by Meredith Rawls | Feb 17, 2014 | Daily Paper Summaries
What do you call two stars hurtling around each other with bursts of X-rays every few decades? An X-ray transient, of course! This special flavor of X-ray binary features a neutron star or black hole together with a low-mass star.
by Elizabeth Lovegrove | Feb 13, 2012 | Daily Paper Summaries
When the light from a distant quasar finally arrives at Earth, it often carries far more information than it did when it was emitted – the shadows of gas and galaxies that have intervened over the cosmic distances between us and the source. These features can tell us how the universe evolves in both space and time, by allowing us to sample both low and high redshifts for structures that would not otherwise be visible. This paper uses a new IR spectrograph, FIRE, deployed on the Magellan 6.5 m telescopes, to present the first high-redshift sample of Mg II absorption systems, including the most distant Mg II system yet found (z = 5.33). The authors show that the number of strong Mg II systems appears to peak and decline in number along with the star formation history of the universe, suggesting a correlation between the two, while weak Mg II systems stay mysteriously constant.