Unravelling the baffling mystery of the ultrahot wind
phenomenon in white dwarfs

J 2019

Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs

REINDL, Nicole; Matthew BAINBRIDGE; N. PRZYBILLA; S. GEIER; Milan PRVÁK et. al.

Základní údaje

Originální název

Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs

Autoři

REINDL, Nicole; Matthew BAINBRIDGE; N. PRZYBILLA; S. GEIER; Milan PRVÁK; Jiří KRTIČKA; R. H. OSTENSEN; J. TELTING a K. WERNER

Vydání

Monthly Notices of the Royal Astronomical Society, Oxford, OXFORD UNIV PRESS, 2019, 0035-8711

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Full Text

Impakt faktor

Impact factor: 5.357

Kód RIV

RIV/00216224:14310/19:00107950

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1093/mnrasl/sly191

UT WoS

000482176700020

EID Scopus

2-s2.0-85057147551

Klíčová slova anglicky

stars: AGB and post-AGB; stars: evolution; stars: magnetic field

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 28. 3. 2020 13:08, Mgr. Marie Novosadová Šípková, DiS.

Anotace

ORIG CZ

V originále

The presence of ultrahigh excitation (UHE) absorption lines (e.g. OVIII) in the optical spectra of several of the hottest white dwarfs poses a decades-long mystery and is something that has never been observed in any other astrophysical object. The occurrence of such features requires a dense environment with temperatures near 10(6) K, by far exceeding the stellar effective temperature. Here we report the discovery of a new hot wind white dwarf, GALEXJ014636.8+323615. Astonishingly, we found for the first time rapid changes of the equivalent widths of the UHE features, which are correlated to the rotational period of the star (P=0.242035 d). We explain this with the presence of a wind-fed circumstellar magnetosphere in which magnetically confined wind shocks heat up the material to the high temperatures required for the creation of the UHE lines. The photometric and spectroscopic variability of GALEXJ014636.8+323615 can then be understood as consequence of the obliquity of the magnetic axis with respect to the rotation axis of the white dwarf. This is the first time a wind-fed circumstellar magnetosphere around an apparently isolated white dwarf has been discovered and finally offers a plausible explanation of the ultrahot wind phenomenon.

Česky

Studujeme nově objeveného bílého trpaslíka GALEXJ014636.8+323615, který má ve svém spektru čáry vysoce ionizovaných prvků. Tyto čáry vykazují periodickou proměnnost odpovídající rotační periodě hvězdy. Tento jev vysvětlujeme jako důsledek větrem vyplnované magnetosféry.

Návaznosti

GA16-01116S, projekt VaV

Název: Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Investor: Grantová agentura ČR, Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Citovat

REINDL, Nicole; Matthew BAINBRIDGE; N. PRZYBILLA; S. GEIER; Milan PRVÁK; Jiří KRTIČKA; R. H. OSTENSEN; J. TELTING a K. WERNER. Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs. Monthly Notices of the Royal Astronomical Society. Oxford: OXFORD UNIV PRESS, 2019, roč. 482, č. 1, s. "L93"-"L98", 6 s. ISSN 0035-8711. Dostupné z: https://doi.org/10.1093/mnrasl/sly191.

@article{1599999,
   author = {Reindl, Nicole and Bainbridge, Matthew and Przybilla, N. and Geier, S. and Prvák, Milan and Krtička, Jiří and Ostensen, R. H. and Telting, J. and Werner, K.},
   article_location = {Oxford},
   article_number = {1},
   doi = {https://doi.org/10.1093/mnrasl/sly191},
   keywords = {stars: AGB and post-AGB; stars: evolution; stars: magnetic field},
   language = {eng},
   issn = {0035-8711},
   journal = {Monthly Notices of the Royal Astronomical Society},
   title = {Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs},
   url = {https://ui.adsabs.harvard.edu/abs/2019MNRAS.482L..93R/abstract},
   volume = {482},
   year = {2019}
}

TY  - JOUR
ID  - 1599999
AU  - Reindl, Nicole - Bainbridge, Matthew - Przybilla, N. - Geier, S. - Prvák, Milan - Krtička, Jiří - Ostensen, R. H. - Telting, J. - Werner, K.
PY  - 2019
TI  - Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs
JF  - Monthly Notices of the Royal Astronomical Society
VL  - 482
IS  - 1
SP  - "L93"-"L98"
EP  - "L93"-"L98"
PB  - OXFORD UNIV PRESS
SN  - 00358711
KW  - stars: AGB and post-AGB
KW  - stars: evolution
KW  - stars: magnetic field
UR  - https://ui.adsabs.harvard.edu/abs/2019MNRAS.482L..93R/abstract
L2  - https://ui.adsabs.harvard.edu/abs/2019MNRAS.482L..93R/abstract
N2  - The presence of ultrahigh excitation (UHE) absorption lines (e.g. OVIII) in the optical spectra of several of the hottest white dwarfs poses a decades-long mystery and is something that has never been observed in any other astrophysical object. The occurrence of such features requires a dense environment with temperatures near 10(6) K, by far exceeding the stellar effective temperature. Here we report the discovery of a new hot wind white dwarf, GALEXJ014636.8+323615. Astonishingly, we found for the first time rapid changes of the equivalent widths of the UHE features, which are correlated to the rotational period of the star (P=0.242035 d). We explain this with the presence of a wind-fed circumstellar magnetosphere in which magnetically confined wind shocks heat up the material to the high temperatures required for the creation of the UHE lines. The photometric and spectroscopic variability of GALEXJ014636.8+323615 can then be understood as consequence of the obliquity of the magnetic axis with respect to the rotation axis of the white dwarf. This is the first time a wind-fed circumstellar magnetosphere around an apparently isolated white dwarf has been discovered and finally offers a plausible explanation of the ultrahot wind phenomenon.
ER  -

REINDL, Nicole; Matthew BAINBRIDGE; N. PRZYBILLA; S. GEIER; Milan PRVÁK; Jiří KRTIČKA; R. H. OSTENSEN; J. TELTING a K. WERNER. Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs. \textit{Monthly Notices of the Royal Astronomical Society}. Oxford: OXFORD UNIV PRESS, 2019, roč.~482, č.~1, s.~''L93''-''L98'', 6 s. ISSN~0035-8711. Dostupné z: https://doi.org/10.1093/mnrasl/sly191.

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