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Are supermassive black holes going to eat the universe?

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The largest black holes grow faster than their galaxies, according to new research.

Two studies from separate groups of researchers find that so-called supermassive black holes are bigger than astronomers would have calculated from their surroundings alone. Supermassive black holes are enormous gravity wells found in the center of large galaxies.

No stress, though: The black holes are generally no longer growing, and they aren’t capable of eating their host galaxies for dinner. [Science Fact or Fiction? The Plausibility of 10 Sci-Fi Concepts]

“The black hole is tiny compared to the whole galaxy, so we are very safe!” said Guang Yang, a graduate student at The Pennsylvania State University who led one of the new studies.

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Yang’s study found that the larger the galaxy, the faster the black hole grew in comparison to the birth rate of the galaxy’s stars. The other study found that the masses of supermassive black holes are about 10 times greater than would be expected if these central black holes grew at the same rate as the galaxies they inhabit.

Galaxies and their black holes

Astronomers are interested in the relationships between black holes and their galaxies for two main reasons. First, if they can calculate the size of one based on another, they can determine, say, the mass of a supermassive black hole even if they can’t directly measure it. Second, any constant relationships between the two can help explain the laws that govern how galaxies are formed.

In the first study, published this month in the journal Monthly Notices of the Royal Astronomical Society and available on the preprint site ArXiv, Yang and his colleagues used data on more than 30,000 galaxies from the Great Observatories Origins Deep Survey (GOODS). The astronomical survey combined observations from the Hubble Space Telescope, the Chandra X-ray Observatory and the Spitzer Space Telescope, and more than 500,000 galaxies from the Cosmic Evolution Survey (COSMOS), which uses both space- and ground-based telescopes to explore the universe. The galaxies were between 4.3 billion and 12.2 billion light-years from Earth.

The research team found that the larger the galaxy, the larger the ratio between its black hole’s growth rate and its growth rate of stars. A galaxy containing 100 billion of Earth’s sun’s worth of stars (a measurement known as solar mass) has 10 times the ratio as a galaxy with 10 billion of the sun’s worth of stars. [The Strangest Black Holes in the Universe]

“Our paper suggests big galaxies can feed their black holes more effectively than small galaxies,” Yang told Live Science. “So, those big galaxies finally end up with very big black holes. However, it is still an unsolved mystery whether the black holes can affect galaxy formation in return.”

Going ultra

A second study, also available on ArXiv and set to be published in April in the journal Monthly Notices of the Royal Astronomical Society, similarly found that the larger the galaxy, the weirder its relationship with its black hole.

That research, headed by astrophysicist Mar Mezcua at the Institute of Space Sciences in Barcelona, Spain, focused on 72 galaxies no more than about 3.5 billion light-years from Earth. The galaxies were all “brightest cluster galaxies,” a term that refers to the biggest and brightest galaxies in the nearby universe. Using X-ray and radio-wave data from the Chandra X-ray Observatory, the Australia Telescope Compact Array, the Karl G. Jansky Very Large Array and the Very Long Baseline Array, the researchers compared the masses of supermassive black holes to estimates made using traditional methods that assumed that black holes and their galaxies grow more or less at the same rate.

Instead of finding the two growing in lockstep, the research team discovered that the black holes in their study were 10 times larger than would have been predicted with traditional means. In fact, many qualified not just as supermassive black holes, which clock in at a few billion solar masses, but as ultramassive black holes, which can be up to 40 billion times the mass of Earth’s sun.

No one previously knew that brightest cluster galaxies could host such enormous black holes, the researchers reported. The black holes could have formed in two ways, they wrote. One possibility is that the black hole grew first and the galaxy grew later. Another possibility is that these black holes are the descendants of “seed” black holes that formed when the galaxies were much younger and more productive in star formation. The bottom line, though, is that black holes and their galaxies don’t always grow as a matching set.  

Editor’s Note: This article was updated to correct a statement saying ultramassive black holes can be up to 40 “million” times the mass of the sun; they are up to 40 billion times the mass of our sun.

Original article on Live Science.

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India: Head of ‘world’s largest family’ Ziona Chana dies – leaving behind 39 wives and 94 children | World News

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A man said to be the head of the world’s largest family has died in northeastern India.

Ziona Chana had 39 wives, 94 children and 33 grandchildren – all of whom lived together in a four-storey pink house with about 100 rooms in Baktawng in Mizoram state.

The 76-year-old was the leader of a local Christian sect, named Chana, founded by his father in 1942 and with a current membership of hundreds of families.

Ziona married his first wife when he was 17 and claimed he once married 10 women in a year.

They shared a dormitory near his private bedroom and locals said he liked to have seven or eight of them by his side at all times.

The chief minister of Mizoram confirmed his death on Twitter, saying the village of Baktawng had become a “major tourist attraction” because of the family.

With a total of 167 members, the family is the world’s largest, according to local media, although this depends on whether you count Mr Chana’s grandchildren.

In a 2011 interview with Reuters, Ziona said: “I am ready to expand my family and willing to go to any extent to marry.

“I have so many people to care for and look after, and I consider myself a lucky man.”

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Vladimir Putin: ‘Where is the proof’ Russia is waging a cyber war against the United States? | World News

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Russian leader Vladimir Putin has denied claims his country is waging a cyber war against the United States.

In an exclusive interview with NBC News, the Russian president rebuffed accusations Russian hackers, or the government itself, is using technological warfare against America – as baseless.

He said claims his country was involved in cyber attacks had become “farcical”, asking: “Where is the evidence? Where is the proof?”

Mr Navalny at a court hearing earlier this year
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Kremlin critic Alexei Navalny remains in prison

“We have been accused of all kinds of things: election interference, cyber attacks and so on and so forth. And not once, not one time did they bother to produce any kind of evidence or proof,” he said.

Evidence has been put forward by US intelligence services of Russian hackers targeting the federal government and meddling in US elections.

Mr Putin also denied ordering the poisoning of Kremlin critic Alexei Navalny.

Pressed on whether he had any involvement, he said: “Look, such decisions in this country are not made by the president.”

Russian intelligence services have been accused of poisoning Mr Navalny, who survived the incident but now remains in a Russian prison.

Asked whether the former opposition leader would make it out of prison alive, Mr Putin said: “He will not be treated any worse than anybody else.”

Joe Biden will be meeting Vladimir Putin on Wednesday
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Joe Biden will be meeting Vladimir Putin on Wednesday

Mr Putin’s comments come just two days before he and Joe Biden are due to sit down for talks in Geneva on Wednesday.

The US president will be fresh from his meeting with NATO leaders, who have signalled that Russia remains a security risk to Western allies.

In his interview with NBC, Mr Putin said Russia would be willing to engage with other countries including the US and would value “predictability and stability”.

The Russian president has made no secret that he supported Mr Biden’s predecessor Donald Trump, who he called “extraordinary” and “talented”.

Mr Putin and Mr Biden have had somewhat more rocky relations, with the current US president agreeing when asked whether he thought the Russian president was a killer.

When this was put to Mr Putin, he replied: “Over my tenure, I’ve gotten used to attacks from all kinds of angles. And none of it surprises me.”

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Finke Desert Race crash: Spectator killed and two injured at Australian off-road event | World News

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A man has died and two others have been injured after a car crashed into spectators during a race in Australia.

The car, which was taking part in the 285-mile (460km) Finke Desert Race, struck a group of people around 22 miles (35km) from the finish.

A 60-year-old man died at the scene.

A man in his 50s was seriously injured and taken to Alice Springs Hospital, while the driver, a woman in her 50s, suffered minor injuries, Northern Territory police confirmed.

Police have issued an appeal for information as they continue to investigate the circumstances.

Motorsport Australia issued a statement calling it “tragic news” and offering “sympathies to the families, friends and all those impacted”.

The governing body also said it would begin its own investigation and provide counselling to all competitors, officials and people associated with the race.

The track is described on its website as having a “reputation for being one of the most difficult off-road courses in one of the most remote places in the world”.

The two-day off-road, multi-terrain race for motorcycles, cars, buggies and quads through desert country between Alice Springs and the town of Aputula, also known as Finke, takes place every June.

The car section of the race has now been cancelled.

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