Galactic cirri in deep optical imaging

TL;DR

This paper investigates the optical colors of Galactic cirri in deep surveys, proposing that multi-band photometry can effectively distinguish dust from extragalactic sources, aiding future deep optical observations.

Contribution

It provides a photometric characterization of Galactic cirri using deep optical data and suggests a method to differentiate dust from extragalactic objects based on color differences.

Findings

Galactic cirri have distinct optical colors from extragalactic sources.

Multi-band optical photometry can help identify Galactic dust.

Deep optical surveys like LSST will improve dust detection.

Abstract

The presence of Galactic cirri in deep optical observations is one of the most challenging problems that the extragalactic community is already facing, and it is expected to be even tougher in the near future with the increasing depth of optical surveys. To address this problem, we have performed a photometric characterization of Galactic cirri in the IAC Stripe82 Legacy Survey using g, r, i and z SDSS bands. Through comprehensive image processing techniques we show that, in most cases, the colors of the cirri differ significantly from the colors of extragalactic sources. This could be a promising way to discern extragalactic features from dust of the Milky-Way. We suggest that the use of multi-band and ultra-deep optical photometry produced by the Large Synoptic Survey Telescope will be very efficient in detecting the Galactic dust with a higher spatial resolution than those provided by far infrared observations.