Why resort to complicated theories that involve mysterious, unknown forces and states of matter? The geocentric model of the Universe nicely explains 1st century C.E. data.
Imagine a spinning skater. She pulls her arms in a little and spins faster. She brings her arms all the way into her chest, and spins really fast, and then bam! she rockets up into the sky. Seven years ago, computer simulations revealed a configuration of two spinning black holes that merged in this way, jumping out of their orbital plane with a velocity of several thousand km/s. Not only is this weird, it’s also important. We know that large galaxies host supermassive black holes at their centers. We also know that galaxies merge, presumably introducing their black holes to one another. If the newly formed black hole were to exit the galaxy entirely, it could carry its accretion disk with it, and be observable as a displaced core.
In the final months of World War II, Vannevar Bush, director of the Office of Scientific Research and Development, prepared a report that would forever shape federal support of scientific research.
Today we take a look back to 1916, when distances were measured in light years and uncertainties weren’t to be included in publications. The nearly 100-year old discovery of a small star has large implications for our understanding of stellar astrophysics, even today.
In today’s “astrophysical classic”, we delve into the seminal paper behind the Kennicutt-Schmidt relation, the empirical correlation between the star formation rate and gas density.
Our special guest astrophysical classics series on Gunn & Peterson 1965 concludes with an examination — and apprehension — of the suspects responsible for reionization.
Gas in the Universe went from being mostly neutral to mostly ionized as the first galaxies formed, and the signature of this process is imprinted in quasar spectra. The review of the classic paper by Gunn & Peterson continues in this second in the three-part series.
This guest post, the first in a three-part series, reviews the classic article by Gunn & Peterson (1965). This paper proposed several fundamental ideas in cosmology, including using distant quasars as “flashlights” to observe the diffuse gas between galaxies.
A classic 1972 paper by Jim Gunn and J. Richard Gott, III describing the growth of clusters from primordial density perturbations and, most famously, the importance of ram pressure stripping in explaining the observed lack of spiral galaxies towards the center of clusters.
This paper presents three famous relations very important for understanding the inner workings of molecular clouds and star formation processes.