While high-redshift quasars are very interesting objects in their own right, their incredible luminosities allow them to act as background light sources that illuminate the intervening universe on our line of sight. One could think of quasars as giant flashlights that the universe uses to make really interesting spectroscopic shadow puppets back here on Earth.
Along with several other graduate students from Harvard University, I attended the first EVLA data reduction workshop in Socorro, New Mexico. Around 25 graduate students and researchers were present, along with many post-doctoral fellows and NRAO staff that devoted their time to help us learn how to use CASA, or Common Astronomy Software Applications.
We know other stars have planets. We know that certain stars have circumstellar disks. We know that before there are planets, there must be a protoplanetary disk; we also know that these two states must be connected through a evolutionary path which includes planet formation.
What if–if we were just so lucky–we found a protoplanetary system that had a disk, that was aligned so perfectly, and that was bright enough, and ….
Many astronomers have an ambivalent relationship towards “dust” in our cosmos. Not quite like what you may find at the back of your cupboard, astrophysical dust is really more like smoke, with particulates roughly micron-sized and composed of carbon, nitrogen, oxygen, silicon, and other things that astronomers broadly term “metals.” Some of the best candidate sites for dust formation include cool stellar winds from evolved stars, and in the aftermath of supernovae and novae.
The units we use to measure time have until recently been always derived from the movements of the heavens, which we have considered immutable because we have never had the accuracy of measurement to notice otherwise. Starting with the Babylonians, we divided our days into neatly divisible blocks of hours, minutes, and then seconds. The advent of extremely accurate atomic clocks that rely upon the hyperfine quantum transitions of Cesium-133 atoms have challenged our traditional notions of time.