Gravitational waves detected again, at furthest distance yet

LIGO spots a third black hole merger, tightens mass limits on gravitons

The Laser Interferometer Gravitational-Wave Observatory, more commonly known as LIGO, announced Thursday that it recently made its third detection of gravitational waves.

"We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses-these are objects we didn't know existed before LIGO detected them", says MIT's David Shoemaker, the newly elected spokesperson for the LIGO Scientific Collaboration (LSC), a body of more than 1,000 worldwide scientists who perform LIGO research together with the European-based Virgo Collaboration.

There was an issue with one detector having a calibration set wrong in Hanover, he said, so no alarm went off. Lett., doi: 10.1103/PhysRevLett.118.221101). In this case, the black holes can spin in any direction relative to their orbital motion. The pipeline takes the noisy data collected by the LIGO detector and processes it to estimate the precise shape of the gravitational wave signal, independent of any preconceived ideas of what those signals should look like. With this, LIGO is starting to create a new branch of science: gravitational wave astronomy.

Scientists will need more data to sort out how the black hole duos form, says physicist Emanuele Berti of the University of MS in Oxford. "A new astronomy of gravitational waves".

The Laser Interferometer Gravitational-wave Observatory (LIGO) in the United States made the detection on January 4 this year, demonstrating that a new window in astronomy has been firmly opened.

A young German scientist - part of the 1,000 who make up the LIGO Scientific Collaboration - saw it "and got us up in the middle of the night, which we love to do".

Meanwhile, the high rate of mergers disfavored a third scenario called "dynamical formation", which has the black holes forming far apart inside a dense stellar cluster.

In all three discoveries, LIGO detected gravitational waves from the energetic mergers of black hole pairs. LIGO's second detection featured two smaller black holes, 14 and eight times the mass of the sun (SN: 7/9/16, p. 8). As pairs of black holes spiral around each other, they also spin like a pair of ice skaters spinning individually while circling around each other. That leads, she said, to a delay known as the "hangup effect" that can be seen in the gravitational waveform.

This is an important detail that can teach us more about the dynamics of our universe, and so far we can only detect the spins of black holes using the brand new technique of gravitational wave measurements.

Simultaneously, the detection does not favour the competing theory according to which binary black holes form in pairs even at the start and eventually merge.

"The new event also provides new opportunities to test Einstein's theory of general relativity". Gravitational waves stretch and then contract spacetime as they pass, just as ripples on a pond move the surface up and then down.

Further, the LIGO-Virgo team was able, through the new observation, to put tighter constraints on the mass of the graviton, the hypothesized particle that supposedly mediates the gravitational force (analogous to the way that the photon, for example, mediates electromagnetic force).

"I think most people would be surprised if general relativity was 100 percent correct, but there's no evidence that it's not yet".

Any dispersion would also imply that the graviton, a theoretical particle that mediates gravitational attraction, would have mass.

The new observation grew out of improvements to LIGO's engineering sensitivity after its last observational run, which concluded in January 2016.

LIGO's next big breakthrough is expected to come from detecting collisions of binary neutron stars - the corpses of dead stars that pack a sun's worth of mass into a city-sized sphere. The new detection, called GW170104, occurred during LIGO's current observation period that began November 30, 2016, and concluded in early May, according to a news release about the discovery issued through LSU. Since the LIGO detectors run constantly, for weeks at a time, the data feed is continually updated. "We now have a second candidate in the "heavy black hole" category", said physicist and LIGO researcher Bangalore Sathyaprakash of Penn State and Cardiff University.

The LIGO-Virgo consortium believes that the addition of the Virgo instrument, slated to come online this summer, could substantially improve the ability to localize gravitational-wave sources in space. The observations will let scientists test theories under conditions that could never be recreated in a lab.

Within tens of seconds, LIGO's search algorithms automatically analyzed the signal, comparing it to waveforms characteristic of gravitational waves.

And where there are gravitational waves, there are black holes, based on the findings at the observatory in rural Livingston Parish. That makes it tough to tie a given LIGO detection event to the pinpoint observations of traditional telescopes. The leading theory is that dark matter is made up of exotic particles created soon after the big bang. More importantly, each detection has offered much more than just a "sighting".

Share

Related News

  • Trump signs waiver keeping US embassy in Tel Aviv -- for now

    Trump signs waiver keeping US embassy in Tel Aviv -- for now

    He was in the process of negotiating peace with the Palestinians, who also had political claims to Jerusalem . Jerusalem's status is one of the most emotionally charged matters separating the Israelis and Palestinians.
    'What are you feeding him?': Pope takes jibe at Trump

    'What are you feeding him?': Pope takes jibe at Trump

    It also sounds a lot like "pizza", which is what reporters originally thought the pope had said. Trump and the pope met privately in a one-on-one conversation in a Vatican study on Wednesday.
    Moody's cuts China credit rating over rising debt

    Moody's cuts China credit rating over rising debt

    Moody's cited the likelihood of a "material rise" in economy-wide debt and the burden that it will place on the state's finances. China's total debt reached 253% of its GDP in 2016, up from 213% in 2013 and 149% in 2008, according to JP Morgan.
  • NBA Finals set: It's Cleveland and Golden State... again

    NBA Finals set: It's Cleveland and Golden State... again

    INSKEEP: That gave LeBron James 5,989 career points in the playoffs, two more than Michael Jordan , the most all time. All three of Boston's walking wounded-Fs Jae Crowder, Jaylen Brown and Amir Johnson-were able to play.

    Late-Night Hosts Address Montana Politician Who Allegedly Body-Slammed Reporter

    Both candidates in the Montana contest were seen as flawed, but Quist in particular was a weak recruit for Democrats. Earlier Thursday, multiple Republicans, including House Speaker Paul Ryan , called on Gianforte to apologize.
    DJI unveils $499 'spark drone' controlled by hand gestures

    DJI unveils $499 'spark drone' controlled by hand gestures

    You'll pay $499 for the base package which includes the drone itself, a battery , a USB charger, and three pairs of propellers. The DJI Spark is a small handheld drone that requires no separate controller, all the work is done on your smartphone.
  • Venus Williams into 3rd round of French Open

    Venus Williams into 3rd round of French Open

    Before the tournament, 1978 US Open finalist and ESPN analyst Pam Shriver backed Williams to contend at Roland Garros . Venus Williams accidentally spilled the beans on the gender of her pregnant sister Serena's baby.

    Why Derek Jeter picked Mother's Day for his No. 2 retirement ceremony

    Judge is already taking a page out of the Jeter playbook by being humble and not talking about himself in postgame interviews. Jeter also took a moment to wish his wife and his mom and any other mothers out there a happy Mother's Day.
    In Trump's private moments, it's small talk and compliments

    In Trump's private moments, it's small talk and compliments

    In Saudi Arabia , he met with King Salman and 55 Muslim and Arab leaders, calling on them to reject radical Islamic terrorism. Before leaving Italy, Trump will meet with the Italian president and prime minister prior to a Thursday flight to Brussels.
  • AMD announces Vega for PCs will come in two months

    AMD also unveiled the Ryzen mobile accelerated processing unit in an ultra-portable laptop references design. The card will be hitting the market after the release of AMD Vega Frontier edition.
    Bourdais fractures pelvis, hip during Indy qualifying crash

    Bourdais fractures pelvis, hip during Indy qualifying crash

    More rain is expected Friday night, which could leave drivers with little rubber on the track when qualifying begins Saturday. Asked about morale within the team , Coyne said: "Everyone's sad because we all know how good this year could have been.
    Siblings allegedly shot by mother have died in Dayton hospital

    Siblings allegedly shot by mother have died in Dayton hospital

    According to the statement of facts, Helton asked that daughter to help remove the bodies of her siblings from the home. WDTN reports that 8-year-old Kamora and 6-year-old Kendon died from their injuries at Dayton Children's Hospital .