Low Surface Brightness Science and Robust Sky Estimation

Session Abstract: The potential for low surface brightness (LSB) science to flourish with Rubin Observatory data is vast, but not without pitfalls. Traditional sky estimation techniques tend to compromise or destroy LSB light. This session will cover current and emerging techniques for estimating robust sky levels with Rubin data, highlighting successes and reviewing future challenges. Anyone with questions or suggestions for discussion topics for this session is encouraged to contact the session chairs, Lee Kelvin and Sugata Kaviraj.

Session Agenda

Welcome, Reminders, and Introduction. [2 min]
Slides - PDF

The low-surface-brightness Universe: a vast new discovery space for LSST. Sugata Kaviraj [3]

This talk will provide a general overview of the significance of the low-surface-brightness Universe. It will describe how LSST could revolutionise our understanding of the evolution of the observable Universe by allowing statistical access to this regime for the first time.
Slides - PDF

Sky Subtraction in an Era of Low Surface Brightness Astronomy. Lee Kelvin [8+2]

Future sky surveys will be deeper, wider and faster than those that came before, putting extra pressure on existing sky estimation and source detection algorithms. In this talk, I will provide an overview of how current sky estimation packages perform with deep simulated Hyper Suprime Cam imaging, and methodologies that may be adopted to mitigate sky oversubtraction.
Slides - PDF

Pushing the limits of source detection algorithms towards low surface brightness light. Nushkia Chamba [8+2]

We present a comparison of four source extraction tools: SExtractor, NoiseChisel, ProFound and Max-Trees Objects for the detection of faint, extended sources and evaluate their performance using objective segmentation quality criteria. We will also discuss a method to automatically optimise segmentation tools for the detection low surface brightness light and suggest various avenues for future improvements in background subtraction, multi-band detection and de-blending.
Slides - Optimized PDF (26mb)    |    Full PDF (106mb)

Testing the current LSST DM Stack Sky Subtraction Using Model Galaxies. Aaron Watkins [8+2]

In order to conduct low surface brightness (LSB) science using LSST imaging, a careful sky subtraction is critical.  Using surface brightness profiles, curves of growth, and integrated magnitudes and colors of injected model galaxies, we show that the current pipeline's sky subtraction routine may have a worryingly large impact on not just LSB science, but galaxy science in general.
Slides - PDF

How much ICL will the Vera Rubin Telescope reveal? Cristina Martinez Lombilla [8+2]

Intra-Cluster Light is a diffuse ensemble that sprawls across the centres of galaxy clusters, detected at very faint surface brightnesses. We evaluate the feasibility to observe and measure this light with LSST, using the regularly reprocessed HSC-SSP PDR2 data of Galaxy And Mass Assembly (GAMA) groups.
Slides - PDF

The intracluster light of Abell 85 as seen by the Hyper Suprime-Cam. Mireia Montes [4+1]

The study of low surface brightness light in large, deep imaging surveys is still uncharted territory as automated data reduction pipelines over-subtract or eliminate this light. In this talk, I will show that using careful data processing can unveil the diffuse light within the cluster using archival data of the Abell 85 cluster of galaxies taken with Hyper Suprime-Cam.
Slides - PDF

Studies of intra-cluster light through stacking Dark Energy Survey Data. Yuanyuan Zhang [4+1]

One way of measuring the statistical properties of intra-cluster light is through stacking the surface brightness measurements of hundreds of galaxy clusters. I will describe our methods that have measured ICL from Dark Energy Survey data to a surface brightness limit of ~ 30 mag/arcsecond^2, as well as the results about intra-cluster light fraction, and how the radial profiles of intra-cluster light compares to weak lensing.
Slides - PDF

Live Recording


Lee Kelvin and Sugata Kaviraj
Thursday, Aug 13
09:00 HST - 12:00 PT - 15:00 EDT - 21:00 CEST - 05:00 AET +1