accretion disk tagged posts

Work gives clues about how powerful jets are driven. The Event Horizon Telescope (EHT) has produced a new image showing details of the magnetic fields in the region closest to the supermassive black hole at the core of the galaxy M87. The new work is providing astronomers with important clues about how powerful jets of material can be produced in that region.

A worldwide team of astronomers using the Event Horizon Telescope, a collection of eight telescopes, including the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, measured a signature of magnetic fields — called polarization — around the black...

When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole. Astronomers study the light from these “tidal disruption events” (TDEs) for clues to the feeding behavior of the supermassive black holes lurking at the centers of galaxies.

New TDE observations led by astronomers at UC Santa Cruz now provide clear evidence that debris from the star forms a rotating disk, ie an accretion disk, around the black hole...

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) found quasi-periodic flickers in millimeter-waves from the center of the Milky Way, Sagittarius (Sgr) A*. The team interpreted these blinks to be due to the rotation of radio spots circling the supermassive black hole with an orbit radius smaller than that of Mercury. This is an interesting clue to investigate space-time with extreme gravity.

“It has been known that Sgr A* sometimes flares up in millimeter wavelength,” tells Yuhei Iwata, the lead author of the paper published in the Astrophysical Journal Letters and a graduate student at Keio University, Japan...

Sandia National Laboratories’ Guillaume Loisel poses with Sandia’s Z machine, where hands-on experiments contradicted a long-standing assumption about the X-ray spectra from the vicinity of black holes in space. Loisel is the lead author of a paper on the experimental results, published in Physical Review Letters. Credit: Randy Montoya, Sandia National Laboratories

Small cracks in basic theories. A long-standing but unproven assumption about the X-ray spectra of black holes in space has been contradicted by hands-on experiments performed at Sandia National Laboratories’ Z machine. Z, the most energetic laboratory X-ray source on Earth, can duplicate the X-rays surrounding black holes that otherwise can be watched only from a great distance and then theorized about...