Nuclear physics. B, Proceedings, supplements最新文献

{"title":"Variability of VHE γ–ray sources","authors":"Stanislav Stefanik,&nbsp;Dalibor Nosek","doi":"10.1016/j.nuclphysbps.2014.10.030","DOIUrl":"10.1016/j.nuclphysbps.2014.10.030","url":null,"abstract":"<div><p>We study changes in the <em>γ</em>–ray intensity at very high energies observed from selected active galactic nuclei. Publicly available data collected by Cherenkov telescopes were examined by means of a simple method utilizing solely the number of source and background events. Our results point to some degree of time variability in signal observed from the investigated sources. Several measurements were found to be excessive or deficient in the number of source events when compared to the source intensity deduced from other observations.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 258-263"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82789452","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}

{"title":"Ultra-high Energy Cosmic Rays and Neutrinos from Gamma-Ray Bursts, Hypernovae and Galactic Shocks","authors":"P. Mészáros","doi":"10.1016/j.nuclphysbps.2014.10.028","DOIUrl":"10.1016/j.nuclphysbps.2014.10.028","url":null,"abstract":"<div><p>I review gamma-ray burst models (GRBs) and observations, and discuss the possible production of ultra-high energy cosmic rays and neutrinos in both the standard internal shock models and the newer generation of photospheric and hadronic GRB models, in the light of current constraints imposed by IceCube, Auger and TA observations. I then discuss models that have been proposed to explain the recent astrophysical PeV neutrino observations, including star-forming and star-burst galaxies, hypernovae and galaxy accretion and merger shocks.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 241-251"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79094812","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}

{"title":"Observational Clues of Galactic Cosmic Rays – from X-ray Point of View","authors":"Aya Bamba","doi":"10.1016/j.nuclphysbps.2014.10.022","DOIUrl":"10.1016/j.nuclphysbps.2014.10.022","url":null,"abstract":"<div><p>X-ray observations are the strong tool to study nonthermal phenomena in the universe. Detecting synchrotron X-rays is the direct evidence of accelerated electrons in the magnetic field, and thermal X-rays from the background plasma of the acceleration sites show us their physical parameters such as temperature, density, and so on. Recent X-ray observations show us the discrepancy of the standard model of Galactic cosmic ray acceleration in supernova remnants and pulsar wind nebulae, such as high acceleration efficiency, amplification of magnetic field on the shock, escape from the shock, and so on. In this paper, we will introduce how present X-ray observatories, and near-future X-ray observatories will, contribute the understanding Galactic cosmic ray acceleration beyond the standard model, together with radio, optical, and gamma-ray observations.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 186-195"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"112821989","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}

{"title":"Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition","authors":"Etienne Parizot","doi":"10.1016/j.nuclphysbps.2014.10.023","DOIUrl":"10.1016/j.nuclphysbps.2014.10.023","url":null,"abstract":"<div><p>We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of 10¹⁷ eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernovæ in the Galaxy is actually released inside superbubbles, which may thus play an important role in the origin of cosmic-rays, and could solve some persistent problems of the standard SNR-GCR scenario in a rather natural way.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 197-212"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113819517","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}

{"title":"Prolegomena","authors":"Omar Tibolla ,&nbsp;Luke Drury","doi":"10.1016/j.nuclphysbps.2014.10.001","DOIUrl":"https://doi.org/10.1016/j.nuclphysbps.2014.10.001","url":null,"abstract":"<div><p>In these preliminary remarks we discuss our motivations for holding the San Vito di Cadore conference as well as some personal reflections on the history and current status of the origin of cosmic rays. We argue that it is time to think beyond the ‘standard model’ and contemplate the possibility of sources other than SNRs contributing to the observed cosmic ray flux even if the bulk originate in SNRs. In fact everyone tacitly assumes that at the very highest energies we do in fact see a new extra-Galactic component, but what it is and where exactly the transition occurs remain subjects of investigation. Similarly the positron excess seen by PAMELA and confirmed by AMS clearly points to an additional source of high-energy leptons in our Galactic neighbourhood. The recent observation by Agile and Fermi of the remarkable Crab gamma-ray flares point to some non-standard and very rapid form of particle acceleration which, if it occurs in other environments, may contribute to the acceleration of cosmic rays. In summary, it is clear that the origin of cosmic rays is a richer field of study than just diffusive shock acceleration in SNRs.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138272546","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}

{"title":"Cosmic-ray acceleration and gamma-ray signals from radio supernovæ","authors":"A. Marcowith ,&nbsp;M. Renaud ,&nbsp;V. Dwarkadas ,&nbsp;V. Tatischeff","doi":"10.1016/j.nuclphysbps.2014.10.011","DOIUrl":"10.1016/j.nuclphysbps.2014.10.011","url":null,"abstract":"<div><p>Core collapse supernovae (SNe) are among the most extreme events in the universe. The are known to harbor among the fastest (but non- or midly-relativistic) shock waves. Once it has crossed the stellar atmosphere, the SN blast wave expands in the wind of the massive star progenitor. In type IIb SNe, the progenitor is likely a Red SuperGiant (RSG) star which has a large mass loss rate and a slow stellar wind producing a very dense circumstellar medium. A high velocity shock and a high density medium are both key ingredients to initiate fast particle acceleration, and fast growing instabilities driven by the acceleration process itself. We have reanalyzed the efficiency of particle acceleration at the forward shock right after the SN outburst for the particular case of the well-known SN 1993J. We find that plasma instabilities driven by the energetic particles accelerated at the shock front grow over intraday timescales. This growth, and the interplay of non-linear process, permit a fast amplification of the magnetic field at the shock, that can explain the magnetic field strengths deduced from the radio monitoring of the source. The maximum particle energy is found to reach 1–10 PeV depending on the instability dominating the amplification process. We derive the time dependent particle spectra and the associated hadronic signatures of secondary particles (gamma-ray, leptons and neutrinos) arising from proton proton interactions.</p><p>We find that the Cherenkov Telescope Array (CTA) should easily detect objects like SN 1993J in particular above 1 TeV, while current generation of Cherenkov telescopes such as H.E.S.S. could only marginaly detect such events. The gamma-ray signal is found to be heavily absorbed by pair production process during the first week after the outburst. We predict a low neutrino flux above 10 TeV, implying a detectability horizon with a KM3NeT-type telescope of 1 Mpc only. We finally discuss the essential parameters that control the particle acceleration and gamma-ray emission in other type of SNe.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 94-100"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90248132","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}

{"title":"List of participants","authors":"","doi":"10.1016/S0920-5632(14)00313-2","DOIUrl":"https://doi.org/10.1016/S0920-5632(14)00313-2","url":null,"abstract":"","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 292-293"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0920-5632(14)00313-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138272657","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}

{"title":"Cosmic Ray Origins: An Introduction","authors":"Roger Blandford,&nbsp;Paul Simeon,&nbsp;Yajie Yuan","doi":"10.1016/j.nuclphysbps.2014.10.002","DOIUrl":"10.1016/j.nuclphysbps.2014.10.002","url":null,"abstract":"<div><p>Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 9-22"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"107716201","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}

{"title":"Nonthermal Emission in the Starburst Galaxies M 82 & NGC 253","authors":"Yoel Rephaeli ,&nbsp;Massimo Persic","doi":"10.1016/j.nuclphysbps.2014.10.029","DOIUrl":"10.1016/j.nuclphysbps.2014.10.029","url":null,"abstract":"<div><p>Detection of high-energy <em>γ</em>-ray emission from the nearby starburst galaxies M 82 and NGC 253 establishes, for the first time, a direct link between leptonic and hadronic processes in an extragalactic non-AGN environment. We review the most relevant aspects of these processes and contrast theoretical predictions with available radio and <em>γ</em>-ray measurements in order to determine the particle spectral properties and energy densities in these galaxies.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 252-257"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"94544178","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}

{"title":"CR electrons: towards a more complete air-Cherenkov view","authors":"Michele Palatiello","doi":"10.1016/j.nuclphysbps.2014.10.032","DOIUrl":"10.1016/j.nuclphysbps.2014.10.032","url":null,"abstract":"<div><p>Very high energy (VHE; <em>E</em> &gt; 30 GeV) cosmic-ray electrons and positrons (CR<span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span>, <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>) reaching the Earth from beyond the solar system are important tracers of recent energetic events in our Galactic neighbourhood (1–2 kpc). Spectral measurements of this radiation may help checking standard astrophysical scenarios of CR<span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span>, <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span> origin (e.g., pulsars, SNRs) versus exotic scenarios (e.g., DM particle annihilation). Air-Cherenkov telescopes can contribute to the measurement of the total VHE flux of CR<span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span>, <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>. This will allow us to consolidate relevant results by, e.g., ATIC, HESS, AMS-02, and <em>Fermi</em>-LAT.</p></div>","PeriodicalId":93343,"journal":{"name":"Nuclear physics. B, Proceedings, supplements","volume":"256 ","pages":"Pages 267-274"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.nuclphysbps.2014.10.032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"93293075","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}