scholarly journals Messengers of the Universe-Cosmic Rays Exploring Supermassive Black Holes

Galaxies ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Anna Uryson
Keyword(s):  
Black Holes ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Supermassive Black Holes ◽  
High Energies ◽  
Recent Developments ◽  
The Universe

Cosmic rays were discovered over one hundred years ago but there are still unsolved problems. One of the hot problems is the origin of cosmic rays of the highest energies. Sources are still unclear and it is neither clear how particles gain ultra-high energies. Possible sources of cosmic rays at the highest energies are supermassive black holes. From this perspective we discuss in a popular form some recent developments in cosmic ray studies along with author’s recent results. The paper also offers materials for further reading.

scholarly journals Studying Cosmic Ray Sources Using Intergalactic Electromagnetic Cascades

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 287
Author(s):  
Anna Uryson
Keyword(s):  
Black Holes ◽  
Particle Acceleration ◽  
Cosmic Rays ◽  
Gamma Ray ◽  
Relative Number ◽  
Cosmic Ray ◽  
Supermassive Black Holes ◽  
Joint Analysis ◽  
Particle Injection ◽  
Superstrong Magnetic Field

In this paper, intergalactic electromagnetic cascades are used as a probe of cosmic ray sources. This is achieved as follows. In extragalactic space, cosmic rays initiate electromagnetic cascades, in which gamma-ray and neutrino emission arises. We used the joint analysis of cosmic ray data, along with extragalactic gamma-ray and neutrino emissions, to study particle acceleration in the vicinity of supermassive black holes. Particle injection spectra depend on processes of particle acceleration, and here we discuss models with various injection spectra. The computations of the propagation of cosmic rays in space were performed using the publicly available TransportCR code. It was found that a new subclass of sources might exist that does not contribute to the particle flux on Earth, instead to gamma-ray and neutrino emissions arising in electromagnetic cascades. In addition, the upper limit of the relative number of ‘exotic’ supermassive black holes surrounded by a superstrong magnetic field is derived.

scholarly journals On the flux of high-energy cosmogenic neutrinos and the influence of the extragalactic magnetic field

2019 ◽  
Vol 488 (1) ◽  
pp. L119-L122 ◽  
Author(s):  
David Wittkowski ◽  
Karl-Heinz Kampert
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Large Scale ◽  
Neutrino Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Observation Time ◽  
Cosmological Time ◽  
Cosmic Background ◽  
The Universe

ABSTRACT Cosmogenic neutrinos originate from interactions of cosmic rays propagating through the universe with cosmic background photons. Since both high-energy cosmic rays and cosmic background photons exist, the existence of high-energy cosmogenic neutrinos is certain. However, their flux has not been measured so far. Therefore, we calculated the flux of high-energy cosmogenic neutrinos arriving at the Earth on the basis of elaborate 4D simulations that take into account three spatial degrees of freedom and the cosmological time-evolution of the universe. Our predictions for this neutrino flux are consistent with the recent upper limits obtained from large-scale cosmic-ray experiments. We also show that the extragalactic magnetic field has a strong influence on the neutrino flux. The results of this work are important for the design of future neutrino observatories, since they allow to assess the detector volume and observation time that are necessary to detect high-energy cosmogenic neutrinos in the near future. An observation of such neutrinos would push multimessenger astronomy to hitherto unachieved energy scales.

Wallace Leslie William Sargent. 15 February 1935 — 29 October 2012

2015 ◽  
Vol 61 ◽  
pp. 467-483
Author(s):  
Donald Lynden-Bell
Keyword(s):  
Black Holes ◽  
Big Bang ◽  
Supermassive Black Holes ◽  
Cosmological Evolution ◽  
Significant Part ◽  
Look Back ◽  
Large Telescopes ◽  
The Big Bang ◽  
The Universe

Wallace Sargent was an astronomer who used large telescopes to great effect. He concentrated on outstanding problems concerning both the origin of the elements and the cosmological evolution of primordial gas clouds. Despite a mainly theoretical education he became an expert spectroscopist and this enabled him to demonstrate that most helium was not formed in stars but was primordial, formed in the Big Bang. This helped to determine the photon : baryon ratio that emerged from it. He played a significant part in the search for the supermassive black holes that were predicted to be in the centres of many galaxies, as is now established. He is most famous for his systematic work with Alec Boksenberg FRS on the intervening hydrogen clouds seen in absorption in the spectra of distant quasars. From their work it appears that most of the 4% of the Universe (by mass) that is now considered to be in normal atoms or ions has indeed been detected, although it is seen at considerable look-back times.

scholarly journals IMPLICATIONS OF PC AND KPC JET ASYMMETRY TO THE COSMIC RAY ACCELERATION

2012 ◽  
Vol 08 ◽  
pp. 331-335
Author(s):  
NECTARIA A. B. GIZANI
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Cosmic Ray ◽  
Directional Asymmetry ◽  
X Ray ◽  
Radio Data ◽  
High Energies ◽  
Cosmic Ray Acceleration

We probe the role that the directional asymmetry, between relativistic outflows and kilo-parsec scale jets, play in the acceleration of cosmic rays. For this reason we use two powerful, nearby Active Galactic Nuclei (AGNs). These radio galaxies are atypical compared to the usual AGN as they contain ring-like features instead of hotspots. Our VLBI radio data have revealed a substantial misalignment between their small and large scale jets. Taking into account the overall information we have obtained about the AGNs themselves (VLA and VLBI radio data at 18 cm) and their clusters (X-ray observations) our study supports the present ideas of powerful radiogalaxies (radio quiet and radio loud) being sources of cosmic rays as well as their ability to accelarate the latter to ultra high energies.

scholarly journals Information Technologies on High-Energy Astrophysics: Cosmic Ray Anisotropy using HAWC Observatory

2019 ◽  
Vol 208 ◽  
pp. 03005
Author(s):  
Eduardo de la Fuente ◽  
Juan Carlos Díaz–Vélez ◽  
Paolo Desiati ◽  
Jose Luis García–Luna ◽  
Janet Torrealba ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
High Altitude ◽  
Information Technologies ◽  
Cherenkov Radiation ◽  
Cosmic Ray ◽  
High Energy ◽  
High Impact ◽  
High Energy Astrophysics ◽  
High Energies ◽  
Radiation Technique

The detection of astroparticles, specially at high energies (>100 GeV), requires special techniques and instruments (telescopes or observatories), for example, those that use the Water Cherenkov radiation technique. In this paper we show an example of how Information Technologies can be used to perform maps and produce high impact results. The latter case is illustrated in the summary of the generation of a high statistics map of cosmic rays at 10 TeV in the northern sky with data collected by the High Altitude Water Cherenkov (HAWC) observatory.

scholarly journals The Gravitational Wave Symphony of Structure Formation: Overview

2015 ◽  
Vol 11 (A29B) ◽  
pp. 283-284
Author(s):  
T. Joseph W. Lazio ◽  
Sarah Burke-Spolaor
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Structure Formation ◽  
Cosmic Strings ◽  
Supermassive Black Holes ◽  
The Universe

This Focus Meeting was designed to lie at the scientific intersection of structure formation and gravitational wave studies. In broad-strokes terms, binary supermassive black holes (BSMBHs) and cosmic strings may both play a central role in shaping the Universe as we know it.

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