Near-infrared variability in dusty white dwarfs: tracing the accretion of planetary material
Author
Rogers, Laura KXu (许偲艺), Siyi
Bonsor, Amy
Hodgkin, Simon
Su, Kate Y L
von Hippel, Ted
Jura, Michael
Affiliation
Univ Arizona, Steward ObservIssue Date
2020-04-07Keywords
methods: observationaltechniques: photometric
circumstellar matter
white dwarfs
infrared: planetary systems
Metadata
Show full item recordPublisher
OXFORD UNIV PRESSCitation
Rogers, L. K., Xu, S., Bonsor, A., Hodgkin, S., Su, K. Y., von Hippel, T., & Jura, M. (2020). Near-infrared variability in dusty white dwarfs: tracing the accretion of planetary material. Monthly Notices of the Royal Astronomical Society, 494(2), 2861-2874.Rights
© 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
The inwards scattering of planetesimals towards white dwarfs is expected to be a stochastic process with variability on human time-scales. The planetesimals tidally disrupt at the Roche radius, producing dusty debris detectable as excess infrared emission. When sufficiently close to the white dwarf, this debris sublimates and accretes on to the white dwarf and pollutes its atmosphere. Studying this infrared emission around polluted white dwarfs can reveal how this planetary material arrives in their atmospheres. We report a near-infrared monitoring campaign of 34 white dwarfs with infrared excesses with the aim to search for variability in the dust emission. Time series photometry of these white dwarfs from the United Kingdom Infrared "felescope (Wide Field Camera) in the J-, H-, and K-bands was obtained over baselines of up to 3 yr. We find no statistically significant variation in the dust emission in all three near-infrared bands. Specifically, we can rule out variability at similar to 1.3 per cent for the 13 white dwarfs brighter than 16th mag in K-band, and at similar to 10 per cent for the 32 white dwarfs brighter than 18th mag over time-scales of 3 yr. Although to date two white dwarfs, SDSS J095904.69-020047.6 and WD 1226+110, have shown K-band variability, in our sample we see no evidence of new K-band variability at these levels. One interpretation is that the tidal disruption events that lead to large variabilities are rare occur on short time-scales, and after a few years the white dwarfs return to being stable in the near-infrared.ISSN
0035-8711EISSN
1365-2966Version
Final published versionSponsors
National Science Foundationae974a485f413a2113503eed53cd6c53
10.1093/mnras/staa873