Tag: quasars
-
The Care and Feeding of Black Holes
[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ] Part 2 of my 4-part series on black holes for Medium members is up; you can read part 1 here. If enough of you read, they may keep me…
-
No quantum foam seen in the cosmic beer glass
[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ] Light from distant black holes doesn’t surf on waves of quantum foam Strongest check yet on quantum gravity effects in astronomy turns up nothing For Ars Technica: Quantum gravity…
-
Using Black Holes to Measure Dark Energy, Like a BOSS
Far from being invisible, black holes are among some of the brightest objects in the Universe. The black holes themselves aren’t emitting light, but the matter they draw in heats up and much of it shoots back out in powerful jets. When that happens, the black hole is known as a quasar, and it can…
-
Measuring black hole rotation halfway across the Universe
Astronomers measured the rotation of a black hole from halfway across the Universe. Astronomers have now used gravitational magnification to measure the rotation rate of a supermassive black hole in a very distant galaxy. From four separate images of the same black hole, R.C. Reis, M.T. Reynolds, J.M. Miller, and D.J. Walton found it was…
-
O, what entangled photons we weave!
(OK, it doesn’t scan. So sue me.) Quantum entanglement is a challenging topic, and one which has tripped up a lot of people (including many physicists!) over the decades. In brief, entanglement involves two (or more) particles constituting a single system: measurement on one particle instantly determines the result of similar measurements on the second,…
-
A glowing filament shows us where the dark matter hides
Astronomers have identified a filament in the cosmic web, which is the pattern formed by dark matter. That web in turn dictates the distribution of galaxies, since the dark matter attracts ordinary matter — atoms — through its gravity. However, it’s hard to spot the filaments connecting the different halos of dark matter, because…
-
A miniature quasar in Andromeda Galaxy
The term “quasar” describes a behavior rather than an object: when a supermassive black hole (SMBH) at the center of a galaxy gorges on gas, the infalling matter produces a lot of light. While most galaxies are known to have SMBHs, not all of those exhibit quasar behavior. Similarly, black holes created from the deaths…
-
Early quasar illuminates a Universe without metals
The moments after the Big Bang left the Universe very hot and dense. In that violent environment, the first nuclei came to be: hydrogen, helium, and lithium…but nothing heavier. The elements more massive than helium (which astronomers perversely refer to as “metals”) were forged by stars and spread through the Universe as those stars died.…
-
Could quasars be standard candles?
Quasars are some of the brightest objects in the Universe—powerful jets emanating from supermassive black holes as they gorge on gas. However, their light is irregular, both varying in brightness between different quasars and fluctuating in time. A new analysis may have found regularities within those fluctuations, which might allow them to be used as…
Bowler Hat Science 