Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















TIME AND SPACE
A middleweight black hole is hiding at the center of a giant star cluster
by Staff Writers
Boston MA (SPX) Feb 10, 2017


In this artist's illustration, an intermediate-mass black hole in the foreground distorts light from the globular star cluster in the background. New research suggests that a 2,200 solar-mass black hole resides at the center of the globular cluster 47 Tucanae. Image courtesy CfA and M. Weiss.

All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 - 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Today, astronomers are announcing new evidence that an intermediate-mass black hole (IMBH) weighing 2,200 Suns is hiding at the center of the globular star cluster 47 Tucanae.

"We want to find intermediate-mass black holes because they are Harvard-Smithsonian Center for Astrophysics
between stellar-mass and supermassive black holes. They may be the primordial seeds that grew into the monsters we see in the centers of galaxies today," says lead author Bulent Kiziltan of the Harvard-Smithsonian Center for Astrophysics (CfA).

This work appears in the Feb. 9, 2017, issue of the prestigious science journal Nature.

47 Tucanae is a 12-billion-year-old star cluster located 13,000 light-years from Earth in the southern constellation of Tucana the Toucan. It contains thousands of stars in a ball only about 120 light-years in diameter. It also holds about two dozen pulsars that were important targets of this investigation.

47 Tucanae has been examined for a central black hole before without success. In most cases, a black hole is found by looking for X-rays coming from a hot disk of material swirling around it. This method only works if the black hole is actively feeding on nearby gas. The center of 47 Tucanae is gas-free, effectively starving any black hole that might lurk there.

The supermassive black hole at the center of the Milky Way also betrays its presence by its influence on nearby stars. Years of infrared observations have shown a handful of stars at our galactic center whipping around an invisible object with a strong gravitational tug. But the crowded center of 47 Tucanae makes it impossible to watch the motions of individual stars.

The new research relies on two lines of evidence. The first is overall motions of stars throughout the cluster. A globular cluster's environment is so dense that heavier stars tend to sink to the center of the cluster. An IMBH at the cluster's center acts like a cosmic "spoon" and stirs the pot, causing those stars to slingshot to higher speeds and greater distances. This imparts a subtle signal that astronomers can measure.

By employing computer simulations of stellar motions and distances, and comparing them with visible-light observations, the team finds evidence for just this sort of gravitational stirring.

The second line of evidence comes from pulsars, compact remnants of dead stars whose radio signals are easily detectable. These objects also get flung about by the gravity of the central IMBH, causing them to be found at greater distances from the cluster's center than would be expected if no black hole existed.

Combined, this evidence suggests the presence of an IMBH of about 2,200 solar masses within 47 Tucanae.

Since this black hole has eluded detection for so long, similar IMBHs may be hiding in other globular clusters. Locating them will require similar data on the positions and motions of both the stars and any pulsars within the clusters.


Comment on this article using your Disqus, Facebook, Google or Twitter login.

.


Related Links
Harvard-Smithsonian Center for Astrophysics
Understanding Time and Space






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

Previous Report
TIME AND SPACE
Middleweight Black Hole Hiding in Giant Star Cluster
Boston MA (SPX) Feb 08, 2017
All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 to 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Today, astronomers are announcing new evidence that an intermediat ... read more


TIME AND SPACE
A new recruit for ESA's astronaut corps

The Outer Space Treaty has been remarkably successful - but is it fit for the modern age?

Full Braking at Alpha Centauri

New Era of Space Travel: Private Station May Replace ISS by Late 2020

TIME AND SPACE
Commercial Launch of Proton-M Carrier Rocket Planned For Early April - Roscosmos

India to launch record 104 satellites next week

ISRO tests C25 Cryogenic Upper Stage of GSLV MkIII

Russia to call tender for 2nd Phase of Vostochny Spaceport construction in Fall

TIME AND SPACE
UAE Aims to Launch Its First Ever Mars Mission in 2020

Opportunity Takes Advantage of her Location to do a Mini Science Campaign

Swirling spirals at the north pole of Mars

Curiosity rover sharpens paradox of ancient Mars

TIME AND SPACE
China looks to Mars, Jupiter exploration

China's first cargo spacecraft to leave factory

China launches commercial rocket mission Kuaizhou-1A

China Space Plan to Develop "Strength and Size"

TIME AND SPACE
NASA seeks partnerships with US companies to advance commercial space technologies

An exciting year in space for Intelsat

Iridium Adds Eighth Launch with SpaceX for Satellite Rideshare

Space, Ukrainian-style: Through Crisis to Revival

TIME AND SPACE
New beam pattern yields more precise radar, ultrasound imaging

Anatomy of a debris incident

Japan's troubled 'space junk' mission fails

New material that contracts when heated holds great industrial potential

TIME AND SPACE
Santa Fe Institute researchers look for life's lower limits

Dedicated Planet Imager Opens Its Eyes to Other Worlds

New planet imager delivers first science at Keck

First footage of a living stylodactylid shrimp filter-feeding at depth of 4826m

TIME AND SPACE
New Horizons Refines Course for Next Flyby

It's Never 'Groundhog Day' at Jupiter

Public to Choose Jupiter Picture Sites for NASA Juno

Experiment resolves mystery about wind flows on Jupiter




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - 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. 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. Privacy Statement