By looking at the spectral changes of the accretion disk emission around black holes, we can trace the physical changes of the accreting material.
There aren’t many places in the universe that you can find a bunch of free neutrons not already trapped inside a nucleus—except in neutron stars. Luckily, neutron stars in violent mergers with other neutron stars, or with black holes, tend to disperse a little bit of their matter into the interstellar medium. Tidal forces eject some matter as the two objects swing around each other in their final orbits. Then, if an accretion disk forms, winds blown off the surface of the disk disperse even more matter. Surman and her colleagues look at the nucleosynthesis that occurs in this latter process, and find something surprising.
By examining their expansion rate over time, Type II supernovae provide a way to measure extragalactic distances.
Field lines are a powerful tool for building intuition for a complex geometric object.
Boss & Keiser examine how magnetic fields with varying initial conditions affect star formation.
Carretti and collaborators have found new evidence that the gigantic bubbles of emission emanating from the center of our Milky Way are the result of winds from supernova explosions, not jets from our supermassive black hole.
The Canada-France Hawaii Telescope weak gravitational lensing survey (CFHTLens), recently released new results to help constrain our cosmological models. While still in its early stages, weak lensing will ultimately be a powerful tool to discover the nature of the mysterious dark energy.
I’ve got pretty bad eyesight. If I take off my glasses and look at the flowers on my window sill, they look like a fuzzy yellow blob. But with glasses, the petals and the patterns cast on them come into focus. This is how I felt when looking at the new observations of the debris disk around AU Mic. Putting on our ALMA glasses, the fuzzy debris disk around AU Mic is sharpening into something surprisingly consistent with our own Solar System.
I recently attended a two-week crash course in the “Astrophysical Applications of Gravitational Lensing”. In this post, I overview a few of the ways astronomers employ lensing to study the Universe, from extrasolar planets to distant quasars and large-scale structure.
The race to be the first to detect gravitational waves is on – are pulsar timing arrays on the verge of a discovery? New predictions based on revised galaxy merger calculations suggest that it may be so.