Posted on by Matt Williams

M87 Releases a Rare and Powerful Outburts of Gamma-ray Radiation

A Hubble Space Telescope image of the giant galaxy M87 shows a 3,000-light-year-long jet of plasma blasting from the galaxy's 6.5-billion-solar-mass central black hole. The blowtorch-like jet seems to cause stars to erupt along its trajectory. These novae are not caught inside the jet, but are apparently in a dangerous neighbourhood nearby. During a recent 9-month survey, astronomers using Hubble found twice as many of these novae going off near the jet as elsewhere in the galaxy. The galaxy is the home of several trillion stars and thousands of star-like globular star clusters. [Image description: A Hubble photo of galaxy M87, which resembles a translucent, fuzzy white cotton ball. The brightness decreases gradually out in all directions from a bright white point of light at the centre. A wavy blue-white jet of material extends from the point-like core outward to the upper right, about halfway across the galaxy. Stars speckle the background.]

In April 2019, the Event Horizon Telescope (EHT) collaboration made history when it released the first-ever image of a black hole. The image captured the glow of the accretion disk surrounding the supermassive black hole (SMBH) at the center of the M87 galaxy, located 54 million light-years away. Because of its appearance, the disk that encircles this SMBH beyond its event horizon (composed of gas, dust, and photons) was likened to a “ring of fire.” Since then, the EHT has been actively imaging several other SMBH, including Sagittarius A* at the center of the Milky Way!

In addition, the EHT has revealed additional details about M87, like the first-ever image of a photon ring and a picture that combines the SMBH and its relativistic jet emanating from its center. Most recently, the EHT released the results of its latest observation campaign. These observations revealed a spectacular flare emerging from M87’s powerful relativistic jet. This flare released a tremendous amount of energy in multiple wavelengths, including the first high-energy gamma-ray outburst observed in over a decade.

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Posted on by Scott Alan Johnston

M87's Jet is Triggering Novae

The jet emerging from the galactic core of M87. NASA/STScI/AURA.

Everyone loves a good mystery, and astronomers have just uncovered a new one in a nearby supermassive galaxy called M87. Like most galaxies, M87 regularly plays host to a smattering of stellar explosions called novae, each the result of a star stealing material from a neighbour. M87 also features a massive jet of plasma blasting out into deep space from the galactic core. These phenomena: the jet and the novae, are unrelated astronomical occurrences, or so scientists believed. But astronomers recently discovered that the novae in M87 seem to be uncharacteristically aligned along the jet, instead of scattered randomly throughout the galaxy. Is the jet somehow triggering nova explosions?

It might be, but the mystery is: how?

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