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Related papers: Magnetic white dwarfs from DESI

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A dynamo mechanism driven by differential rotation when stars merge has been proposed to explain the presence of strong fields in certain classes of magnetic stars. In the case of the high field magnetic white dwarfs (HFMWDs), the site of…

Solar and Stellar Astrophysics · Physics 2018-05-16 Gordon P. Briggs , Lilia Ferrario , Christopher A. Tout , Dayal T. Wickramasinghe

Four magnetic white dwarfs have been found in the course of the Hamburg/ESO Survey for bright QSOs. The objects have been selected as QSO candidate on the basis of its blue continuum and the apparent absence of strong hydrogen or helium…

Astrophysics · Physics 2011-05-23 D. Reimers , S. Jordan , D. Koester , N. Bade , Th. Koehler , L. Wisotzki

We present an homogeneous analysis of all DA stars labeled as magnetic in the Montreal White Dwarf Database (MWDD). Our sample is restricted to almost all known magnetic white dwarf showing clear sign of splitting ($B \gtrsim$ 1-2 MG) that…

Solar and Stellar Astrophysics · Physics 2023-02-01 François Hardy , Patrick Dufour , Stefan Jordan

We present a detailed model atmosphere analysis of hot white dwarfs in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our sample includes 19,321 unique targets with $G_{\rm BP}-G_{\rm RP}\leq0$. We use the DESI spectra…

We present our findings on the spectral analysis of seven magnetic white dwarfs that were presumed to be double degenerates. We obtained time-resolved spectroscopy at the Gemini Observatory to look for evidence of binarity or fast rotation.…

Solar and Stellar Astrophysics · Physics 2023-06-28 Adam Moss , Mukremin Kilic , P. Bergeron , Megan Firgard , Warren Brown

We cross-matched 1.3 million white dwarf (WD) candidates from Gaia EDR3 with spectral data from LAMOST DR7 within 3 arcsec. Applying machine learning described in our previous work, we spectroscopically identified 6,190 WD objects after…

Solar and Stellar Astrophysics · Physics 2021-10-04 Xiao Kong , A-Li Luo

Weak magnetic field has been searched for on only a small number of white dwarfs. Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to previous studies this number increases up to about 25% in the kG…

Astrophysics · Physics 2007-05-23 S. Jordan , R. Aznar Cuadrado , R. Napiwotzki , H. M. Schmid , S. K. Solanki

The origin of highly-magnetized white dwarfs has remained a mystery since their initial discovery. Recent observations indicate that the formation of high-field magnetic white dwarfs is intimately related to strong binary interactions…

Solar and Stellar Astrophysics · Physics 2015-05-20 J. Nordhaus , S. Wellons , D. S. Spiegel , B. D. Metzger , E. G. Blackman

We present a detailed model atmosphere analysis of massive white dwarfs with $M > 0.9~M_\odot$ and $T_{\rm eff}\geq11,000$ K in the Montreal White Dwarf Database 100 pc sample and the Pan-STARRS footprint. We obtained follow-up optical…

Magnitude-limited samples have shown that 20-25 per cent of cataclysmic variables contain white dwarfs with magnetic fields of Mega Gauss strength, in stark contrast to the approximately 5 per cent of single white dwarfs with similar…

Solar and Stellar Astrophysics · Physics 2021-02-10 S. G. Parsons , B. T. Gänsicke , M. R. Schreiber , T. R. Marsh , R. P. Ashley , E. Breedt , S. P. Littlefair , H. Meusinger

White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks. This is a rare class of objects with only eight published systems. In this work, we perform a…

When a star exhausts its nuclear fuel, it either explodes as a supernova or more quiescently becomes a white dwarf, an object about half the mass of our Sun with a radius of about that of the Earth. About one fifth of white dwarfs exhibit…

We have carried out a search for massive white dwarfs (WDs) in the direction of young open star clusters using the Gaia DR2 database. The aim of this survey was to provide robust data for new and previously known high-mass WDs regarding…

Solar and Stellar Astrophysics · Physics 2021-05-26 Harvey B. Richer , Ilaria Caiazzo , Helen Du , Steffani Grondin , James Hegarty , Jeremy Heyl , Ronan Kerr , David R. Miller , Sarah Thiele

High-field magnetic white dwarfs have been long suspected to be the result of stellar mergers. However, the nature of the coalescing stars and the precise mechanism that produces the magnetic field are still unknown. Here we show that the…

Solar and Stellar Astrophysics · Physics 2012-09-13 E. García-Berro , S. Torres , P. Lorén-Aguilar , G. Aznar-Siguán , J. Camacho , B. Külebi , J. Isern , L. G. Althaus , A. H. Córsico

We present an overview of the sample of northern hemisphere white dwarfs within 40 pc of the Sun detected from $Gaia$ Data Release 2 (DR2). We find that 521 sources are spectroscopically confirmed degenerate stars, 111 of which were first…

Wickramasinghe et al. (2014) and Briggs et al. (2015) have proposed that the strong magnetic fields observed in some single white dwarfs (MWDs) are formed by a dynamo driven by differential rotation when two stars, the more massive one with…

Solar and Stellar Astrophysics · Physics 2018-01-31 G. Briggs , Lilia Ferrario , C. A. Tout , D. T. Wickramasinghe

Binary stars containing a white dwarf and a main-sequence star, WDMS binaries, can be used to study a wide range of aspects of stellar astrophysics. We build a magnitude-limited sample of unresolved WDMS binaries from Gaia DR3 to enlarge…

Context: About 10% of white dwarfs have magnetic fields with strength in the range between about 10^5 and 3x10^8 G. It is not known whether the remaining white dwarfs are not magnetic, or if they have a magnetic field too weak to be…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. D. Landstreet , S. Bagnulo , G. G. Valyavin , L. Fossati , S. Jordan , D. Monin , G. Wade

In this article we describe the search for white dwarfs (WDs) in the multi-band photometric data of the Capodimonte deep field survey. The WD candidates were selected through the V-R_C vs B-V color-color diagram. For two bright objects, the…

Astrophysics · Physics 2009-11-13 R. Silvotti , S. Catalan , M. Cignoni , J. M. Alcala' , M. Capaccioli , A. Grado , M. Pannella