Stellar Photometry and Astrometry with Discrete Point Spread Functions

Abstract

The key features of the MATPHOT algorithm for precise and accurate stellar photometry and astrometry using discrete Point Spread Functions are described. A discrete Point Spread Function (PSF) is a sampled version of a continuous PSF which describes the two-dimensional probability distribution of photons from a point source (star) just above the detector. The shape information about the photon scattering pattern of a discrete PSF is typically encoded using a numerical table (matrix) or a FITS image file. Discrete PSFs are shifted within an observational model using a 21-pixel-wide damped sinc function and position partial derivatives are computed using a five-point numerical differentiation formula. Precise and accurate stellar photometry and astrometry is achieved with undersampled CCD observations by using supersampled discrete PSFs that are sampled 2, 3, or more times more finely than the observational data. The precision and accuracy of the MATPHOT algorithm is demonstrated by using the C-language MPD code to analyze simulated CCD stellar observations; measured performance is compared with a theoretical performance model. Detailed analysis of simulated Next Generation Space Telescope observations demonstrate that millipixel relative astrometry and millimag photometric precision is achievable with complicated space-based discrete PSFs. For further information about MATPHOT and MPD, including source code and documentation, see http://www.noao.edu/staff/mighell/matphot

19 pages, 22 figures, accepted for publication in MNRAS

References in corpus (1)

• The Photometry of Undersampled Point Spread Functions

Cited by in corpus (36)

• 3.6 and 4.5 Micron Phase Curves and Evidence for Non-Equilibrium Chemistry in the Atmosphere of Extrasolar Planet HD 189733b
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering
• Orbital Phase Variations of the Eccentric Giant Planet HAT-P-2b
• The 4.5 $\mu$m full-orbit phase curve of the hot Jupiter HD 209458b
• 3.6 and 4.5 $\mu$m $Spitzer$ Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b
• HST hot-Jupiter transmission spectral survey: Haze in the atmosphere of WASP-6b
• Atmospheric Characterization of the Hot Jupiter Kepler-13Ab
• Spitzer Observations Confirm and Rescue the Habitable-Zone Super-Earth K2-18b for Future Characterization
• 3.6 and 4.5 $\mu$m Phase Curves of the Highly-Irradiated Eccentric Hot Jupiter WASP-14b
• Spitzer Transits of the Super-Earth GJ1214b and Implications for Its Atmosphere
• HST hot-Jupiter transmission spectral survey: Clear skies for cool Saturn WASP-39b
• Warm Spitzer Photometry of Three Hot Jupiters: HAT-P-3b, HAT-P-4b and HAT-P-12b
• Spitzer Secondary Eclipse Observations of Five Cool Gas Giant Planets and Empirical Trends in Cool Planet Emission Spectra
• Spitzer and z' Secondary Eclipse Observations of the Highly Irradiated Transiting Brown Dwarf KELT-1b
• Micro-pixel accuracy centroid displacement estimation and detector calibration
• Constraints on the Atmospheric Circulation and Variability of the Eccentric Hot Jupiter XO-3b
• Warm Spitzer and Palomar Near-IR Secondary Eclipse Photometry of Two Hot Jupiters: WASP-48b and HAT-P-23b
• The HST PanCET Program: Hints of Na I & Evidence of a Cloudy Atmosphere for the Inflated Hot Jupiter WASP-52b
• Solar-to-supersolar sodium and oxygen absolute abundances for a "hot Saturn" orbiting a metal-rich star
• Spitzer IRAC Sparsely Sampled Phase Curve of the Exoplanet WASP-14b
• Evidence of a Clear Atmosphere for WASP-62b: the Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone
• Planet-Induced Stellar Pulsations in HAT-P-2's Eccentric System
• Finding binary active galactic nuclei by the centroid shift in imaging surveys
• The five largest satellites of Uranus: astrometric observations spread over 29 years at the Pico dos Dias Observatory
• Performance analysis of the Least-Squares estimator in Astrometry
• Characterizing K2 Candidate Planetary Systems Orbiting Low-Mass Stars III: A High Mass & Low Envelope Fraction for the Warm Neptune K2-55b
• Detectability of Supermassive Dark Stars with the Roman Space Telescope
• Far-Infrared double-Fourier interferometers and their spectral sensitivity
• A Spitzer Search for Transits of Radial Velocity Detected Super-Earths
• Statistically optimal fitting of astrometric signals
• Astrometry with PRAIA
• Scientific performance analysis of the SYZ telescope design vs. the RC telescope design
• Optimal Follow-Up of Gravitational-Wave Events with the UltraViolet EXplorer (UVEX)
• An Algorithm for Detecting Quantum-Gravity Photon Dispersion in Gamma-Ray Bursts: DISCAN
• Forced Measurement of Astronomical Sources at Low Signal to Noise
• J-PLUS: Turning Off the Bright Stars