Article
Astronomy & Astrophysics
Jose Fonseca, Michele Liguori
Summary: High intensity mapping provides maps of the large-scale distribution of neutral hydrogen in the universe, which can be used to constrain primordial non-Gaussianity and test Einstein's theory of gravity. Foreground contamination is a challenge, but joint analysis does not severely degrade constraints and can help measure the macroscopical properties of foregrounds accurately.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Cheng-Zong Ruan, Carolina Cuesta-Lazaro, Alexander Eggemeier, Cesar Hernandez-Aguayo, Carlton M. Baugh, Baojiu Li, Francisco Prada
Summary: The upcoming generation of galaxy surveys will allow us to test cosmological models with higher precision. To achieve this, more accurate theoretical predictions are needed. In this study, we investigate the validity of the Skew-T (ST) probability distribution function (PDF) of halo pairwise peculiar velocities in modified gravity cosmologies to improve small-scale predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Andrew Repp, Istvan Szapudi
Summary: Indicator functions are used to identify density regions and characterize clustering density dependence; their power spectra are biased versions of linear spectra, aiding in non-linearity excision; indicator-function spectra can calculate theoretical covariance matrices for CIC, facilitating parameter estimation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Didam G. A. Duniya, Mazuba Kumwenda
Summary: The next generation of cosmological surveys will provide unprecedented precision and allow for the most stringent tests of theoretical ideas. To fully utilize these measurements, effective analytical tools and the best cosmological observables must be identified.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Suvodip Mukherjee, Joseph Silk
Summary: Distinguishing astrophysical black holes from primordial black holes can be achieved through the redshift evolution of their respective merger rates. By using the stochastic gravitational wave background for a joint estimation, it is possible to differentiate between these two populations. The latest constraints on black hole merger rates provide insights for future detector sensitivities in distinguishing between astrophysical and primordial black holes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Cristina Cigarran Diaz, Suvodip Mukherjee
Summary: This study explores the synergy between the LVK detectors and spectroscopic galaxy surveys such as DESI and SPHEREx to measure cosmological parameters related to the cosmic expansion history and GW bias parameters. By analyzing the 3D spatial cross-correlation between dark GW sources and spectroscopic galaxy samples, precise measurements of the Hubble constant and dark energy equation of state can be obtained. The combination of Euclid with DESI and SPHEREx shows potential for marginal gains in measuring cosmological parameters, particularly at high redshifts.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jianming Zhang, Qiyue Qian, Yiqing Guo, Xin Wang, Xiao-Dong Li
Summary: The study investigates the role of gravitational waves in the heat death of the Universe, finding that they lead to energy dissipation in dynamical systems, transitioning to a state of rest and death. Energy loss due to gravitational wave emission in dark matter systems is estimated through N-body simulations, though the analysis may be invalidated by multiple unknown factors.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Andrew Repp, Istvan Szapudi
Summary: Researchers have discovered that correlations between specific 'slices' of the density field determine the variance and covariance of CIC probabilities. Explicit formulas have been derived to accurately predict the variance and covariance among subvolumes of a simulated galaxy catalogue, enabling the use of CIC measurements for cosmological parameter estimation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
D. Herman, R. A. Watson, K. J. Andersen, R. Aurlien, R. Banerji, M. Bersanelli, S. Bertocco, M. Brilenkov, M. Carbone, L. P. L. Colombo, H. K. Eriksen, M. K. Foss, C. Franceschet, U. Fuskeland, S. Galeotta, M. Galloway, S. Gerakakis, E. Gjerlow, B. Hensley, M. Iacobellis, M. Ieronymaki, H. T. Ihle, J. B. Jewell, A. Karakci, E. Keihanen, R. Keskitalo, G. Maggio, D. Maino, M. Maris, A. Mennella, S. Paradiso, B. Partridge, M. Reinecke, A. -S. Suur-Uski, T. L. Svalheim, D. Tavagnacco, H. Thommesen, D. J. Watts, I. K. Wehus, A. Zacchei
Summary: This study describes a method for correcting the differential non-linearities (DNL) of Analog-to-Digital Converters (ADCs) in the BEYONDPLANCK analysis framework, which is similar to the method used in the official Planck Low Frequency Instrument (LFI) Data Processing Center (DPC) analysis. The method relies on the binned rms noise profile of each detector data stream and applies correction only to samples significantly affected by ADC DNLs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Physics, Particles & Fields
Thais Lemos, Ruchika, Joel C. Carvalho, Jailson Alcaniz
Summary: Measurements of the characteristic length scale rs of baryon acoustic oscillations (BAO) provide a reliable determination of the distance-redshift relation. The best estimate of rs at the drag epoch is currently provided by Cosmic Microwave Background (CMB) observations assuming the validity of the standard ?CDM model. Inferring rs from low-z observations and comparing it with CMB estimates allows for a consistency test of the standard cosmology. This study combines angular BAO measurements and type Ia Supernovae data to estimate the absolute BAO scale and finds good agreement between low-z estimates of rs and the CMB sound horizon at drag epoch.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
N. Miranda, J. C. Freytag, J. Nordin, R. Biswas, V Brinnel, C. Fremling, M. Kowalski, A. Mahabal, S. Reusch, J. van Santen
Summary: This paper presents SNGuess, a model designed to identify young extragalactic nearby transients with high accuracy. By calculating features from astronomical alert data, SNGuess provides suggestions for follow-up observations. It is a lightweight and easily re-trainable model that can assist in optimizing observation strategies and selecting candidate transients.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Sebastian Najera, Aldo Gamboa, Alejandro Aguilar-Nieto, Celia Escamilla-Rivera
Summary: The authors argue for a thorough revision of the negative mass cosmology (NMC) model as it requires fine-tuning of physical predictions to be compatible with current cosmological surveys, obscuring its original motivation. A more rigorous theoretical treatment is deemed necessary to make the NMC a viable cosmological model.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
W. R. Arcus, J-P Macquart, M. W. Sammons, C. W. James, R. D. Ekers
Summary: The study compared the dispersion measure statistics of FRBs detected by ASKAP and Parkes telescopes, finding similar patterns in their data. By modeling the DM distribution and fitting the population parameters, conclusions about the spectral index and burst energy distribution were drawn, revealing the impact of redshift evolutionary models on the parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Andrew Pontzen, Martin P. Rey, Corentin Cadiou, Oscar Agertz, Romain Teyssier, Justin Read, Matthew D. A. Orkney
Summary: A new method is introduced to reduce numerical diffusion in adaptive mesh refinement (AMR) simulations of cosmological galaxy formation, with particular focus on dwarf galaxies. By using genetic modification to create 'velocity-zeroed' initial conditions, it suppresses grid-relative streaming without significantly altering large-scale structure or dark matter accretion history. The resulting simulation shows a more physical onset of star formation, especially recommended for small galaxies at high redshifts.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
David Benisty
Summary: By implementing the timing argument, the study suggests the possibility of a past encounter between M31 and the Milky Way, but rules it out due to the predicted mass of the Local Group being too large, indicating that such an encounter is not possible for the LG system.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Jia-Rui Niu, Wei-Wei Zhu, Bing Zhang, Mao Yuan, De-Jiang Zhou, Yong-Kun Zhang, Jin-Chen Jiang, J. L. Han, Di Li, Ke-Jia Lee, Pei Wang, Yi Feng, Dong-Zi Li, Rui Luo, Fa-Yin Wang, Zi-Gao Dai, Chen-Chen Miao, Chen-Hui Niu, Heng Xu, Chun-Feng Zhang, Wei-Yang Wang, Bo-Jun Wang, Jiang-Wei Xu
Summary: The study reports the properties of more than 800 bursts from the repeating fast radio burst source FRB 20201124A, without finding credible spin periods, while questioning some theoretical scenarios. The results suggest that these bursts are unlikely to come from pulsar spin periods and identify periodicities in fine structures.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Jin-Chen Jiang, Wei-Yang Wang, Heng Xu, Jiang-Wei Xu, Chun-Feng Zhang, Bo-Jun Wang, De-Jiang Zhou, Yong-Kun Zhang, Jia-Rui Niu, Ke-Jia Lee, Bing Zhang, Jin-Lin Han, Di Li, Wei-Wei Zhu, Zi-Gao Dai, Yi Feng, Wei-Cong Jing, Dong-Zi Li, Rui Luo, Chen-Chen Miao, Chen-Hui Niu, Chao-Wei Tsai, Fa-Yin Wang, Pei Wang, Ren-Xin Xu, Yuan-Pei Yang, Zong-Lin Yang, Ju-Mei Yao, Mao Yuan
Summary: In this study, we report the statistical properties of radio bursts from the repeating FRB source FRB 20201124A. We found that the RM values of the bursts varied within a small range during the observation period, and the bursts exhibited high degrees of polarization with certain variations in polarization angles.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2022)
Article
Multidisciplinary Sciences
F. Y. Wang, G. Q. Zhang, Z. G. Dai, K. S. Cheng
Summary: Fast radio bursts (FRBs) are cosmic sources emitting millisecond-duration radio bursts, and their physical nature and central engine are still unclear. Recent observations on FRB 20201124A show a significant variation in rotation measure on a daily timescale. Researchers propose a physical model that explains these observations, suggesting that the repeating signal comes from a binary system containing a magnetar and a Be star.
NATURE COMMUNICATIONS
(2022)
Article
Astronomy & Astrophysics
Z. Y. Zhao, G. Q. Zhang, F. Y. Wang, Z. G. Dai
Summary: Recent observations have found that some repeating fast radio bursts (FRBs) exhibit complex variations and reversals in Faraday rotation measures (RMs), suggesting they originate from magnetized environments. One possible explanation is that pulsars in binary systems, particularly those with high-mass companions and strong stellar outflows, generate these repeating FRBs. In this study, the researchers investigate the RM variations caused by stellar winds and a potential stellar disk, suggesting that by monitoring long-term RM changes, the environments of repeating FRBs can be revealed.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
K. B. Yang, Q. Wu, F. Y. Wang
Summary: This study measures the baryon content of the universe using fast radio bursts (FRBs) and finds that baryons are not missing, but residing in the intergalactic medium (IGM).
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Physics, Multidisciplinary
Bo-Jun Wang, Heng Xu, Jin-Chen Jiang, Jiang-Wei Xu, Jia-Rui Niu, Ping Chen, Ke-Jia Lee, Bing Zhang, Wei-Wei Zhu, Su-Bo Dong, Chun-Feng Zhang, Hai Fu, De-Jiang Zhou, Yong-Kun Zhang, Pei Wang, Yi Feng, Ye Li, Dong-Zi Li, Wen-Bin Lu, Yuan-Pei Yang, R. N. Caballero, Ce Cai, Mao-Zheng Chen, Zi-Gao Dai, A. Esamdin, Heng-Qian Gan, Jin-Lin Han, Long-Fei Hao, Yu-Xiang Huang, Peng Jiang, Cheng-Kui Li, Di Li, Hui Li, Xin-Qiao Li, Zhi-Xuan Li, Zhi-Yong Liu, Rui Luo, Yun-Peng Men, Chen-Hui Niu, Wen-Xi Peng, Lei Qian, Li-Ming Song, Jing-Hai Sun, Fa-Yin Wang, Min Wang, Na Wang, Wei-Yang Wang, Xue-Feng Wu, Shuo Xiao, Shao-Lin Xiong, Yong-Hua Xu, Ren-Xin Xu, Jun Yang, Xuan Yang, Rui Yao, Qi-Bin Yi, You-Ling Yue, Dong-Jun Yu, Wen-Fei Yu, Jian-Ping Yuan, Bin-Bin Zhang, Song-Bo Zhang, Shuang-Nan Zhang, Yi Zhao, Wei-Kang Zheng, Yan Zhu, Jin-Hang Zou
Summary: In this paper, a collection of 1863 burst dynamic spectra of FRB 20201124A measured with the FAST telescope is presented. This dataset represents the largest sample of pulses detected for any FRB so far.
Article
Astronomy & Astrophysics
X. D. Jia, J. P. Hu, F. Y. Wang
Summary: This study presents a novel non-parametric method to estimate the Hubble constant as a function of redshift by diagonalizing the covariance matrix. A decreasing trend in the Hubble constant is found with a significance of a 5.6 sigma confidence level using data from type Ia supernovae, baryon acoustic oscillation, and observed Hubble parameter. The Hubble constant is consistent with the local distance ladder at low redshift and drops to the value measured from the cosmic microwave background at high redshift. Our results may relieve the Hubble tension, favoring recent solutions and novel physics.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
F. Y. Wang, Q. Wu, Z. G. Dai
Summary: Research has found that the repetition pattern of FRBs shows a large range of time memory, from a few minutes to about an hour. This memory is detected through burst-rate structures and the Hurst exponent. The waiting time distribution follows an approximate power-law tail, consistent with a time-varying Poisson model. Simulations suggest that these characteristics can be explained within a self-organized criticality system driven in a correlation way, such as random walk functions. These properties indicate a correlated triggering mechanism, favoring the crustal failure mechanism of neutron stars.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Qin Wu, Zhen-Yin Zhao, Fa-Yin Wang
Summary: Recently, a physical connection between antiglitch/glitch and fast radio burst (FRB)-like bursts of the Galactic magnetar SGR J1935+2154 has been discovered. A proposed model suggests that these phenomena can be explained by an asteroid tidally captured and disrupted by the magnetar, leading to sudden changes in rotational frequency and the production of bright radio bursts. This model provides a unified explanation for the observed events.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Review
Astronomy & Astrophysics
Jian-Ping Hu, Fa-Yin Wang
Summary: The lambda CDM model fits most astronomical observations well but still contains areas of unknown phenomenology. With improved precision and number of observations, discrepancies in key cosmological parameters have emerged, particularly the significant deviation of 4 sigma to 6 sigma between the Hubble constant (H0) estimations from the local distance ladder and the cosmic microwave background (CMB) measurement. This review focuses on reevaluating the H0 tension and identifying evidence for new physics beyond the lambda CDM model, which leans towards modifications in the late-time universe.
Article
Astronomy & Astrophysics
Yong-Kun Zhang, Di Li, Bing Zhang, Shuo Cao, Yi Feng, Wei-Yang Wang, Yuanhong Qu, Jia-Rui Niu, Wei-Wei Zhu, Jin-Lin Han, Peng Jiang, Ke-Jia Lee, Dong-Zi Li, Rui Luo, Chen-Hui Niu, Chao-Wei Tsai, Pei Wang, Fa-Yin Wang, Zi-Wei Wu, Heng Xu, Yuan-Pei Yang, Jun-Shuo Zhang, De-Jiang Zhou, Yu-Hao Zhu
Summary: We report the observations of FRB 20220912A using the Five-hundred-meter Aperture Spherical radio Telescope. The observations reveal that the FRB has a steep energy distribution and complex circular polarization characteristics. The findings imply that the circular polarization mechanism of FRBs likely originates from an intrinsic radiation mechanism.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Jia-Lun Li, Yu-Peng Yang, Shuang-Xi Yi, Jian-Ping Hu, Fa-Yin Wang, Yan-Kun Qu
Summary: Gamma-ray bursts (GRBs) are energetic events that can be used to explore the high-redshift universe. We find correlations between plateau luminosity, end time of plateau, and isotropic energy release in GRB samples. These correlations can be used to constrain cosmological parameters and serve as standard candles. Using different combinations of optical and X-ray samples, we obtain different constraints for flat and non-flat Lambda CDM models.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Zhao-Yang Xia, Yuan-Pei Yang, Qiao-Chu Li, Fa-Yin Wang, Bo-Yang Liu, Zi-Gao Dai
Summary: In this paper, the authors investigate the polarization evolution of fast radio bursts (FRBs) by analyzing the Faraday conversion (FC) effect in a binary system involving an FRB source. They find that the radial magnetic field of a strongly magnetized high-mass companion star can induce circular polarization (CP) in an FRB, with the degree of CP oscillating symmetrically around the zero point. The authors also observe significant polarization variations near the superior conjunction of the binary orbit and explore the effect of the rotation of the companion star.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Rui-Nan Li, Zhen-Yin Zhao, Zhifu Gao, Fa-Yin Wang
Summary: Recent observations have found complex variations in repeating fast radio bursts (FRBs), which are related to binary systems containing supermassive black holes and neutron stars. These systems produce low-frequency gravitational-wave signals that can be used to detect FRBs and serve as independent cosmological probes.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Xiao Tian, Jia-Lun Li, Shuang-Xi Yi, Yu-Peng Yang, Jian-Ping Hu, Yan-Kun Qu, Fa-Yin Wang
Summary: This paper investigates the plateau phase in radio afterglows of gamma-ray bursts (GRBs) and explores the correlations between various parameters of the radio plateaus. The study finds that radio plateaus may have a different physical mechanism compared to X-ray and optical plateaus. The research also demonstrates the potential of using GRBs as standard candles to constrain cosmological parameters when combined with other probes.
ASTROPHYSICAL JOURNAL
(2023)
