Study confirms models on the evolution of our universe.
More than half of the matter in our universe has so far remained hidden from us. However, astrophysicists had a hunch where it might be: In so-called filaments, unfathomably large thread-like structures of hot gas that surround and connect galaxies and galaxy clusters. A team led by the University of Bonn has now for the first time observed a gas filament with a length of 50 million light years. Its structure is strikingly similar to the predictions of computer simulations. The observation therefore also confirms our ideas about the origin and evolution of our universe. The results are published in the journal Astronomy & Astrophysics.
We owe our existence to a tiny aberration. Pretty much exactly 13.8 billion years ago, the Big Bang occurred. It is the beginning of space and time, but also of all matter that makes up our universe today. Although it was initially concentrated at one point, it expanded at breakneck speed — a gigantic gas cloud in which matter was almost uniformly distributed.
Almost, but not completely: In some parts the cloud was a bit denser than in others. And for this reason alone there are planets, stars, and galaxies today. This is because the denser areas exerted slightly higher gravitational forces, which drew the gas from their surroundings towards them. More and more matter therefore concentrated at these regions over time. The space between them, however, became emptier and emptier. Over the course of a good 13 billion years, a kind of sponge structure developed: large “holes” without any matter, with areas in between where thousands of galaxies are gathered in a small space, so-called galaxy clusters.
Fine web of gas threads
If it really happened that way, the galaxies and clusters should still be connected by remnants of this gas, like the gossamer-thin threads of a spider web. “According to calculations, more than half of all baryonic matter in our universe is contained in these filaments — this is the form of matter of which stars and planets are composed, as are we ourselves,” explains Prof. Dr. Thomas Reiprich from the Argelander Institute for Astronomy at the University of Bonn. Yet it has so far escaped our gaze: Due to the enormous expansion of the filaments, the matter in them is extremely diluted: It contains just ten particles per cubic meter, which is much less than the best vacuum we can create on Earth.
However, with a new measuring instrument, the eROSITA space telescope, Reiprich and his colleagues were now able to make the gas fully visible for the first time. “eROSITA has very sensitive detectors for the type of X-ray radiation that emanates from the gas in filaments,” explains Reiprich. “It also has a large field of view — like a wide-angle lens, it captures a relatively large part of the sky in a single measurement, and at a very high resolution.” This allows detailed images of such huge objects as filaments to be taken in a comparatively short time.
Confirmation of the standard model
In their study, the researchers examined a celestial object called Abell 3391/95. This is a system of three galaxy clusters, which is about 700 million light years away from us. The eROSITA images show not only the clusters and numerous individual galaxies, but also the gas filaments connecting these structures. The entire filament is 50 million light years long. But it may be even more enormous: The scientists assume that the images only show a section.
“We compared our observations with the results of a simulation that reconstructs the evolution of the universe,” explains Reiprich. “The eROSITA images are strikingly similar to computer-generated graphics. This suggests that the widely accepted standard model for the evolution of the universe is correct.” Most importantly, the data show that the missing matter is probably actually hidden in the filaments.
Reiprich is also a member of the Transdisciplinary Research Area (TRA) “Building blocks of matter and fundamental interactions” at the University of Bonn. In six different TRAs, scientists from the most diverse faculties and disciplines come together to work collaboratively on future-relevant research topics of the University of Excellence.
Reference: “The Abell 3391/95 galaxy cluster system. A 15 Mpc intergalactic medium emission filament, a warm gas bridge, infalling matter clumps, and (re-) accelerated plasma discovered by combining SRG/eROSITA data with ASKAP/EMU and DECam data” by T.H. Reiprich, A. Veronica, F. Pacaud, M.E. Ramos-Ceja, N. Ota, J. Sanders, M. Kara, T. Erben, et al., Accepted, Astronomy & Astrophysics.
Participating institutions and funding:
Almost 50 scientists from institutions in Germany, the USA, Switzerland, Chile, Australia, Spain, South Africa, and Japan participated in the study.
eROSITA was developed with funding from the Max Planck Society and the German Aerospace Center (DLR). The telescope was launched into space last year on board a Russian-German satellite whose construction was supported by the Russian space agency Roskosmos. This work also used the Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab, and the Australian Square Kilometre Array Pathfinder (ASKAP) telescope, built and operated by CSIRO (Commonwealth Scientific and Industrial Research Organisation). The current study was funded by several research funding organizations in the participating countries.
New species of crested dinosaur identified in Mexico
A team of palaeontologists in Mexico have identified a new species of dinosaur after finding its 72 million-year-old fossilized remains almost a decade ago, Mexico’s National Institute of Anthropology and History (INAH) said on Thursday.
The new species, named Tlatolophus galorum, was identified as a crested dinosaur after 80% of its skull was recovered, allowing experts to compare it to other dinosaurs of that type, INAH said.
The investigation, which also included specialists from the National Autonomous University of Mexico, began in 2013 with the discovery of an articulated tail in the north-central Mexican state of Coahuila, where other discoveries have been made.
“Once we recovered the tail, we continued digging below where it was located. The surprise was that we began to find bones such as the femur, the scapula and other elements,” said Alejandro Ramírez, a scientist involved in the discovery.
Later, the scientists were able to collect, clean and analyze other bone fragments from the front part of the dinosaur’s body.
The palaeontologists had in their possession the crest of the dinosaur, which was 1.32 meters long, as well as other parts of the skull: lower and upper jaws, palate and even a part known as the neurocranium, where the brain was housed, INAH said.
The Mexican anthropology body also explained the meaning of the name – Tlatolophus galorum – for the new species of dinosaur.
Tlatolophus is a mixture of two words, putting together a term from the indigenous Mexican language of Nahuatl that means “word” with the Greek term meaning “crest”. Galorum refers to the people linked to the research, INAH said.
(Reporting by Abraham Gonzalez; Writing by Drazen Jorgic; Editing by Ana Nicolaci da Costa)
Alberta family searches for answers in teen's sudden death after COVID exposure, negative tests – CBC.ca
A southern Alberta mother and father are grappling with the sudden, unexplained death of their 17-year-old daughter, and with few answers, they’re left wondering if she could be the province’s youngest victim of COVID-19.
Sarah Strate — a healthy, active Grade 12 student at Magrath High School who loved singing, dancing and being outdoors — died on Monday, less than a week after being notified she’d been exposed to COVID-19.
While two tests came back negative, her parents say other signs point to the coronavirus, and they’re waiting for more answers.
“It was so fast. It’s all still such a shock,” said Sarah’s mother, Kristine Strate. “She never even coughed. She had a sore throat and her ears were sore for a while, and [she had] swollen neck glands.”
Kristine said Sarah developed mild symptoms shortly after her older sister — who later tested positive for COVID-19 — visited from Lethbridge, one of Alberta’s current hot spots for the virus.
The family went into isolation at their home in Magrath on Tuesday, April 20. They were swabbed the next day and the results were negative.
‘Everything went south, super-fast’
By Friday night, Sarah had developed fever and chills. On Saturday, she started vomiting and Kristine, a public health nurse, tried to keep her hydrated.
“She woke up feeling a bit more off on Monday morning,” Kristine said. “And everything went south, super-fast.”
Sarah had grown very weak and her parents decided to call 911 when she appeared to become delirious.
“She had her blanket on and I was talking to her and, in an instant, she was unresponsive,” said Kristine, who immediately started performing CPR on her daughter.
When paramedics arrived 20 minutes later, they were able to restore a heartbeat and rushed Sarah to hospital in Lethbridge, where she died.
“I thought there was hope once we got her heart rate back. I really did,” recalled Sarah’s father, Ron.
“He was praying for a miracle, and sometimes miracles don’t come,” said Kristine.
Searching for answers
At the hospital, the family was told Sarah’s lungs were severely infected and that she may have ended up with blood clots in both her heart and lungs, a condition that can be a complication of COVID-19.
But a second test at the hospital came back negative for COVID-19.
“There really is no other answer,” Ron said. “When a healthy 17-year-old girl, who was sitting up in her bed and was able to talk, and within 10 minutes is unconscious on our floor — there was no reason [for it].”
The province currently has no record of any Albertans under the age of 20 who have died of COVID-19.
According to the Strate family, the medical examiner is running additional blood and tissue tests, in an effort to uncover the cause of Sarah’s death.
‘Unusual but not impossible’
University of Alberta infectious disease specialist Dr. Lynora Saxinger, who was not involved in Sarah’s treatment, says it is conceivable that further testing could uncover evidence of a COVID-19 infection, despite two negative test results.
However, she hasn’t seen a similar case in Alberta.
“It would be unusual but not impossible because no test is perfect. We have had cases where an initial test is negative and then if you keep on thinking it’s COVID and you re-test, you then can find COVID,” she said.
According to Saxinger, the rate of false negatives is believed to be very low. But it can happen if there are problems with the testing or specimen collection.
She says people are more likely to test positive after symptoms develop.
“The best sensitivity of the test is around day four or five of having symptoms,” she said. “So you can miss things if you test very, very early. And with new development of symptoms, it’s always a good time to re-test because then the likelihood of getting a positive test is a little higher. But again, no test is perfect.”
Sarah deteriorated so quickly — dying five days after she first developed symptoms — she didn’t live long enough to make it to her follow-up COVID-19 test. Instead, it was done at the hospital.
‘An amazing kid’
The Strate family now faces an agonizing wait for answers — one that will likely take months — about what caused Sarah’s death.
But Ron, who teaches at the school where Sarah attended Grade 12, wants his daughter to be remembered for the life she lived, not her death.
Sarah was one of five children. Ron says she was strong, active and vibrant and had plans to become a massage therapist after graduating from high school.
She played several sports and loved to sing and dance as part of a show choir. She was a leader in the school’s suicide prevention group and would stand up for other students who were facing bullying.
“She’s one of the leaders in our Hope Squad … which goes out and helps kids to not be scared,” he father said.
“She’s an amazing kid.”
Sarah would often spend hours helping struggling classmates, and her parents hope her kindness is not forgotten.
“She’d done so many good things. Honestly, I’ve got so many messages from parents saying, ‘You have no idea how much your daughter helped our kid,'” said Ron.
“This 17-year-old girl probably lived more of a life in 17 years than most adults will live in their whole lives. She was so special. I love her so much.”
China launches key module of space station planned for 2022
BEIJING (Reuters) -China launched an unmanned module on Thursday containing what will become living quarters for three crew on a permanent space station that it plans to complete by the end of 2022, state media reported.
The module, named “Tianhe”, or “Harmony of the Heavens”, was launched on the Long March 5B, China’s largest carrier rocket, at 11:23 a.m. (0323 GMT) from the Wenchang Space Launch Centre on the southern island of Hainan.
Tianhe is one of three main components of what would be China’s first self-developed space station, rivalling the only other station in service – the International Space Station (ISS).
The ISS is backed by the United States, Russia, Europe, Japan and Canada. China was barred from participating by the United States.
“(Tianhe) is an important pilot project in the building of a powerful nation in both technology and in space,” state media quoted President Xi Jinping as saying in a congratulatory speech.
Tianhe forms the main living quarters for three crew members in the Chinese space station, which will have a life span of at least 10 years.
The Tianhe launch was the first of 11 missions needed to complete the space station, which will orbit Earth at an altitude of 340 to 450 km (211-280 miles).
In the later missions, China will launch the two other core modules, four manned spacecraft and four cargo spacecraft.
Work on the space station programme began a decade ago with the launch of a space lab Tiangong-1 in 2011, and later, Tiangong-2 in 2016.
Both helped China test the programme’s space rendezvous and docking capabilities.
China aims to become a major space power by 2030. It has ramped up its space programme with visits to the moon, the launch of an uncrewed probe to Mars and the construction of its own space station.
In contrast, the fate of the ageing ISS – in orbit for more than two decades – remains uncertain.
The project is set to expire in 2024, barring funding from its partners. Russia said this month that it would quit the project from 2025.
Russia is deepening ties with China in space as tensions with Washington rise.
Moscow has slammed the U.S.-led Artemis moon exploration programme and instead chosen to join Beijing in setting up a lunar research outpost in the coming years.
(Reporting by Ryan Woo and Liangping Gao; Editing by Christian Schmollinger, Simon Cameron-Moore and Lincoln Feast.)