On Surface Brightness and Flux Calibration for Point and Compact Extended Sources in the AKARI Far-IR All-Sky Survey (AFASS) Maps

Abstract

The AKARI Infrared Astronomical Satellite produced the all-sky survey (AFASS) maps in the far-IR at roughly arc-minute spatial resolution, enabling us to investigate the whole sky in the far-IR for objects having surface brightnesses greater than a few to a couple of dozen MJy/sr. While the AFASS maps are absolutely calibrated against large-scale diffuse emission, it was uncertain whether or not an additional flux correction for point sources was necessary. Here, we verify that calibration for point-source photometry in the AFASS maps is proper. With the aperture correction method based on the empirical point-spread-function templates derived directly from the AFASS maps, fluxes in the AKARI bright source catalogue (BSC) are reproduced. The AKARI BSC fluxes are also satisfactorily recovered with the 1 sigma aperture, which is the empirical equivalent of an infinite aperture. These results confirm that in the AFASS maps far-IR photometry can be properly performed by using the aperture correction method for point sources and by summing all pixel values within an appropriately defined aperture of the intended target (i.e., the aperture photometry method) for extended sources.

arXiv comment8 pages, 3 figures, to be published on PASJ (AKARI Special Issue)

References in corpus (12)

• The Infrared Astronomical Mission AKARI
• The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background: I. Limits and Detections
• The Infrared Camera (IRC) for AKARI - Design and Imaging Performance
• The Far-Infrared Surveyor (FIS) for AKARI
• Infrared Emission from the Radio Supernebula in NGC 5253: A Proto-Globular Cluster?
• Detection of the Cosmic Far-Infrared Background in the AKARI Deep Field South
• The $AKARI$ Far-Infrared All-Sky Survey Maps
• Calibration and Performance of the AKARI Far-Infrared Surveyor (FIS) -- Slow-Scan Observation Mode for Point Sources
• Calibration of the AKARI Far-infrared All Sky Survey Maps
• Characterization and Improvement of the Image Quality of the Data Taken with the Infrared Camera (IRC) Mid-Infrared Channels onboard AKARI
• Point source calibration of the AKARI/FIS all-sky survey maps for staking analysis
• Surface Brightness Correction for Compact Extended Sources Observed by the AKARI Far-Infrared Surveyor (FIS) in the Slow-Scan Mode

Cited by in corpus (3)

• A new study on a type Iax stellar remnant and its probable association with SN 1181
• 3D structure of HII region Sh2-235 from tunable-filter optical observations
• AKARI Mission Program: Excavating Mass Loss History in Extended Dust Shells of Evolved Stars (MLHES) I. Far-IR Photometry