A Search for TeV Gamma Ray Emission from X-ray Binary Stars PDF Download

Author: Christopher Charles Geoffrey Bowden
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Chang Dong Rho
Publisher:
ISBN:
Category :
Languages : en
Pages : 204

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"Astrophysical sources of very-high-energy (VHE) gamma-ray radiation provide unique information about astrophysical particle acceleration and cosmic-ray production. In particular, compact binary systems, composed of a compact object (a neutron star or black hole) in orbit with a massive stellar companion, provide an ideal environment for VHE gamma-ray production. They are not only powerful particle accelerators, but they also exhibit periodic emission that makes them excellent astrophysical laboratories. However, only a handful of binary systems have ever been observed in VHE gamma rays. Partly, this is because VHE gamma-ray binaries appear to be very rare, and part is due to observational bias. Most instruments operating at TeV are pointed and must allocate time to observing many kinds of objects. The High Altitude Water Cherenkov (HAWC) Observatory, on the other hand, has high uptime (duty cycle >95%) and a wide field of view (2 sr), making it well-suited for observing transient and time-varying sources such as binaries. HAWC is also currently the only detector that is sensitive to gamma-ray photons above 10 TeV. Collected HAWC data spanning33 months between November 2014 and January 2018 are used to analyze the known and candidate VHE gamma-ray binary systems in this work. "Microquasars" are a special subclass of X-ray binaries that are also candidate VHE gamma-ray sources. Unlike other types of binaries, compact objects in microquasars accrete matter from their companion star. This process forms an accretion disk around the compact object and relativistic jets of particles are released perpendicular to the accretion disk. This feature is very similar to active galactic nuclei (AGN), only smaller in size. Given the fact that direct observation of particle acceleration in distant AGN is very challenging, microquasars grant the valuable opportunity to model similar processes using nearby objects in our own Galaxy. SS 433 is a known microquasar that has two jets ("east" and "west") terminating in radio lobes of a surrounding supernova remnant, W 50. The recent observation of SS 433 with HAWC marked the first direct evidence of gamma-ray emission from the jets of a microquasar. Using HAWC data, we have measured a VHE flux of [formula not rendered] at the jet interaction region e1 in the east lobe and [formula not rendered] in the west lobe with a combined post-trial statistical significance of 5:4. The systematic studies used to confirm the VHE gamma-ray emission at 20 TeV from the SS 433 jet interaction regions is discussed in this work, along with a brief description of the theoretical interpretation associated with the observation. The HAWC data were also used to search for gamma rays from the known VHE binaries HESS J0632+057 and LS 5039. No emission was observed from HESS J0632+057, so we compute upper limits on its flux. Emission at low statistical significance is observed from LS 5039, which is located in a crowded region of the Galactic plane and is contaminated by gamma rays from nearby extended sources. A multiple-source analysis of the region surrounding LS 5039, as well as a time-series analysis of the light curve from LS 5039, are presented. At this time, data from HAWC are not significant enough to support multi-TeV emission from LS 5039"--Pages xi-xiii.

Author: Dimitris E Alexandreas
Publisher:
ISBN:
Category :
Languages : en
Pages : 134

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Author: The Cta Consortium
Publisher: World Scientific
ISBN: 9813270101
Category : Science
Languages : en
Pages : 365

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This book summarizes the science to be carried out by the upcoming Cherenkov Telescope Array, a major ground-based gamma-ray observatory that will be constructed over the next six to eight years. The major scientific themes, as well as core program of key science projects, have been developed by the CTA Consortium, a collaboration of scientists from many institutions worldwide.CTA will be the major facility in high-energy and very high-energy photon astronomy over the next decade and beyond. CTA will have capabilities well beyond past and present observatories. Thus, CTA's science program is expected to be rich and broad and will complement other major multiwavelength and multimessenger facilities. This book is intended to be the primary resource for the science case for CTA and it thus will be of great interest to the broader physics and astronomy communities. The electronic version (e-book) is available in open access.

Author: Daniel David Weeks
Publisher:
ISBN:
Category : Gamma ray astronomy
Languages : en
Pages : 402

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Author: Andrew Harold Szentgyorgyi
Publisher:
ISBN:
Category :
Languages : en
Pages : 456

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Author: Patrick Olson Slane
Publisher:
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Category :
Languages : en
Pages : 434

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Author: J. Truemper
Publisher: Springer Science & Business Media
ISBN: 9400945949
Category : Science
Languages : en
Pages : 306

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The idea to hold a conference on the Evolution of Close-Binary X-ray sources grew in the summer of 1984. At that time we were hoping that some new results would be harvested in the months to come which would stimulate further work. We were particularly looking towards the Euro pean X-ray Observatory, EXOSAT, for new contributions. How lucky we were; quite unexpected developments took place. Just prior to the conference, quasi-periodic oscillations (now known as QPO) were discovered in three bright low-mass X-ray binaries: GX 5-1, Sco X-1, and Cyg X-2. They played an important role at the meeting. The possibility that QPOs imply a neutron star magnetic dipole field, and a neutron star rotation period in the millisecond range, received a lot of attention. This is not surprising, as it lends support to the idea, suggested earlier, that the 6-msec binary radio pulsar PSR 1953+29 evolved from a stage in which it was a bright low-mass X-ray binary. There was special interest in the possibility of white dwarf collapse into a neutron star. This is a. particularly attractive way to form the bright low-mass X-ray binaries, often referred to as galactic bulge sources. It would allow for the possibility of a very young neutron star in a very old binary system. The relatively high magnetic fields that one could infer from QPO could then be explained.

Author: Felix A. Aharonian
Publisher: World Scientific
ISBN: 9789812561732
Category : Science
Languages : en
Pages : 516

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Gamma ray astronomy, the branch of high energy astrophysics that studies the sky in energetic ?-ray photons, is destined to play a crucial role in the exploration of nonthermal phenomena in the Universe in their most extreme and violent forms. The great potential of this discipline offers impressive coverage of many OC hot topicsOCO of modern astrophysics and cosmology, such as the origin of galactic and extragalactic cosmic rays, particle acceleration and radiation processes under extreme astrophysical conditions, and the search for dark matter."

Author: Philip Gregory Edwards
Publisher:
ISBN:
Category : Double stars
Languages : en
Pages :

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