由中国科学院紫金山天文台牵头,联合国内外多家研究机构组成的研究团队,利用500 m口径球面射电望远镜中国天眼(FAST)取得重要突破——在国际上首次捕捉到重复快速射电暴(fost rodio bursts,FRB)的法拉第旋转量(rotation measure,RM)发...由中国科学院紫金山天文台牵头,联合国内外多家研究机构组成的研究团队,利用500 m口径球面射电望远镜中国天眼(FAST)取得重要突破——在国际上首次捕捉到重复快速射电暴(fost rodio bursts,FRB)的法拉第旋转量(rotation measure,RM)发生剧烈跃变并随后回落的详细演化过程。这一发现结果为“快速射电暴起源于双星系统”的假说提供了迄今为止最有力的观测证据。2026年1月16日,相关研究成果发表于《Science》。展开更多
We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parame...We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parameter E(z)from the DESI BAO Alcock-Paczynski(AP)data using Gaussian process to perform the null test.We find strong evidence of accelerated expansion from the DESI BAO AP data.By reconstructing the deceleration parameter q(z) from the DESI BAO AP data,we find that accelerated expansion persisted until z■0.7 with a 99.7%confidence level.Additionally,to provide insights into the Hubble tension problem,we propose combining the reconstructed E(z) with D_(H)/r_(d) data to derive a model-independent result r_(d)h=99.8±3.1 Mpc.This result is consistent with measurements from cosmic microwave background(CMB)anisotropies using the ΛCDM model.We also propose a model-independent method for reconstructing the comoving angular diameter distance D_(M)(z) from the distance modulus μ,using SNe Ia data and combining this result with DESI BAO data of D_(M)/r_(d) to constrain the value of r_(d).We find that the value of r_(d),derived from this model-independent method,is smaller than that obtained from CMB measurements,with a significant discrepancy of at least 4.17σ.All the conclusions drawn in this paper are independent of cosmological models and gravitational theories.展开更多
With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unk...With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unknown.Therefore,by studying the formation and orbital transformation mechanism of satellites,planets and stars,the author puts forward a new theory on the formation and evolution of stars and galaxies,thus revealing the hierarchical structure of galaxies and the formation and evolution laws of main sequence stars,red giants,white dwarfs,black dwarfs,supernovae,neutron stars,black holes and quasars.Some special phenomena in the course of star formation and evolution,such as sunspots,flares,fast radio bursts and gamma-ray bursts,have also been revealed.展开更多
旋涡星系图像中所蕴含的旋臂信息,尤其是旋臂数量,对研究星系结构演化和星系动力学具有重要价值.在当前星系观测数据爆发式增长的背景下,如何快速识别出旋臂数量成为旋涡星系研究的重要问题.基于Galaxy Zoo DECaLS(Dark Energy Camera L...旋涡星系图像中所蕴含的旋臂信息,尤其是旋臂数量,对研究星系结构演化和星系动力学具有重要价值.在当前星系观测数据爆发式增长的背景下,如何快速识别出旋臂数量成为旋涡星系研究的重要问题.基于Galaxy Zoo DECaLS(Dark Energy Camera Legacy Survey)数据集,研究ResNet(Residual Networks)模型从旋涡星系图像中识别旋臂数量的方法,通过对比分析ResNet在不同网络层数下的实验结果,得出具有32层网络结构的ResNet模型,即ResNet32效果最佳,其总体准确率为83%,识别效果优于ViT(Vision Transformer)、EfficientNet和DenseNet等网络模型.在对不同旋臂数量的识别方面,识别准确率与训练样本的多少有较强的关系,拥有2个旋臂的图像数量有6800张,其F1分数(F1-Score)值达到0.9,而有4个旋臂的图像数量只有237张,其F1-Score值也最低.实验进一步分析了融合传统星系图像特征的识别效果,发现融合传统星系图像特征在提升旋臂数量识别方面作用有限.展开更多
文摘由中国科学院紫金山天文台牵头,联合国内外多家研究机构组成的研究团队,利用500 m口径球面射电望远镜中国天眼(FAST)取得重要突破——在国际上首次捕捉到重复快速射电暴(fost rodio bursts,FRB)的法拉第旋转量(rotation measure,RM)发生剧烈跃变并随后回落的详细演化过程。这一发现结果为“快速射电暴起源于双星系统”的假说提供了迄今为止最有力的观测证据。2026年1月16日,相关研究成果发表于《Science》。
基金supported in part by the National Key Research and Development Program of China (Grant No.2020YFC2201504)the National Natural Science Foundation of China (Grant Nos.12588101 and 12535002)。
文摘We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parameter E(z)from the DESI BAO Alcock-Paczynski(AP)data using Gaussian process to perform the null test.We find strong evidence of accelerated expansion from the DESI BAO AP data.By reconstructing the deceleration parameter q(z) from the DESI BAO AP data,we find that accelerated expansion persisted until z■0.7 with a 99.7%confidence level.Additionally,to provide insights into the Hubble tension problem,we propose combining the reconstructed E(z) with D_(H)/r_(d) data to derive a model-independent result r_(d)h=99.8±3.1 Mpc.This result is consistent with measurements from cosmic microwave background(CMB)anisotropies using the ΛCDM model.We also propose a model-independent method for reconstructing the comoving angular diameter distance D_(M)(z) from the distance modulus μ,using SNe Ia data and combining this result with DESI BAO data of D_(M)/r_(d) to constrain the value of r_(d).We find that the value of r_(d),derived from this model-independent method,is smaller than that obtained from CMB measurements,with a significant discrepancy of at least 4.17σ.All the conclusions drawn in this paper are independent of cosmological models and gravitational theories.
文摘With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unknown.Therefore,by studying the formation and orbital transformation mechanism of satellites,planets and stars,the author puts forward a new theory on the formation and evolution of stars and galaxies,thus revealing the hierarchical structure of galaxies and the formation and evolution laws of main sequence stars,red giants,white dwarfs,black dwarfs,supernovae,neutron stars,black holes and quasars.Some special phenomena in the course of star formation and evolution,such as sunspots,flares,fast radio bursts and gamma-ray bursts,have also been revealed.
文摘旋涡星系图像中所蕴含的旋臂信息,尤其是旋臂数量,对研究星系结构演化和星系动力学具有重要价值.在当前星系观测数据爆发式增长的背景下,如何快速识别出旋臂数量成为旋涡星系研究的重要问题.基于Galaxy Zoo DECaLS(Dark Energy Camera Legacy Survey)数据集,研究ResNet(Residual Networks)模型从旋涡星系图像中识别旋臂数量的方法,通过对比分析ResNet在不同网络层数下的实验结果,得出具有32层网络结构的ResNet模型,即ResNet32效果最佳,其总体准确率为83%,识别效果优于ViT(Vision Transformer)、EfficientNet和DenseNet等网络模型.在对不同旋臂数量的识别方面,识别准确率与训练样本的多少有较强的关系,拥有2个旋臂的图像数量有6800张,其F1分数(F1-Score)值达到0.9,而有4个旋臂的图像数量只有237张,其F1-Score值也最低.实验进一步分析了融合传统星系图像特征的识别效果,发现融合传统星系图像特征在提升旋臂数量识别方面作用有限.
