检索结果-南通市图书馆

Search for gamma-ray line signals around the black hole at the galactic center with DAMPE observation

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2022年第6期65卷 150-158页

作者： Tian-Ci Liu Ji-Gui Cheng Yun-Feng liang en-wei liang Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China

The adiabatic growth of a black hole(BH)may enhance the dark matter(DM)density surrounding it,causing a spike in the DM density profile.The spike around the supermassive BH at the center of the Milky Way may lead to a dramatic enhancement of the gamma-ray flux of DM annihilation from the galactic center(GC).In this work,we analyze the gamma-ray data of the innermost region(i.e.,the inner 1°)of the GC to search for potential line-like signals from the BH spike.Such line-like signals could be generated in the process of DM particles annihilating into double photons.We adopt the gamma-ray data from the Dark Matter Particle Explorer(DAMPE).Although the DAMPE has a much smaller effective area than the Fermi-LAT,the gamma-ray line search can benefit from its unprecedented high energy resolution.No significant line-like signals are found in our analysis.We derive upper limits on the cross section of the annihilation based on this non-detection.We find that despite the DAMPE’s small effective area for photon detection,we can still place strong constraints on the cross section(≥10^(-27)cm^(3)s^(-1))in the spike scenario due to the very bright model-expected flux from the spike.Our results indicate that either DM does not annihilate primarily through theγγchannel in the mass range we considered or no sharp density spike is present at the GC.

关键词： dark matter γ-ray telescopes black holes galactic center

Is TOL 1326–379 a Prototype ofγ-Ray Emitting FR0 Radio Galaxy?

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第3期22卷 47-56页

作者： Wen-Jing Fu Hai-Ming Zhang Jin Zhang Yun-Feng liang Su Yao en-wei liang Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China School of Physics Beijing Institute of TechnologyBeijing 100081China Max-Planck-Institute für Radioastronomie Auf dem Hügel 69D-53121 BonnGermany

With the possible spacial association to the Fermi/LAT source 3 FGL J 1330.0-3818,TOL 1326-379 may be the first one that is identified as a 7-ray emitting Fanaroff-Riley type 0 radio galaxy(FRO RG).We analyze the~12 yr Fermi/LAT observation data of thisγ-ray source and examine its association to TOL 1326-379.We show that theγ-ray source(named as J1331.0-3818)is tentatively detected with a TS value of 28.7,3 FGL J 1330.0-3818 is out of the 95%containment of J1331.0-3818,and their positions are spatially separated~0°.2.4 FGL J1331.3-3818 falls into the 68%containment of J1331.0-3818,suggesting that our result agrees with that reported in the Fourth Fermi LAT Source Catalog.TOL 1326-379 is out of the 95%containment of J1331.0-3818,and their positions are spatially separated~0°.4,indicating that the association between J1331.0-3818 and TOL 1326-379 is quite ambiguous.However,we do not find other possible potential radio or X-ray counterpart within the circle centered at J1331.0-3818 with a radius of 0°.4.The spectral energy distribution(SED)of TOL 1326-379 shows a bimodal feature as seen in theγ-ray emitting RGs.We fit the SED with the one-zone leptonic model and find that the average energy spectrum of J1331.0-3818 agrees with the model prediction.Assuming that J1331.0-3818 is an unidentified 7-ray source,we derive the upper-limit of theγ-ray flux for TOL 1326-379.It is not tight enough to exclude this possibility with the SED modeling.Based on these results,we cautiously argue that theγ-ray source J1331.0-3818 is associated with TOL 1326-379 and its jet radiation physic is similar to thoseγ-ray emitting RGs.

关键词： radiation mechanisms:non-thermal galaxies:active galaxies galaxies:radio jets gamma-rays:galaxies

Probing the Progenitor of High-z Short-duration GRB 201221D and its Possible Bulk Acceleration in Prompt Emission

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第7期22卷 176-190页

作者： Hao-Yu Yuan Hou-Jun Lü Ye Li Bin-Bin Zhang Hui Sun Jared Rice Jun Yang en-wei liang Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210093China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Mathematics and Physical Science Southwestern Adventist UniversityKeeneTX 76059USA

The growing observed evidence shows that the long-and short-duration gamma-ray bursts(GRBs) originate from massive star core-collapse and the merger of compact stars,respectively.GRB 201221 D is a short-duration GRB lasting~0.1 s without extended emission at high redshift z=1.046.By analyzing data observed with the Swift/BAT and Fermi/GBM,we find that a cutoff power-law model can adequately fit the spectrum with a soft E=113keV,and isotropic energy E=1.36× 10erg.In order to reveal the possible physical origin of GRB 201221 D,we adopted multi-wavelength criteria(e.g.,Amati relation,ε-parameter,amplitude parameter,local event rate density,luminosity function,and properties of the host galaxy),and find that most of the observations of GRB 201221 D favor a compact star merger origin.Moreover,we find that α is larger than 2+βin the prompt emission phase which suggests that the emission region is possibly undergoing acceleration during the prompt emission phase with a Poynting-flux-dominated jet.

关键词： (stars:)gamma-ray burst:individual(GRB 201221D) stars:massive acceleration of particles

Lsyn-Esyn,p-δrelation in active galactic nucleus jets and implication for the physical origin of the Lp-Ep,z-Γ_0 relation of gamma-ray bursts

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2020年第9期20卷 201-209页

作者： Xiao-Li Huang en-wei liang School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China

High energy photon radiations of gamma-ray bursts(GRBs)and active galactic nuclei(AGNs)are dominated by their jet radiations.We examine whether the synchrotron radiations of jets in BL Lacs,flat spectrum radio quasars(FSRQs),and Narrow Line Seyfert 1 galaxies(NLS1s)follow the relation between the prompt gamma-ray emission and the initial Lorentz factor(Γ0)of GRBs.It is shown that the AGN sample does not agree with the Lp-Ep,z-Γ0 relation of GRBs.In addition,we obtain a tight relation of Lsyn∝Е0.45±0.15δ3.50±0.25 syn,p for FSRQs and NLS1 galaxies,where Lsyn is the luminosity at peak photon energy Esyn,p of the synchrotron radiations.This relation is different from the Lp-Ep,z-Γ0 relation of GRB s.The dependence of Lsyn toδis consistent with the expectation of the Doppler boosting effect for the FSRQs and NLS1 galaxies,but it is not for GRBs.We argue thatΓ0 may be a representative of the kinetic power of the radiating region and the tight Lp-Ep,z-Γ0 relation is shaped by the radiation physics and the jet power together.

关键词： gamma-ray burst:general quasars:general BL Lacertae objects:general galaxies:Seyfert stars:jets radiation mechanisms:non-thermal

Comparison of thermodynamic behaviors of two regular-AdS black holes

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2022年第2期74卷 99-104页

作者： Sen Guo Ya-Ling Huang en-wei liang Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China School of Electrical engineering SouthWest JiaoTong UniversityChengdu 610031China

Considering the negative cosmological constant of an anti-de Sitter(AdS)background as a positive thermodynamic pressure in the extended phase space,we investigate the P-υ critical behavior and of the cooling-heating phase transition of the regular Hayward-AdS(HAd S)black hole(BH),and compare the difference of some thermodynamic processes in both the HAdS BH and the BardeenAdS(BAdS)BH.We found that the phase transition of the BAdS BH tends to be more the van der Waals(vdW)phase transition.For the cooling-heating phase transition,we obtained the inversion curves of the HAdS BH are always higher than the BAdS BH under the same pressure and magnetic charge.We also compare the smallest existence mass,the zero-temperature remnant,and the critical magnetic charge for these two BHs.The results suggested that the inner horizon and the outer horizon of the Hayward BH are easier to merge,and the singularity is easier to expose.

关键词： regular black hole phase transition thermodynamic

Comparisons of Jet Properties between GeV Radio Galaxies and Blazars

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第9期17卷 15-24页

作者： Zi-wei Xue Jin Zhang wei Cui en-wei liang Shuang-Nan Zhang Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China University of Chinese Academy of Sciences Beijing 100049China Department of Physics and Astronomy Purdue UniversityWest LafayetteIN 47907USA Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

We compile a sample of spectral energy distributions （SEDs） of 12 GeV radio galaxies （RGs）, including eight FR I RGs and four FR II RGs. These SEDs can be represented with the one-zone leptonic model. No significant unification, as expected in the unification model, is found for the derived jet parameters between FR I RGs and BL Lacertae objects （BL Lacs） and between FR II RGs and flat spectrum radio quasars （FSRQs）. However, on average FR I RGs have a larger ＇Tb （break Lorentz factor of electrons） and lower B （magnetic field strength） than FR II RGs, analogous to the differences be- tween BL Lacs and FSRQs. The derived Doppler factors （~） of RGs are on average smaller than those of blazars, which is consistent with the unification model such that RGs are the misaligned parent pop- ulations of blazars with smaller tS. On the basis of jet parameters from SED fits, we calculate their jet powers and the powers carded by each component, and compare their jet compositions and radiation efficiencies with blazars. Most of the RG jets may be dominated by particles, like BL Lacs, not FSRQs. However, the jets of RGs with higher radiation efficiencies tend to have higher jet magnetization. A strong anticorrelation between synchrotron peak frequency and jet power is observed for GeV RGs and blazars in both the observer and co-moving frames, indicating that the ＂sequence＂ behavior among blazars, together with the GeV RGs, may be intrinsically dominated by jet power.

关键词： galaxies： active -- galaxies： general -- galaxies jets -- gamma rays galaxies -- radiation mechanisms non-thermal

GRB 190530A:From Precursor,Prompt Emission to Afterglow all Originated from Synchrotron Radiation

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第6期22卷 22-32页

作者： Hui-Ya Liu Xiang-Gao Wang Li-Ping Xin Zi-Min Zhou liang-Jun Chen Bing Li Yuan-Gui Yang Qi Luo Cheng-Kui Li Shao-Lin Xiong Ling-Jun Wang Xu-Hui Han Li-Ming Song Jian-Yan wei en-wei liang Shuang-Nan Zhang Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China GXU-NAOC Center for Astrophysics and Space Sciences Nanning 530004China CAS Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physics and Electronic Information Huaibei Normal UniversityHuaibei 235000China

GRB 190530A was jointly observed by the High energy X-ray Telescope of the Hard X-ray Modulation Telescope(Insight-HXMT/HE)and the Ground-Based Wide-Angle Camera network(GWAC-N)with the extremely large field of view.After triggered by Insight-HXMT/HE and Fermi/GBM,we observed the optical emission of GRB 190530A,using the 30 cm telescope of GWAC(GWAC-F30)to search and locate its position.Subsequent observation of the late afterglow of GRB 190530A was made with the 2.16 m telescope at Xinglong Observatory.In this paper,we make a detailed exploration of the origin of GRB 190530A.In the prompt emission,a“double-tracking”pattern is presented both for the low-energy spectral indexαand the peak energy Epin the Band function with Insight-HXMT/HE and Fermi/GBM data;the results of GRB 190530A are consistent with the Amati and Yonetoku correlations;the spectral lag(τ)versus energy(E)can be estimated withτ=-3.0±0.06+(0.17±0.03)logE.The synchrotron radiation can account for the origin of GRB190530A prompt emission behaviors.Theαand Epof the precursor are essentially the same as that of the main prompt emission,implying that they have the same origin.For the afterglow,it can be described with the external forward shock model in ISM circumburst medium.In summary,from precursor,prompt emission to afterglow of GRB 190530A all originated from synchrotron radiation.

关键词： (stars)gamma-ray burst:individual(GRB 190530A)-(stars)gamma-ray burst general-virtual observatory tools

Fermi/LAT observations of lobe-dominant radio galaxy 3C 207 and possible radiation region of γ-rays

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2018年第6期18卷 93-98页

作者： Sheng-Chu Guo Hai-Ming Zhang Jin Zhang 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

3 C 207 is a lobe-dominant radio galaxy with a one sided jet and bright knots, spanning a kpcMpc scale, which have been resolved in the radio, optical and X-ray bands. This target was confirmed as a γ-ray emitter with Fermi/LAT, but it is uncertain whether the γ-ray emission region is the core or knots due to the low spatial resolution of Fermi/LAT. We present an analysis of its Fermi/LAT data acquired during the past 9 years. Different from the radio and optical emission from the core, it is found that theγ-ray emission is steady without detection of flux variation at over a 2σ confidence level. This likely implies that the γ-ray emission is from its knots. We collect the radio, optical and X-ray data of knot-A,the closest knot from the core at 1.4′′, and compile its spectral energy distribution(SED). Although the single-zone synchrotron+SSC+IC/CMB model that assumes knot-A is at rest can reproduce the SED in the radio-optical-X-ray band, the predicted γ-ray flux is lower than the LAT observations and the derived magnetic field strength deviates from the equipartition condition by 3 orders of magnitude. Assuming that knot-A is moving relativistically, its SED from radio to γ-ray bands would be represented well with the single-zone synchrotron+SSC+IC/CMB model under the equipartition condition. These results likely suggest that the γ-ray emission may be from knot-A via the IC/CMB process and the knot should have relativistical motion. The jet power derived from our model parameters is also roughly consistent with the kinetic power estimated with radio data.

关键词： galaxies: active galaxies: jets radiation mechanisms: non-thermal galaxies: individual(3C 207)

Physical origin of multi-wavelength emission of GRB 100418A and implications for its progenitor

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2012年第4期12卷 411-418页

作者： Lan-wei Jia Xue-Feng Wu Hou-Jun Lti Shu-Jin Hou en-wei liang Department of Physics Guangzhou University Guangzhou 510006 China Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences Guangxi University Nanning 530004 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Department of Physics and Astronomy University of Nevada Las Vegas Las Vegas NV 89154 USA Department of Physics and Institute of Theoretical Physics and Astrophysics Xiamen University Xiamen 361005 China

Swift GRB 100418A is a long burst at z = 0.624 without detection of any associated supernova （SN）. Its light curves in both the prompt and afterglow phases are similar to GRB 060614, a nearby long GRB without an associated SN. We analyze the observational data of this event and discuss the possible origins of its multiwavelength emission. We show that its joint light curve at 1 keV derived from Swift BAT and XRT observations is composed of two distinguished components. The first component, whose spectrum is extremely soft （Γ = 4.32）, ends with a steep decay segment, indicating the internal origin of this component. The second component is a slowly-rising, broad bump which peaks at ～ 10 5 s post the BAT trigger. Assuming that the late bump is due to onset of the afterglow, we derive the initial Lorentz factor （Γ 0 ） of the GRB fireball and find that it significantly deviates from the relation between the Γ 0 and isotropic gamma-ray energy derived from typical GRBs. We also check whether it follows the same anti-correlation between X-ray luminosity and the break time observed in the shallow decay phase of many typical GRBs, which is usually regarded as a signal of late energy injection from the GRB central engine. However, we find that it does not obey this correlation. We propose that the late bump could be contributed by a two-component jet. We fit the second component with an off-axis jet model for a constant medium density and find the late bump can be represented by the model. The derived jet half-opening angle is 0.30 rad and the viewing angle is 0.315 rad. The medium density is 0.05 cm 3 , possibly suggesting that it may be from a merger of compact stars. The similarity between GRBs 060614 and 100418A may indicate that the two GRBs are from the same population and the late bump observed in the two GRBs may be a signal of a two-component jet powered by the GRB central engine.

关键词： gamma-rays： bursts — individual： GRB 060614 GRB 100418A