dc.contributor.author | Littlefair, S. P. | |
dc.contributor.author | Burningham, B. | |
dc.contributor.author | Helling, Ch | |
dc.date.accessioned | 2017-06-01T15:46:34Z | |
dc.date.available | 2017-06-01T15:46:34Z | |
dc.date.issued | 2017-05-01 | |
dc.identifier.citation | Littlefair , S P , Burningham , B & Helling , C 2017 , ' Robust detection of quasi-periodic variability : A HAWKI mini survey of late T dwarfs ' , Monthly Notices of the Royal Astronomical Society , vol. 466 , no. 4 , pp. 4250-4258 . https://doi.org/10.1093/mnras/stw3376 | |
dc.identifier.issn | 1365-2966 | |
dc.identifier.other | ArXiv: http://arxiv.org/abs/1703.01245v1 | |
dc.identifier.other | ORCID: /0000-0003-4600-5627/work/64327315 | |
dc.identifier.uri | http://hdl.handle.net/2299/18272 | |
dc.description | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. ©: 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. | |
dc.description.abstract | We present HAWK-I J-band light curves of five late-type T dwarfs (T6.5-T7.5) with a typical duration of four hours, and investigate the evidence for quasi-periodic photometric variability on intra-night timescales. Our photometry reaches precisions in the range 7-20 mmag, after removing instrumental systematics that correlate with sky background, seeing and airmass. Based upon a Lomb-Scargle periodogram analysis, the latest object in the sample - ULAS J2321 (T7.5) - appears to show quasi-periodic variability with a period of 1.64 hours and an amplitude of 3 mmag. Given the low amplitude of variability and presence of systematics in our lightcurves, we discuss a Bayesian approach to robustly determine if quasi-periodic variability is present in a lightcurve affected by red noise. Using this approach, we conclude that the evidence for quasi-periodic variability in ULAS J2321 is not significant. As a result, we suggest that studies which identify quasi-periodic variables using the false alarm probability from a Lomb-Scargle periodogram are likely to over-estimate the number of variable objects, even if field stars are used to set a higher false alarm probability threshold. Instead we argue that a hybrid approach combining a false alarm probability cut, followed by Bayesian model selection, is necessary for robust identification of quasi-periodic variability in lightcurves with red noise. | en |
dc.format.extent | 9 | |
dc.format.extent | 3149584 | |
dc.language.iso | eng | |
dc.relation.ispartof | Monthly Notices of the Royal Astronomical Society | |
dc.subject | brown dwarfs | |
dc.title | Robust detection of quasi-periodic variability : A HAWKI mini survey of late T dwarfs | en |
dc.contributor.institution | Centre for Astrophysics Research (CAR) | |
dc.contributor.institution | School of Physics, Astronomy and Mathematics | |
dc.description.status | Peer reviewed | |
rioxxterms.versionofrecord | 10.1093/mnras/stw3376 | |
rioxxterms.type | Journal Article/Review | |
herts.preservation.rarelyaccessed | true | |