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Pixel level decorrelation in service of the Spitzer microlens parallax survey

Dang, Lisa and Calchi Novati, S. and Carey, S. and Cowan, N. B. (2020) Pixel level decorrelation in service of the Spitzer microlens parallax survey. Monthly Notices of the Royal Astronomical Society, 497 (4). pp. 5309-5317. ISSN 0035-8711. doi:10.1093/mnras/staa2245.

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Microlens parallax measurements combining space-based and ground-based observatories can be used to study planetary demographics. In recent years, the Spitzer Space Telescope was used as a microlens parallax satellite. Meanwhile, Spitzer IRAC has been employed to study short-period exoplanets and their atmospheres. As these investigations require exquisite photometry, they motivated the development of numerous self-calibration techniques now widely used in the exoplanet atmosphere community. Specifically, pixel level decorrelation (PLD) was developed for starring-mode observations in uncrowded fields. We adapt and extend PLD to make it suitable for observations obtained as part of the Spitzer Microlens Parallax Campaign. We apply our method to two previously published microlensing events, OGLE-2017-BLG-1140 and OGLE-2015-BLG-0448, and compare its performance to the state-of-the-art pipeline used to analyses Spitzer microlensing observation. We find that our method yields photometry 1.5–6 times as precise as previously published. In addition to being useful for Spitzer, a similar approach could improve microlensing photometry with the forthcoming Nancy Grace Roman Space Telescope.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Dang, Lisa0000-0003-4987-6591
Calchi Novati, S.0000-0002-7669-1069
Carey, S.0000-0002-0221-6871
Cowan, N. B.0000-0001-6129-5699
Additional Information:© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2020 July 22. Received 2020 July 20; in original form 2020 March 3. We would like to thank our referee, D. Bennett, for constructive criticism. We would also like to thank P. Mroz for the discussions of microlensing modelling and R. Poleski for help with MULENSMODEL and useful comments on the manuscript. This work was supported in part through a Visiting Graduate Researcher Fellowship (VGRF) at Caltech’s Infrared Processing and Analysis Center (Caltech/IPAC), McGill University’s Graduate Mobility Award, the Technologies for Exo-Planetary Science (TEPS) International Internship program, and the Natural Sciences and Engineering Research Council of Canada (NSERC)’s Postgraduate Scholarships-Doctoral Fellowship. This work is based on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by an award issued by JPL/Caltech. DATA AVAILABILITY. The Spitzer data underlying this article are publicly available and were provided by NASA/IPAC Infrared Science Archive. The remaining data and code underlying this article will be shared on reasonable request to the corresponding author.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Infrared Processing and Analysis Center (IPAC)UNSPECIFIED
McGill UniversityUNSPECIFIED
Technologies for Exo-Planetary Science (TEPS)UNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Subject Keywords:gravitational lensing: micro, techniques: photometric, infrared: planetary systems
Issue or Number:4
Record Number:CaltechAUTHORS:20201204-161631917
Persistent URL:
Official Citation:Lisa Dang, S Calchi Novati, S Carey, N B Cowan, Pixel level decorrelation in service of the Spitzer microlens parallax survey, Monthly Notices of the Royal Astronomical Society, Volume 497, Issue 4, October 2020, Pages 5309–5317,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106925
Deposited By: George Porter
Deposited On:05 Dec 2020 02:22
Last Modified:16 Nov 2021 18:58

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