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

• Main Authors: Borlaff, Alejandro S, Marcum, Pamela M, Alpaslan, Mehmet, Temi, Pasquale, Chamba, Nushkia, Chojnowski, Drew S, Fanelli, Michael N, Koekemoer, Anton M, Laine, Seppo, Lopez-Rodriguez, Enrique, Siemiginowska, Aneta
• Format: Journal Article
• Language: English
• Published: 02-05-2024
• Subjects: Physics - Astrophysics of Galaxies; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics
• DOI: 10.48550/arxiv.2405.01625

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.