Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)最新文献_第2页

The Theory Of Pulsar Wind Nebulae: Recent Progress 脉冲星风星云理论:最新进展

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2020-01-13 DOI: 10.22323/1.354.0033

E. Amato

{"title":"The Theory Of Pulsar Wind Nebulae: Recent Progress","authors":"E. Amato","doi":"10.22323/1.354.0033","DOIUrl":"https://doi.org/10.22323/1.354.0033","url":null,"abstract":"Pulsar Wind Nebulae are highly intriguing astrophysical objects in many respects. They are the brightest and closest class of relativistic sources, and hence the ultimate laboratory for the physics of relativistic plasmas: several processes observed (or inferred to occur) in other classes of relativistic sources can here be studied with unique detail, like the acceleration and collimation of relativistic outflows, or the acceleration of particles at relativistic shocks. \u0000Here I review the current status of our theoretical understanding of Pulsar Wind Nebulae in light of the most recent 2D and 3D MHD modelling of these sources. I will discuss how these studies are taking us to the point when we can reliably use multi-wavelength observations of these nebulae as a diagnostics of the hidden physics of the pulsar wind and of the mechanism(s) through which particles are accelerated at the highly relativistic shock that terminates the wind. \u0000Finally I will briefly discuss recent progress in the modelling of evolved Pulsar Wind Nebulae and of the escape of particles from these systems. This effort is instrumental to credibly assess the role of Pulsar Winds as sources of cosmic ray leptons, and has recently been recognised to have important implications also on cosmic ray transport in the Galaxy.","PeriodicalId":164251,"journal":{"name":"Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116019221","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: 13

Gamma-Rays From Large-Scale Outflows In Starburst Galaxies 星暴星系中大规模流出的伽马射线

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-12-17 DOI: 10.22323/1.354.0029

G. Romero, A. Muller

引用次数: 3

3D Numerical Study Of An Anisotropic Heat Transfer In Outer Layers Of Magnetized Neutron Stars 磁化中子星外层各向异性传热的三维数值研究

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-12-12 DOI: 10.22323/1.354.0059

I. A. Kondratyev, S. Moiseenko, G. Bisnovatyi-Kogan, M. Glushikhina

{"title":"3D Numerical Study Of An Anisotropic Heat Transfer In Outer Layers Of Magnetized Neutron Stars","authors":"I. A. Kondratyev, S. Moiseenko, G. Bisnovatyi-Kogan, M. Glushikhina","doi":"10.22323/1.354.0059","DOIUrl":"https://doi.org/10.22323/1.354.0059","url":null,"abstract":"Periodic changes in a thermal soft X-ray flux of a rotating neutron star indicate a non-uniform distribution of the surface temperature. A possible cause of this phenomenon is a suppression of the heat flux across the magnetic field lines in a crust and an envelope of magnetized neutron stars. In this paper we study three-dimensional effects, associated with non-axisymmetric magnetic fields in neutron stars. We calculate the surface temperature distribution by solving numerically a three dimensional heat transfer equation in a magnetized neutron star crust. We adopt an anisotropic (tensorial) electron thermal conductivity coefficient, which is derived as an analytical solution of the Boltzmann equation with a Chapman-Enskog method. To calculate the surface temperature distribution, we construct a local one-dimensional plane-parallel model (\"Ts-Tb\"-relationship) of a magnetized neutron star envelope. We then use it as an outer boundary condition for the three-dimensional problem in the crust to find the self-consistent solution. To study possible observational manifestations from anisotropic temperature distributions we calculate light curves with a composite black-body model. Our calculations show, that a non-axisymmetric magnetic field distribution can lead to the irregular non-sinusoidal shape of a pulse profile as well as in some cases a significant amplification of pulsations of the thermal flux in comparison to the pure-dipolar magnetic field configurations.","PeriodicalId":164251,"journal":{"name":"Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121752979","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: 1

Unraveling The Complex Nature Of The Very High-Energy $gamma$-Ray Blazar PKS 2155-304 揭开高能伽马射线Blazar PKS 2155-304的复杂本质

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-12-04 DOI: 10.22323/1.354.0027

A. Wierzcholska, M. Zacharias, F. Jankowsky, S. Wagner, H. Collaboration

{"title":"Unraveling The Complex Nature Of The Very High-Energy $gamma$-Ray Blazar PKS 2155-304","authors":"A. Wierzcholska, M. Zacharias, F. Jankowsky, S. Wagner, H. Collaboration","doi":"10.22323/1.354.0027","DOIUrl":"https://doi.org/10.22323/1.354.0027","url":null,"abstract":"PKS 2155-304 is a blazar located in the Southern Hemisphere, monitored with the High Energy Stereoscopic System (H.E.S.S.) at very high energy (VHE, E>100 GeV) $gamma$ rays every year since 2002. Thanks to the large data set collected in the VHE range and simultaneous coverage in optical, ultraviolet (UV), X-ray and high energy $gamma$-ray ranges, this object is an excellent laboratory to study spectral and temporal variability in blazars. However, despite many years of dense monitoring, the nature of the variability observed in PKS 2155-304 remains puzzling. In this paper, we discuss the complex spectral and temporal variability observed in PKS 2155-304. The data discussed include VHE $gamma$-ray data collected with H.E.S.S. between 2013 and 2016, complemented with multiwavelength (MWL) observations from Fermi-LAT, Swift-XRT, Swift-UVOT, SMARTS, and the ATOM telescope. During the period of monitoring, PKS 2155-304 was transitioning from its lower state to the flaring states, and exhibiting different flavors of outbursts. For the first time, orphan optical flare lasting a few months was observed. Correlation studies show an indication of correlation between the X-ray and VHE $gamma$-ray fluxes. Interestingly, a comparison of optical and X-ray or VHE $gamma$-ray fluxes does not show global correlation. However, two distinct tracks in the diagram were found, which correspond to the different flaring activity states of PKS 2155-304.","PeriodicalId":164251,"journal":{"name":"Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117126922","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

Centrifugal acceleration of protons in the vicinity of a supermassive black hole 超大质量黑洞附近质子的离心加速度

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-11-30 DOI: 10.22323/1.354.0086

Alexey Gunya, Y. Istomin

{"title":"Centrifugal acceleration of protons in the vicinity of a supermassive black hole","authors":"Alexey Gunya, Y. Istomin","doi":"10.22323/1.354.0086","DOIUrl":"https://doi.org/10.22323/1.354.0086","url":null,"abstract":"Acceleration of protons in the active galactic nuclei is considered. The largest energy is achieved by protons during centrifugal acceleration in the magnetosphere of the central machine. When the proton accelerated in the magnetosphere of a black hole approaches light cylinder surface, acceleration occurs mainly in the azimuthal direction, i.e. the acceleration is centrifugal. In this paper the acceleration of a proton having smaller synchrotron losses compared to the electron is considered. As a proton experiences the highest energy increase while accelerating near the light surface, a partial solution for the maximum Lorentz factor can be obtained there. In the analysis the obtained dependence of the maximum energy on the parameter of particle magnetization $ kappa $ and parameter $ alpha $ which reflects the relation of toroidal $ B_phi $ and poloidal $ B_T $ magnetic fields , has led to the conclusion that the achievement of theoretical maximum limit of Lorentz factor value $ gamma_m=kappa^{-1}$ is not possible for an accelerated particle in the magnetosphere of a black hole due to restrictions of the topology of toroidal and poloidal magnetic fields imposed. The analysis of special cases of the relation of toroidal and poloidal magnetic field has shown that in the presence of magnetic field that is significantly more toroidal the maximum Lorentz factor value reaches $gamma_m = kappa^ {-2/3} $, in case when toroidal field becomes smaller in comparison to poloidal field the maximum Lorentz factor value does not exceed $gamma_m = kappa^ {-1/2} $. For a number of objects, such as M87 and Sgr. A *, maximum Lorentz factor values for accelerated protons for scenarios of existence or lack of toroidal magnetic field have been derived. The obtained results for magnetosphere of Sgr. A * has confirmed by the experimental data obtained on the massive HESS of Cherenkov telescopes.","PeriodicalId":164251,"journal":{"name":"Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114894437","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

CTA 102 -- Year Over Year Receiving You CTA 102—年复一年地接纳你

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-11-20 DOI: 10.22323/1.354.0025

M. Zacharias, M. Boettcher, F. Jankowsky, J. Lenain, S. Wagner, A. Wierzcholska

引用次数: 0

UHE Cosmic Rays And Agn Jets UHE宇宙射线和Agn射流

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-11-11 DOI: 10.22323/1.354.0019

F. Rieger

引用次数: 2

The Interaction Of AGN Jets With Obstacles AGN射流与障碍物的相互作用

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-11-01 DOI: 10.22323/1.354.0005

N. Torres-Albà

引用次数: 1

5.5 years multi-wavelength variability of Mrk 421: evidences of leptonic emission from the radio to TeV Mrk 421的5.5年多波长变异性:从射电到TeV的轻子发射证据

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-09-28 DOI: 10.22323/1.354.0032

V. Sliusar, A. Arbet-Engels, D. Baack, M. Balbo, M. Beck, A. Biland, M. Blank, T. Bretz, Kai Brügge, M. Bulinski, J. Buss, M. Doerr, D. Dorner, D. Elsaesser, D. Hildebrand, R. Iotov, M. Klinger, K. Mannheim, D. Neise, M. Noethe, A. Paravac, W. Rhode, B. Schleicher, K. Sedlaczek, A. Shukla, L. Tani, F. Theissen, R. Walter

{"title":"5.5 years multi-wavelength variability of Mrk 421: evidences of leptonic emission from the radio to TeV","authors":"V. Sliusar, A. Arbet-Engels, D. Baack, M. Balbo, M. Beck, A. Biland, M. Blank, T. Bretz, Kai Brügge, M. Bulinski, J. Buss, M. Doerr, D. Dorner, D. Elsaesser, D. Hildebrand, R. Iotov, M. Klinger, K. Mannheim, D. Neise, M. Noethe, A. Paravac, W. Rhode, B. Schleicher, K. Sedlaczek, A. Shukla, L. Tani, F. Theissen, R. Walter","doi":"10.22323/1.354.0032","DOIUrl":"https://doi.org/10.22323/1.354.0032","url":null,"abstract":"Mrk 421 is a high-synchrotron-peaked blazar featuring bright and persistent GeV and TeV emission. We use the longest and densest ongoing unbiased observing campaign obtained at TeV and GeV energies during 5.5 years with the FACT telescope and the Fermi-LAT detector. The contemporaneous multi-wavelength observations were used to characterize the variability of the source and to constrain the underlying physical mechanisms. We study and correlate light curves obtained by nine different instruments from radio to gamma rays and found two significant results. The TeV and X-ray light curves are very well correlated with lag, if any, shorter than a day. The GeV light curve varies independently and accurately leads the variations observed at long wavelengths, in particular in the radio band. We find that the observations match the predictions of leptonic models and suggest that the physical conditions vary along the jet, when the emitting region moves outwards.","PeriodicalId":164251,"journal":{"name":"Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124379566","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

Time Variability Of Low Angular Momentum Accretion Flows Around Black Hole. 黑洞周围低角动量吸积流的时间变异性。

Proceedings of High Energy Phenomena in Relativistic Outflows VII — PoS(HEPRO VII) Pub Date : 2019-07-01 DOI: 10.22323/1.354.0068

Ishika Palit, A. Janiuk, P. Suková

引用次数: 1