Photometry of K2 Campaign 9 bulge data

Abstract

In its Campaign 9, K2 observed dense regions toward the Galactic bulge in order to constrain the microlensing parallaxes and probe for free-floating planets. Photometric reduction of the \emph{K2} bulge data poses a significant challenge due to a combination of the very high stellar density, large pixels of the Kepler camera, and the pointing drift of the spacecraft. Here we present a new method to extract K2 photometry in dense stellar regions. We extended the Causal Pixel Model developed for less-crowded fields, first by using the pixel response function together with accurate astrometric grids, second by combining signals from a few pixels, and third by simultaneously fitting for an astrophysical model. We tested the method on two microlensing events and a long-period eclipsing binary. The extracted K2 photometry is an order of magnitude more precise than the photometry from other method.

References in corpus (40)

• emcee: The MCMC Hammer
• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The K2 Mission: Characterization and Early results
• Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve
• Real-Time Difference Imaging Analysis of MOA Galactic Bulge Observations During 2000
• Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing
• Toward High-Precision Astrometry with WFPC2. I. Deriving an Accurate PSF
• No large population of unbound or wide-orbit Jupiter-mass planets
• Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
• The Kepler Pixel Response Function
• Korea Microlensing Telescope Network Microlensing Events from 2015: Event-Finding Algorithm, Vetting, and Photometry
• Triple Microlens OGLE-2008-BLG-092L: Binary Stellar System with a Circumprimary Uranus-type Planet
• Criteria for Sample Selection to Maximize Planet Sensitivity and Yield from Space-Based Microlens Parallax Surveys
• Microlensing of Blended Stellar Images
• A Neptune-mass Free-floating Planet Candidate Discovered by Microlensing Surveys
• OGLE-III Microlensing Events and the Structure of the Galactic Bulge
• Kepler-like Multi-Plexing for Mass Production of Microlens Parallaxes
• First Space-based Microlens Parallax Measurement of an Isolated Star: Spitzer Observations of OGLE-2014-BLG-0939
• Campaign 9 of the $K2$ Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey
• MOA 2003-BLG-37: A Bulge Jerk-Parallax Microlens Degeneracy
• A PSF-based approach to Kepler/K2 data. I. Variability within the K2 Campaign 0 star clusters M 35 and NGC 2158
• High Precision Photometry for K2 Campaign 1
• Modeling microlensing events with MulensModel
• Microlensing Characterization of Wide-Separation Planets
• Exoplanet Transit Parallax
• UKIRT microlensing surveys as a pathfinder for $WFIRST$: The detection of five highly extinguished low-$|b|$ events
• A Causal, Data-Driven Approach to Modeling the Kepler Data
• OGLE-2016-BLG-1190Lb: First Spitzer Bulge Planet Lies Near the Planet/Brown-Dwarf Boundary
• Extracting Microlensing Signals from K2 Campaign 9
• Finite source effects in microlensing: A precise, easy to implement, fast and numerical stable formalism
• An Isolated Microlens Observed from K2, Spitzer and Earth
• A New Type of Ambiguity in the Planet and Binary Interpretations of Central Perturbations of High-Magnification Gravitational Microlensing Events
• Spitzer Microlensing Program as a Probe for Globular Cluster Planets. Analysis of OGLE-2015-BLG-0448
• The KMTNet/K2-C9 (Kepler) Data Release
• Analytic Relations between the Observed Gravitational Microlensing Parameters With and Without the Effect of Blending
• Measurement of Source Star Colors with the K2C9-CFHT Multi-color Microlensing Survey
• Empirical microlensing event rates predicted by a phenomenological model
• Predictions for the Detection and Characterization of a Population of Free-Floating Planets with K2 Campaign 9
• OGLE-2017-BLG-1130: The First Binary Gravitational Microlens Detected From Spitzer Only

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• Kepler K2 Campaign 9: I. Candidate short-duration events from the first space-based survey for planetary microlensing
• K2: Background Survey -- the search for undiscovered transients in Kepler/K2 data
• OGLE-2018-BLG-0799Lb: a $q\sim 2.7\times 10^{-3}$ Planet with Spitzer Parallax
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• Determination of rotation periods for a large sample of asteroids from K2 Campaign 9