A DANCE OF BLACK HOLES:
UNIQUE PAIR OF SUPERMASSIVE BLACK HOLES IN
AN ORDINARY GALAXY DISCOVERED BY XMM-NEWTON
A pair of supermassive black holes in orbit around one another have been discovered by an international research team including Stefanie Komossa from the Max Planck Institute for Radio Astronomy in Bonn, Germany. This is the first time such a pair could be found in an ordinary galaxy. They were discovered because they ripped apart a star when ESA’s space observatory XMM-Newton happened to be looking in their direction.
The findings are published in the May 10 issue of the Astrophysical Journal, and appeared online today at the astrophysics preprint server.
Most massive galaxies in the universe are thought to harbor at least one supermassive black hole at their center. Two supermassive black holes are the smoking gun that the galaxy has merged with another. Thus, finding binary supermassive black holes can tell astronomers about how galaxies evolved into their present-day shapes and sizes.
To date, only a few candidates for close binary supermassive black holes have been found. All are in active galaxies where they are constantly ripping gas clouds apart, in the prelude to crushing them out of existence.
In the process of destruction, the gas is heated so much that it shines at many wavelengths, including X-rays. This gives the galaxy an unusually bright center, and leads to it being called active. The new discovery, reported by Fukun Liu from Peking University in China, and colleagues, is important because it is the first to be found in a galaxy that is not active.
“There might be a whole population of quiescent galaxies that host binary black holes in their centers,” says co-author Stefanie Komossa, Max-Planck-Institut für Radioastronomie, Bonn, Germany. But finding them is a difficult task because in quiescent galaxies, there are no gas clouds feeding the black holes, and so the cores of these galaxies are truly dark.
The only hope that the astronomers have is to be looking in the right direction at the moment one of the black holes goes to work, and rips a star to pieces. Such an occurrence is called a ‘tidal disruption event.’ As the star is pulled apart by the gravity of the black hole, it gives out a flare of X-rays.
In an active galaxy, the black hole is continuously fed by gas clouds. In a quiescent galaxy, the black hole is fed by tidal disruption events that occur sporadically and are impossible to predict. So, to increase the chances of catching such an event, researchers use ESA’s X-ray observatory, XMM-Newton, in a novel way.
Usually, the observatory collects data from designated targets, one at a time. Once it completes an observation, it slews to the next. The trick is that during this movement, XMM-Newton keeps the instruments turned on and recording. Effectively this surveys the sky in a random pattern, producing data that can be analyzed for unknown or unexpected sources of X-rays.
On 10 June 2010, a tidal disruption event was spotted by XMM-Newton in galaxy SDSS J120136.02+300305.5, approximately 2 billion light-years away. Komossa and her colleagues were scanning the data for such events and scheduled follow-up observations just days later with XMM-Newton and NASA’s Swift satellite.
The galaxy was still spilling X-rays into space. It looked exactly like a tidal disruption event caused by a supermassive black hole but as they tracked the slowly fading emission day after day something strange happened.
The X-rays fell below detectable levels between days 27 and 48 after the discovery. Then they re-appeared and continued to follow a more expected fading rate, as if nothing had happened.
Now, thanks to Fukun Liu, this behavior can be explained. “This is exactly what you would expect from a pair of supermassive black holes orbiting one another,” says Liu.
Liu had been working on models of black hole binary systems that predicted a sudden plunge to darkness and then the recovery because the gravity of one of the black holes disrupted the flow of gas onto the other, temporarily depriving it of fuel to fire the X-ray flare. He found that two possible configurations were possible to reproduce the observations of J120136.
In the first, the primary black hole contained 10 million solar masses and was orbited by a black hole of about a million solar masses in an elliptical orbit. In the second solution, the primary black hole was about a million solar masses in a circular orbit.
In both cases, the separation between the black holes was relatively small: 0.6 milliparsec, or about 2 thousandths of a light-year. This is about the width of our solar system.
Being this close, the fate of this newly discovered black hole pair is sealed. They will radiate their orbital energy away, gradually spiraling together, until in about two million years time they will merge into a single black hole.
Now that astronomers have found this first candidate for a binary black hole in a quiescent galaxy, the search is inevitably on for more. XMM-Newton will continue its slew survey. This detection will also spur interest in a network of telescopes that search the whole sky for tidal disruption events.
“Once we have detected thousands of tidal disruption events, we can begin to extract reliable statistics about the rate at which galaxies merge,” says Stefanie Komossa.
When binary black holes merge, they are predicted to release a massive burst of energy into the universe but not mostly in X-rays. “The final merger is expected to be the strongest source of gravitational waves in the universe,” states Fukun Liu.
“The innovative use of XMM-Newton’s slew observations made the detection of this binary supermassive black hole system possible,” concludes Norbert Schartel, ESA’s XMM-Newton Project Scientist. “This demonstrates the important role that long-lasting space observatories have in detecting such rare events that can potentially open new areas in astronomy.”
As of 2012, 15% of the US American population without health insurance was African-American. Considering the role economic status plays in healthcare sheds light on the racial discrepancy with respect to treating mental illness. Many people with health insurance find that their companies don’t cover the cost of mental illness treatment, and those without any health insurance find themselves facing incredibly high prices to pay for medical care, or opting not to pursue treatment at all. These obstacles often lead Black folks in the states to “rely on family, religious and social communities for emotional support rather than turning to health care professionals, even though this may at times be necessary,” states NAMI’s fact sheet on African American Community Mental Health.
Even if able to pay for treatment, many Black folks encounter prejudices and biases from medical caregivers. Black people, especially Black men, are frequently misdiagnosed when it comes to mental illness. For example, most prominently in the 1960s, white doctors institutionalized Black men involved in civil rights protests (particularly in Detroit) on the grounds that the behaviors these men defended as political activism was really schizophrenic rage and volatility. Also, medical practitioners’ prescriptions sometimes reflect discriminatory and generally racial assumptions that Black people do not need as much medicine as white people. Studies conducted by the University of Michigan’s School of Public Health discovered that Black US Americans are 1.5 times as likely to be denied antidepressant treatment. No one wants tell you that the system is sick. No one wants to tell you that the healthcare system intentionally keeps historically marginalized groups like queer folks, and Black folks, and people who happen to find themselves at the intersection of queerness and Blackness sick.
do something out of the ordinary like catch a matinee…
i feel like storm is under appreciated, but i dont know why i mean like look at this chick:
STORM WITH A FLAWLESS MOHAWK
STORM WITH LONG FLOWY HAIR
MOTHER FREAKING STORM
Oberyn Nymeros Martell, Tyrion muttered under his breath as he fell in beside the man. The Red Viper of Dorne. And what in the seven hells am I supposed to do with him? He knew the man only by reputation, to be sure… but the reputation was fearsome. When he was no more than sixteen, Prince Oberyn had been found abed with the paramour of old Lord Yronwood, a huge man of fierce repute and short temper. A duel ensued, though in view of the prince’s youth and high birth, it was only to first blood. Both men took cuts, and honor was satisfied. Yet Prince Oberyn soon recovered, while Lord Yronwood’s wounds festered and killed him. Afterward men whispered that Oberyn had fought with a poisoned sword, and ever thereafter friends and foes alike called him the Red Viper.
Him and his partner were sexy as fuck
The collision between the Milky Way Galaxy and the Andromeda Galaxy.
welp, looks like we pretty fucked.
facts about this: 1. it isn’t going to happen for a while
2. we are actually going to survive this and the sky will look amazing that night scientist have predictedIf that happens we are good and dead dumb ass , two whole galaxy’s be coming one the whole planet is going to move by millions of miles , wtf hope I’m not out of weed that day .
Yeah, this isn’t happening in our lifetime.
"I hope I’m not out of weed"
Kanye West on Jimmy Kimmel Live!
i can’t believe they called this a rant. Kanye West just put my evolution as person in words. i’ve been saying this for years.
in all honestly as much as I like to dump on Kanye I’ll admit that reading this it makes a lot more sense than it sounded on TV.
I’m telling y’all, Kanye is a genius. He knows exactly what he’s doing.
He’s actually pretty remarkable. He has suffered from acute depression in the past. His story could potentially save lives.
Pay close attention to the things they call rant. They don’t want you to hear it.
Avengers in a nutshell.