J/MNRAS/526/5800 HST/COS UV spectroscopic survey of white dwarfs I (Sahu+, 2023)
An HST COS ultraviolet spectroscopic survey of 311 DA white dwarfs.
I. Fundamental parameters and comparative studies.
Sahu S., Gansicke B.T., Tremblay P.-E., Koester D., Hermes J.J.,
Wilson D.J., Toloza O., Hoskin M.J., Farihi J., Manser C.J., Redfield S.
<Mon. Not. R. Astron. Soc. 526, 5800-5823 (2023)>
=2023MNRAS.526.5800S 2023MNRAS.526.5800S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Stars, white dwarf ; Spectra, ultraviolet ;
Effective temperatures ; Stars, masses ; Stars, ages
Keywords: techniques: spectroscopic - catalogues - stars: white dwarfs -
ultraviolet: stars - stars: fundamental parameters.
Abstract:
White dwarf studies carry significant implications across multiple
fields of astrophysics, including exoplanets, supernova explosions,
and cosmological investigations. Thus, accurate determinations of
their fundamental parameters (Teff and log g) are of utmost
importance. While optical surveys have provided measurements for many
white dwarfs, there is a lack of studies utilising ultraviolet (UV)
data, particularly focusing on the warmer ones that predominantly emit
in the UV range. Here, we present the medium-resolution far-UV
spectroscopic survey of 311 DA white dwarfs obtained with Cosmic
Origins Spectrograph (COS) onboard Hubble Space Telescope confirming
49 photometric Gaia candidates. We used 3D extinction maps,
parallaxes, and hydrogen atmosphere models to fit the spectra of the
stars that lie in the range 12000<Teff<33000K, and 7≤logg<9.2. To
assess the impact of input physics, we employed two mass-radius
relations in the fitting and compared the results with previous
studies. The comparisons suggest the COS Teff are systematically lower
by 3 per cent on average than Balmer line fits while they differ by
only 1.5 per cent from optical photometric studies. The mass
distributions indicate that the COS masses are smaller by
approximately 0.05M☉ and 0.02M☉ than Balmer lines and
photometric masses, respectively. Performing several tests, we find
that the discrepancies are either arising due to issues with the COS
calibration, broadening theories for hydrogen lines, or interstellar
reddening which needs further examination. Based on comparative
analysis, we identify 30 binary candidates drawing attention for
follow-up studies to confirm their nature.
Description:
The main catalogue (table1.dat) provides the fundamental parameters of
311 DA white dwarfs derived from HST COS far-ultraviolet spectroscopic
observations using COS grating G130M centered at wavelength
1291Å(R∼16000). The parallaxes are taken from Gaia EDR3 catalogue.
table2.dat provides the parameters of 257 white dwarfs derived using
the Pan- STARSS photometry (grizy bands) that are in common with HST
COS sample.
table3.dat provides the parameters of 123 white dwarfs from ESO SN Ia
Progenitor Survey (SPY) (Koester et al., 2009A&A...505..441K 2009A&A...505..441K, Cat.
J/A+A/505/441) that are in common with HST COS sample using updated
models in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 200 311 UV spectroscopic parameters from HST COS survey
table2.dat 59 257 Photometric parameters from Pan-STARRS data
table3.dat 53 123 Updated optical spectroscopic parameters from
SPY survey (Koester et al., Cat. J/A+A/505/441)
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See also:
J/A+A/505/441 : UVES/VLT spectra of white dwarfs. III (Koester+ 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Object WD name used in this work
26- 47 A22 --- WDJ WDJ J2000 Name (WDJHHMMSS.ss+DDMMSS.ss)
49- 63 F15.11 deg RAdeg Right Ascension (J2000)
65- 79 F15.11 deg DEdeg Declination (J2000)
81- 85 I5 K Teffmont Effective temperature from mont (1)
87- 89 I3 K e_Teffmont Uncertainty in effective temperature
from mont (1)
91- 95 I5 --- Tefflp Effective temperature from lp (1)
97- 99 I3 --- e_Tefflp Uncertainty in effective temperature
from lp (1)
101-104 F4.2 [cm/s2] loggmont Surface gravity from mont (1)
106-109 F4.2 [cm/s2] e_loggmont Uncertainty in surface gravity
from mont (1)
111-114 F4.2 [cm/s2] ce-loggmont Uncertainty in surface gravity from mont
for 1sigma confidence ellipse (1)
116-119 F4.2 [cm/s2] logglp Surface gravity from lp (1)
121-124 F4.2 [cm/s2] e_logglp Uncertainty in surface gravity (1)
126-129 F4.2 [cm/s2] ce-logglp Uncertainty in surface gravity from lp for
1sigma confidence ellipse (1)
131-134 F4.2 Msun Massmont Mass from mont (1)
136-139 F4.2 Msun e_Massmont Uncertainty in mass from mont (1)
141-144 F4.2 Msun Masslp Mass from lp (1)
146-149 F4.2 Msun e_Masslp Uncertainty in mass from lp (1)
151-155 F5.2 mas plx Parallax from Gaia DR3
157-160 F4.2 mas e_plxmont Fit error in parallax from mont (1)
162-165 F4.2 mas e_plxlp Fit error in parallax from lp (1)
167-170 I4 Myr tAgemont Cooling age from mont in million years (1)
172-175 I4 Myr tAgelp Cooling age from lp in million years (1)
177-180 F4.2 --- chi2 chi2 from the fitting
182-200 I19 --- GaiaDR3 Gaia DR3 ID
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Note (1): "mont" and "lp" refers to the parameters derived from Montreal
and La-Plata Mass-radius relations respectively.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Object WD name
26- 30 I5 K TeffPS Effective temperature from Pan-STARRS data
32- 35 I4 K e_TeffPS Uncertainty in effective temperature
from Pan-STARRS data
37- 41 F5.3 [cm/s2] loggPS Surface gravity from Pan-STARRS data
43- 47 F5.3 [cm/s2] e_loggPS Uncertainty in surface gravity
from Pan-STARRS data
49- 53 F5.3 Msun MassPS Mass from Pan-STARRS data
55- 59 F5.3 Msun e_MassPS Uncertainty in mass from Pan-STARRS data
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Object WD name
24- 28 I5 K TeffK09u Effective temperature from SPY survey
30- 32 I3 K e_TeffK09u Uncertainty in effective temperature
from SPY survey
34- 37 F4.2 [cm/s2] loggK09u Surface gravity from SPY survey
39- 42 F4.2 [cm/s2] e_loggK09u Uncertainty in surface gravity
from SPY survey
44- 47 F4.1 --- S/N Signal to noise
49- 53 F5.2 --- chi2 chi2 from the fitting
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Acknowledgements:
Snehalata Sahu, snehalatash30[at]gmail.com
(End) Patricia Vannier [CDS] 17-Nov-2023