A road-map to white dwarf pollution: Tidal disruption, eccentric grind-down, and dust accretion
نویسندگان
چکیده
A significant fraction of white dwarfs show metal lines indicative pollution with planetary material but the accretion process remains poorly understood. The main aim this paper is to produce a road-map illustrating several potential routes for dwarf and link these paths observational outcomes. Our proposed road begins tidal disruption scattered asteroid formation highly eccentric disc wide range fragment sizes. Accretion fragments by Poynting-Robertson (PR) drag alone too slow explain observed rates. Instead, in second stage, processes including differential apsidal precession cause high-velocity collisions between fragments. Large asteroids more when they disrupt, causing rapid grind-down generating short intense bursts dust production, whereas smaller grind down over longer periods time. In final collisionally produced circularises accretes onto via forces. We that optically thin PR produces large infrared (IR) excesses rate exceeds 10^7 g/s. hypothesise around accreting at high rate, no detected excess, circularisation requires enhanced - instance due presence gas near disc's pericentre.
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2021
ISSN: ['0035-8711', '1365-8711', '1365-2966']
DOI: https://doi.org/10.1093/mnras/stab3009