Saturday, 18 August, 2018

Scientists discover galaxy that appears to lack dark matter

Astronomers baffled by distant galaxy that doesn't have any dark matter Galaxy without any dark matter baffles astronomers
Glenn Montgomery | 30 March, 2018, 00:48

This galaxy, NGC 1052-DF2, is the size of the Milky Way but only has 1/200 the amount of stars, with no dense center or spiral arms or black hole. What has scientists so curious about this galaxy is that it is unusually transparent and appears to contain no dark matter.

Although it has never been directly observed, scientists are confident that this elusive material exists because of the gravitational effects it appears to have on astronomical objects.

The scientists then used larger telescopes - including the W.M. Keck Observatory in Hawaii and the Hubble Space Telescope - to do followup observations. "I spent an hour just staring at this image", van Dokkum said as he recalled first seeing the Hubble image of NGC 1052-DF2. "It's so rare, particularly these days after so many years of Hubble, that you get an image of something and you say, 'I've never seen that before.' This thing is astonishing: a huge blob that you can look through. It is literally a see-through galaxy", he added.

But none of the ultra-diffuse galaxies discovered so far have been found to be lacking in dark matter. By looking at the dynamical properties of ten globular clusters - essentially, a very large ball of stars - orbiting the galaxy, it allowed the team to work out an independent value of the galaxies mass. Dokkum said that the discovery challenges the standard ideas of galaxy formation. In other words, dark matter doesn't seem to be exerting its gravity on normal matter in that galaxy.

Paradoxically, the discovery of a galaxy without dark matter may actually confirm that the stuff actually exists by contradicting hypotheses advanced by dark matter doubters. "How do you create a galaxy without dark matter first?" "But what would you get if there were no dark matter at all?"

Ultra-Diffuse galaxies had actually been recognized formerly in various other galaxy collections. That would only make sense if there was no dark matter at all acting on them, a finding confirmed when the researchers subsequently calculated the mass of the galaxy. "This whole story is one of dark matter being the scaffolding on which every galaxy is built", said van Dokkum. In one, a sudden explosion of massive star-birth inside the galaxy could have cleared out all of its gas and dark matter. Of course, they point out that most of the things we've found that look similar have turned out to have an excess of dark matter, so there's a lot we still need to figure out here. The researchers then set about measuring the movements of the clusters as a way to estimate the galaxy's total mass.

The galaxy, charmingly named NGC1052-DF2, is about 65 million light-years away and is about one two-hundredths the mass of our own Milky Way galaxy. Yet in this unusual galaxy, the projected signatures of these exotic effects are not seen.

The team is already hunting for more dark-matter deficient galaxies.

The discovery of NGC1052-DF2 will hopefully go a long way in the future study of dark matter, which sounds odd, but its lack of dark matter will help scientist understand why it occurs in other places. The gas crunched together in balls, lit up as stars, and formed planets and galaxies. The researchers, led by Mr. Peter van Downey of the University of Yale, USA, made the relevant publication in Nature magazine and relayed by the Athenian News Agency.

Dark matter does not emit electromagnetic radiation, and remains immune to direct observation.

But that doesn't mean the results in this paper provide ideal support for dark matter theories either.

Recommended

  • Former Nederland vet

    Former Nederland vet "Doc Joe" pleads guilty to sexual assault

    A Lexington County man has been sentenced to 50 years without parole after being convicted for sexually assaulting two minors. When the victim refused the man allegedl punched the windscreen of the man's auto with enough force to crack the windscreen.
    Sen. McConnell on hemp: 'Make this a legal crop'

    Sen. McConnell on hemp: 'Make this a legal crop'

    Is this the same as it's distant cousin? I think we've moved past that. Most of the hemp for these sales was imported from China and Canada.
    Gettleman on Odell Beckham: 'You don't quit on talent'

    Gettleman on Odell Beckham: 'You don't quit on talent'

    We're not looking to get rid of him, OK? "Neither Odell nor his agent have contacted us regarding either report ", Gettleman said. In no way does this suggest a trade is going to happen, or that the Rams and Giants are deep in talks on a deal.
  • Dow Jones falls almost  350 points as tech stocks decline

    Dow Jones falls almost 350 points as tech stocks decline

    The remarks come ahead of a Senate hearing on data privacy set for next month. 3 drug stocks that made big moves today. Microsoft was the biggest gainer in the 30-company Dow and the Standard & Poor's 500 index, climbing almost 8 percent.
    NASA's James Webb Space Telescope again delayed

    NASA's James Webb Space Telescope again delayed

    That panel's recommendations and NASA's own findings will be combined in a report to be delivered to Congress this summer. Since the project began in 1996, its scope has widened and its budget has ballooned from $0.5 billion to $8.8 billion.
    Trump To Replace VA Secretary David Shulkin

    Trump To Replace VA Secretary David Shulkin

    Jackson recently presided over Trump's first presidential physical and gave the president a clean bill of health. The president has told a number of advisers that he wants to oust Shulkin , once a favorite in his Cabinet.
  • Car Attempts to Ram Into French Military, Suspect Escapes

    Car Attempts to Ram Into French Military, Suspect Escapes

    Police sealed off the area and began a search for the driver, while the army stepped up security around the barracks, Brulon said. The 25-year-old gunman, who claimed to be representing the Islamic State, was later shot dead by the police.
    Family of woman killed by self-driving Uber reaches settlement

    Family of woman killed by self-driving Uber reaches settlement

    After the accident, Uber temporarily suspended its self-driving program in Arizona, Pittsburgh, Toronto, and San Francisco . On March 18, at around 10 p.m., an Uber self-driving vehicle hit a woman as she was crossing a street in Tempe, Arizona .
    No charges for La. officers in Alton Sterling's shooting death

    No charges for La. officers in Alton Sterling's shooting death

    Federal authorities opened a civil rights investigation immediately after the shooting and released their findings in May 2017. Body camera and surveillance video haven't been released, but cellphone video of the encounter went viral.
  • Serial's Adnan Syed granted retrial by Maryland court

    Serial's Adnan Syed granted retrial by Maryland court

    Adnan Syed , whose murder conviction was the subject of the true-crime podcast's first season, was just granted a new trial . Today, the Maryland Court of Special Appeals decided it would uphold that ruling, paving the way for Syed's new case.
    Fortnite is smashing YouTube records too

    Fortnite is smashing YouTube records too

    Wyatt also commented that "gaming has never been bigger on YouTube than it is today, and that's a statistical fact". The other record broken by Fortnite was for the title of the biggest ever single live gaming stream on YouTube .
    CBSE Class X Maths, XII Economics to be held again

    CBSE Class X Maths, XII Economics to be held again

    As Ananya Sanyal, a student from Noida, said: "This question paper was not too hard , I knew answers to most of the questions". Meanwhile, Human Resource Development Minister Prakash Javadekar said, the government has taken cognizance of CBSE paper leak.

Facebook damage limitation continues with simplified privacy settings - but only on mobile Facebook damage limitation continues with simplified privacy settings - but only on mobile For Android and iOS mobile app users, the setting menu has gone under the knife reappearing with chunkier, more descriptive menus. Facebook took a large hit over the past week as more and more information is exposed about how user data is treated.

Indian government seeks buyer for majority stake in Air India Indian government seeks buyer for majority stake in Air India The funds saved can help the government bolster its finances and boost spending on health and education. Air India serves 54 domestic and 39 global destinations and has been loss-making for many years.

'Roseanne' delivers big ratings in much-awaited ABC return 'Roseanne' delivers big ratings in much-awaited ABC return What do you think about the Roseanne season 10 premiere ratings? The second episode at 8:30 scored a 5.3/21 and 18.6 million viewers.

Former Disney Channel Star Caroline Sunshine Joins President Trump's White House Staff Former Disney Channel Star Caroline Sunshine Joins President Trump's White House Staff Kevin McCarthy (R-CA), as well as for the College Republican National Committee and the California Republican Party. The question "is nothing sacred anymore" has arguably become an irrelevant one when talking about 45's White House.

Actor Corey Feldman Says He Was Stabbed in Car, LAPD Investigating Actor Corey Feldman Says He Was Stabbed in Car, LAPD Investigating The LAPD does not have a suspect description, nor has it determined what weapon was used in the alleged attack. Feldman , 46, tweeted about the incident from his hospital bed early Wednesday morning.

United States and South Korea to revise trade pact with currency side deal United States  and South Korea to revise trade pact with currency side deal South Korea will change its pharmaceutical payment program for innovative drugs to make US companies eligible for reimbursements. The deal was hailed by the officials as innovative and visionary and one that may inform future negotiations as they arise.

Twitter to ban cryptocurrency ads Twitter to ban cryptocurrency ads Facebook banned cryptocurrency ads in January and Google said it would outlaw such ads starting in June. Since the ads were running relevant to the cryptocurrency, promoting the ICOs (Initial Coin Offering).

Uber sells south-east operations to Grab Uber sells south-east operations to Grab While both sides said the move would benefit customers, analysts raised concerns a lack of competition could push up prices. New entrants and the strength of second-place regional players such as Lyft Inc.in the USA have complicated those efforts.

Mega Millions jackpot at $458M Mega Millions jackpot at $458M Jackpot winners choose whether to receive 30 annual payments, each five percent higher than the last, or a lump-sum payment. The Mega Millions jackpot is growing as the jackpot has increased to an estimated $502 million for Friday's drawing.

USA and South Korea reach agreement on trade, steel tariffs USA  and South Korea reach agreement on trade, steel tariffs Yet, the revised agreement likely will have little immediate impact on South Korea's exports to the United States. The auto sector is among the most contentious issues in South Korea's trade dealings with the U.S.

64 dead in Russian shopping mall inferno 64 dead in Russian shopping mall inferno The investigators were checking information that emergency exits of the shopping mall were blocked when the fire broke out. Kemerovo Regional Governor Aman Tuleyev has signed an order declaring mourning in the region from Tuesday to Thursday.

Former NFL cheerleader claims she was sacked over Instagram picture, report says Former NFL cheerleader claims she was sacked  over Instagram picture, report says Saintsations management told her she had a "dirty face" in the pictures, which invited attention from players, Davis said. Lawyers for the Saints told the Herald-Tribune Monday the team did not discriminate against Davis because of her gender .

Suspicious Packages Turn Up at DC Military Installations Suspicious Packages Turn Up at DC Military Installations The current scare comes in the wake of the Austin package bombings that left two people dead and several injured. Law enforcement officials asked not to be identified discussing the case because the investigation continues.

John Bolton, famously abrasive, is an experienced operator in the 'swamp' John Bolton, famously abrasive, is an experienced operator in the 'swamp' Over the past year, Ambassador Bolton has periodically visited the White House , to advise the POTUS. They, too, tried to channel the president's go-it-alone impulses, but neither was skillful enough.

Waymo announces new fleet of self-driving Jaguar I-Pace crossovers Waymo announces new fleet of self-driving Jaguar I-Pace crossovers For season five it is also anticipated that the new Gen 2 Formula E cars will compete on the full Grand Prix circuit. The vehicles "will soon be playing a vital full-time role in Waymo's driverless transportation service", it said .