Two-dimensional aperture photometry - Signal-to-noise ratio of point-source observations and optimal data-extraction techniques

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Publications of the Astronomical Society of the Pacific; (USA)

DOI:https://doi.org/10.1086/132477· OSTI ID:5557479

Howell, S B ^[1]

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1. Science Applications International Corp., Tucson, AZ (USA)

New methodology and associated software techniques for use when performing two-dimensional aperture photometry with data from areal detectors are presented. It is shown that applying simple Poisson statistics to point sources only works in certain limited regimes and that for many situations the 'CCD equation' must be employed to get accurate results. Sky or background subtraction is again found to be of critical importance and, of five background estimation methods tried, each had some difficulties in producing a 'correct' background value. CCD growth curves are introduced as a means of correcting the flux from faint or crowded sources, when measured with very small (optimum) apertures. These optimum apertures are of interest as they are shown to give large increases in S/N for point-source observations. The usage of these small apertures along with CCD growth curves is discussed and presented with emphasis on their use for time-resolved CCD photometry. 13 refs.

• OSTI ID: 5557479
• Journal Information: Publications of the Astronomical Society of the Pacific; (USA), Vol. 101; ISSN 0004-6280
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
PHOTOMETRY
DATA PROCESSING
APERTURES
BACKGROUND RADIATION
CHARGE-COUPLED DEVICES
OPTIMIZATION
POINT SOURCES
POISSON EQUATION
SIGNAL-TO-NOISE RATIO
STATISTICS
DIFFERENTIAL EQUATIONS
EQUATIONS
MATHEMATICS
OPENINGS
PARTIAL DIFFERENTIAL EQUATIONS
PROCESSING
RADIATION SOURCES
RADIATIONS
SEMICONDUCTOR DEVICES
640100* - Astrophysics & Cosmology