Previous studies, using a variety of telescopes, suggested there was a jet, but these reports -- including the orientation of the suspected jets -- often contradicted each other and were not considered definitive.
Credit X-ray: NASA/CXC/UCLA/Z.Li et al; Radio: NRAO/VLA
"For decades astronomers have looked for a jet associated with the Milky Way's black hole. Our new observations make the strongest case yet for such a jet," said Zhiyuan Li of Nanjing University in China, lead author of a study appearing in an upcoming edition of The Astrophysical Journal and available online now.
Jets of high-energy particles are found throughout the universe, on large and small scales. They are produced by young stars and by black holes a thousand times larger than the Milky Way's black hole. They play important roles in transporting energy away from the central object and, on a galactic scale, in regulating the rate of formation of new stars.
"We were very eager to find a jet from Sgr A* because it tells us the direction of the black hole's spin axis. This gives us important clues about the growth history of the black hole," said Mark Morris of the University of California at Los Angeles, a co-author of the study.
The study shows the spin axis of Sgr A* is pointing in one direction, parallel to the rotation axis of the Milky Way, which indicates to astronomers that gas and dust have migrated steadily into Sgr A* over the past 10 billion years. If the Milky Way had collided with large galaxies in the recent past and their central black holes had merged with Sgr A*, the jet could point in any direction.
The jet appears to be running into gas near Sgr A*, producing X-rays detected by Chandra and radio emission observed by the VLA. The two key pieces of evidence for the jet are a straight line of X-ray emitting gas that points toward Sgr A* and a shock front -- similar to a sonic boom -- seen in radio data, where the jet appears to be striking the gas. Additionally, the energy signature, or spectrum, in X-rays of Sgr A* resembles that of jets coming from supermassive black holes in other galaxies.
Scientists think jets are produced when some material falling toward the black hole is redirected outward. Since Sgr A* is presently known to be consuming very little material, it is not surprising that the jet appears weak. A jet in the opposite direction is not seen, possibly because of gas or dust blocking the line of sight from Earth or a lack of material to fuel the jet.
The region around Sgr A* is faint, which means the black hole has been quiet in the past few hundred years. However, a separate Chandra study announced last month shows that it was at least a million times brighter before then.
"We know this giant black hole has been much more active at consuming material in the past. When it stirs again, the jet may brighten dramatically," said co-author Frederick K. Baganoff of the Massachusetts Institute of Technology in Cambridge, Mass.
Astronomers have suggested the giant bubbles of high-energy particles extending out from the Milky Way and detected by NASA's Fermi Gamma Ray Telescope in 2008 are caused by jets from Sgr A* that are aligned with the rotation axis of the galaxy. The latest results from Chandra support this explanation.
The supermassive black hole at the center of the Milky Way is about four million times more massive than our Sun and lies about 26,000 light-years from Earth. The Chandra observations in this study were taken between September 1999 and March 2011, with a total exposure of about 17 days.NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra Program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.
Megan Watzke | EurekAlert!
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences