Download or read book Transient Radiation Emission from Astrophysical Jets written by Yuen-Lam Wong and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Radiation Emission from Astrophysical Jets written by Yuen-lam Wong and published by . This book was released on 2007 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Jet Paradigm written by Tomaso Belloni and published by Springer. This book was released on 2009-12-21 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of the ?rst case of superluminal radio jets in our galaxy in 1994 from the bright and peculiar X-ray source GRS 1915+105 has opened the way to a major shift in the direction of studies of stellar-mass accreting binaries. The past decade has seen an impressive increase in multi-wavelength studies. It is now known that all black hole binaries in our galaxy are radio sources and most likely their radio emission originates from a powerful jet. In addition to the spectacular events related to the ejection of superluminal jets, steady jets are known from many systems. Compared with their supermassive cousins, the nuclei of active galaxies, stellar-mass X-ray binaries have the advantage of varying on time scales accessible within a human life (sometimes even much shorter than a second). This has led to the ?rst detailed studies of the relation between accretion and ejection. It is even possible that, excluding their “soft” periods, the majority of the power in gal- tic sources lies in the jets and not in the accretion ?ows. This means that until a few years ago we were struggling with a physical problem, accretion onto compact objects, without considering one of the most important components of the system. Models that associate part of the high-energy emission and even the fast aperiodic variability to the jet itself are now being proposed and jets can no longer be ignored.
Download or read book On the Nature of Emission from Relativistic Jets written by Patrick Kelly Crumley and published by . This book was released on 2015 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several longstanding questions in astrophysics center on the make up of relativistic astrophysical jets seen in microquasars, blazars, gamma-ray bursts, and super-Eddington tidal disruption events. What carries the energy in these jets? Is the majority of the energy carried by Poynting flux or by the baryonic matter? How is this energy converted into the non-thermal gamma-rays and X-rays seen in these systems? While there are many different theoretical models for launching a relativistic jet and producing the non-thermal emission observed in these astrophysical systems, often times the observational data are not good enough to convincingly discriminate between models. This thesis is comprised of several different projects that address these questions for several different astrophysical systems. First I discuss some general considerations of the synchrotron radiation from electrons accelerated by magnetic reconnection in a Poynting dominated jet. I show that the super-Eddington tidal disruption events (TDE) represent an unique opportunity to test different emission mechanisms in relativistic jets. I find that a magnetic dominated jet model can most easily explain the broadband observations in the observed super-Eddington TDE Sw J1644+57. In gamma-ray bursts, that hadronic emission models cannot explain the high energy ( >100 MeV) gamma-rays observed by the Fermi Large Area Telescope. I also include a chapter that suggests using the radio monitoring of the diffuse cloud in the galactic center object G2's to distinguish between different models of G2. Early observations of G2 after periapse passage suggests this prediction was correct.
Download or read book Relativistic Astrophysics of the Transient Universe written by Maurice H. P. M. Van Putten and published by Cambridge University Press. This book was released on 2012-07-05 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unified treatment of electromagnetic, hadronic and gravitational radiation processes associated with relativistic outflows from compact objects is ideal for researchers interested in the transient universe. It examines relativistic outflows and radiation processes and links contemporary astronomy to gravitational-wave experiments.
Download or read book Astrophysical Jets and Beams written by Michael D. Smith and published by Cambridge University Press. This book was released on 2012-02-16 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date study of astrophysical jets that will appeal to students and researchers in all areas of astrophysics.
Download or read book Constraining the Jet Properties of the New Transient X ray Binary Swift J1745 26 with the Submillimeter Array and James Clerk Maxwell Telescope written by Alexandra Jean Tetarenko and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accreting astrophysical sources are an important end-result of intricate stellar dynamics. A particularly puzzling aspect of this accretion process is the production and evolution of plasma outflows (known as jets). Although astrophysical jets have been studied for decades in accreting sources, the underlying physics that governs jet behaviour is still poorly understood. Since black hole X-ray binary (BHXRB) systems evolve on short timescales, the steady, compact relativistic plasma jet that is present at the onset of a BHXRB outburst serves as an important probe of jet physics and analogue for the universal process of jet production in other astrophysical systems. The detailed properties of BHXRB jets are encoded in the broadband spectral energy distribution (SED). However, we could only recently begin to fill in a large void in our broadband coverage, the mm/sub-mm regime. In this thesis, I discuss the results obtained from our observing campaign of the 2012 outburst of the new transient BHXRB, Swift J1745-26. These observations represent the first ever simultaneous radio and multiple-band mm/sub-mm observations of a BHXRB. The instruments used to obtain the data were the Karl G. Jansky Very Large Array (VLA), the Submillimeter Array (SMA) and the Submillimetre Common User Bolometer Array 2 detector on the James Clerk Maxwell Telescope (SCUBA-2 on the JCMT). With the combination of radio and mm/sub-mm data, I am able to directly measure the spectral indices in and between the radio and mm/sub-mm regimes as well as probe a relatively untested part of the jet spectrum (mm/sub-mm regime). I present these spectral measurements to determine whether the jet emission in the mm/sub-mm regime is consistent with typical jet models, where a single power-law can accurately describe the radio through sub-mm SED, as well as to constrain the origin of high mm/sub-mm fluxes that have been observed in the few BHXRBs in outburst. The spectral fitting process revealed that both the mm (230 GHz) and sub-mm (350 GHz) measurements are consistent with extrapolations from contemporaneous radio data (1-30 GHz) of a slightly inverted spectra (i.e., I measure higher flux density at higher frequencies). This indicates that even at higher mm/sub-mm frequencies a power-law can sufficiently describe the spectrum. Moreover, this suggests that the mechanism driving spectral inversion could be the same mechanism driving high mm/sub-mm fluxes in outbursting BHXRBs, rather then anomalous excess emission. Finally, I consider the effects of complex spectral features and flux variability at radio frequencies on our interpretation of the jet spectrum. Our analysis solidifies the importance of the mm/sub-mm regime in bridging the crucial gap between radio and IR frequencies in the jet spectrum, demonstrates the capacity of current mm/sub-mm instruments to address questions in this regime, and justifies the need to explore this regime in multiple sources.
Download or read book Nuclei in the Cosmos written by Heinz Oberhummer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear astrophysics as it stands today is a fascinating science. Even though, compared to other scientific fields, it is a young discipline which has developed only in this century, it has answered many questions concerning the under standing of our cosmos. One of these great achievements was the concept of nucleosynthesis, the creation of the elements in the early universe in interstellar matter and in stars. Nuclear astrophysics has continued, to solve many riddles of the evolution of the myriads of stars in our cosmos. This review volume attempts to provide an overview of the current status of nuclear astrophysics. Special emphasis is given to the interdisciplinary nature of the field: astronomy, nuclear physics, astrophysics and particle physics are equally involved. One basic effort of nuclear astrophysics is the collection of ob servational facts with astronomical methods. Laboratory studies of the nuclear processes involved in various astrophysical scenarios have provided fundamen tal information serving both as input for and test of astrophysical models. The theoretical understanding of nuclear reaction mechanisms is necessary, for example, to extrapolate the experimentally determined reaction rates to the thermonuclear energy range, which is relevant for the nuclear processes in our cosmos. Astrophysical models and calculations allow us to simulate how nuclear processes contribute to driving the evolution of stars, interstellar matter and the whole universe. Finally, elementary particle physics also plays an important role in the field of nuclear astrophysics, for instance through weak interaction processes involving neutrinos.
Download or read book Microquasars written by Alberto J. Castro-Tirado and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Third Microquasar Workshop (or the 'Fifth' Workshop on Galactic Relativ istic Jet Sources), was held in Granada, Andalucia (Spain) on 11-13 September 2000. The aim of this workshop in Granada, following the previous Microquasar Workshops in Greenbelt (1997) and Paris (1998) and the Workshops on galactic sources with relativistic jets in Jodrell Bank (1996) and Milton Keynes (1998), was to focus on the theoretical and observational aspects of microquasars. The study of microquasars, the sources in our Galaxy displaying powerful re lativistic jets, is a rapidly advancing field in astrophysics. The new instrumentation on ground (MERLIN, SCUBA, VLA, VLT) and aboard satellites (ASCA, BSAX, ISO, IXAE and RXTE) has provided important results, and much more is expected to come from Chandra and XMM-Newton. In the further future, powerful instru mentation will come online in the sub-mm (ALMA) and gamma-rays (INTEG RAL), extending our coverage to important regions for the study of microquasars. Energy transport via relativistic jets is one of the most important physical mechan isms taking place in compact objects. Large efforts have been devoted to properly understand the disk-jet connection, and even the effects of rotation or magnetic fields. Several new important advances have been made recently, both from the point of view of the theoretical treatment of jets and the different new observational tests.
Download or read book Virtual Astrophysical Jets written by Silvano Massaglia and published by Springer Science & Business Media. This book was released on 2013-06-05 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings are the result of a three-day meeting held in Oogliani (Italy), on October 2-4 2003, whose title was "VIrtual Astrophysical Jets 2003". Our goal in convening this meeting was to gather some of the scientists among the most active in the field of numerical simulations and modelling of astrophysi cal jets. For keeping the participants close to the "real world", we also invited a few observers to give up-to-date reviews outlining the state-of-the-art of jet observations. The principal aim of the meeting was thus to present and critically discuss the state-of-the-art numerical simulations, analytical models and laboratory ex periments for reproducing the main aspects of astrophysical jets and compar ing them with observations. The discussion has been focused on the following topics: • Observations and intepretions of jets from young stars and AGNs, comparisons of models with observations; • MHO accelerations of jets: steady self-similar models, MHO numerical simula tions of time-dependent accelerations mechanisms; • Jet stability and interaction with the ambient: formation of knots in YSO jets, jet survival to instabilities, deceleration of relativistic jets in FRI sources, simulations of jets-IGM interactions, jets propagation and galaxy formation; • Numerical codes and their validation: relativistic MHO codes, comparisons among different numerical schemes, jets in the laboratory and code validation. These topics have been discussed intensively during the meeting, and the out come of these discussions is presented in this volume. The contributions have been divided in five sections.
Download or read book Jets from Stars and Galactic Nuclei written by Wolfgang Kundt and published by Springer. This book was released on 1996-05-15 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Jets are ubiquitous in the Universe, but ill-understood. Conservative books base their interpretations on focused stellar winds, ejected "bullets", black-hole central engines, and in-situ upgrading of electron energies via shocks. This volume, however, attempts a uniform interpretation of the bipolar-flow family, involving extremely relativistic pair plasma as the jet substance, and rotating magnets (possibly burning disks) as the central engines. Among the discussed sources are SS 433, YSO jets, planetary nebulae, our galactic center, and the class of extragalactic QSOs, both radio-loud and radio-quiet.
Download or read book Handbook of X ray and Gamma ray Astrophysics written by Cosimo Bambi and published by Springer Nature. This book was released on with total page 5912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compact Stellar X ray Sources written by Walter Lewin and published by Cambridge University Press. This book was released on 2006-04-06 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray astronomy is the prime available window on astrophysical compact objects: black holes, neutron stars and white dwarfs. In this book, prominent experts provide a comprehensive overview of the observations and astrophysics of these objects. This is a valuable reference for graduate students and active researchers.
Download or read book Radiative Processes in Astrophysics written by George B. Rybicki and published by John Wiley & Sons. This book was released on 2008-09-26 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiative Processes in Astrophysics: This clear, straightforward, and fundamental introduction is designed to present-from a physicist's point of view-radiation processes and their applications to astrophysical phenomena and space science. It covers such topics as radiative transfer theory, relativistic covariance and kinematics, bremsstrahlung radiation, synchrotron radiation, Compton scattering, some plasma effects, and radiative transitions in atoms. Discussion begins with first principles, physically motivating and deriving all results rather than merely presenting finished formulae. However, a reasonably good physics background (introductory quantum mechanics, intermediate electromagnetic theory, special relativity, and some statistical mechanics) is required. Much of this prerequisite material is provided by brief reviews, making the book a self-contained reference for workers in the field as well as the ideal text for senior or first-year graduate students of astronomy, astrophysics, and related physics courses. Radiative Processes in Astrophysics also contains about 75 problems, with solutions, illustrating applications of the material and methods for calculating results. This important and integral section emphasizes physical intuition by presenting important results that are used throughout the main text; it is here that most of the practical astrophysical applications become apparent.
Download or read book Astrophysical Jets written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Many astrophysical sources - especially those powered by release of gravitational energy - are associated with an outflow of material, generally taking place along the axis of symmetry of the system. In the most extreme cases, the outflow is accelerated to relativistic speeds; such a phenomenon is known as an astrophysical jet. When a relativistic jet points close to our line of sight, the observed radiation is strongly Doppler-boosted. Most spectacular cases of astrophysical jets are those produced by active galactic nuclei, where the measured spectrum - presumably dominated by the radiation from the jet - reaches up to the multi-GeV range. Our knowledge of these jets is limited: we don't fully understand how are they formed, collimated, and accelerated, and what is the process of conversion of the bulk energy of the jet into radiation. We anticipate that the increased sensitivity of GLAST will provide us with spectacular data yielding new insights as to their origin and structure.
Download or read book JET Simulations Experiments and Theory written by Christophe Sauty and published by Springer. This book was released on 2019-08-02 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2008, the European FP6 JETSET project ended. JETSET, for Jet, Simulations, Experiments, and Theory, was a joint research network of European expert teams on protostellar jets. The present proceedings are a collection of contributions presenting new results obtained by those groups since the end of the JETSET program. This is also the occasion to celebrate Kanaris Tsinganos’ important contributions to this network and for his enlightening insight in the subject that inspired us all. Some of the former JETSET students are now in the academic world and the subject has never been so alive. So we present here a collection of results of what has been done in the field of protostellar jets in the past ten years from the theoretical, numerical, observational and experimental point of view. We also present new challenges in the field of protostellar jets and what we should expect from the development of new instruments and new numerical codes in the near future. We also gather results on the impact of the study of protostellar jets on other jet studies in particular on relativistic jets. As a matter of fact, it is time for a new network.
Download or read book Pathways to Discovery in Astronomy and Astrophysics for the 2020s written by National Academies of Sciences, Engineering, and Medicine and published by . This book was released on 2022-08-04 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: The steering committee was specifically asked to (1) provide an overview of the current state of astronomy and astrophysics science, and technology research in support of that science, with connections to other scientific areas where appropriate; (2) identify the most compelling science challenges and frontiers in astronomy and astrophysics, which shall motivate the committee’s strategy for the future; (3) develop a comprehensive research strategy to advance the frontiers of astronomy and astrophysics for the period 2022-2032 that will include identifying, recommending, and ranking the highest-priority research activities; (4) utilize and recommend decision rules, where appropriate, that can accommodate significant but reasonable deviations in the projected budget or changes in urgency precipitated by new discoveries or unanticipated competitive activities; (5) assess the state of the profession, including workforce and demographic issues in the field, identify areas of concern and importance to the community, and where possible, provide specific, actionable, and practical recommendations to the agencies and community to address these areas. This report proposes a broad, integrated plan for space- and ground-based astronomy and astrophysics for the decade 2023-2032. It also lays the foundations for further advances in the following decade.
