 (2024)>
=2024ApJ...972..151Z 2024ApJ...972..151Z (SIMBAD/NED BibCode)
ADC_Keywords: Models, atmosphere ; Photometry, SDSS ; Photometry, UBVRI ;
Photometry, ultraviolet ; Stars, double and multiple
Keywords: Binary stars - Radial velocity - Computational methods
Abstract:
The Doppler beaming effect, induced by the reflex motion of stars,
introduces flux modulations and serves as an efficient method to
photometrically determine mass functions for a large number of close
binary systems, particularly those involving compact objects. In order
to convert observed beaming-flux variations into a radial-velocity
curve, precise determination of the beaming factor is essential.
Previously, this factor was calculated as a constant, assuming a
power-law profile for stellar spectra. In this study, we present a
novel approach to directly compute this factor. Our new method not
only simplifies the computation, especially for blue bands and cool
stars, but also enables us to evaluate whether the relationship
between beaming flux and radial velocity can be accurately described
as linear. We develop a Python code and compute a comprehensive
beaming-factor table for commonly used filter systems covering
main-sequence, subgiant, and giant stars, as well as hot subdwarf and
white dwarf stars. Both the code and our table are archived and
publicly available on Zenodo: doi:10.5281/zenodo.13049419.
Description:
Zheng et al.(2024ApJ...972..151Z 2024ApJ...972..151Z) propose a new and direct method to
compute beaming factors under different filters. Here we present a
pre-computed beaming factor library for quick reference. These factors
are generated with the python module BeamingFactor for CSST,Gaia,
SDSS, UBVRI, TESS and Kepler filter systems. For easier downloading or
python code that generates this library, please refer to
https://github.com/shift-method/beamingfactor.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
atlas9.dat 81 2465320 Beaming factors computed with ATLAS 9
(Castelli & Kurucz, 2003IAUS..210P.A20C)
synthetic spectra
tmap.dat 93 267696 Beaming factors computed with TMAP
(Huegelmeyer et al., 2007ASPC..372...87H 2007ASPC..372...87H)
synthetic spectra
phoenix.dat 101 7921914 Beaming factors computed with PHOENIX
(Husser et al., 2013A&A...553A...6H 2013A&A...553A...6H)
synthetic spectra
tlusty.dat 84 365872 Beaming factors computed with TLUSTY
(Lanz & Hubeny, 2003ApJS..146..417L 2003ApJS..146..417L,
2007ApJS..169...83L 2007ApJS..169...83L) synthetic spectra
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Byte-by-byte Description of file: atlas9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 K Teff [3500/50000] Effective temperature
7- 8 I2 0.1[cm/s2] logg [0/50] Surface gravity
(All values are multiplied by 10)
10- 12 I3 0.1 [M/H] [-40/5] Metallicity
(All values are multiplied by 10)
14- 18 A5 --- alpha [False/True ] False for solar abundance,
True for alpha +0.4
20- 22 F3.1 --- DY Helium abundance (0 for solar value)
24 I1 km/s vturb Micro-turbulence velocity
26- 29 F4.2 mag E(B-V) Stellar extinction E(B-V)
31- 39 F9.6 --- BFFIT [0.82/36.03] Beaming factors
from linear fitting
41- 47 E7.2 --- e_BFFIT Beaming factor uncertainties
from linear fitting
49- 57 F9.6 --- BFC [0.82/36.04] A reference index (Do not use
BFFIT when it deviate from this value too
much)
59- 66 F8.5 --- D1 D1 index
68- 70 F3.1 --- D2 D2 index
72- 74 F3.1 --- D5 D5 index
76- 81 A6 --- Band Filter name (G1)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tmap.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 K Teff [50000/190000] Effective temperature
8- 10 F3.1 [cm/s2] logg [5.0/9.0] Surface gravity
12- 14 F3.1 --- H [0/1] Hydrogen abundance in percentage by mass
16- 18 F3.1 --- He [0/1] Helium abundance in percentage by mass
20- 23 F4.2 mag E(B-V) Stellar extinction E(B-V)
25- 32 F8.6 --- BFFIT [0.87/1.55] Beaming factors from linear fitting
34- 40 E7.2 --- e_BFFIT Beaming factor uncertainties from linear fitting
42- 59 F18.16 --- BFC [0.88/1.55] A reference index (Do not use BFFIT
when it deviate from this value too much)
61- 68 F8.5 --- D1 D1 index
70- 77 F8.5 --- D2 D2 index
79- 86 F8.5 --- D5 D5 index
88- 93 A6 --- Band Filter name (G1)
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Byte-by-byte Description of file: phoenix.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 K Teff [2300/12000] Effective temperature
7- 9 F3.1 [cm/s2] logg [0/6] Surface gravity
11- 14 F4.1 [-] Z [-4.0/1.0] Metallicity
16- 19 F4.2 mag E(B-V) Stellar extinction E(B-V)
21- 30 F10.6 --- BFFIT [-4.32/67.84] Beaming factors from linear fit
32- 38 E7.2 --- e_BFFIT Beaming factor uncertainties from linear fit
40- 62 F23.19 --- BFC [-4.32/68.64] A reference index (Do not use
BFFIT when it deviate from this value too much)
64- 71 F8.5 --- D1 D1 index
73- 80 F8.5 --- D2 D2 index
82- 89 F8.5 --- D5 D5 index
91- 94 F4.1 --- alpha [-0.2/1.2] Alpha elements abundances (0 for sun)
96-101 A6 --- Band Filter name (G1)
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Byte-by-byte Description of file: tlusty.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 K Teff [15000/55000] Effective temperature
7- 10 F4.2 [cm/s2] logg [1.75/4.75] Surface gravity
12- 14 F3.1 Sun Z [0/2] Ratio of Z/Zsun
(A value 0 refers to metal free)
16- 19 F4.2 mag E(B-V) Stellar extinction E(B-V)
21- 28 F8.6 --- BFFIT [1.06/6.98] Beaming factors from linear fitting
30- 36 E7.2 --- e_BFFIT Beaming factor uncertainties from linear fitting
38- 55 F18.16 --- BFC [1.05/6.98] A reference index (Do not use BFFIT
when it deviate from this value too much)
57- 64 F8.5 --- D1 D1 index
66- 73 F8.5 --- D2 D2 index
75- 77 F3.1 --- D5 D5 index
79- 84 A6 --- Band Filter name (G1)
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Global notes:
Note (G1): Filter names as follows:
u_SDSS = SDSS u band
g_SDSS = SDSS g band
r_SDSS = SDSS r band
i_SDSS = SDSS i band
z_SDSS = SDSS z band
NUVC = CSST NUV band
uC = CSST u band
gC = CSST g band
rC = CSST r band
iC = CSST i band
zC = CSST z band
yC = CSST y band
U = U band
B = B band
V = V band
R = R band
I = I band
G = Gaia G band
Gbp = Gaia Gbp band
Grp = Gaia Grp band
TESS = TESS band
kepler = Kepler band
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Acknowledgements:
Zheng Chuanjie, zhengchuanjie(at)nao.cas.cn
(End) Patricia Vannier [CDS] 20-Dec-2024