Connect with us

Latest News

Are supermassive black holes going to eat the universe?

Published

on

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.

More From LiveScience

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.

Source link

Latest News

Tiger Woods was unaware of his ‘grave’ injuries after car crash, says first officer on scene | US News

Published

on

Tiger Woods did not appear to be “aware of how gravely he was injured” after his car crash in California, the first officer on the scene has said.

The 45-year-old golf star suffered serious leg injuries when his car hit a kerb and then a tree before rolling several times on the border of Rolling Hills Estates and Rancho Palos Verdes in Los Angeles on Tuesday morning.

No other cars were involved.

Carlos Gonzalez, a deputy from the Los Angeles County Sheriff’s Department, told NBC News he arrived within minutes of a 911 call from a member of the public.

Asked if Woods was aware of his injuries, the officer said: “He didn’t mention anything. I don’t think he was aware of how gravely he was injured at the time.

Tiger Woods celebrates after making a birdie on the 18th hole
Image:
Tiger Woods is one of the most successful golfers ever

“It could be a mixture of adrenaline. It could have been shock.

“Again, it was very quick – the moment I arrived from the moment he rolled over – so I don’t know if he had time to fully assess his injuries.”

Woods’s 2021 Genesis SUV was found 12m (40ft) from the road. Aerial footage showed the car on its side, with its front end heavily damaged and its airbags deployed.

Asked if Woods was saying anything at that point, the officer replied: “He wasn’t. I saw his eyes, because it was dark in there, and my first role as a first responder is to assess the passenger, the occupants of the vehicle, and I want to keep them calm as well.”

Please use Chrome browser for a more accessible video player

Aftermath of Tiger Woods’ car crash

He asked Woods if he could tell him his first name: “He looked at me and he said, ‘Tiger’.”

“It took me a half second, but I saw his face and I thought, oh yeah, you’re Tiger Woods,” continued the officer.

He asked the sportsman questions to assess his physical and mental state.

“He seemed calm. He didn’t seem like he was in distress, and he was able to kind of talk to me a little bit,” the officer said.

“I noticed the passenger compartment seemed mostly in tact and he didn’t seem like he was in any further danger.

“I did consider pulling him out myself, but I decided it would be better to wait for the fire departments since they have the specialised tools and training to remove people safely from vehicles like that.”

Police officers look over the damaged car. Pic: AP
Image:
The golfer had to be pried from the car through the windscreen. Pic: AP

Carlos Gonzalez said earlier that Woods was “very fortunate” to survive the crash.

Authorities investigating the incident have said there is no evidence Woods was impaired at the time.

Asked if a toxicology report was ordered at the scene, the officer said he was “unaware” of one.

“At the scene we are looking for evidence of intoxication, like if there is an odour of an alcoholic beverage or if there is an open container, or prescription medication.

“At this time we didn’t see any evidence of impairment, and anything beyond that, in terms of medical or toxicology, I wouldn’t be aware at this time.”

Woods's open fractures affect both the upper and lower portions of the tibia and fibula bones. File pic
Image:
Woods’s open fractures affect both the upper and lower portions of the tibia and fibula bones. File pic

He suggested Woods’s injuries may have been more severe if he had not been wearing a seat belt.

“This accident was traumatic in many ways. There is a lot of energy that went into the speeds that made the vehicle travel the distances that it did, the fact that it rolled, the injuries that Mr Woods sustained, and I’ve seen collisions that didn’t look as serious where the occupants were injured much more severely,” he said.

“I think that is a testament to the fact that he was wearing a seat belt, the airbags worked as intended and modern vehicles are much more safe than they used to be.”

Woods, a 15-time major champion, was cut free from the vehicle and rushed to Harbor-UCLA Medical Center where he underwent significant surgery and is recovering from his injuries.

A statement from his TGR foundation said he is “currently awake, responsive and recovering in his hospital room”.

The officer added: “I have a lot of sympathy for Mr Woods because I’m sure he’s going through something traumatic and I’m sure he’s going through a lot of pain, so I’m hoping for a speedy recovery for him.”

Source link

Continue Reading

Latest News

Ex-Syrian agent convicted by German court in landmark torture trial | World News

Published

on

A former member of Syrian president Bashar al Assad’s secret police has been sentenced by a German court to four-and-a-half years in jail for facilitating the torture of prisoners.

Human rights activists hope the landmark ruling will set a precedent for other cases connected to the 10-year-old Syrian civil war.

Eyad al Gharib was convicted of accessory to crimes against humanity and sentenced by the Koblenz state court.

It was the first time that a court outside Syria had ruled in a case alleging Syrian government officials committed crimes against humanity.

The court heard Gharib had arrested at least 30 anti-government protesters at the start of the conflict in 2011 and sent them to an intelligence facility where he knew detainees were tortured.

The verdict gives hope to the 800,000 Syrians in Germany who say they were tortured in government facilities after attempts to establish an international tribunal for Syria failed.

Gharib’s lawyers had asked for an acquittal, saying he had carried out the arrests in and around Damascus under duress by his superiors.

The 44-year-old had asked the court to consider him a witness in broader legal efforts against the Syrian government.

Syrian government officials did not testify during the trial and the Assad regime has denied it tortures prisoners.

Syrian defendant Eyad Al-Gharib in court in Germany
Image:
Gharib’s lawyers had asked for an acquittal, saying he had carried out the arrests under duress

“This is an important step forward in the process of securing accountability for the Syrian government’s systematic use of torture against civilians,” said Steve Kostas, a lawyer with the Open Society Foundation’s Justice Initiative, which is representing Syrian plaintiffs.

Syrian human rights lawyer Anwar al Bunni said the unprecedented verdict would speed up efforts to bring charges against former members of the Syrian government suspected of war crimes who have fled to Europe.

He said: “History has been made. The first verdict against a member of the Syrian regime’s torture and murder machine is a verdict against the whole regime, not just against one individual.

“It gives hope that justice is possible.”

The same court will continue hearings in the case of a second suspect, a former intelligence officer charged with 58 murders in a Damascus prison where prosecutors say at least 4,000 opposition activists were tortured in 2011 and 2012.

Source link

Continue Reading

Latest News

COVID-19: Ghana receives 600,000 free vaccine doses as part of global scheme | World News

Published

on

A flight carrying 600,000 doses of the AstraZeneca coronavirus vaccine has arrived in Ghana as part of a global effort to immunise the world’s poorest people.

The delivery comes eight months after the launch of the COVAX initiative – the World Health Organisation’s (WHO) sharing scheme which is aimed at ensuring global vaccine equity.

The shots will be used to kick-start a vaccination drive that will prioritise frontline health workers and others at high risk, according to a plan presented by Ghanaian health officials.

“This is a momentous occasion, as the arrival of the COVID-19 vaccines into Ghana is critical in bringing the pandemic to an end,” Anne-Claire Dufay of UNICEF Ghana, and WHO country representative, Francis Kasolo, said in a statement.

“These 600,000 COVAX vaccines are part of an initial tranche of deliveries.”

They added the shots paid for by the scheme and produced by the Serum Institute of India will “represent part of the first wave of COVID vaccines headed to several low and middle-income countries”.

The roll-out in Ghana is a milestone for the initiative that is trying to narrow a politically sensitive gap between the millions of people being vaccinated in wealthier countries and the comparatively few who have received shots in less-developed parts of the world.

The scheme aims to deliver a total of 2.3 billion doses by the end of the year, including 1.8 billion to poorer countries at no cost to their governments.

Although it hopes to cover up to 20% of countries’ populations, it will not be sufficient for nations to reach herd immunity and effectively contain the spread of the virus.

The African Union (AU) has been trying to help its 55 member states buy more doses in a push to immunise 60% of the continent’s 1.3 billion people over three years.

Last week, its vaccine team said 270 million doses of AstraZeneca, Pfizer and Johnson & Johnson vaccines secured for delivery this year had been taken up.

China has donated small batches of its Sinopharm vaccine to countries including Zimbabwe and Equatorial Guinea.

Russia has offered to supply 300 million doses of its Sputnik V vaccine to the AU scheme along with a financing package.

But many countries are largely reliant on COVAX.

On Tuesday, WHO Director-General Tedros Adhanom Ghebreyesus urged wealthy nations to share vaccine doses with COVAX, saying the goal of equitable distribution was “in jeopardy”.

Boris Johnson has said the UK will share the majority of its surplus COVID-19 vaccines with COVAX, but has not said how many.

Source link

Continue Reading

Trending