Low-surface-brightness galaxies

My undergraduate honors thesis research concerned low-surface-brightness (LSB) galaxies. As the name indicates, LSB galaxies have significantly lower surface brightness than typical galaxies, which makes them very difficult to detect. Although many LSB galaxies are dwarf galaxies, some, such as Malin 1, are giant spirals. Thus, some have suggested that LSB galaxies may contain a significant amount of baryons and thus help solve the so-called 'missing baryon' problem.

In Hayward, Irwin, & Bregman (2005), we proposed a novel method for detecting LSB galaxies using supernovae (SNe). We used data from ROTSE, an experiment whose primary purpose is to study the prompt optical emission from gamma-ray bursts (GRBs). When not chasing GRBs, the ROTSE robotic telescopes image the entire sky approximately every night; these 'sky patrols' are very useful for identifying variable stars and other transients. I searched the sky patrol data for objects with light curves that appear like SNe light curves with no host galaxy contamination (see the above figure, from Hayward et al. 2005, for a synthetic SN light curve). We argued that such objects should be either SNe in LSB hosts or stars unassociated with any galaxy. Unfortunately, the amount of ROTSE sky patrol data available at the time was not sufficient to detect any LSB galaxies. However, we were able to use the non-detection to constrain the contribution of LSB galaxies to the optical luminosity density and baryonic and dark matter densities of the local Universe.

© Christopher C. Hayward 2015-2016; all text may not be reproduced without permission. Images and animations can be used for non-commercial purposes with proper attribution. Last updated December 13, 2016.