Our Galaxy’s Supermassive Black Hole Has Pooped Out a Big Bright Flare

❝ The supermassive black hole at the heart of the Milky Way, Sagittarius A*, is relatively quiet. It’s not an active nucleus, spewing light and heat into the space around it; most of the time, the black hole’s activity is low key, with minimal fluctuations in its brightness.

Most of the time. Recently, astronomers caught it going absolutely bananas, suddenly growing 75 times brighter before subsiding back to normal levels. That’s the brightest we’ve ever seen Sgr A* in near-infrared wavelengths…

❝ “I was pretty surprised at first and then very excited,” astronomer Tuan Do of the University of California Los Angeles told ScienceAlert.

“The black hole was so bright I at first mistook it for the star S0-2, because I had never seen Sgr A* that bright. Over the next few frames, though, it was clear the source was variable and had to be the black hole. I knew almost right away there was probably something interesting going on with the black hole.”

The explosions in the video up top from DOCTOR STRANGELOVE are little pinpricks compared to the energy from interaction with a black hole. Luckily, not a neighborhood happenstance.

Fermi Bubbles are burps from our galaxy’s black hole eating stars

Last year, astronomers analysing data from NASA’s orbiting Fermi Gamma Ray Telescope made an extraordinary announcement. They said that Fermi had spotted two giant bubbles emanating from the centre of the galaxy, stretching some 20,000 light years above and below the galactic plane.

These bubbles are clearly some kind of shockwave in which high energy electrons interact with photons, giving up their energy in the form of gamma rays.

But what could have caused such a shockwave, which is many times bigger than astronomers would expect to see from a supernova?

Kwong Sang Chen at The University of Hong Kong and a few pals say think they know. They say the bubbles are the remnants of stars that have been eaten by the supermassive black hole at the centre of the galaxy. What this idea may also explain is the energy distribution of cosmic rays, which astronomers have puzzled over for decades.

Our galaxy’s supermassive black hole is, well, huge–some 4 million times more massive than the Sun. Chen and co assume that a star falls into it every 1000 years or so. When this happens, part of the star is devoured by the black hole, while the rest is burped back out into space in the form of high energy protons.

These protons heat up the gas and dust surrounding the black hole creating an expanding bubble of high energy electrons. This cannot expand far in the plane of the galaxy where it is absorbed.

But the electrons can travel far into the space above and below the galactic plane, creating the gamma ray bubbles seen by Fermi. This explains why the edge of the bubble is so well defined.

RTFA for notes of other questions in astrophysics resolved by this theory. Poisonally, the burp alone impresses the crap out of me.

Wave-generated white hole boosts Hawking radiation theory

A team of UBC physicists and engineers have designed an experiment featuring a trough of flowing water to help bolster a 35-year-old theory proposed by eminent physicist Stephen Hawking.

In 1974, Hawking predicted that black holes–often thought of having gravitational pulls so strong that nothing escapes from them–emit a very weak level of radiation. According to the theory, pairs of photons are torn apart by a black hole’s gravitational field–one photon falls into the black hole, but the other escapes as a form of radiation.

In results outlined in the latest issue of Physical Review Letters, a team of UBC researchers led by international postdoctoral researcher Silke Weinfurtner put the test to Hawking’s theory by creating a ‘white hole’ in a six-metre-long flume of flowing water.

Placing an airplane wing-shaped obstacle in the path of the flowing water created a region of high-velocity flow which blocked surface waves, generated downstream, from traveling upstream. The obstruction simulated a white hole, the temporal reverse of a black hole.

The shallow surface waves divided into pairs of deep-water waves, analogous to the photon pairs featured in Hawking’s theory. Like in black holes, they showed that the analog would also emit a thermal spectrum of radiation.

While this creative simulation obviously doesn’t prove Hawking’s theory, it does show that his ideas apply broadly,” says UBC theoretical physicist William Unruh…

“In addition to their relevance to Hawking’s theory, the experiments have raised a number of unanswered fluid mechanics questions of engineering interest,” says Researcher in Environmental Fluid Mechanics Gregory Lawrence.

Like a lot of good science, more questions than answers may result. Devising rigorous and accurate analogues surely helps.

Fermi Telescope finds giant structure in center of our galaxy

NASA’s Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centered in the Milky Way. The feature spans 50,000 light-years and may be the remnant of an eruption from a supersized black hole at the center of our galaxy.

“What we see are two gamma-ray-emitting bubbles that extend 25,000 light-years north and south of the galactic center,” said Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who first recognized the feature. “We don’t fully understand their nature or origin.”

The structure spans more than half of the visible sky, from the constellation Virgo to the constellation Grus, and it may be millions of years old…

Finkbeiner and his team discovered the bubbles by processing publicly available data from Fermi’s Large Area Telescope (LAT). The LAT is the most sensitive and highest-resolution gamma-ray detector ever launched. Gamma rays are the highest-energy form of light.

Other astronomers studying gamma rays hadn’t detected the bubbles partly because of a fog of gamma rays that appears throughout the sky. The fog happens when particles moving near the speed of light interact with light and interstellar gas in the Milky Way. The LAT team constantly refines models to uncover new gamma-ray sources obscured by this so-called diffuse emission. By using various estimates of the fog, Finkbeiner and his colleagues were able to isolate it from the LAT data and unveil the giant bubbles…

Hints of the bubbles appear in earlier spacecraft data. X-ray observations from the German-led Roentgen Satellite suggested subtle evidence for bubble edges close to the galactic center, or in the same orientation as the Milky Way. NASA’s Wilkinson Microwave Anisotropy Probe detected an excess of radio signals at the position of the gamma-ray bubbles.

Click on the photo up above for the LAT team’s latest and best view of the gamma-ray feature. It took 2 years of data collection.

Thanks, WOK3

Is our universe at home within a larger universe?


Einstein-Rosen bridge

Could our universe be located within the interior of a wormhole which itself is part of a black hole that lies within a much larger universe..?

Such a scenario in which the universe is born from inside a wormhole (also called an Einstein-Rosen Bridge) is suggested in a paper from Indiana University theoretical physicist Nikodem Poplawski in Physics Letters B…

Poplawski takes advantage of the Euclidean-based coordinate system called isotropic coordinates to describe the gravitational field of a black hole and to model the radial geodesic motion of a massive particle into a black hole.

In studying the radial motion through the event horizon (a black hole’s boundary) of two different types of black holes — Schwarzschild and Einstein-Rosen, both of which are mathematically legitimate solutions of general relativity — Poplawski admits that only experiment or observation can reveal the motion of a particle falling into an actual black hole. But he also notes that since observers can only see the outside of the black hole, the interior cannot be observed unless an observer enters or resides within.

“This condition would be satisfied if our universe were the interior of a black hole existing in a bigger universe,” he said. “Because Einstein’s general theory of relativity does not choose a time orientation, if a black hole can form from the gravitational collapse of matter through an event horizon in the future then the reverse process is also possible. Such a process would describe an exploding white hole: matter emerging from an event horizon in the past, like the expanding universe…”

“From that it follows that our universe could have itself formed from inside a black hole existing inside another universe,” he said.

In philosophical terms, this is all logical to a materialist. And reasonably incomprehensible to any idealist or religionist.

The infinite reduction of material reality makes perfect sense to any observer of all physical science. Something always comes from something. As it is true for the observable universe it is logical to expect the same from any extensions beyond our current ability to observe and measure.