Magnetic dynamos in white dwarfs -- I. Explaining the dearth of bright intermediate polars in globular clusters
arXiv:2105.11459 · doi:10.1093/mnrasl/slab054
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 in GCs are typically very old systems ( 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 cataclysmic variables 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.
letter accepted for publication by MNRAS
References in corpus (11)
- On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model-Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
- How mergers magnetise massive stars
- A radio pulsing white dwarf binary star
- Dynamical Formation of Close Binaries in Globular Clusters II: Cataclysmic Variables
- A common origin of magnetism from planets to white dwarfs
- On the initial binary population for star cluster simulations
- A Thousand and One Nova Outbursts
- The MAVERIC Survey: Chandra/ACIS Catalog of Faint X-ray sources in 38 Galactic globular clusters
- Mass Evaporation Rate of Globular Clusters in a Strong Tidal Field
- Magnetic white dwarfs in post-common-envelope binaries
- MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters -- II. Cataclysmic variables -- progenitors and population at birth
Cited by in corpus (15)
- Carbon-Oxygen Phase Separation in MESA White Dwarf Models
- Heat transport and convective velocities in compositionally-driven convection in neutron star and white dwarf interiors
- Period bouncers as detached magnetic cataclysmic variables
- Magnetic field breakout from white dwarf crystallization dynamos
- A Short Intense Dynamo at the Onset of Crystallization in White Dwarfs
- Can we reveal the core-chemical composition of ultra-massive white dwarfs through their magnetic fields?
- Fast and Slow Crystallization-driven Convection in White Dwarfs
- Magnetic field evolution for crystallization-driven dynamos in C/O white dwarfs
- A Deep Search for Faint Chandra X-ray Sources, Radio Sources, and Optical Counterparts in NGC 6752
- The formation of the magnetic symbiotic star FN Sgr
- Breaking the degeneracy in magnetic cataclysmic variable X-ray spectral modeling using X-ray light curves
- A promising formation channel for symbiotic X-ray binaries: cases of IGR J17329-2731 and 4U 1700+24
- Reevaluating the Origin of Detectable Cataclysmic Variables in Globular Clusters: Testing the Importance of Dynamics
- Slow convection and fast rotation in crystallization-driven white dwarf dynamos
- Magnetic dynamos in white dwarfs -III: explaining the occurrence of strong magnetic fields in close double white dwarfs