A Method To Characterize the Wide-Angle Point Spread Function of Astronomical Images

Abstract

Uncertainty in the wide-angle Point Spread Function (PSF) at large angles (tens of arcseconds and beyond) is one of the dominant sources of error in a number of important quantities in observational astronomy. Examples include the stellar mass and shape of galactic halos and the maximum extent of starlight in the disks of nearby galaxies. However, modeling the wide-angle PSF has long been a challenge in astronomical imaging. In this paper, we present a self-consistent method to model the wide-angle PSF in images. Scattered light from multiple bright stars is fitted simultaneously with a background model to characterize the extended wing of the PSF using a Bayesian framework operating on pixel-by-pixel level. The method is demonstrated using our software elderflower and is applied to data from the Dragonfly Telephoto Array to model its PSF out to 20-25 arcminutes. We compare the wide-angle PSF of Dragonfly to that of a number of other telescopes, including the SDSS PSF, and show that on scales of arcminutes the scattered light in the Dragonfly PSF is markedly lower than that of other wide-field imaging telescopes. The energy in the wings of the Dragonfly point-spread function is sufficiently low that optical cleanliness plays an important role in defining the PSF. This component of the PSF can be modelled accurately, highlighting the power of our self-contained approach.

26 pages, 14 figures, accepted for publication in ApJ

References in corpus (14)

• Array Programming with NumPy
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• The Stellar Populations of Praesepe and Coma Berenices
• Markov Chain Monte Carlo Methods for Bayesian Data Analysis in Astronomy
• Principal Component Analysis of the Time- and Position-Dependent Point Spread Function of the Advanced Camera for Surveys
• Parametrizing the Stellar Haloes of Galaxies
• The influence of diffuse scattered light I. The PSF and its role to observations of the edge-on galaxy NGC 5907
• The Sloan Digital Sky Survey extended point spread functions
• A missing outskirts problem? Comparisons between stellar halos in the Dragonfly Nearby Galaxies Survey and the TNG100 simulation
• A deconvolution-based algorithm for crowded field photometry with unknown Point Spread Function
• Point spread function tails and the measurements of diffuse stellar halo light around edge-on disc galaxies
• Blind deconvolution in astronomy with adaptive optics: the parametric marginal approach
• Comparing PyMorph and SDSS photometry. I. Background sky and model fitting effects
• On the varied origins of up-bending breaks in galaxy disks

Cited by in corpus (12)

• Euclid: Early Release Observations -- Programme overview and pipeline for compact- and diffuse-emission photometry
• Tidal Distortions in NGC1052-DF2 and NGC1052-DF4: Independent Evidence for a Lack of Dark Matter
• Stellar halos from The Dragonfly Edge-on Galaxies Survey
• Beyond Ultra-diffuse Galaxies. I. Mass--Size Outliers among the Satellites of Milky Way Analogs
• Introducing the Condor Array Telescope. 1. Motivation, Configuration, and Performance
• Joint Modelling of Dust Scattering and Thermal Emission: The Spider Complex
• A Recipe for Unbiased Background Modeling in Deep Wide-Field Astronomical Images
• Performance Assessment of the KASI-Deep Rolling Imaging Fast-optics Telescope pathfinder
• Distributed Aperture Telescopes and the Dragonfly Telephoto Array
• Quantitative Morphology of Galactic Cirrus in Deep Optical Imaging
• J-PLUS: Turning Off the Bright Stars
• Analysis of Galactic cirrus filaments in HSC-SSP high-resolution deep images using artificial neural networks