Scientists Determine the Nature of Black Hole Jets

Oct 06, 2006
Artist's concept of an active galaxy
Artist´s concept of an active galaxy. Credit: NASA E/PO, Sonoma State University, Aurore Simonnet

NASA and Italian scientists using Swift have for the first time determined what the particle jets streaming from black holes are made of.

Black hole particle jets are commonly seen in quasars and other celestial objects, shooting off at nearly light speed. According to the Swift team, these jets appear to be made of protons and electrons, solving a mystery as old as the discovery of jets themselves in the 1970s. The jets observed by Swift contain about the mass of Jupiter if it were pulverized and blasted out into intergalactic space.

Black hole particle jets typically escape the confines of their host galaxies and flow for hundreds of thousands of light years. They are a primary means of redistributing matter and energy in the universe. They are a key to understanding galaxy formation and are tied to numerous cosmic mysteries, such as the origin of ultrahigh-energy cosmic rays.

"Black hole jets are one of the great paradoxes in astronomy," said Rita Sambruna of NASA's Goddard Space Flight Center, Greenbelt, Md. "How is it that black holes, so efficient at pulling matter in, can also accelerate matter away at near light speed? We still don't know how these jets form, but at least we now have a solid idea about what they're made of."

The composition of black hole jets has been the topic of heated debate for several decades. Scientists generally agree that the jets must be made either of electrons and their antimatter partners, called positrons, or an even mix of electrons and protons. Recent theoretical and observational advances have pointed in the direction of the latter. The Swift data provides the most compelling evidence to date that the jets must have protons.

Most quasars have jets. A quasar is bright galaxy core fueled by a supermassive black hole containing the mass of millions to billions of suns confined within a region about the size of our solar system. The particle jets, usually in opposing pairs, shoot off perpendicularly from the flat disk of gas that swirls around the black hole.

Sambruna's team, comprising researchers at Goddard and the Merate Observatory, Merate, Italy, studied a type of quasar called a blazar. Blazars are quasars with their particle jets aimed in our direction, as if we are staring down the barrel of the gun. The team studied two blazars, called 0212+735 and PKS 0537-286, both over 10 billion light years away.

Previously, telescopes have not been able to capture much detail of black hole jets in a wavelength region between X-rays and gamma rays, corresponding to an energy range of 10 kiloelectron volts (keV) and above. This range, however, is precisely where Swift is most sensitive.

Sambruna's team found a peak in the detection rate of light particles, called photons, at 10 keV and then a downturn. That is, the number of X-ray photons climbed steadily until 10 keV and then declined. From this information and new computer modeling led by Fabrizio Tavecchio and Gabriele Ghisellini at Merate Observatory, the team could rule out the presence of electron-positron pairs.

The analysis took several steps. The Swift data provided enough information to determine the jet was moving at 99.9 percent light speed and contained 200 billion trillion trillion trillion trillion particles. From this, the scientists could determine the total kinetic energy, which is a first. Comparing the kinetic energy of motion with the radiated energy of light, the scientists could determine the mass of the jet and ultimately its content.

"The jet contains about the same mass as Jupiter, which means the central black hole is like a cannon firing a massive pulverized planet at near light speed clear out of the galaxy," said Tavecchio. "That's an enormous amount of energy leaving the black hole system, and this is happening throughout the universe."

The finding is a major step towards determining how jets are created, a goal for the Gamma-ray Large Area Space Telescope, or GLAST, planned for launch in the fall 2007.

Launched in November 2004, Swift is a NASA mission in partnership with the Italian Space Agency and the Particle Physics and Astronomy Research Council, United Kingdom, and is managed by Goddard. Penn State University, University Park, Pa., personnel control science and flight operations from the Mission Operations Center.

Researchers are presenting their findings today at the High Energy Astrophysics Division of the American Astronomical Society meeting in San Francisco.

Source: by Christopher Wanjek, NASA/Goddard Space Flight Center

Explore further: Quest for extraterrestrial life not over, experts say

add to favorites email to friend print save as pdf

Related Stories

Black hole makes 'String of Pearls' clusters

Apr 01, 2014

(Phys.org) —Huge young star clusters resembling a string of pearls around a black hole in the centre of a galaxy 120 million light-years away have been discovered by researchers at Swinburne University ...

The search for seeds of black holes

Mar 27, 2014

(Phys.org) —How do you grow a supermassive black hole that is a million to a billion times the mass of our sun? Astronomers do not know the answer, but a new study using data from NASA's Wide-field Infrared ...

A new 'fast and furious' black hole

Feb 28, 2014

A black hole with extremely powerful jets has been found in the nearby galaxy Messier 83 (M83) by a team of Australian and American researchers, as we report in the journal Science today. ...

NuSTAR telescope takes first peek into core of supernova

Feb 19, 2014

(Phys.org) —Astronomers have peered for the first time into the heart of an exploding star in the final minutes of its existence. The feat by the high-energy X-ray satellite NuSTAR provides details of the ...

Recommended for you

Quest for extraterrestrial life not over, experts say

Apr 18, 2014

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

Continents may be a key feature of Super-Earths

Apr 18, 2014

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Exoplanets soon to gleam in the eye of NESSI

Apr 18, 2014

(Phys.org) —The New Mexico Exoplanet Spectroscopic Survey Instrument (NESSI) will soon get its first "taste" of exoplanets, helping astronomers decipher their chemical composition. Exoplanets are planets ...

User comments : 0

More news stories

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.