J/ApJ/944/56 SDSS magnetic white dwarfs rich in hydrogen (Amorim+, 2023)
Catalog of magnetic white dwarfs with hydrogen dominated atmospheres.
Amorim L.L., Kepler S.O., Kulebi B., Jordan S., Romero A.D.
<Astrophys. J., 944, 56 (2023)>
=2023ApJ...944...56A 2023ApJ...944...56A
ADC_Keywords: Stars, white dwarf; Magnetic fields; Effective temperatures;
Spectra, optical
Keywords: White dwarf stars ; DA stars
Abstract:
White dwarfs are excellent research laboratories as they reach
temperatures, pressures, and magnetic fields that are unattainable on
Earth. To better understand how these three physical parameters
interact with each other and with other stellar features, we
determined the magnetic field strength for a total of
804 hydrogen-rich white dwarfs (WDs) of which 287 are not in the
literature. We fitted the spectra observed with the Sloan Digital Sky
Survey using atmospheric models that consider the Zeeman effect due to
the magnetic field at each point in the stellar disk. Comparing
magnetic and nonmagnetic WDs, the literature already shows that the
magnetic ones have on average higher mass than the nonmagnetic. In
addition to that, magnetic fields are more common in cooler WDs than
in hotter WDs. In consonance, we found that those with higher magnetic
field strengths tend to have higher masses, and lower temperatures,
for which models indicate the crystallization process has already
started. This reinforces the hypothesis that the field is being
generated and/or amplified in the cooling process of the white dwarf.
Our sample constitutes the largest number of white dwarfs with
determined magnetic fields to date.
Description:
To build our sample, we visually investigated all DA spectra from SDSS
DR7 to DR16 searching for Zeeman splittings and concatenated the
selected ones with those previously known until data release 7,
resulting in a total of 804 magnetic white dwarfs with SDSS spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 804 The SDSS magnetic white dwarfs rich in hydrogen
(DAHs)
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
II/306 : The SDSS Photometric Catalog, Release 8 (Adelman-McCarthy+, 2011)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/AJ/130/734 : Magnetic WDs from SDSS DR2 and DR3 (Vanlandingham+, 2005)
J/A+A/506/1341 : Magnetic fields in white dwarfs (Kuelebi+, 2009)
J/MNRAS/429/2934 : SDSS magnetic white dwarf stars (Kepler+, 2013)
J/MNRAS/480/1547 : Full Evolutionary Sequences of Massive WDs (Lauffer+, 2018)
J/MNRAS/499/1890 : Gaia white dwarfs within 40pc. II. (McCleery+, 2020)
J/MNRAS/508/3877 : Catalogue of white dwarfs in Gaia EDR3 (Gentile+, 2021)
J/ApJ/935/L12 : Magnetic field measurements of young WDs (Bagnulo+, 2022)
J/MNRAS/518/3055 : Gaia white dwarfs within 40pc. III (O'Brien+, 2023)
J/A+A/682/A5 : Gaia white dwarfs Classification (Vincent+, 2024)
J/A+A/690/A10 : Magnetic fields in featureless WDs (Berdyugin+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS Position-based identifier
(JHHMMSS.ss+DDMMSS.s)
21- 36 A16 --- Sp-ID SDSS Plate-MJD-Fiber identifier
38- 41 F4.2 Msun Mstar [0.18/1.4]? Mass (1)
43- 47 I5 K Teff [5212/67365]? Effective Temperature (1)
49- 53 I5 K TSDSS [8000/50000] Temperature used for model (2)
55- 60 F6.2 MG B [0.5/779] Dipole magnetic field strength of the
offset dipole from best fit YAWP model (3)
62- 67 A6 MG e_B ? Uncertainty in B (4)
69- 73 F5.2 --- zoff [-0.5/0.5]? Z-offset from the center in the YAWP
model in stellar radius R* (3)
75- 79 F5.2 deg i [0/90] Inclination of the dipole in the YAWP
model to the line of sight (3)
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Note (1): Masses and effective temperatures from
Gentile Fusillo+ 2021, J/MNRAS/508/3877 when available.
Note (2): TSDSS is the temperature we used for the magnetic field model,
computed using non-magnetic atmospheric models and SDSS colors g, r, and i.
Note (3): We used the code (YAWP) presented by Kulebi+ (2009A&A...506.1341K 2009A&A...506.1341K)
to determine the strength of the magnetic fields across the surface of
the star that better matches the observed spectrum, assuming an
off-center dipole inclined in relation to our line of sight.
Note (4): The uncertainty computed through least squares.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jan-2025