Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)最新文献

{"title":"Ten years of All-sky Neutrino Point-SourceSearches","authors":"T. Carver","doi":"10.22323/1.358.0851","DOIUrl":"https://doi.org/10.22323/1.358.0851","url":null,"abstract":"These proceedings present the results of point-like neutrino source searches using ~10 yrs of IceCube data from Apr.~6, 2008 to Jul.~10, 2018. We evaluate the significance of an astrophysical signal from a point-like source looking for an excess of clustered neutrino events with energies above ~1 TeV among the background of atmospheric muons and neutrinos. We perform a full sky scan, a search based on a selected source catalog, and a catalog population study. The most significant location in the Northern hemisphere from the full-sky scan is compatible with the Seyfert galaxy NGC 1068. This object had also been identified in the source catalog search which finds a 2.9 $sigma$ excess after accounting for statistical trials. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that collectively correlations with sources in the Northern catalog are inconsistent with background at the level of 3.3 $sigma$. These results motivate further interest in such point-like sources which should become observable or ruled out after accumulation of more data or with future detectors.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124193535","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":"Neutrinos from Primordial Black Hole Evaporation","authors":"Pranav Dave, I. Taboada","doi":"10.22323/1.358.0863","DOIUrl":"https://doi.org/10.22323/1.358.0863","url":null,"abstract":"Primordial Black Holes (PBHs) are candidates for dark matter as well as ultra-high energy cosmic rays. PBHs are speculated to exist over a large range of masses, from below $10^{15}$ g to $10^3$ M$_odot$. Here we search for PBHs with an initial mass of $sim 10^{15}$ g. Hawking radiation by black holes of this initial mass predicts their evaporation at present time. PBHs are expected to produce copious amounts of high-energy neutrinos and gamma rays right before evaporating. Gamma-ray instruments such as Fermi, VERITAS, HAWC, HESS, and Milagro have conducted searches for evaporating PBHs during their last second to a year of existence. They are able to detect bursts from PBHs in a range of $10^{-3}$ to $0.1$ pc. We present sensitivity to PBH evaporation using one year of neutrino data by IceCube. In these proceedings, we detail the changes to adapt IceCube's standard neutrino flare search, aka time-dependent point source search, into one that is appropriate for evaporating BHs. These proceedings serve as proof of concept for a first-ever search for evaporating PBHs using neutrinos that can use 10 years of IceCube data.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132021354","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 Extremely Distributed Observatory: Status and Perspectives of a Global Cosmic Ray Detection Framework","authors":"D. Góra, K. A. Cheminant, D. A. Castillo, D. Beznosko, N. Dhital, A. Duffy, P. Homola, K. Kopanski, P. Kovács, Marta Marek, A. Mozgova, V. Nazari, Michal Niedzwiecki, W. Noga, K. Smelcerz, K. Smolek, J. Stasielak, O. Sushchov, D. Ostrogorski, K. Rzecki, Krzysztof W. Woźniak, J. Zamora-Saá","doi":"10.22323/1.358.0272","DOIUrl":"https://doi.org/10.22323/1.358.0272","url":null,"abstract":"The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a project dedicated to global studies of extremely extended cosmic-ray phenomena, the cosmic-ray ensembles (CRE), beyond the capabilities of existing detectors and observatories. Up to date cosmic-ray research has been focused on detecting single air showers, while the search for ensembles of cosmic-rays, which may spread over a significant fraction of the Earth, is a scientific terra incognita. The key idea of CREDO is to combine existing cosmic-ray detectors (large professional arrays, educational instruments, individual detectors, such as smartphones, etc.) into a worldwide network, thus enabling a global analysis. The second goal of CREDO involves a large number of participants (citizen science!), assuring the geographical spread of the detectors and managing manpower necessary to deal with vast amount of data to search for evidence for cosmic-ray ensembles. In this paper the status and perspectives of the project are presented.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121027883","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":"Novel Signals from Neutron Star Mergers at 511 keV","authors":"V. Takhistov","doi":"10.22323/1.358.0803","DOIUrl":"https://doi.org/10.22323/1.358.0803","url":null,"abstract":"Synergetic observations of multi-band coincidence signals from merging neutron stars have definitively marked the significance of multi-messenger astronomy. We present a new generic signature of neutron star mergers, positron emission and the associated 511 keV radiation, produced from ejected neutron-rich radioactive merger material. Accounting for historical neutron star mergers within the Milky Way allows to readily explain the origin of the long-observed 511 keV emission line from the Galactic Center. Further, we draw a direct link between heavy element production ($r$-process nucleosynthesis) and 511 keV emission, which signifies the surprising recent observations of Reticulum II ultra-faint dwarf spheroidal galaxy as a smoking gun of our proposal. This novel tracer of neutron star mergers provides a distinct handle for exploring binary merger history.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125359049","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":"Global changes of CR geomagnetic cutoff rigidities and two- parametric representation of long-term variation spectra","authors":"L. Dorman, P. Kobelev, V. Yanke","doi":"10.22323/1.358.1187","DOIUrl":"https://doi.org/10.22323/1.358.1187","url":null,"abstract":"The values for two-parametric variations spectra are determined for the whole period of observations in 1957-2017 years. A long-period changes of spectra with taking into account of cut-off rigidity changes are presented.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126598592","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":"Subsystem Development for the All-Sky Medium Energy Gamma-ray Observatory (AMEGO) prototype","authors":"S. Griffin, T. A. Team","doi":"10.22323/1.358.0565","DOIUrl":"https://doi.org/10.22323/1.358.0565","url":null,"abstract":"The gamma-ray sky from several hundred keV to $sim$ a hundred MeV has remained largely unexplored due to the challenging nature of detecting gamma rays in this regime. At lower energies, Compton scattering is the dominant interaction process whereas at higher energies pair production dominates, with a crossover at about 10 MeV depending on the material. Thus, an instrument designed to work in this energy range must be optimized for both Compton and pair-production events. The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a NASA Probe-class mission concept being submitted to the Astro2020 review. The instrument is designed to operate from 200 keV to $>$10 GeV and is made of four major subsystems: a plastic anti-coincidence detector for rejecting cosmic-ray events, a silicon tracker for tracking pair-production products and tracking and measuring the energies of Compton-scattered electrons, a CZT calorimeter for measuring the energy and location of Compton scattered photons, and a CsI calorimeter for measuring the energy of the pair-production products at high energies. A prototype instrument comprising each subsystem is currently being developed in preparation for a beam test and a balloon flight. In this contribution we discuss the current status of the prototype subsystems.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"251 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121035642","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":"Indicators of Space Weather Events in Cosmic Rays Flux During the Solar Cycle 24","authors":"A. Gil, R. Modzelewska, S. Moskwa, A. Siluszyk, M. Siluszyk, A. Wawrzynczak","doi":"10.22323/1.358.1079","DOIUrl":"https://doi.org/10.22323/1.358.1079","url":null,"abstract":"Solar originating events are repeatedly observable in cosmic ray flux measured at the ground by neutron monitors. We analyze time intervals of halo coronal mass ejections (CMEs), as well as sudden storm commencements (SSCs) appearance during solar cycle 24. We consider neutron monitor data, as well as, solar, heliospheric and geomagnetic activity parameters, around those periods, using different mathematical tools. Our computations show that the fractal dimension calculated for each week of studied period, based on Oulu neutron monitor hourly data, decreases around those events. Skewness and kurtosis change abruptly from the background average value. \u0000Since an influence of space weather phenomena on energy infrastructure is well known, in the next step we consider a list of electrical grids failures which occurred in southern Poland during the studied time intervals of halo CMEs and SSCs occurrence. Based on the data from Institute of Meteorology and Water Management-Polish National Research Institute we exclude from the analysis failures caused by the meteorological effects.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124970067","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":"Anisotropic Cosmic-ray Enhancement (ACRE): Case Studies of 07-Jun-2015 and 26-Aug-2018","authors":"A. Gil, G. Kovaltsov, V. Mikhailov, A. Mishev, S. Poluianov, I. Usoskin","doi":"10.22323/1.358.1081","DOIUrl":"https://doi.org/10.22323/1.358.1081","url":null,"abstract":"We present a phenomenological study of a new type of event, named the anisotropic cosmic ray enhancement (ACRE). Such events are characterized by a small, 2–5 %, increase of the count rate of a set of polar neutron monitors (NMs) appropriately located. The first studied representative of ACRE event was observed during 12-19 UT on 07-Jun-2015. Another, smaller event took place during 3 – 8 UT on 26-Aug-2018. Other possible candidates are still under consideration. \u0000During the ACRE event of 07-Jun-2015 (Figure 1) the enhancement in cosmic-ray flux, as measured by (sub)polar NMs was very anisotropic. It was detected only by low-rigidity NMs having their asymptotic directions in the south-west quadrant in GSE coordinates. According to space-borne measurements, there were no solar energetic particles present during that time. A neutron detector onboard the PAMELA instrument did not record any increase either, while it was located off the ACRE region. The near-Earth interplanetary conditions were quiet, with some small disturbances, causing a gradual increase in the strength of heliospheric magnetic field followed by the solar wind speed growth observed after the ACRE event. However, there was a strong solar wind shear region south-west off the Earth. We propose that the event was related to crossing of the boundary layer between two regions with different heliospheric parameters, causing a strong gradient of low-rigidity particles. \u0000During the ACRE event on 26-Aug-2018 (Figure 2) the enhancement in cosmic-ray flux was observed even by high-rigidity, up to 8 GV (Mexico NM), NMs, but located only in the Northern hemisphere. There was no statistically significant signal in the Southern hemisphere, even for polar NMs, implying that the event was highly anisotropic. Some disturbances in the near-Earth interplanetary conditions were recorded during this event, namely a gradual growth of heliospheric magnetic field strength, followed by the increase of solar wind speed occurring after the event. \u0000Here we report a new type of the cosmic-ray transient event. More detailed analysis and modelling studies of the ACRE-type events are planned for forthcoming work.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132764872","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 by Cygnus A or the bulk of non-local radio galaxies?","authors":"B. Eichmann","doi":"10.22323/1.358.0245","DOIUrl":"https://doi.org/10.22323/1.358.0245","url":null,"abstract":"The great potential that radio galaxies are the birthplace of ultra-high-energy cosmic rays (UHECRs) has been shown by numerous works so far. \u0000In addition to the close-by Fanaroff and Riley (FR) radio galaxy Centaurus A that most likely provides the dominant UHECR contribution at the highest energies, there is an other contributor between 5 EeV and 30 EeV needed. \u0000The exceptionally bright radio source Cygnus A is a prominent source candidate, but it is shown in this work, that the impact by the extragalactic magnetic field on the CR propagation causes some serious issues: Either the arrival directions of the CRs provide a high degree of anisotropy or the delay exceeds the source age. \u0000Alternatively, the low-energetic UHECRs can originate in the bulk of FR-I or FR-II sources. For such a scenario, the necessary jet dynamics of FR sources are discussed, showing that FR-I RGs can in principle provide the observed amount of UHECR energy as well as a proper spectral behavior. In contrast, the bulk of FR-II RGs most likely contribute less than 25%.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126520897","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":"Differential Rotation of the Sun as a Source of Galactic Cosmic Rays Quasi-biennial Oscillations","authors":"A. Gil, M. Alania","doi":"10.22323/1.358.1080","DOIUrl":"https://doi.org/10.22323/1.358.1080","url":null,"abstract":"Quasi-biennial oscillations belong to the most prominent mid-term periodicities with a duration shorter than 11-year cycle and longer than solar rotation. Sunspot number and area, intensity of coronal green line, solar radio flux, number of H$alpha$ flares, solar wind velocity, interplanetary magnetic field, as well as cosmic rays exhibit quasi-biennial oscillations in their temporal changes. However it was deeply studied, the source of the quasi-biennial oscillations is unrevealed yet. One of the concepts relates quasi-biennial oscillations to a high-frequency component of the solar dynamo functioning within the Sun's interior. Here, we propose as the origin of quasi-biennial oscillations of cosmic rays solar differential rotation.","PeriodicalId":166008,"journal":{"name":"Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131864164","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}