Monthly Notices of the Royal Astronomical Society: Letters最新文献_第4页

Gas Phase Ions in Protoplanetary Disks from Collisions of Solids 原行星盘中来自固体碰撞的气相离子

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2024-01-09 DOI: 10.1093/mnrasl/slae004

Jakob Penner, G. Wurm, J. Teiser

引用次数: 0

The jet composition of GRB 230307A: Poynting-flux-dominated outflow? GRB 230307A 的喷流成分：以 Poynting 流量为主的外流？

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2024-01-02 DOI: 10.1093/mnrasl/slad203

Zhao-Wei Du, HouJun Lü, Xiaoxuan Liu, EnWei Liang

{"title":"The jet composition of GRB 230307A: Poynting-flux-dominated outflow?","authors":"Zhao-Wei Du, HouJun Lü, Xiaoxuan Liu, EnWei Liang","doi":"10.1093/mnrasl/slad203","DOIUrl":"https://doi.org/10.1093/mnrasl/slad203","url":null,"abstract":"\u0000 The jet composition of GRB plays an important role in understanding the energy dissipation and radiation mechanisms in GRB physics, but it is poorly constrained from the observational data. Recently, an interesting long-duration GRB 230307A with redshift z =0.065 has attracted great attention. The lack of detected thermal emission and mini-structure of prompt emission lightcurve of this burst suggest that the outflow is Poynting-flux-dominated and point towards the ICMART model. In this paper, we invoke two independent methods to investigate the jet composition of GRB 230307A. The high magnetization parameter (σ > 7 or ever large) forR0 = 1010 cm that is used to suppress thermal component, strongly suggests that a significant fraction of the outflow energy is likely in a Poynting flux entrained with the baryonic matter. Moreover, it is found that the radiation efficiency of this burst for typical values εe = 0.1 and εB = 0.01 can reach as high as 50% which disfavors the internal shock model, but is consistent with ICMART model. Finally, a possible unified picture to produce GRB 230307A originated from a compact star merger is also discussed.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"32 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139390380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light curve and hardness tests for millilensing in GRB 081122A, GRB 081126A, GRB 110517B, and GRB 210812A GRB 081122A、GRB 081126A、GRB 110517B和GRB 210812A中毫光的光曲线和硬度测试

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-12-29 DOI: 10.1093/mnrasl/slad202

O. Mukherjee, Robert Nemiroff

{"title":"Light curve and hardness tests for millilensing in GRB 081122A, GRB 081126A, GRB 110517B, and GRB 210812A","authors":"O. Mukherjee, Robert Nemiroff","doi":"10.1093/mnrasl/slad202","DOIUrl":"https://doi.org/10.1093/mnrasl/slad202","url":null,"abstract":"Analyses are given on four recent gravitational millilensing claims on gamma-ray bursts (GRBs): GRB 081122A, GRB 081126A, GRB 110517B, and GRB 210812A. Two tests, a light curve similarity test and a hardness similarity test, compare different temporal sections of a single GRB to see if they are statistically similar. The hardness similarity test shows that the ratio between the second and the first emission episodes in each energy channel differed from the same ratio averaged over all energy channels at above 90 per cent confidence level in GRB 081122A. Additionally, the light curve similarity test applied to GRB 081122A, GRB 081126A, and GRB 110517B separately indicated a high likelihood that the two emission episodes in each GRB were not from the same parent emission episode. This conclusion was reached with confidence levels of 4.8 sigma for GRB 081122A, 3.08 sigma for GRB 081126A, and 8.45 sigma for GRB 110517B. However, these tests did not detect a significant difference between the pulses of GRB 210812A. Consequently, our results suggest that while GRB 210812A could not be conclusively ruled out, the other three GRBs do not show clear evidence of millilensing.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"153 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139145857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Strontium-rich Ultra Metal-poor Star in the Atari Disk Component 阿塔里盘成分中的一颗富锶超贫金属星

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-12-20 DOI: 10.1093/mnrasl/slad197

M. Mardini, A. Frebel, A. Chiti

{"title":"A Strontium-rich Ultra Metal-poor Star in the Atari Disk Component","authors":"M. Mardini, A. Frebel, A. Chiti","doi":"10.1093/mnrasl/slad197","DOIUrl":"https://doi.org/10.1093/mnrasl/slad197","url":null,"abstract":"We report on the discovery of the first ultra metal-poor (UMP) star 2MASS J20500194−6613298 (J2050−6613; [Fe/H] = −4.05) selected from the Gaia BP/RP spectral catalog that belongs to the ancient Atari disk component. We obtained a high-resolution spectrum for the star with the MIKE spectrograph on the Magellan-Clay telescope. J2050−6613 displays a typical chemical abundance pattern for UMP stars, including carbon and zinc enhancements. In contrast, J2050−6613 shows extremely high [Sr/Fe] and [Sr/Ba] ratios compared to other stars in the [Fe/H] <−4.0 regime. J2050−6613 is most likely an early Population II star that formed from a gas cloud that was chemically enriched by a massive Population III hypernova (E >1052 erg). Such a Population III core-collapse hypernova could simultaneously explain the origin of the abundance pattern of light and heavy elements of 2MASS J2050−6613 if a large amount of Sr of ∼10−5 M⊙ was produced, possibly by neutrino-driven (wind) ejecta. Therefore, the abundance pattern of 2MASS J2050−6613 places important constraints on Sr-producing nucleosynthesis sources operating in the Atari progenitor at the earliest times.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"60 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139169362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Neutral Hydrogen Mass in Galaxies Estimated via Optical Spectroscopy 通过光学光谱估算的星系中性氢质量

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-12-05 DOI: 10.1093/mnrasl/slad186

D. Bizyaev

引用次数: 0

Short-lived repeating fast radio bursts from tidal disruption of white dwarfs by intermediate-mass black holes 中质量黑洞潮汐扰动白矮星产生的短寿命重复快速射电暴

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-12-05 DOI: 10.1093/mnrasl/slad187

Jing-Tong Xing, Tong Liu

引用次数: 0

Quantifying chaos and randomness in magnetar bursts 量化磁星脉冲串中的混沌和随机性

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-12-01 DOI: 10.1093/mnrasl/slad184

S. Yamasaki, E. Göğüş, T. Hashimoto

{"title":"Quantifying chaos and randomness in magnetar bursts","authors":"S. Yamasaki, E. Göğüş, T. Hashimoto","doi":"10.1093/mnrasl/slad184","DOIUrl":"https://doi.org/10.1093/mnrasl/slad184","url":null,"abstract":"\u0000 In this study, we explore the dynamical stability of magnetar bursts within the context of the chaos-randomness phase space for the first time, aiming to uncover unique behaviors compared to various astrophysical transients, including fast radio bursts (FRBs). We analyze burst energy time series data from active magnetar sources SGR J1550−5418 and SGR J1935+2154, focusing on burst arrival time and energy differences between consecutive events. We find a distinct separation in the time domain, where magnetar bursts exhibit significantly lower randomness compared to FRBs, solar flares, and earthquakes, with a slightly higher degree of chaos. In the energy domain, magnetar bursts exhibit a broad consistency with other phenomena, primarily due to the wide distribution of chaos-randomness observed across different bursts and sources. Intriguingly, contrary to expectations from the FRB-magnetar connection, the arrival time patterns of magnetar bursts in our analysis do not exhibit significant proximity to repeating FRBs in the chaos-randomness plane. This finding may challenge the hypothesis that FRBs are associated with typical magnetar bursts but indirectly supports the evidence that FRBs may primarily be linked to special magnetar bursts like peculiar X-ray bursts from SGR J1935+2154 observed simultaneously with Galactic FRB 200428.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":" 754","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138610563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the extremely low polarization in Comet C/2023 P1 (Nishimura) 关于 C/2023 P1 彗星（Nishimura）中极低的极化现象

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-11-28 DOI: 10.1093/mnrasl/slad181

M. Zheltobryukhov, E. Zubko, E. Chornaya, A. Kochergin, D. Hines, G. Videen

引用次数: 0

Chaotic Type I Migration in Turbulent Discs 湍流盘中的 I 型混沌迁移

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-11-27 DOI: 10.1093/mnrasl/slad183

Yinhao Wu, Yi-Xian Chen, Douglas N C Lin

{"title":"Chaotic Type I Migration in Turbulent Discs","authors":"Yinhao Wu, Yi-Xian Chen, Douglas N C Lin","doi":"10.1093/mnrasl/slad183","DOIUrl":"https://doi.org/10.1093/mnrasl/slad183","url":null,"abstract":"By performing global hydrodynamical simulations of accretion discs with driven turbulence models, we demonstrate that elevated levels of turbulence induce highly stochastic migration torques on low-mass companions embedded in these discs. This scenario applies to planets migrating within gravito-turbulent regions of protoplanetary discs as well as stars and black holes embedded in the outskirts of active galactic nuclei (AGN) accretion discs. When the turbulence level is low, linear Lindblad torques persists in the background of stochastic forces and its accumulative effect can still dominate over relatively long timescales. However, in the presence of very stronger turbulence, classical flow patterns around the companion embedded in the disc are disrupted, leading to significant deviations from the expectations of classical Type I migration theory over arbitrarily long timescales. Our findings suggest that the stochastic nature of turbulent migration can prevent low-mass companions from monotonically settling into universal migration traps within the traditional laminar disc framework, thus reducing the frequency of three-body interactions and hierarchical mergers compared to previously expected. We propose a scaling for the transition mass ratio from classical to chaotic migration q∝αR, where αR is the Reynolds viscosity stress parameter, which can be further tested and refined by conducting extensive simulations over the relevant parameter space.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139233541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

VLBI detection of the AE Aqr twin, LAMOST J024048.51+195226.9 VLBI探测到AE Aqr双胞胎，LAMOST J024048.51+195226.9

Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-11-22 DOI: 10.1093/mnrasl/slad178

Pengfei Jiang, Lang Cui, Xiang Liu, Bo Zhang, Yongfeng Huang, H. Cao, Tao An, Jun Yang, Fengchun Shu, Guiping Tan, J. Yuan

引用次数: 0