Astronomers discover 83 supermassive black holes 13 billion light-years away

Agencies
March 15, 2019

Washington, Mar 15: Astronomers have discovered 83 quasars powered by supermassive black holes 13 billion light-years away from the Earth, from a time when the universe was less than 10 per cent of its present age.

“It is remarkable that such massive dense objects were able to form so soon after the Big Bang,” said Michael Strauss, a professor at Princeton University in the US.

“Understanding how black holes can form in the early universe, and just how common they are, is a challenge for our cosmological models,” Strauss said in a statement.

This finding, published in The Astrophysical Journal, increases the number of black holes known at that epoch  considerably, and reveals, for the first time, how common they are early in the universe’s history.

In addition, it provides new insight into the effect of black holes on the physical state of gas in the early universe in its first billion years.

Supermassive black holes, found at the centers of galaxies, can be millions or even billions of times more massive than the Sun.

While they are prevalent today, it is unclear when they first formed, and how many existed in the distant early universe.

A supermassive black hole becomes visible when gas accretes onto it, causing it to shine as a “quasar.” Previous studies have been sensitive only to the very rare, most luminous quasars, and thus the most massive black holes.

The new discoveries probe the population of fainter quasars, powered by black holes with masses comparable to most black holes seen in the present-day universe.

The team used data taken with “Hyper Suprime-Cam” (HSC) instrument, mounted on the Subaru Telescope of the National Astronomical Observatory of Japan, which is located on the summit of Maunakea in Hawaii.

The researchers selected distant quasar candidates from the sensitive HSC survey data.

They then carried out an intensive observational campaign to obtain spectra of those candidates, using three telescopes: the Subaru Telescope; the Gran Telescopio Canarias on the island of La Palma in the Canaries, Spain; and the Gemini South Telescope in Chile.

The survey revealed 83 previously unknown very distant quasars.

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ABDUL AZIZ SHE…
 - 
Saturday, 16 Mar 2019

SUBHAANALLAH

 

 
ALLAH ALMIGHTY CREATED EVERTHING  INCLUDING WHOLE UNIVERSE AND WHAT IS IN IT,

HUMAN BEING CANNOT REACH TO UNDERSTAND IT,  HUMAN LIFE NOT SUFFEICENT TO REACH AND KNOW EVERYTHING.

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News Network
August 8,2020

The Kozhikode International Airport located at Karipur is not safe for the landing of flights in rainy season, according to an air-safety expert, who had warned the aviation ministry and the civil aviation regulator about this in 2011. 

The warning was particularly about the dangers of permitting passenger aircraft to land on runway 10 of the airport during rains and unfavourable wind conditions. 

Nine years later, on August 7, 2020, the warning became a reality when an Air India Express pilots landed in tailwind conditions and the aircraft overshot the tabletop runway to drop off the end and crash.

 “An aircraft landing on runway 10 in tailwind will experience poor braking action due to heavy rubber deposits … All such flights … are endangering the lives of all on board,’’ said Capt Mohan Ranganathan, in a letter sent on June 17, 2011 to then director general of civil aviation Bharat Bhushan and Nasim Zaidi, chairman of a civil aviation safety advisory committee, which was formed after the May 2010 Mangaluru air crash which killed 158 people.

“My warning issued after the Mangaluru crash was ignored. It is a table-top runway with a down slope. The buffer zone at the end of the runway is inadequate,” Capt Ranganathan said. Given the topography, he pointed out, the airport should have a buffer of 240m at the end of the runway, but it only has 90m (which the DGCA had approved). “Moreover, the space on either side of the runway is only 75m instead of the mandatory 100m,” he added.

Capt Ranganathan said there is no guideline for operations on a table-top runway when it is raining. “Runway 10 approach should not be permitted in view of the lack of runway end safety area (RESA) and the terrain beyond the end of the runway. RESA of 240m should be immediately introduced and runway length has to be reduced to make the operations safe,” his letter said.

If an aircraft is unable to stop within the runway, there is no RESA beyond the end. The ILS localiser antenna is housed on a concrete structure and the area beyond is a steep slope. “The Air India Express accident in Mangalore should have alerted AAI to make the runway conditions safe. We have brought up the issue of RESA during the initial Casac-sub group meetings. We had specifically mentioned that the declared distances for both runways have to be reduced in order to comply with ICAO Annex 14 requirement,” Capt Ranganathan said.

He said the condition of the runway strip was known to DGCA teams that have been conducting inspection and safety assessments. “Have they considered the danger involved? Did the DGCA or the airlines lay down any operational restrictions or special procedures?”

The letter also refers to Approach and Landing Accident Reduction (ALAR) training, which is supposed to be mandatory before every monsoon, but airlines don’t follow it, he said. “70% of accidents take place during approach and landing and that is why this training is essential,” he added.

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Agencies
February 14,2020

Lucknow, Feb 14: Uttar Pradesh doctor Kafeel Khan was on Friday booked under the National Security Act (NSA) over his alleged anti-CAA speech at Aligarh Muslim University on December 12, 2019.

The Uttar Pradesh slapped NSA on Kafeel Khan on Friday even as the doctor waited to be released from jail despite being granted bail on Monday in connection with his alleged inflammatory speech.

SP Crime Dr Arvind said that there were sufficient grounds to book the doctor under NSA.

The suspended pediatrician, Kafeel Khan, was arrested for allegedly delivering a controversial speech during Anti-CAA protests on December 12 at the Aligarh Muslim University or AMU. While he was granted bail on Monday, his family members claimed on Thursday that he was yet to be released.

Dr Kafeel Khan's brother Adeel Ahmed Khan had issued a statement saying that despite being granted bail Mathura jail authorities had not honoured the court's order.

Dr Kafeel Khan was arrested by the UP Special Task Force from Mumbai on January 29 for participating anti-CAA protest at AMU. A case was registered against him at the Civil Lines police station here for promoting enmity between different religions.

After his arrest in Mumbai, Dr Khan was brought to Aligarh, from where he was shifted to the district jail in neighbouring Mathura.

According to police, this was done as a precautionary measure in view of the anti-CAA protests on the AMU campus and at the Eidgah grounds in the old city. Police had said that the Dr Khan's presence in the Aligarh jail could have aggravated the law and order situation in the city.

The doctor was earlier arrested for his alleged role in the death of over 60 children in one week at the BRD Medical College in Gorakhpur in August 2017. Short supply of oxygen at the children's ward was blamed at that time for the deaths.

About two years later, a state government probe cleared Khan of all major charges, prompting him to seek an apology from the Yogi Adityanath government.

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Agencies
February 29,2020

Doha, Feb 29: The United States signed a landmark deal with the Taliban on Saturday, laying out a timetable for a full troop withdrawal from Afghanistan within 14 months as it seeks an exit from its longest-ever war.

President Donald Trump urged the Afghan people to embrace the chance for a new future, saying the deal held out the possibility of ending the 18-year conflict.

"If the Taliban and the government of Afghanistan live up to these commitments, we will have a powerful path forward to end the war in Afghanistan and bring our troops home," he said on the eve of the event in Doha.

Secretary of State Mike Pompeo arrived in the Qatari capital to witness the signing of the accord, while Defence Secretary Mark Esper was in Kabul for a separate joint declaration with the Afghan government.

The agreement is expected to lead to a dialogue between the Kabul government and the Taliban that, if successful, could ultimately see the Afghan war wind down.

But the position of the Afghan government, which has been excluded from direct US-Taliban talks, remains unclear and the country is gripped by a fresh political crisis amid contested election results.

The United States and its allies will withdraw all their forces from Afghanistan within 14 months if the Taliban abide by the Doha agreement, Washington and Kabul said in a joint statement.

After an initial reduction of troops to 8,600 within 135 days of Saturday's signing, the US and its partners "will complete the withdrawal of their remaining forces from Afghanistan within 14 months... and will withdraw all their forces from remaining bases", the declaration stated.

The Doha accord was drafted over a tempestuous year of dialogue marked by the abrupt cancellation of the effort by Trump in September.

The signing comes after a week-long, partial truce that has mostly held across Afghanistan, aimed at building confidence between the warring parties and showing the Taliban can control their forces.

NATO Secretary General Jens Stoltenberg heralded the agreement as a "first step to lasting peace".

"The way to peace is long and hard. We have to be prepared for setbacks, spoilers, there is no easy way to peace but this is an important first step," the Norwegian former prime minister told reporters in Kabul.

Since the US-led invasion that ousted the Taliban after the September 11, 2001 attacks, America has spent more than $1 trillion in fighting and rebuilding in Afghanistan.

About 2,400 US soldiers have been killed, along with unknown tens of thousands of Afghan troops, Taliban fighters and Afghan civilians.

The insurgents said they had halted all hostilities Saturday in honour of the agreement.

"Since the deal is being signed today, and our people are happy and celebrating it, we have halted all our military operations across the country," Taliban spokesman Zabihullah Mujahid told AFP.

Close to 30 nations were represented at Saturday's signing in the Qatari capital.

While Kabul will not be represented at the Doha ceremony, set for 1245 GMT, it will send a six-person taskforce to the Qatari capital to make initial contact with the Taliban political office, established in 2013.

Any insurgent pledge to guarantee Afghanistan is never again used by jihadist movements such as Al-Qaeda and the Islamic State group to plot attacks abroad will be key to the deal's viability.

The Taliban's sheltering of Al-Qaeda was the main reason for the US invasion following the 9/11 attacks.

The group, which had risen to power in the 1990s in the chaos of civil war, suffered a swift defeat at the hands of the US and its allies. They retreated before re-emerging to lead a deadly insurgency against the new government in Kabul.

After the NATO combat mission ended in December 2014, the bulk of Western forces withdrew from the country, leaving it in an increasingly precarious position.

While Afghans are eager to see an end to the violence, experts say any prospective peace will depend on the outcome of talks between the Taliban and the Kabul government.

But with President Ashraf Ghani and rival Abdullah Abdullah at loggerheads over contested election results, few expect the pair to present a united front, unlike the Taliban, who would then be in a position to take the upper hand in negotiations.

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