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GRB 210610B:The Internal and External Plateau as Evidence for the Delayed Outflow of Magnetar

Research in astronomy and astrophysics 2024年第7期24卷 170-180页

作者： Yi-Ning Wei Xiang-Gao Wang Da-Bin Lin Wei-Kang Zheng Liang-Jun Chen Sheng-Yu Yan Shuang-Xi Yi Qi Wang Zi-Min Zhou Hui-Ya Liu En-Wei Liang Guangxi Key Laboratory for Relativistic astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China GXU-NAOC Center for astrophysics and Space Sciences Nanning 530004China Department of astronomy University of CaliforniaBerkeleyCA 94720-3411USA Department of Physics and Tsinghua Center for astrophysics(THCA) Tsinghua UniversityBeijing 100084China School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China

After launching a jet,outflows of magnetar were used to account for the achromatic plateau of afterglow and the early X-ray flux plateau known as“internal plateau”.The lack of detecting magnetic dipole emission together with the energy injection feature in a single observation poses confusion until the long gamma-ray burst(GRB)210610B is *** 210610B is presented with an optical bump following an early X-ray plateau during the afterglow *** plateau followed by a steep decline flux overlays in the steadily decaying X-ray flux with indexα_(X,1)~2.06,indicating an internal origin and that can be fitted by the spin-down luminosity law with the initial plateau luminosity log_(10)L_(X)~48.29 erg s~(-1)and the characteristic spin-down timescale T~2818 s.A subsequent bump begins at~4000 s in the R band with a rising indexα_(R,1)~-0.30 and peaks at~14125 s,after which a decay indexα_(R,2)~0.87 and finally transiting to a steep decay withα_(R,3)~1.77 achieve the closure relation of the external shock for the normal decay phase as well as the magnetar spin-down energy injection phase,provided that the average value of the photon indexΓ_γ=1.80 derived from the spectral energy distributions(SEDs)between the X-ray and optical *** closure relation also works for the late X-ray *** to the traditional picture of GRB,the outflow powers the early X-ray plateau by dissipating energy internally and collides with the leading decelerating blast burst as time goes on,which could interpret the exotic feature of GRB *** carry out a Markov Chain Monte Carlo simulation and obtain a set of best parameters:■.The artificial light curve can fit the afterglow data *** that,we estimated the average Lorentz factor and the X-ray radiation efficiency of the later ejecta are 35%and 0.13%,respectively.

关键词： (stars)gamma-ray burst individual(GRB 210610B)-(stars)gamma-ray burst general-stars jets

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2.5-dimensional solution of the advective accretion disk:a self-similar approach

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Chinese Journal of astronomy and astrophysics 2009年第2期9卷 157-167页

作者： Shubhrangshu Ghosh Banibrata Mukhopadhyay Indian Institute of astrophysics Koramangala astronomy and astrophysics programme Department of Physics Indian Institute of Science

We provide a 2.5-dimensional solution to a complete set of viscous hydrodynamical equations describing accretion-induced outflows and plausible jets around black holes/compact objects. We prescribe a self-consistent advective disk-outflow coupling model, which explicitly includes the information of vertical flux. Inter-connecting dynamics of an inflow-outflow system essentially upholds the conservation laws. We provide a set of analytical family of solutions through a self-similar approach. The flow parameters of the disk-outflow system depend strongly on the viscosity parameter α and the cooling factor f.

关键词： accretion -- accretion disk -- black hole physics -- hydrodynamics --galaxies jets

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Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

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Research in astronomy and astrophysics 2016年第4期16卷 7-14页

作者： Debbijoy Bhattacharya Parameswaran Sreekumar Banibrata Mukhopadhyay Ishan Tomar Manipal Centre for Natural Sciences Manipal UniversityManipal 576104India Indian Institute of astrophysics Bangalore 560034India astronomy and astrophysics programme Department of PhysicsIndian Institute of ScienceBangalore 560012India Space astronomy Group ISRO Satellite CentreKarthik NagarBangalore 560037India

Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes： fiat spectrum radio quasars （FSRQs） and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in ＂7-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in 7-ray luminosity between the two classes is significantly reduced. In order to ex- plain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.

关键词： BL Lacertae objects: general -- quasars: general -- galaxies: jets -- black hole physics --relativistic processes -- gravitation

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The role of FAST in pulsar timing arrays

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Research in astronomy and astrophysics 2019年第2期19卷 39-54页

作者： George Hobbs Shi Dai Richard N.Manchester Ryan M.Shannon Matthew Kerr Ke-Jia Lee Ren-Xin Xu CSIRO astronomy and Space Science Department of astronomy School of Physics Peking University Kavli Institute for astronomy and astrophysics Peking University Max-Planck-Institut für Radioastronomie

The Five-hundred-meter Aperture Spherical radio Telescope(FAST) will become one of the world-leading telescopes for pulsar timing array(PTA) research. The primary goals for PTAs are to detect(and subsequently study) ultra-low-frequency gravitational waves, to develop a pulsar-based time standard and to improve solar system planetary ephemerides. FAST will have the sensitivity to observe known pulsars with significantly improved signal-to-noise ratios and will discover a large number of currently unknown pulsars. We describe how FAST will contribute to PTA research and show that jitter-and timing-noise will be the limiting noise processes for FAST data sets. Jitter noise will limit the timing precision achievable over data spans of a few years while timing noise will limit the precision achievable over many years.

关键词： stars:pulsars gravitational waves

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Deformable microlaser force sensing

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Light(Science & Applications) 2024年第6期13卷 1196-1209页

作者： Eleni Dalaka Joseph SHill Jonathan H.H.Booth Anna Popczyk Stefan R.Pulver Malte C.Gather Marcel Schubert Centre of Biophotonics SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsUK Humboldt Centre for Nano-and Biophotonics Department of ChemistryUniversity of CologneKölnGermany School of Psychology and Neuroscience University of St AndrewsSt Mary’s QuadSouth StreetSt AndrewsUK Institute for Bioengineering of Catalonia BarcelonaSpain

Mechanical forces are key regulators of cellular behavior and function,affecting many fundamental biological processes such as cell migration,embryogenesis,immunological responses,and pathological *** force sensors and imaging techniques have been developed to quantify these otherwise invisible forces in single cells and in ***,current techniques rely heavily on high-resolution microscopy and do not allow interrogation of optically dense tissue,reducing their application to 2D cell cultures and highly transparent biological ***,we introduce DEFORM,deformable microlaser force sensing,a spectroscopic technique that detects sub-nanonewton forces with unprecedented spatio-temporal *** is based on the spectral analysis of laser emission from dye-doped oil microdroplets and uses the force-induced lifting of laser mode degeneracy in these droplets to detect nanometer *** validation by atomic force microscopy and development of a model that links changes in laser spectrum to applied force,DEFORM is used to measure forces in 3D and at depths of hundreds of microns within tumor spheroids and late-stage Drosophila *** furthermore show continuous force sensing with single-cell spatial and millisecond temporal resolution,thus paving the way for non-invasive studies of biomechanical forces in advanced stages of embryogenesis,tissue remodeling,and tumor invasion.

关键词： invasion otherwise hundreds

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MHD Seismology of a loop-like filament tube by observed kink waves

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Research in astronomy and astrophysics 2015年第10期15卷 1713-1724页

作者： Vaibhav Pant Abhishek K Srivastava Dipankar Banerjee Marcel Goossens Peng-Fei Chen Navin Chandra Joshi Yu-Hao Zhou Indian Institute of astrophysics Department of Physics Indian Institute of Technology(BHU) Center of Excellence in Space Sciences Centre for Mathematical Plasma astrophysics Department of Mathematics School of astronomy and Space Science Nanjing University Key Lab of Modern astronomy and astrophysics Nanjing University School of Space Research Kyung Hee University

We report and analyze observational evidence of global kink oscillations in a solar filament as observed in Ha by instruments administered by National Solar Observatory （NSO）/Global Oscillation Network Group （GONG）. An M1.1-class flare in active region （AR） 11692 occurred on 2013 March 15 and induced a global kink mode in the filament lying towards the southwest of AR 11692. We find periods of about 61-67 minutes and damping times of 92-117 minutes at positions of three ver- tical slices chosen in and around the filament apex. We find that the waves are damped. From the observed period of the global kink mode and damping timescale using the theory of resonant absorption, we perform prominence seismology. We estimate a lower cut-off value for the inhomogeneity length scale to be around 0.34-0.44 times the radius of the filament cross-section.

关键词： Sun: oscillations -- Sun: magnetic fields -- Sun: filament

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Seismic study of solar convection and overshooting: results of nonlocal convection

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Research in astronomy and astrophysics 2013年第9期13卷 1127-1140页

作者： Chun-Guang Zhang Li-Cai Deng Da-Run Xiong Jrgen Christensen-Dalsgaard Key Laboratory of Optical astronomy National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Purple Mountain Observatory Chinese Academy of Sciences Stellar astrophysics Centre Department of Physics and Astronomy Aarhus University

Local mixing-length theory is incapable of describing nonlocal phenom- ena in stellar convection, such as overshooting. Therefore standard solar models con- structed with local mixing-length theory significantly deviate from the Sun at the boundaries of the convection zone, where convection becomes less efficient and nonlo- cal effects are important. The differences between observed and computed frequencies mainly come from the region near the surface, while the localized difference in sound speed is just below the convective envelope. We compute a solar envelope model using Xiong＇s nonlocal convection theory, and carry out helioseismic analysis. The nonlocal model has a smooth transition at the base of the convection zone, as revealed by helio- seismology. It reproduces solar frequencies more accurately, and reduces the localized difference in sound speed between the Sun and standard solar models.

关键词： convection -- Sun: interior -- Sun: helioseismology

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Flux and spectral variation characteristics of 3C 454.3 at the GeV band

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Research in astronomy and astrophysics 2018年第4期18卷 23-42页

作者： Hai-Ming Zhang Jin Zhang Rui-Jing Lu Ting-Feng Yi Xiao-Li Huang En-Wei Liang Guangxi Key Laboratory for Relativistic astrophysics Department of Physics Guangxi University Key Laboratory of Space astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Department of Physics Yunnan Normal University

We analyze the long-term lightcurve of 3C 454.3 observed with Fermi/LAT and investigate its relation to flux in the radio,optical and X-ray *** fitting the 1-day binned Ge V lightcurve with multiple Gaussian functions（MGF）,we propose that the typical variability timescale in the Ge V band is 1–10 *** Ge V flux variation is accompanied by the spectral variation characterized as fluxtracking,i.e.,＂harder when brighter.＂The Ge V flux is correlated with the optical and X-ray fluxes,and a weak correlation betweenγ-ray flux and radio flux is also ***γ-ray flux is not correlated with the optical linear polarization degree for the global lightcurves,but they show a correlation for the lightcurves before MJD *** power density spectrum of the global lightcurve shows an obvious turnover at^7.7 d,which may indicate a typical variability timescale of 3C 454.3 in theγ-ray *** is also consistent with the derived timescales by fitting the global lightcurve with *** spectral evolution and an increase in the optical linear polarization degree along with the increase inγ-ray flux may indicate that the radiation particles are accelerated and the magnetic field is ordered by the shock processes during the *** addition,the nature of 3C 454.3 may be consistent with a self-organized criticality system,similar to Sagittariusand thus the outbursts could be from plasmoid ejections driven by magnetic *** may further support the idea that the jet radiation regions are magnetized.

关键词： gamma rays galaxies — galaxies jets — quasars individual(3C 454.3)

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Variations of helioseismic parameters due to magnetic field generated by a flux transport model

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Research in astronomy and astrophysics 2021年第4期21卷 235-242页

作者： Shao-Lan Bi Tan-Da Li Kang Liu Jie Jiang Ya-Guang Li Jing-Hua Zhang Xian-Fei Zhang Ya-Qian Wu Department of astronomy Beijing Normal UniversityBeijing 100875China School of Physics and astronomy University of BirminghamEdgbastonBirminghamB152TTUK School of Space and Environment Beihang UniversityBeijing 100871China Sydney Institute for astronomy(SIfA) School of PhysicsUniversity of SydneyNSW 2006Australia Stellar astrophysics Centre Department of Physics and AstronomyAarhus UniversityNy Munkegade 120DK-8000 Aarhus CDenmark National Astronomical Observatories Chinese Academy of SciencesBeijing

The change of sound speed has been found at the base of the convection during the solar cycles,which can be used to constrain the solar internal magnetic *** aim to check whether the magnetic field generated by the solar dynamo can lead to the cyclic variation of the sound speed detected through *** basic configuration of magnetic field in the solar interior was obtained by using a Babcock-Leighton(BL)type flux transport *** reconstructed one-dimensional solar models by assimilating magnetic field generated by an established dynamo and examined their influences on the structural *** results show that magnetic field generated by the dynamo is able to cause noticeable change of the sound speed profile at the base of the convective zone during a solar *** features of this theoretical prediction are also similar to those of the helioseismic results in solar cycle 23 by adjusting the free parameters of the dynamo model.

关键词： Sun:oscillations Sun:activity Sun:interior

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LAMOST Time-Domain survey:first results of four K2 plates

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Research in astronomy and astrophysics 2021年第11期21卷 213-232页

作者： Song Wang Hao-Tong Zhang Zhong-Rui Bai Hai-Long Yuan Mao-Sheng Xiang Bo Zhang Wen Hou Fang Zuo Bing Du Tan-Da Li Fan Yang Kai-Ming Cui Yi-Lun Wang Jiao Li Mikhail Kovalev Chun-Qian Li Hao Tian Wei-Kai Zong Heng-Geng Han Chao Liu A-Li Luo Jian-Rong Shi Jian-Ning Fu Shao-Lan Bi Zhan-Wen Han Ji-Feng Liu Key Laboratory of Optical astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Max-Planck Institute for astronomy Konigstuhl 17D-69117 HeidelbergGermany Department of astronomy Beijing Normal UniversityBeijing 100875China School of Physics and astronomy University of BirminghamBirmingham B152TTUK Stellar astrophysics Centre Department of Physics and AstronomyAarhus UniversityNy Munkegade 120DK-8000 Aarhus CDenmark College of astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China Yunnan Astronomical Observatory Chinese Academy of SciencesKunming 650216China Key Lab of Space astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China WHU-NAOC Joint Center for astronomy Wuhan UniversityWuhan 430072China

From Oct.2019 to Apr.2020,LAMOST performed a time-domain(TD)spectroscopic survey of four K2 plates with both low-and medium-resolution *** low-resolution spectroscopic survey acquired 282 exposures(≈46.6 h)over 25 nights,yielding a total of about 767000 spectra,and the medium-resolution survey took 177 exposures(≈49.1 h)over 27 nights,collecting about 478000 *** than 70%/50%of low-resolution/medium-resolution spectra have signal-to-noise ratio higher than *** determine stellar parameters(e.g.,Teff,log g,[Fe/H])and radial velocity(RV)with different methods,including LASP,DD-Payne and *** general,these parameter estimations from different methods show good agreement,and the stellar parameter values are consistent with those of *** use the Gaia DR2 RV values to calculate a median RV zero point(RVZP)for each spectrograph exposure by exposure,and the RVZP-corrected RVs agree well with the APOGEE *** stellar evolutionary and spectroscopic masses are estimated based on the stellar parameters,multi-band magnitudes,distances and extinction ***,we construct a binary catalog including about 2700 candidates by analyzing their light curves,fitting the RV data,calculating the binarity parameters from medium-resolution spectra and cross-matching the spatially resolved binary catalog from Gaia *** LAMOST TD survey is expected to represent a breakthrough in various scientific topics,such as binary systems,stellar activity,stellar pulsation,etc.

关键词： astronomical database:miscellaneous catalogs stars:fundamental parameters binaries:general binaries:spectroscopic

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