Revised calibration for near- and mid-infrared images from ~4000 pointed observations with AKARI/IRC

TL;DR

This paper updates the calibration process for AKARI/IRC infrared images from ~4000 observations, improving image accuracy and photometry compared to previous surveys, and provides calibrated data and tools online.

Contribution

It presents recent calibration updates for AKARI/IRC infrared images, enhancing image quality and photometric accuracy using the latest data reduction toolkit.

Findings

90% of images have position accuracy better than 1.5"

Photometric uncertainties are 2-4 times smaller than AllWISE at similar wavelengths

Calibrated images and tools are publicly available online

Abstract

The Japanese infrared astronomical satellite AKARI performed ~4000 pointed observations for 16 months until the end of 2007 August, when the telescope and instruments were cooled by liquid Helium. Observation targets include solar system objects, Galactic objects, local galaxies, and galaxies at cosmological distances. We describe recent updates on calibration processes of near- and mid-infrared images taken by the Infrared Camera (IRC), which has nine photometric filters covering 2-27 um continuously. Using the latest data reduction toolkit, we created calibrated and stacked images from each pointed observation. About 90% of the stacked images have a position accuracy better than 1.5". Uncertainties in aperture photometry estimated from a typical standard sky deviation of stacked images are a factor of ~2-4 smaller than those of AllWISE at similar wavelengths. The processed images together with documents such as process logs as well as the latest toolkit are available online.