This month’s undergraduate research post features pulsars as a probe of our galaxy’s magnetic field, and the possibility of asymmetries in supernovae associated with gamma-ray bursts.
The authors identify two distinct sequences of blue straggler stars in the globular cluster NGC 392. They hypothesize that one branch is formed via stellar mergers and the other is binary stars undergoing mass transfer. This is the second globular cluster found to possess this double sequence.
The densest galaxy in the local Universe may have been found. M60-UCD1 is most likely a tidally-stripped remnant of a more massive progenitor galaxy. Strader et al. predicts that the progenitor of M60-UCD1 was ~ 50-200 times more massive, suggesting that it was once an elliptical galaxy that has been stripped of most of its mass.
In this article, the authors report their serendipitous discovery of two stellar mass-black holes in the globular cluster M22, however theoretical work predicts that there should only be one stellar-mass black hole!
Globular clusters are some of the most massive and densest star clusters observed. What are the progenitors of old globular clusters that we see orbiting the Milky Way and other galaxies? What evolutionary and dynamical effects have these clusters experienced? What determines the physical properties of old globular clusters? Why are there two “distinct” classes of globular clusters and what properties determine these physical states? These are the questions the authors aim to answer.
Miller & Davies investigate whether central black holes should exist in low mass stellar systems such as globular clusters.
Strader et al. search for the elusive intermediate mass black holes in globular clusters.
“A galaxy is a gravitationally bound collection of stars whose properties cannot be explained by a combination of baryons and Newton’s laws of gravity.” (Willman & Strader, http://arxiv.org/abs/1203.2608)