Detecting low surface brightness dwarfs in the big data era
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This dissertation focuses on the detection of low surface brightness (LSB) galaxies via a variety of methods across several different environments. The detection of LSB galaxies is important for a number of reasons, such as solving problems with current cosmology models on small scales; probing the nature of dark matter and galaxy evolution models; and allowing investigation of new and unexpected phenomena in the low surface brightness Universe. Despite the importance of LSB objects, the robust and well-quantified detection of LSB objects has proven to be challenging. This is motivated by the need to reconcile cosmological theory (in the form of simulations) with observations of near-field and small-scale structure in the Universe. LSB dwarf galaxies are an ideal medium to test theoretical predictions for cosmology, galaxy evolution, and dark matter and to impose constraints upon them via observations. Observing dwarf galaxies in different environments allows the testing of different theoretical predictions. I will discuss how I have detected LSB galaxies across different environments, initially through targeting radio sources without optical counterparts, and then through the development and testing of an LSB galaxy detection algorithm for use in optical imaging data. This algorithm was used on 9 square degrees around M101, finding 38 new LSB dwarf candidates. Some of these candidates were then observed with HST to determine if they are associated with M101 or if they are background LSB galaxies. These observations extended the satellite LF for M101 down to M_V = -7.4 and the resulting satellite LF was compared to that of other Local Volume galaxies. This comparison found far greater scatter in the satellite LFs than predicted by theory and showed tentative links between galactic environment, star forming fraction and the satellite LF; also unpredicted by theory. I also report on the first direct observational evidence of a tidal formation mechanism for UDGs via the detection of NGC 2708 Dw1 and NGC 5631 Dw1 with associated stellar streams.