cosmic microwave background, cosmology, gravitational lensing

Although the particles of dark matter continue to allude us, astronomers continue to find evidence of it. In a recent study, they have seen its effect from the edge of visible space, when the universe was just 1.5 billion years old.

Dark matter doesn’t emit its own light, nor does it absorb light like a dark cloud. But it does affect light gravitationally. So clumps of dark matter create a gravitational lens that deflects and focuses light. Astronomers have long used this effect to map dark matter within galactic clusters. You can even see this lensing effect in the recent Webb deep field images. The light from more distant galaxies is warped by the mass of closer galaxies, which astronomers can map to calculate the distribution of dark matter in those closer galaxies.

But in this latest study, the galaxies are so distant that there aren’t really any more distant galaxies. Certainly none bright enough that we can see their lensed light. So instead, the team used the light from the cosmic microwave background (CMB). To map dark matter, the team used data from the Subaru Hyper Suprime-Cam Survey (HSC), and identified about 1.5 million faint and distant galaxies. They then used data from the Plank satellite to see how CMB light was deflected. From this, they created a map of dark matter in the early universe.

cosmic microwave background, cosmology, gravitational lensing

The cosmic microwave background as seen by different satellites. Credit: NASA/JPL-Caltech/ESA

It’s the most distant measure of dark matter ever made, and it opens a possible crack in our current model of the universe. In the standard cosmological model, known as the LCDM model, dark energy drives the expansion of the universe, striving to push galaxies apart, while the gravitational attraction of matter and dark matter cause galaxies to clump together. According to LCDM, the scale at which we observe fluctuations in the cosmic background drives the scale at which galaxies cluster together, which tells us how densely galaxies should be clustered in the early universe. In this latest work, the amount of galactic clustering in the early period is slightly less than predicted by the LCDM model.

The uncertainty of the team’s measurements means their result isn’t conclusive. It’s possible that they simply under measured the clumping scale. But if it’s right, it suggests that the laws of the universe were a bit different 12 billion years ago. Combined with observations that show a tension in the rate of cosmic expansion, they could be on to something.

There are a lot of possibilities. But the biggest success of this work is that we now have actual data. It’s a big first step, and as we get more data from telescopes such as the James Webb Space Telescope and Vera Rubin Observatory, we should be able to solve this mystery, and finally learn if the cosmic laws really were different in the dark and distant past.

Reference: Miyatake, Hironao, et al. “First Identification of a CMB Lensing Signal Produced by 1.5 Million Galaxies at z ~ 4: Constraints on Matter Density Fluctuations at High Redshift.” Physical Review Letters 129.6 (2022): 061301.

TECH NEWS RELATED

What's in Biden's big climate and health plan?

Hundreds of billions of dollars for clean energy projects, cheaper prescription drugs and new corporate taxes are a few of the key items in US President Joe Biden’s massive investment plan, which Congress has now passed. Here’s a closer look at the signature elements of the package, which represents ...

View more: What's in Biden's big climate and health plan?

Ukraine nuclear plant standoff stirs Chernobyl memories

Anastasiya Rudenko clutches the gleaming gold medal her late husband Viktor was awarded for working in the Chernobyl nuclear disaster zone. He died in 2014 from bladder cancer — perhaps a result of radiation, she thinks. Now she mourns his loss in the Ukrainian village of Vyschetarasivka, across the ...

View more: Ukraine nuclear plant standoff stirs Chernobyl memories

Four dead in China flash flood; 11 died in Gambia's worst floods in decades

Four people were killed and nine others injured in a flash flood in southwest China on Saturday, local authorities said. Footage published by Chinese media showed water rising rapidly in a river on the outskirts of Sichuan province’s Pengzhou city. Tourists who had been playing in the initially shallow ...

View more: Four dead in China flash flood; 11 died in Gambia's worst floods in decades

Pope urges help for drought-hit Somalia

Pope Francis on Sunday called for international help for Somalia to fight a “deadly” drought that the UN says has displaced one million people. The 85-year-old pontiff drew attention to what he called the “serious humanitarian crisis” in Somalia and parts of surrounding countries after his weekly Angelus prayer ...

View more: Pope urges help for drought-hit Somalia

China and Thailand kick off joint air force drills

Thailand and China kicked off a joint air force exercise on Sunday, the kingdom’s military said, the first such drills in years following a pause forced by Covid-19. The “Falcon Strike” exercise comes after China’s biggest-ever military drills around Taiwan, which were conducted in retaliation to a visit there ...

View more: China and Thailand kick off joint air force drills

US to boost Taiwan trade, conduct air, sea transits

The United States will boost trade with Taiwan in response to China’s “provocative” behaviour, the White House said Friday, as it insisted on the right of air and sea passage through the tense strait. A new trade plan will be unveiled within days, while US forces will transit the ...

View more: US to boost Taiwan trade, conduct air, sea transits

Taiwan's frontline islanders unfazed by beat of China war drum

Not far from the rusted-out tanks and anti-landing spikes that litter the beaches of the Taiwanese island where he lives, 92-year-old veteran Yang Yin-shih reads his newspaper in the shadow of the enemy that regularly adorns its pages. Several miles from Yang’s home on the tiny Kinmen Islands is ...

View more: Taiwan's frontline islanders unfazed by beat of China war drum

NASA explains strange stringy object photographed by Perseverance rover

One photo taken recently by NASA’s Perseverance rover on Mars showed an unusual noodle-like object lying on the surface of the Red Planet, but scientists have an explanation. The photo was taken on July 12 and depicted what looked like a tangled web of string in the lower right ...

View more: NASA explains strange stringy object photographed by Perseverance rover

ESO's Very Large Telescope Catches A Starburst Galaxy Brimming In A 'Whirlpool of Gold'

Chinese commercial carrier rocket Smart Dragon-3 completes ground tests

Hubble sees red supergiant star Betelgeuse slowly recovering after blowing its top

Shenzhou XIV astronauts to conduct their first spacewalk in coming days

AFRL Inspire event with Tedx-style talks to be livestreamed

Pentagon says US weapons not used to attack Crimea airbase

North Korea criticises UN chief over denuclearisation call

Indonesia, US troops hold live-fire drill as China tensions mount

Dark thoughts haunt Ukrainians in shadow of nuclear crisis

Iran hints it may accept compromise on nuclear deal

Iran seeks 3 more Khayyam satellites

Colombia to restart peace talks with ELN rebels

OTHER TECH NEWS

Top Car News Car News