Subjects: Astronomy >> Astrophysical processes submitted time 2023-01-17 Cooperative journals: 《天文研究与技术》
Abstract: Blazar is a very active AGN. Studying its broad band spectral index is the effective method to understand its internal structure and radiation mechanism. The data in this paper adopts the SMARTS database data that has been published so far. There are 682 groups of observation data with quasi-simultaneity in B, V, R, J, K bands. The characteristics of its broad band spectral index are studied using LombScargle Periodogram (LSP) method. The results show that 3C 454.3 optical and infrared band light variations are positively correlated; There are two dominant periods in optical and infrared band, which are about 1.2 yr and 4.5 yr, respectively; In the double black hole structure model, the mass ratio of double black holes is 2/1.
Subjects: Astronomy >> Astrophysical processes submitted time 2020-07-10 Cooperative journals: 《天文研究与技术》
Abstract:基于Owens Valley Radio Observatory (OVRO) 40米望远镜观测数据,我们收集了耀变体CGRaBS J0835+6835在15GHz射电波段的数据(约12年)。利用Lomb-Scargle periodogram (LSP)方法和加权小波Z变换(Weight Wavelet Z-transform,WWZ)方法,我们检测到了CGRaBS J0835+6835存在一个约560天左右的准周期震荡(Quasi-periodic oscillation,QPO)。我们运用超大质量双黑洞系统中的螺旋喷流模型,估算了它的主黑洞质量M的范围约为3.7×108M⊙~3.5X109 M⊙。为了探究此源是否存在聚束效应,我们使用双指数函数拟合6个爆发过程,发现光变多普勒因子δV的平均值约为10.76。这表明此源的射电辐射存在明显的聚束效应。
Subjects: Library Science,Information Science >> Library Science submitted time 2023-10-08 Cooperative journals: 《知识管理论坛》
Abstract: [Purpose/significance] From the perspective of inter-institutional cooperation, this paper explores the cross-border synergy of library related interests and combines the development and deployment process of the next-generation library service platform LSP to study how libraries can adapt to the service upgrades under the new situation. [Method/process] Firstly, this paper put forward the concept of crossborder collaboration, analyzed the collaboration subjects and characteristics, summarized the crossborder collaboration mechanism in LSP construction, analyzed the elements of this mechanism, takes the FOLIO project deployment of Duke University Library as an example to show the actual operation of this mechanism, and discussed its enlightenment, reference and the future development trend. [Result/ conclusion] LSP will have a far-reaching impact on the service mode of the next generation library. There is a cross-border collaboration mechanism in the process of LSP development, which is common in the platform development of microservice architecture. When developing LSP, domestic libraries should improve the organizational structure and coordination mechanism, build multiple participation channels to ensure library service innovation and resource sharing, formulate various standards and specifications, deepen technical cooperation, and give sufficient human resources to support the implementation of domestic FOLIO.
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: We attempt to explain the recent ATLAS 3σ excess of dilepton events with an invariant mass near Z peak through the gluino-mediated sbottom production in a simplified scenario inspired by the minimal supersymmetric Standard Model. The additional Z bosons c
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: In this work we show that the general singlet extension of the minimal supersymmetric standard model (MSSM) can naturally provide a self-interacting singlino dark matter to solve the small cosmological scale anomalies (a large Sommerfeld enhancement facto
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-11-27 Cooperative journals: 《天文研究与技术》
Abstract: We find that the optical band light curve of the blazar PKS 0422 + 004 observed by the Transiting Exoplanet Survey Satellite (TESS) has a quasiperiodic oscillation (QPO) of about 7.4 days in sector 32. We use the Lomb-Scargle Periodogram (LSP) method to search for significant periods, and further validate them using the Weighted Wavelet Z-transform (WWZ) method for time-frequency domain analysis. Finally, based on Schwarzschild black hole (a=0) and extreme Kerr black hole (a=0. 998 2) models, we estimate the mass of the central black hole of this blazar. We obtain black hole masses of 1. 11 × 109 M☉ (Schwarzschild black hole) and 7.07 × 109M☉ (extreme Kerr black hole) with a main period of 7.4 days.
Subjects: Astronomy >> Astrophysical processes submitted time 2021-06-18 Cooperative journals: 《天文研究与技术》
Abstract:我们利用Lomb-Scargle periodogram方法和加权小波Z变换(Weight Wavelet Z-transform)方法分析了耀变体CGRaBS J0929+5013和 J2146-1525在15 GHz射电和伽马波段约12年的观测数据。分析结果表明耀变体CGRaBS J0929+5013和J2146-1525在射电波段可能存在准周期振荡信号。它们的准周期分别为1435天(3.93年)和1321天(3.62年),且置信度均>3(99.7%);而在伽马波段光变周期性较弱。基于超大质量双黑洞系统中的螺旋喷流模型估算了耀变体CGRaBS J0929+5013和J2146-1525的主黑洞质量的分别为4.3×109和2.7×109。为了探讨射电和伽马波段的光变起源,我们用离散相关函数分别计算了耀变体CGRaBS J0929+5013和J2146-1525射电与伽马波段之间的相关性,发现它们之间没有明显的相关性。这表明它们的辐射可能来自不同的区域。
Subjects: Astronomy >> Astrophysical processes submitted time 2021-11-12 Cooperative journals: 《天文研究与技术》
Abstract:Owens Valley Radio Observatory (OVRO)40米望远镜的观测数据显示了BL Lac 天体 CGRaBS J0141-0928在15 GHz射电波段的剧烈光变. 我们利用Lomb-Scargle-Periodogram (LSP)方法和加权小波Z变换(Weight Wavelet Z-transform,WWZ)方法以及Jurkevich方法分析了CGRaBS J0141-0928的光变周期, 结果显示该天体具有约为649天的准周期振荡(Quasi-Periodic OScillation, QPO), 其置信度为4.4σ, 其准周期振荡可能是由喷流的螺旋运动产生. 我们用双指数函数拟合了其中2 个爆发的过程, 从而得到其光变时标, 进而估算其平均多普勒因子为3.8, 这表明CGRaBS J0141-0928 在射电辐射波段存在显著的聚束效应. 采用DCF(Discrete Correlation Function) 方法对射电波段分别与Gamma-ray、光学 R 波段的光变相关性进行分析, 发现光学光变与射电光变有强相关性,且光学光变超前于射电光变66±40天.
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: We examine various direct and indirect experimental constraints on the nearly minimal supersymmetric standard model (nMSSM) and obtain the following observations: (i) The combination of current experiments stringently constrains the parameter space, setti
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: We investigate the possibility of observing the exotic decay mode of the top quark into the lightest stop (t~1t~1\tilde t_1) and neutralino (χ~01χ~10\tilde\chi^0_1) in the minimal supersymmetric standard model with R-parity at the upgraded Tevatron. First
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: We examine various direct and indirect experimental constraints on the nearly minimal supersymmetric standard model (nMSSM) and obtain the following observations: (i) The combination of current experiments stringently constrains the parameter space, setti
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: Recently the ATLAS collaboration reported a 3σ excess in the leptonic-Z + jets + EmissTTmiss_{T}^{miss} channel. This may be interpreted in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) by gluino pair production with the decay chain g~→qq??χ~0
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: In split supersymmetry the gauginos and higgsinos are the only supersymmetric particles possibly accessible at foreseeable colliders like the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). In order to account for the cosmic
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: The maximal U(1)LU(1)LU(1)_L supersymmetric inverse seesaw mechanism (MLSIS) provides a natural way to relate asymmetric dark matter (ADM) with neutrino physics. In this paper we point out that MLSIS is a natural outcome if one dynamically realizes the in
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: In some supersymmetric models like split supersymmetry or models with nonuniversal gaugino mass, ‘bino [lightest sparticle (LSP)] and wino [next-to-lightest sparticle (NLSP)] may have rather small mass splitting in order to provide the correct dark matter
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: We explore the explanation of the Fermi Galactic Center excess (GCE) in the next-to-minimal supersymmetric Standard Model. We systematically consider various experimental constraints including the dark matter (DM) relic density, DM direct detection result
Peer Review Status:Awaiting Review
Subjects: Physics Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-12-28
Abstract: The ATLAS collaboration recently reported a 3σ excess in the leptonic-Z + jets + EmissTTmiss_{T}^{miss} channel. We intend to interpret this excess by squark pair production in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The decay chain we
Peer Review Status:Awaiting Review