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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Magnetic dynamos in white dwarfs - I. Explaining the dearth of bright intermediate polars in globular clusters

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Author(s):
Belloni, Diogo [1, 2] ; Schreiber, Matthias R. [1, 3] ; Salaris, Maurizio [4] ; Maccarone, Thomas J. [5] ; Zorotovic, Monica [6]
Total Authors: 5
Affiliation:
[1] Univ Tecn Federico Santa Maria, Dept Fis, Av Espana 1680, Valparaiso - Chile
[2] Natl Inst Space Res, Av Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[3] Millenium Nucleus Planet Format, Valparaiso 2340000 - Chile
[4] Liverpool John Moores Univ, Astrophys Res Inst, 146 Brownlow Hill, Liverpool L3 5RF, Merseyside - England
[5] Texas Tech Univ, Dept Phys & Astron, Box 41051, Sci Bldg, Lubbock, TX 79409 - USA
[6] Univ Valparaiso, Inst Fis & Astron, Av Gran Bretana 1111, Valparaiso 2360102 - Chile
Total Affiliations: 6
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 505, n. 1, p. L74-L78, JUL 2021.
Web of Science Citations: 2
Abstract

Recently, Bahramian et al. investigated a large sample of globular clusters (GCs) and found that bright intermediate polars (IPs) are a factor of 10 less frequent in GCs than in the Galactic field. We theoretically investigate here this discrepancy based on GC numerical simulations. We found that, due to disruptive dynamical interaction, there is on average a reduction of only half of bright IP progenitors, which is clearly not enough to explain the observed deficiency. However, if the rotation-and crystallization-driven dynamo scenario recently proposed by Schreiber et al. is incorporated in the simulations, the observed rareness of bright IPs in GCs can be reproduced. This is because bright cataclysmic variables (CVs) in GCs are typically very old systems (greater than or similar to 10 Gyr), with white dwarfs that almost fully crystallized before mass transfer started, which does not allow strong magnetic fields to be generated. The observed mass density of bright IPs in GCs can be recovered if around one-third of the bright CVs dynamically formed through mergers have magnetic field strengths similar to those of IPs. We conclude that the observed paucity of bright IPs in GCs is a natural consequence of the newly proposed rotation-and crystallization-driven dynamo scenario. (AU)

FAPESP's process: 17/14289-3 - Magnetic Cataclysmic variables: secular evolution with the BSE code and emission modelling with the CYCLOPS code
Grantee:Diogo Teixeira Belloni
Support Opportunities: Scholarships in Brazil - Post-Doctoral