An international team of astrophysicists, including Japanese academics working at Academia Sinica, has discovered direct evidence about the shape of dark matter's distribution, a press release from the research institute said yesterday.
Dark matter is a cosmic enigma that has fascinated astrophysicists for many years. Because dark matter is invisible and no “dark matter particle” has been discovered, its existence is only inferred from a gravitational effect on other visible celestial matter or theoretical models, the scientists said.
Recently, astrophysicists from Japan and Taiwan, including postdoctoral fellow Nobuhiro Okabe from the Institute of Astronomy and Astrophysics at Academia Sinica, have found evidence that dark matter is distributed in an elliptical shape in massive clusters of galaxies, a finding that confirms a major prediction in the prevailing theory about dark matter.
The team observed the clusters of galaxies using the Subaru Telescope's Prime Focus Camera. Observations with the camera yielded wide-field images of massive clusters of galaxies — typically located 3 billion light years from Earth — which the team then used to measure and analyze dark matter distribution, the institute said in a press statement.
From analysis of the images, the team obtained evidence that the distribution of dark matter in the clusters has, on average, an extremely flattened shape rather than a simple spherical shape. The degree of the flattening was quite large, corresponding to a ratio of 2:1 in terms of the ratio of the major to minor axes of the ellipse.
The team's article, , entitled “Direct measurement of dark matter halo ellipticity from two-dimensional lensing shear maps of 25 massive clusters,” was published online on April 23 in Monthly Notices of the Royal Astronomical Society, a leading astrophysics journal.
A group of Taiwanese-American and Tibetan-American students at Harvard University on Saturday disrupted Chinese Ambassador to the US Xie Feng’s (謝鋒) speech at the school, accusing him of being responsible for numerous human rights violations. Four students — two Taiwanese Americans and two from Tibet — held up banners inside a conference hall where Xie was delivering a speech at the opening ceremony of the Harvard Kennedy School China Conference 2024. In a video clip provided by the Coalition of Students Resisting the CCP (Chinese Communist Party), Taiwanese-American Cosette Wu (吳亭樺) and Tibetan-American Tsering Yangchen are seen holding banners that together read:
UNAWARE: Many people sit for long hours every day and eat unhealthy foods, putting them at greater risk of developing one of the ‘three highs,’ an expert said More than 30 percent of adults aged 40 or older who underwent a government-funded health exam were unaware they had at least one of the “three highs” — high blood pressure, high blood lipids or high blood sugar, the Health Promotion Administration (HPA) said yesterday. Among adults aged 40 or older who said they did not have any of the “three highs” before taking the health exam, more than 30 percent were found to have at least one of them, Adult Preventive Health Examination Service data from 2022 showed. People with long-term medical conditions such as hypertension or diabetes usually do not
POLICE INVESTIGATING: A man said he quit his job as a nurse at Taipei Tzu Chi Hospital as he had been ‘disgusted’ by the behavior of his colleagues A man yesterday morning wrote online that he had witnessed nurses taking photographs and touching anesthetized patients inappropriately in Taipei Tzu Chi Hospital’s operating theaters. The man surnamed Huang (黃) wrote on the Professional Technology Temple bulletin board that during his six-month stint as a nurse at the hospital, he had seen nurses taking pictures of patients, including of their private parts, after they were anesthetized. Some nurses had also touched patients inappropriately and children were among those photographed, he said. Huang said this “disgusted” him “so much” that “he felt the need to reveal these unethical acts in the operating theater
Heat advisories were in effect for nine administrative regions yesterday afternoon as warm southwesterly winds pushed temperatures above 38°C in parts of southern Taiwan, the Central Weather Administration (CWA) said. As of 3:30pm yesterday, Tainan’s Yujing District (玉井) had recorded the day’s highest temperature of 39.7°C, though the measurement will not be included in Taiwan’s official heat records since Yujing is an automatic rather than manually operated weather station, the CWA said. Highs recorded in other areas were 38.7°C in Kaohsiung’s Neimen District (內門), 38.2°C in Chiayi City and 38.1°C in Pingtung’s Sandimen Township (三地門), CWA data showed. The spell of scorching