Tag Archives: Chandra X-Ray Observatory

Chandra captures black hole outburst over eight months

Four-frame movie of black hole outburst

Astronomers using the Chandra X-ray space telescope have documented the motion of two blobs moving away from a stellar-mass black hole over a period of eight months, producing a four-frame movie from their images and estimating the speed of those blobs to be 80% that of the speed of light.

The gif animation to the right shows that short movie.

The black hole and its companion star make up a system called MAXI J1820+070, located in our Galaxy about 10,000 light years from Earth. The black hole in MAXI J1820+070 has a mass about eight times that of the Sun, identifying it as a so-called stellar-mass black hole, formed by the destruction of a massive star. (This is in contrast to supermassive black holes that contain millions or billions of times the Sun’s mass.)

The companion star orbiting the black hole has about half the mass of the Sun. The black hole’s strong gravity pulls material away from the companion star into an X-ray emitting disk surrounding the black hole.

While some of the hot gas in the disk will cross the “event horizon” (the point of no return) and fall into the black hole, some of it is instead blasted away from the black hole in a pair of short beams of material, or jets. These jets are pointed in opposite directions, launched from outside the event horizon along magnetic field lines. The new footage of this black hole’s behavior is based on four observations obtained with Chandra in November 2018 and February, May, and June of 2019, and reported in a paper led by Mathilde Espinasse of the Universit√© de Paris.

Hubble has produced similar movies of the activity around the Crab Nebula. Sadly, we don’t have enough space telescopes like these in orbit to monitor such objects more frequently and thus photograph their behavior more completely. If we did we’d be able to get a much better understanding of their ongoing activity. We would also be able to produce more movies such as this, with much higher resolution and more continuous coverage.

Chandra goes into safe mode

When it rains it pours: The Chandra X-ray Observatory went into into safe mode on October 10 for reasons that are either not yet understood or have not yet been revealed.

Chandra, Spitzer, and Hubble are the three remaining of the original four great observatories proposed in the late 1980s, with the Compton Gamma-Ray Observatory the fourth. Compton was de-orbited in 2000. Spitzer’s infrared observational capabilities became limited when its cryogenic cooling gas became exhaused in 2009.

Hubble and now Chandra are both in safe mode, leaving astronomy badly crippled.

This situation is actually the fault of the astronomical community, which in the early 2000s put all its money behind the James Webb Space Telescope, leaving little for the construction of replacement space telescopes for either Hubble or Chandra. In addition, the astronomical community has continued to put is money behind similar big, expensive, and giant projects like Webb, pushing for WFIRST with its 2011 decadal survey. Like Webb, WFIRST will cost billions and take almost a decade to build and launch, assuming there are no delays.

Meanwhile, the workhorses in orbit are failing one by one.

Chandra looks back at the Crab Nebula

Link here. It is almost twenty years since the Chandra X-Ray Observatory was launched, and in celebration the science team have released another X-ray image of the Crab Nebula, taken in 2017 in league with an optical image from the Hubble Space Telescope and an infrared image from the Spitzer Space Telescope. They have also provided links to all similar past images, going back to 1999.

Some of the images are actually videos, in 2002 and 2011, showing the Crab’s dynamic nature. You can actually see flares and waves of radiation rippling out from its center.