Article
Astronomy & Astrophysics
S. Dhawan, E. Morstell
Summary: The nature of dark matter and the possibility of it being comprised of primordial black holes are investigated using Type Ia supernovae. The fraction of dark matter in compact objects is constrained to be below 0.50 at 95% confidence level, demonstrating robustness to different cosmological models. With a prior assumption on the homogeneity parameter, it is found that the fraction of dark matter in primordial black holes is less than 0.32 at 95% confidence level. The study concludes that stellar mass primordial black holes cannot account for all of the observed dark matter.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Heinrich Steigerwald, Davi Rodrigues, Stefano Profumo, Valerio Marra
Summary: Residuals in the Hubble diagram at optical wavelengths and host galaxy stellar mass in SNe Ia are observed to correlate. Progenitor channels based on dark matter, including the proposal of triggering 'normal' SNe Ia with asteroid-mass PBHs, have attracted attention. A method to estimate the local DM density and velocity dispersion is presented, and a luminosity step is found in SN Ia progenitors based on high versus low DM density.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rajendra P. Gupta
Summary: Ia supernovae are used as standard candles in cosmology, and their luminosity is found to depend on their distance when physical constants are allowed to evolve. Results suggest that SNeIa luminosities could have been much higher in the past, potentially leading to significant discrepancies in distance estimations for early supernovae. Variations in constants are given, showing that they can only vary concurrently rather than individually.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
C. Meldorf, A. Palmese, D. Brout, R. Chen, D. Scolnic, L. Kelsey, L. Galbany, W. G. Hartley, T. M. Davis, A. Drlica-Wagner, M. Vincenzi, J. Annis, M. Dixon, O. Graur, C. Lidman, A. Moller, P. Nugent, B. Rose, M. Smith, S. Allam, D. L. Tucker, J. Asorey, J. Calcino, D. Carollo, K. Glazebrook, G. F. Lewis, G. Taylor, B. E. Tucker, A. G. Kim, H. T. Diehl, M. Aguena, F. Andrade-Oliveira, D. Bacon, E. Bertin, S. Bocquet, D. Brooks, D. L. Burke, J. Carretero, M. Carrasco Kind, F. J. Castander, M. Costanzi, L. N. da Costa, S. Desai, P. Doel, S. Everett, I Ferrero, D. Friedel, J. Frieman, J. Garcia-Bellido, M. Gatti, D. Gruen, J. Gschwend, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. J. James, K. Kuehn, M. March, J. L. Marshall, F. Menanteau, R. Miquel, R. Morgan, F. Paz-Chinchon, M. E. S. Pereira, A. A. Plazas Malagon, E. Sanchez, V Scarpine, I Sevilla-Noarbe, E. Suchyta, G. Tarle, T. N. Varga
Summary: Cosmological analyses with type Ia supernovae often overlook the varying dust properties in host galaxies, resulting in inaccurate conclusions. In this study, we use advanced modeling to characterize the dust parameters of 1100 Dark Energy Survey SN host galaxies and find that host dust has important impacts on SN cosmology, including a wide range of dust law slope R-V, lower R-V in high-stellar mass hosts compared to low-mass hosts, and a significant correlation between the Hubble diagram residuals of red SNe Ia and host R-V. These findings confirm recent predictions based on dust and provide insights into the "mass step" and intrinsic scatter in SN Ia analyses.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
G. Taylor, C. Lidman, B. E. Tucker, D. Brout, S. R. Hinton, R. Kessler
Summary: This study presents a revised Spectral Adaptive Light Curve Template (SALT2-2021) for fitting the light curves of Type Ia supernovae (SNe Ia), which introduces significant changes in the UV region and alters the distance measurements of SNe Ia. By applying the revised SALT2 surface to public data and cosmic microwave background constraints, a change in the dark energy equation-of-state parameter is found, emphasizing the importance of controlling and reducing systematic uncertainties for future supernova analyses.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Lluis Galbany, Mat Smith, Salvador Duarte Puertas, Santiago Gonzalez-Gaitan, Ismael Pessa, Masao Sako, Jorge Iglesias-Paramo, A. R. Lopez-Sanchez, Mercedes Molla, Jose M. Vilchez
Summary: We used data from the Sloan Digital Sky Survey-II Supernova Survey and SDSS DR16 fiber spectroscopy to investigate the correlation between type Ia supernova light-curve parameters and Hubble residuals with host galaxy properties. We found that fixed-aperture fiber spectroscopy suffers from aperture effects, which can be corrected using integral field spectroscopy. Our study provides insights into the relationship between supernovae and their host galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Yan-Hong Yao, Xin-He Meng
Summary: This paper investigates the impact of backreaction effects in the spatially averaged inhomogeneous Universe and proposes new effective sources for backreaction effects, namely the effective perfect fluid energy density and pressure. The backreaction models are fitted using two metrics, the Friedmann-Lemaitre-Robertson-Walker metric and a template metric with an evolving curvature parameter. The results show that there are significant parameter tensions between different data sets, indicating a need for modifications in the treatment of the geometrical instantaneous spatially-constant curvature.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
Bikash R. Dinda, Narayan Banerjee
Summary: We applied a model-independent and nonparametric approach based on Gaussian process regression to constrain the peak absolute magnitude, M-B, of type Ia supernovae using the Pantheon sample and cosmic chronometer data. Our analysis yielded percent level bounds on M-B as M-B = -19.384 +/- 0.052. Including baryon acoustic oscillation data and the prior of comoving sound horizon from Planck 2018 CMB observations resulted in tighter constraints at the subpercent level. Combining Pantheon compilation, baryon acoustic oscillation observations, and cosmic chronometer observations, we obtained consistent values for M-B around -19.4.
Article
Physics, Multidisciplinary
Junchao Wang, Zhiqi Huang, Lu Huang
Summary: Much of the research in supernova cosmology is based on the assumption that the peak luminosity of type Ia supernovae (SNe Ia) is independent of the galactic environment. Recent studies suggest a significant correlation between standardized luminosity and the progenitor age of SNe Ia, casting doubt on the direct evidence of cosmic acceleration. This study incorporates the uncertainties of progenitor ages into a Bayesian inference framework and finds a weaker dependence of supernova standardized luminosity on the progenitor age, but the correlation remains significant. The research confirms that the bias in progenitor age could be the primary cause of the observed extra dimming of distant SNe Ia when intrinsic scatter is not included in the analysis. Model comparison using the PAge formalism suggests that the ΛCDM model remains a good fit when intrinsic scatter is included, but faces challenges without it.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Astronomy & Astrophysics
Alice G. Stone, Heather T. Johnson, John M. Blondin, Richard A. Watson, Kazimierz J. Borkowski, Carla Frohlich, Ivo R. Seitenzahl, Stephen P. Reynolds
Summary: The youngest Galactic supernova remnant, G1.9+0.3, exhibits highly asymmetric features, suggesting an asymmetric explosion. Simulation studies show that in the 2D model at the age of G1.9+0.3, almost no iron is observed, while in the 3D model some characteristics resemble those of G1.9+0.3.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
James D. Keegans, Marco Pignatari, Richard J. Stancliffe, Claudia Travaglio, Samuel Jones, Brad K. Gibson, Dean M. Townsley, Broxton J. Miles, Ken J. Shen, Gareth Few
Summary: In this study, complete abundance yields for 39 models of Type Ia supernova explosions were calculated based on three progenitors and 13 metallicities. The results show that the understanding of nucleosynthesis in Type Ia supernovae is influenced by different progenitor masses and compositions. The reliability of the results is further confirmed by comparing them with relevant models from previous literature.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
L. Kelsey, M. Sullivan, P. Wiseman, P. Armstrong, R. Chen, D. Brout, T. M. Davis, M. Dixon, C. Frohmaier, L. Galbany, O. Graur, R. Kessler, C. Lidman, A. Moeller, B. Popovic, B. Rose, D. Scolnic, M. Smith, M. Vincenzi, T. M. C. Abbott, M. Aguena, S. Allam, O. Alves, J. Annis, D. Bacon, E. Bertin, S. Bocquet, D. Brooks, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, M. Costanzi, L. N. da Costa, M. E. S. Pereira, S. Desai, H. T. Diehl, S. Everett, I. Ferrero, J. Frieman, J. Garcia-Bellido, D. Gruen, R. A. Gruendl, J. Gschwend, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. J. James, K. Kuehn, N. Kuropatkin, G. F. Lewis, J. Mena-Fernandez, R. Miquel, A. Palmese, F. Paz-Chinchon, A. Pieres, A. A. Plazas Malagon, M. Raveri, M. Rodriguez-Monroy, A. K. Romer, E. Sanchez, V. Scarpine, M. Schubnell, I. Sevilla-Noarbe, E. Suchyta, M. E. C. Swanson, G. Tarle, D. L. Tucker, N. Weaverdyck
Summary: Recent analyses have found correlations between the color of type Ia supernovae and their mass-step size, as well as the relationship between SN Ia host galaxy stellar mass and SN Ia Hubble residual. The study suggests that different colored SNe show differences in their Hubble residual, with blue SNe in low mass/blue environments exhibiting the lowest scatter.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. M. Diego, G. Bernstein, W. Chen, A. Goobar, J. P. Johansson, P. L. Kelly, E. Mortsell, J. W. Nightingale
Summary: The observed magnifications and light curves of the quadruply imaged iPTF16geu supernova provide valuable insights into the lens system and suggest the need for contributions from microlensing structures. By combining macro and micro lens models, we find that higher stellar surface mass densities are preferred and conclude that microlensing from the baryonic component is sufficient to explain the observed flux ratios and light curves.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Young-Wook Lee, Chul Chung, Pierre Demarque, Seunghyun Park, Junhyuk Son, Yijung Kang
Summary: Recent studies have found significant correlations between progenitor age and Hubble residual in supernova cosmology, suggesting a strong dependence of supernova luminosity standardization on progenitor age. This systematic bias with redshift may challenge the current understanding of an accelerating universe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Anirban Dutta, Avinash Singh, G. C. Anupama, D. K. Sahu, Brajesh Kumar
Summary: The study examines the optical and ultraviolet properties of Type Ia supernova SN 2017hpa, finding that it falls within the normal range for this type of supernova. Spectroscopic analysis reveals unique features in the evolution of SIII and CII absorption lines, providing insights into the composition and velocity gradients in the supernova ejecta.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yu-Peng Chen, Shu Zhang, Long Ji, Shuang-Nan Zhang, Peng-Ju Wang, Ling-Da Kong, Zhi Chang, Jing-Qiang Peng, Qing-Cang Shui, Jian Li, Zhao-Sheng Li, Lian Tao, Ming-Yu Ge, Jin-Lu Qu
Summary: After 49 years of quiescence, 4U 1730-22 became active and had two outbursts in 2021 and 2022; 10 thermonuclear X-ray bursts were detected with Insight-HXMT. Among them, the faintest burst showed a double-peaked profile, placing the source as the seventh accreting neutron star (NS) exhibiting double-peaked type I X-ray bursts; the other bursts showed photospheric radius expansion (PRE). The properties of a double-peaked non-PRE burst indicate that it could be related to a stalled burning front. For the five bright PRE bursts, apart from the emission from the neutron star (NS) surface, we find the residuals both in the soft (<3 keV) and hard (>10 keV) X-ray bands. Time-resolved spectroscopy reveals that the excess can be attributed to an enhanced preburst/persistent emission or the Comptonization of the burst emission by the corona. We find, the burst emission shows a rise until the photosphere touches down to the NS surface rather than the theoretical predicted constant Eddington luminosity. The shortage of the burst emission in the early rising phase is beyond the occlusion by the disk. We speculate that the findings above are due to that the obscured part (not only the lower part) of the NS surface is exposed to the line of sight due to the evaporation of the obscured material by the burst emission, or the burst emission is anisotropic (xi > 1) in the burst early phase. In addition, based on the fluxes of PRE bursts at their touchdown times, we derive a distance estimation as 9.0-12.4 kpc.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Yu-Peng Chen, Shu Zhang, Shuang-Nan Zhang, Long Ji, Peng-Ju Wang, Ling-Da Kong, Zhi Chang, Jing-Qiang Peng, Qing-Cang Shui, Jian Li, Lian Tao, Ming-Yu Ge, Jin-Lu Qu
Summary: 4U 1730-22 had two outbursts in 2021 and 2022 after 49 years of quiescence. NICER observed the onset and tail of the outbursts, providing an excellent opportunity to study the state transition and its underlying mechanism. The research found that the accretion disk is close to the neutron star surface in the high/soft state, and a steep change in the accretion disk emission within 1 day, known as the soft-to-hard transition, may be due to the propeller effect.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Wang-Chen Xue, Xiao-Bo Li, Shao-Lin Xiong, Yong Chen, Shuang-Nan Zhang, Li-Ming Song, Shu Zhang, Ming-Yu Ge, You-Li Tuo, Hai-Tao Li, Dao-Chun Yu, Dong-Ya Guo, Jia-Cong Liu, Yan-Qiu Zhang, Chao Zheng
Summary: The Earth occultation technique is used to construct a background model of the Crab Nebula observed by Insight-HXMT. A Bayesian atmospheric density retrieval method is proposed, which combines Poisson and Gaussian statistics. By modeling the attenuation of X-ray photons during the occultation, the neutral densities of the atmosphere at different altitude ranges are simultaneously retrieved. This method reduces potential systematic bias and maximizes the use of occultation data, resulting in improved density measurements and cross-checking of atmospheric models.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Honghui Liu, Cosimo Bambi, Jiachen Jiang, Javier A. Garcia, Long Ji, Lingda Kong, Xiaoqin Ren, Shu Zhang, Shuangnan Zhang
Summary: We analyze the relativistic reflection spectra of GX 339-4 during its 2021 outburst and find strong relativistic reflection signatures indicating a high black hole spin and an intermediate disk inclination angle. The hard-to-soft transition is accompanied by an increasing disk temperature and a softening corona emission, while the inner disk radius remains stable. The corona height, assuming a lamppost geometry, stays close to the black hole across the state transition. Including Comptonization, the scattering fraction parameter decreases during the transition. Our analysis with a reflection model designed for hot accretion disks supports the scenario of corona property variations during the state transition.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Qing C. Shui, S. Zhang, Yu P. Chen, Shuang N. Zhang, Ling D. Kong, Peng J. Wang, L. Ji, Hong X. Yin, Jin L. Qu, L. Tao, Ming Y. Ge, Jing Q. Peng, Z. Chang, J. Li, P. Zhang
Summary: We systematically analyzed the QPO observations of H1743-322 and found consistent positive correlations between the QPO fractional rms amplitude and nonthermal fraction of the emission, independent of the outburst brightness. However, the QPO rms dependence on frequency and the coronal temperature range differed between the outburst rise and decay phases. The findings suggest a possible connection between the QPO rms differences, hysteresis traces, and corona-jet transitions in H1743-322.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
X. Ma, L. Zhang, L. Tao, Q. C. Bu, J. L. Qu, S. N. Zhang, D. K. Zhou, Y. Huang, S. M. Jia, L. M. Song, S. Zhang, M. Y. Ge, H. X. Liu, Z. X. Yang, W. Yu, E. S. Yorgancioglu
Summary: We present the X-ray timing results of MAXI J1820+070 during its 2018 outburst using Insight-HXMT and NICER observations. LFQPOs are detected in the low/hard state and the hard intermediate state, with an approximately 90-day duration. Our results show the energy dependence of LFQPO characteristics and phase lags, providing new insights into the origin of the radiation from different regions of the accretion disk and the relativistic jet.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Xi-Hong Luo, Shuo Xiao, Shi-Jie Zheng, Ming-Yu Ge, You-Li Tuo, Shao-Lin Xiong, Shuang-Nan Zhang, Fang-Jun Lu, Yue Huang, Cheng Yang, Qi-Jun Zhi, Li-Ming Song, Wen-Xi Peng, Xiang-Yang Wen, Xin-Qiao Li, Zheng-Hua An, Jin Wang, Ping Wang, Ce Cai, Cheng-Kui Li, Xiao-Bo Li, Fan Zhang, Ai-Jun Dong, Wei Xie, Jian-Chao Feng, Qing-Bo Ma, Hua Wang De, Lun-Hua Shang, Xin Xu, Meng-Xuan Zhang, Zi-Ping Dong, Shi-Jun Dang
Summary: The determination of absolute and relative spacecraft position is crucial for various purposes including operation, observations, data analysis, scientific studies, and deep-space exploration. This study presents a navigation accuracy of approximately 20 km using 16-day Crab pulsar data observed with Fermi's Gamma-ray Burst Monitor. Additionally, a new method for joint navigation using repeated bursts from magnetar SGR J1935+2154 observed by the Gravitational-wave High-energy Electromagnetic Counterpart All-sky Monitor and GBM is proposed.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Chen Wang, Jin-Yuan Liao, Ju Guan, Yuan Liu, Cheng-Kui Li, Na Sai, Qi Luo, Jing Jin, Yi Nang, Shuang-Nan Zhang
Summary: The first X-ray source catalog of the Insight-HXMT Galactic Plane Scanning Survey (GPSS) with a sky coverage of b <10 degrees is presented. The catalog includes more than 1300 sources monitored in the 1-100 keV energy band, with 223 sources having a signal-to-noise ratio greater than 5. Flux variabilities and hardness ratios of different source types, such as X-ray binaries and supernova remnants, are analyzed. The results show that X-ray binaries exhibit higher activity and harder spectra compared to other source types.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Engineering, Aerospace
Yidi Wang, Shuangnan Zhang, Minyu Ge, Wei Zheng, Xiaoqian Chen, Shijie Zheng, Fangju Lu
Summary: The recent flight experiments with NICER and Insight-HXMT have shown the feasibility of XNAV in space. However, the current methods employed in these experiments are computationally expensive for handling Crab pulsar data. To solve this problem, a fast algorithm called XTITAN is proposed for on-orbit estimating the pulse phase of Crab pulsar. XTITAN is significantly faster than the methods used in the flight experiments, making it computationally efficient and suitable for onboard computation.
IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
(2023)
Article
Instruments & Instrumentation
Qinyu Wu, Zhixing Ling, Chen Zhang, Quan Zhou, Xinyang Wang, Weimin Yuan, Shuang-Nan Zhang
Summary: In recent years, scientific CMOS (sCMOS) sensors have outperformed CCDs in several aspects: higher readout frame rate, higher radiation tolerance, and higher working temperature. A new method is introduced to measure the image lag of a sCMOS sensor under low-light illumination by extracting the image lag from X-ray photons. The results show that the image lag of the sensor is small and has no significant impact on the imaging quality and energy resolution.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2023)
Article
Astronomy & Astrophysics
Wei Yu, Qing-Cui Bu, Zi-Xu Yang, He-Xin Liu, Liang Zhang, Yue Huang, Deng-Ke Zhou, Jin-Lu Qu, Shuang-Nan Zhang, Shu Zhang, Li-Ming Song, Shu-Mei Jia, Xiang Ma, Lian Tao, Ming-Yu Ge, Qing-Zhong Liu, Jing-Zhi Yan
Summary: This paper presents a time-frequency analysis of the low-frequency quasiperiodic oscillations observed in the black hole X-ray binary MAXI J1820+070, using the Hilbert-Huang transform. The study decomposes the light curve of the quasiperiodic oscillation component and measures its phase lag and broadband noise. The results suggest a physical origin involving the internal shock model of the jet.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Yuan Feng, Ye-Fei Yuan, Shuang-Nan Zhang
Summary: The iron fluorescence emission lines from X-ray binaries and active galactic nuclei are important for studying the physical processes near the event horizon of stellar-mass black holes and supermassive black holes. This study investigated the line profile of relativistic broad iron lines from the cool accretion disk of a black hole due to asymmetric illumination from a moving corona. The results showed that the illumination and line profile depend on the position and velocity of the corona, with the flux received by the disk region below the corona being the most important factor affecting the line profiles.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
M. Y. Ge, C. Z. Liu, S. N. Zhang, F. J. Lu, Z. Zhang, Z. Chang, Y. L. Tuo, X. B. Li, C. K. Li, S. L. Xiong, C. Cai, X. F. Li, R. Zhang, Z. G. Dai, J. L. Qu, L. M. Song, S. Zhang, L. J. Wang
Summary: A double-peak X-ray burst from the Galactic magnetar SGR J1935+2154 was found to be associated with the two radio pulses of FRB 200428 separated by 28.97±0.02 ms. Precise measurements of the timing and spectral properties of the X-ray bursts are crucial for understanding the physical origin of fast radio bursts.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Qing C. Shui, S. Zhang, Shuang N. Zhang, Yu P. Chen, Ling D. Kong, Peng J. Wang, Jing Q. Peng, L. Ji, A. Santangelo, Hong X. Yin, Jin L. Qu, L. Tao, Ming Y. Ge, Y. Huang, L. Zhang, Hong H. Liu, P. Zhang, W. Yu, Z. Chang, J. Li, Wen T. Ye, Pan P. Li, Zhuo L. Yu, Z. Yan
Summary: In this study, phase-resolved spectroscopy is used to investigate LFQPOs in MAXI J1820+070 during its 2018 outburst. The study reveals that the phase difference between QPO harmonics exhibits time variability, and strong concurrent modulations of the spectral index and flux are observed during the bright hard state. Significant modulations in the reflection fraction are also detected during the later stages of the bright hard state.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Shuo Xiao, Jiao-Jiao Yang, Xi-Hong Luo, Shao-Lin Xiong, Yuan-Hong Qu, Shuang-Nan Zhang, Wang-Chen Xue, Xiao-Bo Li, You-Li Tuo, Ai-Jun Dong, Ru-Shuang Zhao, Shi-Jun Dang, Lun-Hua Shang, Qing-Bo Ma, Ce Cai, Jin Wang, Ping Wang, Cheng-Kui Li, Shu-Xu Yi, Zhen Zhang, Ming-Yu Ge, Shi-Jie Zheng, Li-Ming Song, Wen-Xi Peng, Xiang-Yang Wen, Xin-Qiao Li, Zheng-Hua An, Xin Xu, Yue Wang, Chao Zheng, Yan-Qiu Zhang, Jia-Cong Liu, Bin Zhang, Wei Xie, Jian-Chao Feng, De-Hua Wang, Qi-Jun Zhi
Summary: In this work, the minimum variation timescale (MVT) of X-ray bursts from SGR J1935+2154 is systematically studied. The MVTs peak at about 2 ms, supporting the magnetospheric origin in pulsar-like models. The shock radius and Lorentz factor of the jet in GRB-like models are also constrained. The MVT of the XRB associated with FRB 200428 is longer than most bursts, indicating a special radiation mechanism.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)