SAUNAS I: Searching for Low Surface Brightness X-ray Emission with Chandra/ACIS

TL;DR

SAUNAS is a new pipeline that enhances detection of faint diffuse X-ray emissions in Chandra/ACIS data, enabling discovery of low surface brightness structures like super-winds and potential galaxy clusters.

Contribution

It introduces a comprehensive, tested pipeline for detecting low surface brightness X-ray features in archival Chandra data, expanding capabilities for studying faint cosmic structures.

Findings

Successfully detected the 30 kpc X-ray super-wind of NGC 3079

Revealed an extended low surface brightness source near UGC 5101

Demonstrated ability to recover previously undetected structures

Abstract

We present SAUNAS (Selective Amplification of Ultra Noisy Astronomical Signal), a pipeline designed for detecting diffuse X-ray emission in the data obtained with the Advanced CCD Imaging Spectrometer (ACIS) of the Chandra X-ray Observatory. SAUNAS queries the available observations in the Chandra archive, performs photometric calibration, PSF (point spread function) modeling, and deconvolution, point-source removal, adaptive smoothing, and background correction. This pipeline builds on existing and well-tested software including CIAO, VorBin, and LIRA. We characterize the performance of SAUNAS through several quality performance tests, and demonstrate the broad applications and capabilities of SAUNAS using two galaxies already known to show X-ray emitting structures. SAUNAS successfully detects the 30 kpc X-ray super-wind of NGC 3079 using Chandra/ACIS datasets, matching the spatial distribution detected with more sensitive XMM-Newton observations. The analysis performed by SAUNAS reveals an extended low surface brightness source in the field of UGC 5101 in the 0.3-1.0 keV and 1.0-2.0 keV bands. This source is potentially a background galaxy cluster or a hot gas plume associated with UGC 5101. SAUNAS demonstrates its ability to recover previously undetected structures in archival data, expanding exploration into the low surface brightness X-ray universe with Chandra/ACIS.