. 24/7 Space News .
TIME AND SPACE
Mystery of Black Hole Coronae Deepens
by Staff Writers
Saitami, Japan (SPX) Dec 18, 2018

illustration only

Researchers from RIKEN and JAXA have used observations from the ALMA radio observatory located in northern Chile and managed by an international consortium including the National Astronomical Observatory of Japan (NAOJ) to measure, for the first time, the strength of magnetic fields near two supermassive black holes at the centers of an important type of active galaxies.

Surprisingly, the strengths of the magnetic fields do not appear sufficient to power the "coronae," clouds of superheated plasma that are observed around the black holes at the centers of those galaxies.

It has long been known that the supermassive black holes that lie at the centers of galaxies, sometimes outshining their host galaxies, have coronae of superheated plasma around them, similar to the corona around the Sun. For black holes, these coronae can be heated to a phenomenal temperature of one billion degrees Celsius. It was long assumed that, like that of the Sun, the coronae were heated by magnetic field energies. However, these magnetic fields had never been measured around black holes, leaving uncertainty regarding the exact mechanism.

In a 2014 paper, the research group predicted that electrons in the plasma surrounding the black holes would emit a special kind of light, known as synchrotron radiation, as they exist together with the magnetic forces in the coronae. Specifically, this radiation would be in the radio band, meaning electromagnetic waves with a long wavelength and low frequency. And the group set out to measure these fields.

They decided to look at data from two "nearby," in astronomical terms, active galactic nuclei: IC 4329A, which is about 200 million light-years away, and NGC 985, which is approximately 580 million light-years away.

They began by taking measurements using the ALMA observatory in Chile, and then compared them to observations from two other radio telescopes: the VLA observatory in the United States and the ATCA observatory in Australia, which measure slightly different frequency bands. The team found that indeed there was an excess of radio emission originating from synchrotron radiation, in addition to emissions from the "jets" cast out by the black holes.

Through the observations, the team deduced that the coronae had a size of about 40 Schwarzschild radii, the radius of a black hole from which not even light can escape, and a strength of about 10 gauss, a figure that is a bit more than the magnetic field at the surface of the Earth but quite a bit less than that given out by a typical refrigerator magnet.

"The surprise," says Yoshiyuki Inoue, the lead author of the paper, published in The Astrophysical Journal, "is that although we confirmed the emission of radio synchrotron radiation from the corona in both objects, it turns out that the magnetic field we measured is much too weak to be able to drive the intense heating of the coronae around these black holes." He also notes that the same phenomenon was observed in both galaxies, implying that it could be a general phenomenon.

Looking to the future, Inoue says that the group plans to look for signs of powerful gamma rays that should accompany the radio emissions, to further understand what is happening in the environment near supermassive black holes.

Research Report: "Detection of Coronal Magnetic Activity in Nearby Active Supermassive Black Holes," Yoshiyuki Inoue and Akihiro Doi, 2018 Dec. 17, Astrophysical Journal


Related Links
RIKEN
Understanding Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


TIME AND SPACE
Cosmic fountain powered by giant black hole
Huntsville AL (SPX) Dec 17, 2018
Before electrical power became available, water fountains worked by relying on gravity to channel water from a higher elevation to a lower one. This water could then be redirected to shoot out of the fountain and create a centerpiece for people to admire. In space, awesome gaseous fountains have been discovered in the centers of galaxy clusters. One such fountain is in the cluster Abell 2597. There, vast amounts of gas fall toward a supermassive black hole, where a combination of gravitational and ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
Four NASA-sponsored experiments set to launch on Virgin Galactic spacecraft

Russian Progress freighter to fly to ISS under short scheme for second time

Virgin Galactic reaches edge of space in historic flight

Virgin Galactic's SpaceShipTwo reaches space for first time

TIME AND SPACE
Largest piece of SLS rocket test hardware moved for testing

Static test qualifies crew safety launch abort motor for flight in cold conditions

Roscosmos to submit super-heavy rocket project to Government

Aerojet Rocketdyne awarded DARPA contract to design advanced opfires propulsion system

TIME AND SPACE
NASA's InSight takes its first selfie

Opportunity team performs more frequent communication attempts throughout each day

Planetary scientists assist in capturing image of Insight from orbit

InSight's robotic arm ready for some lifting on Mars

TIME AND SPACE
China's Chang'e-4 probe enters lunar orbit

China launches rover for first far side of the moon landing

Evolving Chinese Space Ecosystem To Foster Innovative Environment

China sends 5 satellites into orbit via single rocket

TIME AND SPACE
Scaled back OneWeb constellation Not to affect number of Soyuz boosters

Update from ESA Council, December 2018

CAT rules in favour of Ofcom's EAN authorisation decision

Fleet Space Technologies' Centauri launched aboard SpaceX Falcon 9

TIME AND SPACE
Radiation experiment flies on record-setting SpaceX launch dedicated entirely to small satellites

Astroscale enters technical cooperation with European Space Agency

Deep-learning technique reveals 'invisible' objects in the dark

Researchers develop mathematical solver for analog computers

TIME AND SPACE
Where did the hot Neptunes go

Dancing with the enemy

In search of missing worlds, Hubble finds a fast-evaporating exoplanet

Hubble finds faraway planet vanishing at record speed

TIME AND SPACE
NASA's Juno mission halfway to Jupiter science

Record Setting Course-Correction Puts New Horizons on Track to Kuiper Belt Flyby

Radio JOVE From NASA: Tuning In to Your Local Celestial Radio Show

The PI's Perspective: Share the News - The Farthest Exploration of Worlds in History is Beginning









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.