Search results for "QB1-991"
showing 10 items of 34 documents
Numerical Simulations of Jets from Active Galactic Nuclei
2019
Numerical simulations have been playing a crucial role in the understanding of jets from active galactic nuclei (AGN) since the advent of the first theoretical models for the inflation of giant double radio galaxies by continuous injection in the late 1970s. In the almost four decades of numerical jet research, the complexity and physical detail of simulations, based mainly on a hydrodynamical/magneto-hydrodynamical description of the jet plasma, have been increasing with the pace of the advance in theoretical models, computational tools and numerical methods. The present review summarizes the status of the numerical simulations of jets from AGNs, from the formation region in the neighborho…
A Decade of GRB Follow-Up by BOOTES in Spain (2003–2013)
2016
This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in a previous article and are here reviewed and updated, and additional detection data points are included as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.
ON THE FON ASTROPLATE PROJECT ACCOMPLISHMENT
2019
The plan of the photographic survey of thenorthern sky (FON) was proposed in 1976 in Golosiiv ob-servatory (now MAO NAS of Ukraine) by I. Kolchinskyand A. Onegina. The final project of the Compiled FONACcatalog (FON Astrographic Catalog) is based on the digitaldata of photographic plates exposed at four observatories.They are MAO NAS of Ukraine (Kyiv, Ukraine), Kitabastronomical observatory (Tashkent, Uzbekistan), Hissarastronomical observatory (Dushanbe, Tajikistan), and Bal-done observatory (Latvia)). The total amount of plates is5700. The result is expected to be the catalog of positionsand B-magnitudes of stars covered the declination areafrom -20 to 90 degrees. The estimated mean epoch…
Multimessenger Binary Mergers Containing Neutron Stars: Gravitational Waves, Jets, and γ-Ray Bursts
2021
Neutron stars (NSs) are extraordinary not only because they are the densest form of matter in the visible Universe but also because they can generate magnetic fields ten orders of magnitude larger than those currently constructed on earth. The combination of extreme gravity with the enormous electromagnetic (EM) fields gives rise to spectacular phenomena like those observed on August 2017 with the merger of a binary neutron star system, an event that generated a gravitational wave (GW) signal, a short γ-ray burst (sGRB), and a kilonova. This event serves as the highlight so far of the era of multimessenger astronomy. In this review, we present the current state of our theoretical understand…
Coronal Loops: Observations and Modeling of Confined Plasma
2010
Coronal loops are the building blocks of the X-ray bright solar corona. They owe their brightness to the dense confined plasma, and this review focuses on loops mostly as structures confining plasma. After a brief historical overview, the review is divided into two separate but not independent sections: the first illustrates the observational framework, the second reviews the theoretical knowledge. Quiescent loops and their confined plasma are considered, and therefore topics such as loop oscillations and flaring loops (except for non-solar ones which provide information on stellar loops) are not specifically addressed here. The observational section discusses loop classification and popula…
ASTEROID SEARCH RESULTS FOR DIGITIZED ASTROPLATES OF 1.2m TELESCOPE IN BALDONE
2019
The work on the mass search for asteroids on astroplate images and the determination of their coordi- nates was begun in 2016. The basis for current search was the processing results of digitized photographic plates and films obtained at the observatory in Baldone in 1967-1993. Observations with a single exposure in different spectral bands were carried out using the 1.2m Schmidt telescope in Baldone. We used all observations in the U Johnson's spec- tral band (on plates) and significant part of them in V band (on films). Photometric band U was realized by combining emulsion ORWO Zu1 (Zu2 or Zu21 or Kodak 103aO or IIaO) with UG1 filter. For films with A600 emulsion and filter ZS17 a photome…
A 3-Year Sample of Almost 1,600 Elves Recorded Above South America by the Pierre Auger Cosmic-Ray Observatory
2020
The time and location of the 1,598 verified and reconstructed elves, used for the analysis showcased in this paper, are publicly available on the website of the Pierre Auger Observatory (https://www.auger.org/ index.php/science/data). We wish to thank the World Wide Lightning Location Network (http://wwlln.net), a collaboration among over 50 universities and institutions, for providing the lightning location data used in this paper. We acknowledge Robert Marshall for providing one of the most advanced elve simulations to the public, a key tool in understanding the elves observed by the Pierre Auger Observatory. The successful installation, commissioning, and operation of the Pierre Auger Ob…
Probing the Internal Structure of Magnetized, Relativistic Jets with Numerical Simulations
2016
From an observational point of view, unveiling the physical processes behind the nature of the jets emanating from radio-loud AGN demands the resolution of the structure across the jet with the highest angular resolutions. Relying on a magneto-fluid dynamical description, numerical simulations can help to characterize the internal structure of jets (transversal structure, magnetic field structure, internal shocks, etc.). In the first part of the paper, we shall discuss equilibrium models of magnetized, relativistic, infinite, axisymmetric jets with rotation propagating through a homogeneous, static, unmagnetized ambient medium. Then, these transversal equilibrium profiles will be used to bu…
Neutrino Mass Ordering from Oscillations and Beyond: 2018 Status and Future Prospects
2018
The ordering of the neutrino masses is a crucial input for a deep understanding of flavor physics, and its determination may provide the key to establish the relationship among the lepton masses and mixings and their analogous properties in the quark sector. The extraction of the neutrino mass ordering is a data-driven field expected to evolve very rapidly in the next decade. In this review, we both analyze the present status and describe the physics of subsequent prospects. Firstly, the different current available tools to measure the neutrino mass ordering are described. Namely, reactor, long-baseline (accelerator and atmospheric) neutrino beams, laboratory searches for beta and neutrinol…
Four Years of Real-Time GRB Followup by BOOTES-1B (2005–2008)
2010
Four years of BOOTES-1B GRB follow-up history are summarised for the first time in the form of a table. The successfully followed events are described case by case. Further, the data are used to show the GRB trigger rate in Spain on a per-year basis, resulting in an estimate of 18 triggers and about 51 hours of telescope time per year for real-time triggers. These numbers grow to about 22 triggers and 77 hours per year if we include also the GRBs observable within 2 hours after the trigger. Copyright © 2010 Martin Jelínek et al.