Jet Quenching in Relativistic Heavy Ion Collisions at the LHC

CERN Document Server

Angerami, Aaron

Jet production in relativistic heavy ion collisions is studied using Pb+Pb collisions at a center of mass energy of 2.76 TeV per nucleon. The measurements reported here utilize data collected with the ATLAS detector at the LHC from the 2010 Pb ion run corresponding to a total integrated luminosity of 7 μb−1. The results are obtained using fully reconstructed jets using the anti-kt algorithm with a per-event background subtraction procedure. A centrality-dependent modification of the dijet asymmetry distribution is observed, which indicates a higher rate of asymmetric dijet pairs in central collisions relative to peripheral and pp collisions. Simultaneously the dijet angular correlations show almost no centrality dependence. These results provide the first direct observation of jet quenching. Measurements of the single inclusive jet spectrum, measured with jet radius parameters R = 0.2,0.3,0.4 and 0.5, are also presented. The spectra are unfolded to correct for the finite energy resolution introduced by bot...

The superluminal radio source 4c 39. 25 as relativistic jet prototype. El cuasar superluminal 4C 93. 25 como prototipo de jet relativistia

Energy Technology Data Exchange (ETDEWEB)

Alberdi, A.; Gomez, J.L.; Marcaide, J.M.

1993-01-01

We have developed a numerical code which solves the synchrotron radiation transfer equations to compute the total and polarized emission of bent shocked relativistic jets, and we have applied it to reproduce the compact structure, kinematic evolution of the superluminal radio source 4C 39.25 contains a bent relativistic jet which is misaligned relative to the observer near the core region, leading to a relatively low core brightness. (Author) 12 refs.

Radiatively-driven general relativistic jets

Indian Academy of Sciences (India)

Mukesh K. Vyas

2018-02-10

Feb 10, 2018 ... relativistic jets and shocks induced by non radial nature of the cross section. Isothermal assumption does not contain the effect of the thermal gradient term which is a significant accelerating agent and is very effec- tive close to the BH. It is also the same region where one needs to consider the effects of ...

Relativistic jets in narrow-line Seyfert 1 galaxies. New discoveries and open questions

Directory of Open Access Journals (Sweden)

D’Ammando F.

2013-12-01

Full Text Available Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the γ-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope on board Fermi confirmed that these two are the most numerous classes of identified sources in the extragalactic γ-ray sky, but the discovery of γ-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets. Considering that narrow-line Seyfert 1 galaxies seem to be typically hosted in spiral galaxy, this finding poses intriguing questions about the nature of these objects, the onset of production of relativistic jets, and the cosmological evolution of radio-loud AGN. Here, we discuss the radio-to-γ-rays properties of the γ-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.

Relativistic Jets on all Scales in Accreting Black Holes: Contributions from Simbol-X

Science.gov (United States)

Corbel, Stéphane

2009-05-01

In the last several years, multiwavelength observations of accreting black holes have allowed a general characterisation of black holes properties as they evolve along the course of their outburst cycles. Relativistic jets, in their multiple forms, have profoundly impacted our perception and understanding of emission processes in these systems. In these Proceedings, I will highlight some possible contributions from Simbol-X related to jets in accreting sources.

Relativistic Jets on all Scales in Accreting Black Holes: Contributions from Simbol-X

International Nuclear Information System (INIS)

Corbel, Stephane

2009-01-01

In the last several years, multiwavelength observations of accreting black holes have allowed a general characterisation of black holes properties as they evolve along the course of their outburst cycles. Relativistic jets, in their multiple forms, have profoundly impacted our perception and understanding of emission processes in these systems. In these Proceedings, I will highlight some possible contributions from Simbol-X related to jets in accreting sources.

DISCOVERY OF A PSEUDOBULGE GALAXY LAUNCHING POWERFUL RELATIVISTIC JETS

Energy Technology Data Exchange (ETDEWEB)

Kotilainen, Jari K.; Olguín-Iglesias, Alejandro [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö (Finland); León-Tavares, Jonathan; Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281-S9, B-9000 Gent (Belgium); Anórve, Christopher [Facultad de Ciencias de la Tierra y del Espacio de la Universidad Autónoma de Sinaloa, Blvd. de la Americas y Av. Universitarios S/N, Ciudad Universitaria, C.P. 80010, Culiacán Sinaloa, México (Mexico); Chavushyan, Vahram; Carrasco, Luis, E-mail: jarkot@utu.fi [Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE), Apartado Postal 51 y 216, 72000 Puebla (Mexico)

2016-12-01

Supermassive black holes launching plasma jets at close to the speed of light, producing gamma-rays, have ubiquitously been found to be hosted by massive elliptical galaxies. Since elliptical galaxies are generally believed to be built through galaxy mergers, active galactic nuclei (AGN) launching relativistic jets are associated with the latest stages of galaxy evolution. We have discovered a pseudobulge morphology in the host galaxy of the gamma-ray AGN PKS 2004-447. This is the first gamma-ray emitter radio-loud AGN found to have been launched from a system where both the black hole and host galaxy have been actively growing via secular processes. This is evidence of an alternative black hole–galaxy co-evolutionary path to develop powerful relativistic jets, which is not merger driven.

The GRB-SLSN connection: misaligned magnetars, weak jet emergence, and observational signatures

Science.gov (United States)

Margalit, Ben; Metzger, Brian D.; Thompson, Todd A.; Nicholl, Matt; Sukhbold, Tuguldur

2018-04-01

Multiple lines of evidence support a connection between hydrogen-poor superluminous supernovae (SLSNe) and long-duration gamma-ray bursts (GRBs). Both classes of events require a powerful central energy source, usually attributed to a millisecond magnetar or an accreting black hole. The GRB-SLSN link raises several theoretical questions: What distinguishes the engines responsible for these different phenomena? Can a single engine power both a GRB and a luminous SN in the same event? We propose a unifying model for magnetar thermalization and jet formation: misalignment between the rotation (Ω) and magnetic dipole (μ) axes dissipates a fraction of the spin-down power by reconnection in the striped equatorial wind, providing a guaranteed source of `thermal' emission to power the supernova. The remaining unthermalized power energizes a relativistic jet. We show that even weak relativistic jets of luminosity ˜1046 erg s-1 can escape the expanding SN ejecta implying that escaping relativistic jets may accompany many SLSNe. We calculate the observational signature of these jets. We show that they may produce transient ultraviolet (UV) cocoon emission lasting a few hours when the jet breaks out of the ejecta surface. A longer lived optical/UV signal may originate from a mildly relativistic wind driven from the interface between the jet and the ejecta walls, which could explain the secondary early-time maximum observed in some SLSNe light curves, such as LSQ14bdq. Our scenario predicts a population of GRB from on-axis jets with extremely long durations, potentially similar to the population of `jetted-tidal disruption events', in coincidence with a small subset of SLSNe.

Relativistic jets from accreting black holes

International Nuclear Information System (INIS)

Coriat, Mickael

2010-01-01

Matter ejection processes, more commonly called jets, are among the most ubiquitous phenomena of the universe at ail scales of size and energy and are inseparable from accretion process. This intimate link, still poorly understood, is the main focus of this thesis. Through multi-wavelength observations of X-ray binary Systems hosting a black hole, I will try to bring new constraints on the physics of relativistic jets and the accretion - ejection coupling. We strive first to compare the simultaneous infrared, optical and X-ray emissions of the binary GX 339-4 over a period of five years. We study the nature of the central accretion flow, one of the least understood emission components of X-ray binaries, both in its geometry and in term of the physical processes that take place. This component is fundamental since it is could be the jets launching area or be highly connected to it. Then we focus on the infrared emission of the jets to investigate the physical conditions close to the jets base. We finally study the influence of irradiation of the outer accretion disc by the central X-ray source. Then, we present the results of a long-term radio and X-ray study of the micro-quasar H1743- 322. This System belongs to a population of accreting black holes that display, for a given X-ray luminosity, a radio emission fainter than expected. We make several assumptions about the physical origin of this phenomenon and show in particular that these sources could have a radiatively efficient central accretion flow. We finally explore the phases of return to the hard state of GX 339-4. We follow the re-emergence of the compact jets emission and try to bring new constraints on the physics of jet formation. (author) [fr

Inductive and electrostatic acceleration in relativistic jet-plasma interactions.

Science.gov (United States)

Ng, Johnny S T; Noble, Robert J

2006-03-24

We report on the observation of rapid particle acceleration in numerical simulations of relativistic jet-plasma interactions and discuss the underlying mechanisms. The dynamics of a charge-neutral, narrow, electron-positron jet propagating through an unmagnetized electron-ion plasma was investigated using a three-dimensional, electromagnetic, particle-in-cell computer code. The interaction excited magnetic filamentation as well as electrostatic plasma instabilities. In some cases, the longitudinal electric fields generated inductively and electrostatically reached the cold plasma-wave-breaking limit, and the longitudinal momentum of about half the positrons increased by 50% with a maximum gain exceeding a factor of 2 during the simulation period. Particle acceleration via these mechanisms occurred when the criteria for Weibel instability were satisfied.

CORONA, JET, AND RELATIVISTIC LINE MODELS FOR SUZAKU/RXTE/CHANDRA-HETG OBSERVATIONS OF THE CYGNUS X-1 HARD STATE

International Nuclear Information System (INIS)

Nowak, Michael A.; Trowbridge, Sarah N.; Davis, John E.; Hanke, Manfred; Wilms, Joern; Markoff, Sera B.; Maitra, Dipankar; Tramper, Frank; Pottschmidt, Katja; Coppi, Paolo

2011-01-01

Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard 'low states'. Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the 'focused wind' from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary's focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c 2 . All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus, whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum dependent, none of the broad line fits allow for an inner disk radius that is >40 GM/c 2 .

Studies of relativistic jets in active galactic nuclei with SKA

NARCIS (Netherlands)

Agudo, I.; Bottcher, M.; Falcke, H.; Georganopoulos, M.; Ghisellini, G.; Giovannini, G.; Giroletti, M.; Gomez, J.L.; Gurvits, L.; Laing, R.; Lister, M.; Marti, J.M.; Meyer, E.T.; Mizuno, Y.; O'Sullivan, S.; Padovani, P.; Paragi, Z.; Perucho, M.; Schleicher, D.; Stawarz, L.; Vlahakis, N.; Wardle, J.

2014-01-01

Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different chapters of the previous SKA Science Book (Carilli &

A Universal Scaling for the Energetics of Relativistic Jets From Black Hole Systems

Science.gov (United States)

Nemmen, R. S.; Georganopoulos, M.; Guiriec, S.; Meyer, E. T.; Gehrels, N.; Sambruna, R. M.

2013-01-01

Black holes generate collimated, relativistic jets which have been observed in gamma-ray bursts (GRBs), microquasars, and at the center of some galaxies (active galactic nuclei; AGN). How jet physics scales from stellar black holes in GRBs to the supermassive ones in AGNs is still unknown. Here we show that jets produced by AGNs and GRBs exhibit the same correlation between the kinetic power carried by accelerated particles and the gamma-ray luminosity, with AGNs and GRBs lying at the low and high-luminosity ends, respectively, of the correlation. This result implies that the efficiency of energy dissipation in jets produced in black hole systems is similar over 10 orders of magnitude in jet power, establishing a physical analogy between AGN and GRBs.

Transmission line analogy for relativistic Poynting-flux jets

Science.gov (United States)

Lovelace, R. V. E.; Kronberg, P. P.

2013-04-01

Radio emission, polarization and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet carries a galactic-scale electric current and that it is magnetically dominated. We develop the theory of magnetically dominated or Poynting-flux jets by making an analogy of a Poynting jet with a transmission line or waveguide carrying a net current and having a potential drop across it (from the jet's axis to its radius) and a definite impedance which we derive. The electromagnetic energy flow in the jet is the jet impedance times the square of the jet current. The observed current in 3C 303 can be used to calculate the electromagnetic energy flow in this magnetically dominated jet. Time dependent but not necessarily small perturbations of a Poynting-flux jet are described by the `telegrapher's equations'. These predict the propagation speed of disturbances and the effective wave impedance for forward and backward propagating wave components. A localized disturbance of a Poynting jet gives rise to localized dissipation in the jet which may explain the enhanced synchrotron radiation in the knots of the 3C 303 jet, and also in the apparently stationary knot HST-1 in the jet near the nucleus of the nearby galaxy M87. For a relativistic Poynting jet on parsec scales, the reflected voltage wave from an inductive termination or load can lead to a backward propagating wave which breaks down the magnetic insulation of the jet giving |{boldsymbol E}| /|{boldsymbol B}|ge 1. At the threshold for breakdown, |{boldsymbol E}|/|{boldsymbol B}|=1, positive and negative particles are directly accelerated in the {boldsymbol E} × {boldsymbol B} direction which is approximately along the jet axis. Acceleration can occur up to Lorentz factors ˜107. This particle acceleration mechanism is distinct from that in shock waves and that in magnetic field reconnection.

Numerically calibrated model for propagation of a relativistic unmagnetized jet in dense media

Science.gov (United States)

Harrison, Richard; Gottlieb, Ore; Nakar, Ehud

2018-03-01

Relativistic jets reside in high-energy astrophysical systems of all scales. Their interaction with the surrounding media is critical as it determines the jet evolution, observable signature, and feedback on the environment. During its motion the interaction of the jet with the ambient media inflates a highly pressurized cocoon, which under certain conditions collimates the jet and strongly affects its propagation. Recently, Bromberg et al. (2011b) derived a general simplified (semi)analytic solution for the evolution of the jet and the cocoon in case of an unmagnetized jet that propagates in a medium with a range of density profiles. In this work we use a large suite of 2D and 3D relativistic hydrodynamic simulations in order to test the validity and accuracy of this model. We discuss the similarities and differences between the analytic model and numerical simulations and also, to some extent, between 2D and 3D simulations. Our main finding is that although the analytic model is highly simplified, it properly predicts the evolution of the main ingredients of the jet-cocoon system, including its temporal evolution and the transition between various regimes (e.g., collimated to uncollimated). The analytic solution predicts a jet head velocity that is faster by a factor of about 3 compared to the simulations, as long as the head velocity is Newtonian. We use the results of the simulations to calibrate the analytic model which significantly increases its accuracy. We provide an applet that calculates semi-analytically the propagation of a jet in an arbitrary density profile defined by the user at http://www.astro.tau.ac.il/ ore/propagation.html.

Numerically calibrated model for propagation of a relativistic unmagnetized jet in dense media

Science.gov (United States)

Harrison, Richard; Gottlieb, Ore; Nakar, Ehud

2018-06-01

Relativistic jets reside in high-energy astrophysical systems of all scales. Their interaction with the surrounding media is critical as it determines the jet evolution, observable signature, and feedback on the environment. During its motion, the interaction of the jet with the ambient media inflates a highly pressurized cocoon, which under certain conditions collimates the jet and strongly affects its propagation. Recently, Bromberg et al. derived a general simplified (semi-)analytic solution for the evolution of the jet and the cocoon in case of an unmagnetized jet that propagates in a medium with a range of density profiles. In this work we use a large suite of 2D and 3D relativistic hydrodynamic simulations in order to test the validity and accuracy of this model. We discuss the similarities and differences between the analytic model and numerical simulations and also, to some extent, between 2D and 3D simulations. Our main finding is that although the analytic model is highly simplified, it properly predicts the evolution of the main ingredients of the jet-cocoon system, including its temporal evolution and the transition between various regimes (e.g. collimated to uncollimated). The analytic solution predicts a jet head velocity that is faster by a factor of about 3 compared to the simulations, as long as the head velocity is Newtonian. We use the results of the simulations to calibrate the analytic model which significantly increases its accuracy. We provide an applet that calculates semi-analytically the propagation of a jet in an arbitrary density profile defined by the user at http://www.astro.tau.ac.il/˜ore/propagation.html.

VARIABILITY IN ACTIVE GALACTIC NUCLEI FROM PROPAGATING TURBULENT RELATIVISTIC JETS

Energy Technology Data Exchange (ETDEWEB)

Pollack, Maxwell; Pauls, David; Wiita, Paul J., E-mail: wiitap@tcnj.edu [Department of Physics, The College of New Jersey P.O. Box 7718, Ewing, NJ 08628-0718 (United States)

2016-03-20

We use the Athena hydrodynamics code to model propagating two-dimensional relativistic jets as approximations to the growth of radio-loud active galactic nuclei for various input jet velocities and jet-to-ambient matter density ratios. Using results from these simulations we estimate the changing synchrotron emission by summing the fluxes from a vertical strip of zones behind the reconfinement shock, which is nearly stationary, and from which a substantial portion of the flux variability should arise. We explore a wide range of timescales by considering two light curves from each simulation; one uses a relativistic turbulence code with bulk velocities taken from our simulations as input, while the other uses the bulk velocity data to compute fluctuations caused by variations in the Doppler boosting due to changes in the direction and the speed of the flow through all zones in the strip. We then calculate power spectral densities (PSDs) from the light curves for both turbulent and bulk velocity origins for variability. The range of the power-law slopes of the PSDs for the turbulence induced variations is −1.8 to −2.3, while for the bulk velocity produced variations this range is −2.1 to −2.9; these are in agreement with most observations. When superimposed, these power spectra span a very large range in frequency (about five decades), with the turbulent fluctuations yielding most of the shorter timescale variations and the bulk flow changes dominating the longer periods.

VARIABILITY IN ACTIVE GALACTIC NUCLEI FROM PROPAGATING TURBULENT RELATIVISTIC JETS

International Nuclear Information System (INIS)

Pollack, Maxwell; Pauls, David; Wiita, Paul J.

2016-01-01

We use the Athena hydrodynamics code to model propagating two-dimensional relativistic jets as approximations to the growth of radio-loud active galactic nuclei for various input jet velocities and jet-to-ambient matter density ratios. Using results from these simulations we estimate the changing synchrotron emission by summing the fluxes from a vertical strip of zones behind the reconfinement shock, which is nearly stationary, and from which a substantial portion of the flux variability should arise. We explore a wide range of timescales by considering two light curves from each simulation; one uses a relativistic turbulence code with bulk velocities taken from our simulations as input, while the other uses the bulk velocity data to compute fluctuations caused by variations in the Doppler boosting due to changes in the direction and the speed of the flow through all zones in the strip. We then calculate power spectral densities (PSDs) from the light curves for both turbulent and bulk velocity origins for variability. The range of the power-law slopes of the PSDs for the turbulence induced variations is −1.8 to −2.3, while for the bulk velocity produced variations this range is −2.1 to −2.9; these are in agreement with most observations. When superimposed, these power spectra span a very large range in frequency (about five decades), with the turbulent fluctuations yielding most of the shorter timescale variations and the bulk flow changes dominating the longer periods

The Innermost Regions of Relativistic Jets: Wrapping Up the Enigma

Directory of Open Access Journals (Sweden)

Marscher Alan P.

2013-12-01

Full Text Available What are relativistic jets like within a million Schwarzschild radii of the accreting black hole that powers them? A meeting in Granada, Spain in June 2013, organized by José L. Gómez and his conspirators brought together observers and theorists to survey the current state of observational data and efforts to interpret them. This conference summary reviews the results, insights, arguments, conflicts, and agreements that occurred during five sunny days spent in a windowless room in a hotel at the bottom of the hill that holds the heart of the beautiful city.

Relativistic jet with shock waves like model of superluminal radio source. Jet relativista con ondas de choque como modelo de radio fuentes superluminales

Energy Technology Data Exchange (ETDEWEB)

Alberdi, A.; Gomez, J.L.; Marcaide, J.M.

1993-01-01

The structure of the compact radio sources at milliarcsecond angular resolution can be explained in terms of shock waves propagating along bent jets. These jets consist of narrow-angle cones of plasma flowing at bulk relativistic velocities, within tangled magnetic fields, emitting synchrotron radiation. We have developed a numerical code which solves the synchrotron radiation transfer equations to compute the total and polarized emission of bent shocked relativistic jets, and we have applied it to reproduce the compact structure, kenimatic evolution and time flux density evolution of the superluminal radio source 4C 39.25 and to obtain its jet physical parameters. (Author) 23 ref.

Radio follow-up observations of stellar tidal disruption flares: Constraints on off-axis jets

Directory of Open Access Journals (Sweden)

Körding E.

2012-12-01

Full Text Available Observations of active galactic nuclei (AGN and X-ray binaries have shown that relativistic jets are ubiquitous when compact objects accrete. One could therefore anticipate the launch of a jet after a star is disrupted and accreted by a massive black hole. This birth of a relativistic jet may have been observed recently in two stellar tidal disruption flares (TDFs, which were discovered in gamma-rays by Swift. Yet no transient radio emission has been detected from the tens of TDF candidates that were discovered at optical to soft X-ray frequencies. Because the sample that was followed-up at radio frequencies is small, the non-detections can be explained by Doppler boosting, which reduces the jet flux for off-axis observers. Plus, the existing followup observation are mostly within ∼ 10 months of the discovery, so the non-detections can also be due to a delay of the radio emission with respect to the time of disruption. To test the conjecture that all TDFs launch jets, we obtained 5 GHz follow-up observations with the Jansky VLA of six known TDFs. To avoid missing delayed jet emission, our observations probe 1–8 years since the estimated time of disruption. None of the sources are detected, with very deep upper limits at the 10 micro Jansky level. These observations rule out the hypothesis that these TDFs launched jets similar to radio-loud quasars. We also constrain the possibility that the flares hosted a jet identical to Sw 1644+57.

PARSEC-SCALE FARADAY ROTATION MEASURES FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF ACTIVE GALACTIC NUCLEUS JETS

International Nuclear Information System (INIS)

Broderick, Avery E.; McKinney, Jonathan C.

2010-01-01

It is now possible to compare global three-dimensional general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to multi-wavelength polarized VLBI observations of the pc-scale structure of active galactic nucleus (AGN) jets. Unlike the jet emission, which requires post hoc modeling of the nonthermal electrons, the Faraday rotation measures (RMs) depend primarily upon simulated quantities and thus provide a direct way to confront simulations with observations. We compute RM distributions of a three-dimensional global GRMHD jet formation simulation, extrapolated in a self-consistent manner to ∼10 pc scales, and explore the dependence upon model and observational parameters, emphasizing the signatures of structures generic to the theory of MHD jets. With typical parameters, we find that it is possible to reproduce the observed magnitudes and many of the structures found in AGN jet RMs, including the presence of transverse RM gradients. In our simulations, the RMs are generated in the circum-jet material, hydrodynamically a smooth extension of the jet itself, containing ordered toroidally dominated magnetic fields. This results in a particular bilateral morphology that is unlikely to arise due to Faraday rotation in distant foreground clouds. However, critical to efforts to probe the Faraday screen will be resolving the transverse jet structure. Therefore, the RMs of radio cores may not be reliable indicators of the properties of the rotating medium. Finally, we are able to constrain the particle content of the jet, finding that at pc scales AGN jets are electromagnetically dominated, with roughly 2% of the comoving energy in nonthermal leptons and much less in baryons.

PARSEC-SCALE FARADAY ROTATION MEASURES FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF ACTIVE GALACTIC NUCLEUS JETS

Energy Technology Data Exchange (ETDEWEB)

Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada); McKinney, Jonathan C., E-mail: aeb@cita.utoronto.c, E-mail: jmckinne@stanford.ed [Department of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305-4060 (United States)

2010-12-10

It is now possible to compare global three-dimensional general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to multi-wavelength polarized VLBI observations of the pc-scale structure of active galactic nucleus (AGN) jets. Unlike the jet emission, which requires post hoc modeling of the nonthermal electrons, the Faraday rotation measures (RMs) depend primarily upon simulated quantities and thus provide a direct way to confront simulations with observations. We compute RM distributions of a three-dimensional global GRMHD jet formation simulation, extrapolated in a self-consistent manner to {approx}10 pc scales, and explore the dependence upon model and observational parameters, emphasizing the signatures of structures generic to the theory of MHD jets. With typical parameters, we find that it is possible to reproduce the observed magnitudes and many of the structures found in AGN jet RMs, including the presence of transverse RM gradients. In our simulations, the RMs are generated in the circum-jet material, hydrodynamically a smooth extension of the jet itself, containing ordered toroidally dominated magnetic fields. This results in a particular bilateral morphology that is unlikely to arise due to Faraday rotation in distant foreground clouds. However, critical to efforts to probe the Faraday screen will be resolving the transverse jet structure. Therefore, the RMs of radio cores may not be reliable indicators of the properties of the rotating medium. Finally, we are able to constrain the particle content of the jet, finding that at pc scales AGN jets are electromagnetically dominated, with roughly 2% of the comoving energy in nonthermal leptons and much less in baryons.

Variable jet properties in GRB 110721A: time resolved observations of the jet photosphere

Science.gov (United States)

Iyyani, S.; Ryde, F.; Axelsson, M.; Burgess, J. M.; Guiriec, S.; Larsson, J.; Lundman, C.; Moretti, E.; McGlynn, S.; Nymark, T.; Rosquist, K.

2013-08-01

Fermi Gamma-ray Space Telescope observations of GRB 110721A have revealed two emission components from the relativistic jet: emission from the photosphere, peaking at ˜100 keV, and a non-thermal component, which peaks at ˜1000 keV. We use the photospheric component to calculate the properties of the relativistic outflow. We find a strong evolution in the flow properties: the Lorentz factor decreases with time during the bursts from Γ ˜ 1000 to ˜150 (assuming a redshift z = 2; the values are only weakly dependent on unknown efficiency parameters). Such a decrease is contrary to the expectations from the internal shocks and the isolated magnetar birth models. Moreover, the position of the flow nozzle measured from the central engine, r0, increases by more than two orders of magnitude. Assuming a moderately magnetized outflow we estimate that r0 varies from 106 to ˜109 cm during the burst. We suggest that the maximal value reflects the size of the progenitor core. Finally, we show that these jet properties naturally explain the observed broken power-law decay of the temperature which has been reported as a characteristic for gamma-ray burst pulses.

A Model of Polarisation Rotations in Blazars from Kink Instabilities in Relativistic Jets

Directory of Open Access Journals (Sweden)

Krzysztof Nalewajko

2017-10-01

Full Text Available This paper presents a simple model of polarisation rotation in optically thin relativistic jets of blazars. The model is based on the development of helical (kink mode of current-driven instability. A possible explanation is suggested for the observational connection between polarisation rotations and optical/gamma-ray flares in blazars, if the current-driven modes are triggered by secular increases of the total jet power. The importance of intrinsic depolarisation in limiting the amplitude of coherent polarisation rotations is demonstrated. The polarisation rotation amplitude is thus very sensitive to the viewing angle, which appears to be inconsistent with the observational estimates of viewing angles in blazars showing polarisation rotations. Overall, there are serious obstacles to explaining large-amplitude polarisation rotations in blazars in terms of current-driven kink modes.

Relativistic jets: An astrophysical laboratory for the Doppler effect

Science.gov (United States)

Zakamska, Nadia L.

2018-05-01

Special Relativity is one of the most abstract courses in the standard curriculum for physics majors, and therefore practical applications or laboratory exercises are particularly valuable for providing real-world experiences with this subject. This course poses a challenge for lab development because relativistic effects manifest themselves only at speeds close to the speed of light. The laboratory described in this paper constitutes a low-cost, low-barrier exercise suitable for students whose only background is the standard mechanics-plus-electromagnetism sequence. The activity uses research-quality astronomical data on SS433—a fascinating Galactic X-ray binary consisting of a compact object (a neutron star or a black hole) and a normal star. A pair of moderately relativistic jets moving with v ˜ 0.3 c in opposite directions emanate from the vicinity of the compact object and are clearly detected in optical and radio observations. Following step-by-step instructions, students develop a full kinematic model of a complex real-world source, use the model to fit the observational data, obtain best-fit parameters, and understand the limitations of the model. The observations are in exquisite agreement with the Doppler effect equations of Special Relativity. The complete lab manual, the dataset and the solutions are available in online supplemental materials; this paper presents the scientific and pedagogical background for the exercise.

SPATIAL GROWTH OF CURRENT-DRIVEN INSTABILITY IN RELATIVISTIC ROTATING JETS AND THE SEARCH FOR MAGNETIC RECONNECTION

Energy Technology Data Exchange (ETDEWEB)

Singh, Chandra B.; Pino, Elisabete M. de Gouveia Dal [Department of Astronomy (IAG-USP), University of São Paulo, São Paulo (Brazil); Mizuno, Yosuke, E-mail: csingh@iag.usp.br, E-mail: dalpino@iag.usp.br, E-mail: mizuno@th.physik.uni-frankfurt.de [Institute for Theoretical Physics, Goethe University, D-60438, Frankfurt am Main (Germany)

2016-06-10

Using the three-dimensional relativistic magnetohydrodynamic code RAISHIN, we investigated the influence of the radial density profile on the spatial development of the current-driven kink instability along magnetized rotating, relativistic jets. For the purposes of our study, we used a nonperiodic computational box, the jet flow is initially established across the computational grid, and a precessional perturbation at the inlet triggers the growth of the kink instability. We studied light and heavy jets with respect to the environment depending on the density profile. Different angular velocity amplitudes have been also tested. The results show the propagation of a helically kinked structure along the jet and a relatively stable configuration for the lighter jets. The jets appear to be collimated by the magnetic field, and the flow is accelerated owing to conversion of electromagnetic into kinetic energy. We also identify regions of high current density in filamentary current sheets, indicative of magnetic reconnection, which are associated with the kink-unstable regions and correlated with the decrease of the sigma parameter of the flow. We discuss the implications of our findings for Poynting-flux-dominated jets in connection with magnetic reconnection processes. We find that fast magnetic reconnection may be driven by the kink-instability turbulence and govern the transformation of magnetic into kinetic energy, thus providing an efficient way to power and accelerate particles in active galactic nucleus and gamma-ray-burst relativistic jets.

Relativistic jets and the most powerful radio sources in the universe

International Nuclear Information System (INIS)

Bridle, A.

1987-01-01

Relativistic jets, which are beams of particles and magnetic fields emitting synchrotron radiation that emanate from black holes at the centers of galaxies and quasars, have been one of the most exciting discoveries made at the Very Large Array (VLA) operated by the National Radio Astronomy Observatory (NRAO). The VLA is an array of 27 antennas, each 25 meters in diameter, distributed in a Y-formation with two branches 21 kilometers long and one branch 19 kilometers long. Astronomers can use it to study relativistic jets that generate intense natural radio sources (or transmitters). These sources, associated with regions hundreds of thousands of light years across, are the most powerful in the universe in energy output. In his lecture, Bridle describes how consecutive advances in imaging techniques for radio astronomy have uncovered the properties of the powerful radio sources, culminating in the discovery at the VLA that many of these sources contain radio emitting jets. He then describes some of the NRAO's research on these jets, and discusses the jets' physical properties. He concludes with an outlook for the future: the NRAO's Very Long Baseline Array (VLBA) is to be completed in the early 1990's. The VLBA is an array of ten radio telescopes distributed from Hawaii to St. Croix, from the Canadian border to Texas. With the VLBA, astronomers plan to look more deeply into these radio sources. 15 figs

VLBA AND CHANDRA OBSERVATIONS OF JETS IN FRI RADIO GALAXIES: CONSTRAINTS ON JET EVOLUTION

International Nuclear Information System (INIS)

Kharb, P.; O'Dea, C. P.; Tilak, A.; Baum, S. A.; Haynes, E.; Noel-Storr, J.; Fallon, C.; Christiansen, K.

2012-01-01

We present here the results from new Very Long Baseline Array (VLBA) observations at 1.6 and 5 GHz of 19 galaxies of a complete sample of 21 Uppasala General Catalog (UGC) Fanaroff-Riley type I (FRI) radio galaxies. New Chandra data of two sources, viz., UGC 00408 and UGC 08433, are combined with the Chandra archival data of 13 sources. The 5 GHz observations of 10 'core-jet' sources are polarization-sensitive, while the 1.6 GHz observations constitute second-epoch total intensity observations of nine 'core-only' sources. Polarized emission is detected in the jets of seven sources at 5 GHz, but the cores are essentially unpolarized, except in M87. Polarization is detected at the jet edges in several sources, and the inferred magnetic field is primarily aligned with the jet direction. This could be indicative of magnetic field 'shearing' due to jet-medium interaction, or the presence of helical magnetic fields. The jet peak intensity I ν falls with distance d from the core, following the relation, I ν ∝d a , where a is typically ∼ – 1.5. Assuming that adiabatic expansion losses are primarily responsible for the jet intensity 'dimming,' two limiting cases are considered: (1) the jet has a constant speed on parsec scales and is expanding gradually such that the jet radius r∝d 0 .4 ; this expansion is, however, unobservable in the laterally unresolved jets at 5 GHz, and (2) the jet is cylindrical and is accelerating on parsec scales. Accelerating parsec-scale jets are consistent with the phenomenon of 'magnetic driving' in Poynting-flux-dominated jets. While slow jet expansion as predicted by case (1) is indeed observed in a few sources from the literature that are resolved laterally, on scales of tens or hundreds of parsecs, case (2) cannot be ruled out in the present data, provided the jets become conical on scales larger than those probed by VLBA. Chandra observations of 15 UGC FRIs detect X-ray jets in 9 of them. The high frequency of occurrence of X

The physics of gamma-ray bursts & relativistic jets

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pawan, E-mail: pk@astro.as.utexas.edu [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Zhang, Bing, E-mail: zhang@physics.unlv.edu [Department of Physics & Astronomy, University of Nevada Las Vegas, Las Vegas, NV 89154 (United States)

2015-02-24

We provide a comprehensive review of major developments in our understanding of gamma-ray bursts, with particular focus on the discoveries made within the last fifteen years when their true nature was uncovered. We describe the observational properties of photons from the radio to 100s GeV bands, both in the prompt emission and the afterglow phases. Mechanisms for the generation of these photons in GRBs are discussed and confronted with observations to shed light on the physical properties of these explosions, their progenitor stars and the surrounding medium. After presenting observational evidence that a powerful, collimated, jet moving at close to the speed of light is produced in these explosions, we describe our current understanding regarding the generation, acceleration, and dissipation of the jet. We discuss mounting observational evidence that long duration GRBs are produced when massive stars die, and that at least some short duration bursts are associated with old, roughly solar mass, compact stars. The question of whether a black-hole or a strongly magnetized, rapidly rotating neutron star is produced in these explosions is also discussed. We provide a brief summary of what we have learned about relativistic collisionless shocks and particle acceleration from GRB afterglow studies, and discuss the current understanding of radiation mechanism during the prompt emission phase. We discuss theoretical predictions of possible high-energy neutrino emission from GRBs and the current observational constraints. Finally, we discuss how these explosions may be used to study cosmology, e.g. star formation, metal enrichment, reionization history, as well as the formation of first stars and galaxies in the universe.

General relativistic study of astrophysical jets with internal shocks

Science.gov (United States)

Vyas, Mukesh K.; Chattopadhyay, Indranil

2017-08-01

We explore the possibility of the formation of steady internal shocks in jets around black holes. We consider a fluid described by a relativistic equation of state, flowing about the axis of symmetry (θ = 0) in a Schwarzschild metric. We use two models for the jet geometry: (I) a conical geometry and (II) a geometry with non-conical cross-section. A jet with conical geometry has a smooth flow, while the jet with non-conical cross-section undergoes multiple sonic points and even standing shock. The jet shock becomes stronger, as the shock location is situated farther from the central black hole. Jets with very high energy and very low energy do not harbour shocks, but jets with intermediate energies do harbour shocks. One advantage of these shocks, as opposed to shocks mediated by external medium, is that these shocks have no effect on the jet terminal speed, but may act as possible sites for particle acceleration. Typically, a jet with specific energy 1.8c2 will achieve a terminal speed of v∞ = 0.813c for jet with any geometry, where, c is the speed of light in vacuum. But for a jet of non-conical cross-section for which the length scale of the inner torus of the accretion disc is 40rg, then, in addition, a steady shock will form at rsh ˜ 7.5rg and compression ratio of R ˜ 2.7. Moreover, electron-proton jet seems to harbour the strongest shock. We will discuss possible consequences of such a scenario.

Baryons in the relativistic jets of the stellar-mass black-hole candidate 4U 1630-47.

Science.gov (United States)

Trigo, María Díaz; Miller-Jones, James C A; Migliari, Simone; Broderick, Jess W; Tzioumis, Tasso

2013-12-12

Accreting black holes are known to power relativistic jets, both in stellar-mass binary systems and at the centres of galaxies. The power carried away by the jets, and, hence, the feedback they provide to their surroundings, depends strongly on their composition. Jets containing a baryonic component should carry significantly more energy than electron-positron jets. Energetic considerations and circular-polarization measurements have provided conflicting circumstantial evidence for the presence or absence of baryons in jets, and the only system in which they have been unequivocally detected is the peculiar X-ray binary SS 433 (refs 4, 5). Here we report the detection of Doppler-shifted X-ray emission lines from a more typical black-hole candidate X-ray binary, 4U 1630-47, coincident with the reappearance of radio emission from the jets of the source. We argue that these lines arise from baryonic matter in a jet travelling at approximately two-thirds the speed of light, thereby establishing the presence of baryons in the jet. Such baryonic jets are more likely to be powered by the accretion disk than by the spin of the black hole, and if the baryons can be accelerated to relativistic speeds, the jets should be strong sources of γ-rays and neutrino emission.

RESOLVING THE GEOMETRY OF THE INNERMOST RELATIVISTIC JETS IN ACTIVE GALACTIC NUCLEI

Energy Technology Data Exchange (ETDEWEB)

Algaba, J. C.; Lee, S. S. [Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Nakamura, M.; Asada, K., E-mail: algaba@kasi.re.kr [Academia Sinica, Institute of Astronomy and Astrophysics, 11F of Astronomy-Mathematics Building, AS/NTU. No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C (China)

2017-01-01

In the current paradigm, it is believed that the compact VLBI radio core of radio-loud active galactic nuclei (AGNs) represents the innermost upstream regions of relativistic outflows. These regions of AGN jets have generally been modeled by a conical outflow with a roughly constant opening angle and flow speed. Nonetheless, some works suggest that a parabolic geometry would be more appropriate to fit the high energy spectral distribution properties and it has been recently found that, at least in some nearby radio galaxies, the geometry of the innermost regions of the jet is parabolic. We compile here multi-frequency core sizes of archival data to investigate the typically unresolved upstream regions of the jet geometry of a sample of 56 radio-loud AGNs. Data combined from the sources considered here are not consistent with the classic picture of a conical jet starting in the vicinity of the super-massive black hole (SMBH), and may exclude a pure parabolic outflow solution, but rather suggest an intermediate solution with quasi-parabolic streams, which are frequently seen in numerical simulations. Inspection of the large opening angles near the SMBH and the range of the Lorentz factors derived from our results support our analyses. Our result suggests that the conical jet paradigm in AGNs needs to be re-examined by millimeter/sub-millimeter VLBI observations.

QUASI-STATIC MODEL OF MAGNETICALLY COLLIMATED JETS AND RADIO LOBES. II. JET STRUCTURE AND STABILITY

Energy Technology Data Exchange (ETDEWEB)

Colgate, Stirling A.; Li, Hui [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fowler, T. Kenneth [University of California, Berkeley, CA 94720 (United States); Hooper, E. Bickford [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); McClenaghan, Joseph; Lin, Zhihong [University of California, Irvine, CA 92697 (United States)

2015-11-10

This is the second in a series of companion papers showing that when an efficient dynamo can be maintained by accretion disks around supermassive black holes in active galactic nuclei, it can lead to the formation of a powerful, magnetically driven, and mediated helix that could explain both the observed radio jet/lobe structures and ultimately the enormous power inferred from the observed ultrahigh-energy cosmic rays. In the first paper, we showed self-consistently that minimizing viscous dissipation in the disk naturally leads to jets of maximum power with boundary conditions known to yield jets as a low-density, magnetically collimated tower, consistent with observational constraints of wire-like currents at distances far from the black hole. In this paper we show that these magnetic towers remain collimated as they grow in length at nonrelativistic velocities. Differences with relativistic jet models are explained by three-dimensional magnetic structures derived from a detailed examination of stability properties of the tower model, including a broad diffuse pinch with current profiles predicted by a detailed jet solution outside the collimated central column treated as an electric circuit. We justify our model in part by the derived jet dimensions in reasonable agreement with observations. Using these jet properties, we also discuss the implications for relativistic particle acceleration in nonrelativistically moving jets. The appendices justify the low jet densities yielding our results and speculate how to reconcile our nonrelativistic treatment with general relativistic MHD simulations.

Jet observables without jet algorithms

Energy Technology Data Exchange (ETDEWEB)

Bertolini, Daniele; Chan, Tucker; Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

2014-04-02

We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables — jet multiplicity, summed scalar transverse momentum, and missing transverse momentum — have event shape counterparts that are closely correlated with their jet-based cousins. Due to their “local” computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applications do require knowledge about the jet constituents, we also build a hybrid event shape that incorporates (local) jet clustering information. As a straightforward application of our general technique, we derive an event-shape version of jet trimming, allowing event-wide jet grooming without explicit jet identification. Finally, we briefly mention possible applications of our method for jet substructure studies.

Particle identification with the OPAL jet chamber in the region of the relativistic rise

Energy Technology Data Exchange (ETDEWEB)

Breuker, H; Fischer, H M; Hauschild, M; Hartmann, H; Wuensch, B; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D

1987-10-15

An important goal of the OPAL jet chamber is particle identification at high momenta by exploiting the relativistic rise of the energy loss. Extensive tests have been performed with the full scale prototype of the OPAL jet chamber to measure the energy loss in an argon-methane-isobutane mixture as function of momentum and particle species. The measurements were done under various operating conditions in order to optimise the operationg point, to investigate sources of systematic errors, to monitor the stability of the energy loss measurement and to develop calibration procedures. The particle separation capability in the region of relativistic rise has been studied at gas pressures of 3 and 4 bar. The adopted operation point represents a reasonable compromise between the requirements for particle identification and tracking accuracy.

PROPAGATION OF RELATIVISTIC, HYDRODYNAMIC, INTERMITTENT JETS IN A ROTATING, COLLAPSING GRB PROGENITOR STAR

Energy Technology Data Exchange (ETDEWEB)

Geng, Jin-Jun [School of Astronomy and Space Science, Nanjing University, Nanjing 210046 (China); Zhang, Bing [Department of Physics and Astronomy, University of Nevada Las Vegas, NV 89154 (United States); Kuiper, Rolf, E-mail: gengjinjun@gmail.com, E-mail: zhang@physics.unlv.edu [Institute of Astronomy and Astrophysics, University of Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen (Germany)

2016-12-10

The prompt emission of gamma-ray bursts (GRBs) is characterized by rapid variabilities, which may be a direct reflection of the unsteady central engine. We perform a series of axisymmetric 2.5-dimensional simulations to study the propagation of relativistic, hydrodynamic, intermittent jets through the envelope of a GRB progenitor star. A realistic rapidly rotating star is incorporated as the background of jet propagation, and the star is allowed to collapse due to the gravity of the central black hole. By modeling the intermittent jets with constant-luminosity pulses with equal on and off durations, we investigate how the half period, T , affects the jet dynamics. For relatively small T values (e.g., 0.2 s), the jet breakout time t {sub bo} depends on the opening angle of the jet, with narrower jets more penetrating and reaching the surface at shorter times. For T  ≤ 1 s, the reverse shock (RS) crosses each pulse before the jet penetrates through the stellar envelope. As a result, after the breakout of the first group of pulses at t {sub bo}, several subsequent pulses vanish before penetrating the star, causing a quiescent gap. For larger half periods ( T = 2.0 and 4.0 s), all the pulses can successfully penetrate through the envelope, since each pulse can propagate through the star before the RS crosses the shell. Our results may interpret the existence of a weak precursor in some long GRBs, given that the GRB central engine injects intermittent pulses with a half period T  ≤ 1 s. The observational data seem to be consistent with such a possibility.

Relativistic jet feedback - II. Relationship to gigahertz peak spectrum and compact steep spectrum radio galaxies

Science.gov (United States)

Bicknell, Geoffrey V.; Mukherjee, Dipanjan; Wagner, Alexander Y.; Sutherland, Ralph S.; Nesvadba, Nicole P. H.

2018-04-01

We propose that Gigahertz Peak Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources are the signposts of relativistic jet feedback in evolving galaxies. Our simulations of relativistic jets interacting with a warm, inhomogeneous medium, utilizing cloud densities and velocity dispersions in the range derived from optical observations, show that free-free absorption can account for the ˜ GHz peak frequencies and low-frequency power laws inferred from the radio observations. These new computational models replace a power-law model for the free-free optical depth a more fundamental model involving disrupted log-normal distributions of warm gas. One feature of our new models is that at early stages, the low-frequency spectrum is steep but progressively flattens as a result of a broader distribution of optical depths, suggesting that the steep low-frequency spectra discovered by Callingham et al. may possibly be attributed to young sources. We also investigate the inverse correlation between peak frequency and size and find that the initial location on this correlation is determined by the average density of the warm ISM. The simulated sources track this correlation initially but eventually fall below it, indicating the need for a more extended ISM than presently modelled. GPS and CSS sources can potentially provide new insights into the phenomenon of AGN feedback since their peak frequencies and spectra are indicative of the density, turbulent structure, and distribution of gas in the host galaxy.

Jets in Hydrogen-poor Superluminous Supernovae: Constraints from a Comprehensive Analysis of Radio Observations

Science.gov (United States)

Coppejans, D. L.; Margutti, R.; Guidorzi, C.; Chomiuk, L.; Alexander, K. D.; Berger, E.; Bietenholz, M. F.; Blanchard, P. K.; Challis, P.; Chornock, R.; Drout, M.; Fong, W.; MacFadyen, A.; Migliori, G.; Milisavljevic, D.; Nicholl, M.; Parrent, J. T.; Terreran, G.; Zauderer, B. A.

2018-03-01

The energy source powering the extreme optical luminosity of hydrogen-stripped superluminous supernovae (SLSNe-I) is not known, but recent studies have highlighted the case for a central engine. Radio and/or X-ray observations are best placed to track the fastest ejecta and probe the presence of outflows from a central engine. We compile all the published radio observations of SLSNe-I to date and present three new observations of two new SLSNe-I. None were detected. Through modeling the radio emission, we constrain the subparsec environments and possible outflows in SLSNe-I. In this sample, we rule out on-axis collimated relativistic jets of the kind detected in gamma-ray bursts (GRBs). We constrain off-axis jets with opening angles of 5° (30°) to energies of {E}{{k}}values {ε }e=0.1 and {ε }B=0.01. The deepest limits rule out emission of the kind seen in faint uncollimated GRBs (with the exception of GRB 060218) and from relativistic SNe. Finally, for the closest SLSN-I, SN 2017egm, we constrain the energy of an uncollimated nonrelativistic outflow like those observed in normal SNe to {E}{{k}}≲ {10}48 erg.

The formation and disruption of black hole jets

CERN Document Server

Gabuzda, Denise; Kylafis, Nikolaos

2015-01-01

This book reviews the phenomenology displayed by relativistic jets as well as the most recent theoretical efforts to understand the physical mechanisms at their origin. Relativistic jets have been observed and studied in Active Galactic Nuclei (AGN) for about half a century and are believed to be fueled by accretion onto a supermassive black hole at the center of the host galaxy. Since the first discovery of relativistic jets associated with so-called "micro-quasars" much more recently, it has seemed clear that much of the physics governing the relativistic outflows in stellar X-ray binaries harboring black holes and in AGN must be common, but acting on very different spatial and temporal scales. With new observational and theoretical results piling up every day, this book attempts to synthesize a consistent, unified physical picture of the formation and disruption of jets in accreting black-hole systems. The chapters in this book offer overviews accessible not only to specialists but also to graduat...

Ultra-relativistic heavy-ion collisions - a hot cocktail of hydrodynamics, resonances and jets

Directory of Open Access Journals (Sweden)

Zabrodin E.

2015-01-01

Full Text Available Ultra-relativistic heavy-ion collisions at energies of RHIC and LHC are considered. For comparison with data the HYDJET++ model, which contains the treatment of both soft and hard processes, is employed. The study focuses mainly on the interplay of ideal hydrodynamics, final state interactions and jets, and its influence on the development of harmonics of the anisotropic flow. It is shown that jets are responsible for violation of the number-of-constituent-quark (NCQ scaling at LHC energies. The interplay between elliptic and triangular flows and their contribution to higher flow harmonics and dihadron angular correlations, including ridge, is also discussed.

The energetics of relativistic jets in active galactic nuclei with various kinetic powers

Science.gov (United States)

Musoke, Gibwa Rebecca; Young, Andrew; Molnar, Sandor; Birkinshaw, Mark

2018-01-01

Numerical simulations are an important tool in understanding the physical processes behind relativistic jets in active galactic nuclei. In such simulations different combinations of intrinsic jet parameters can be used to obtain the same jet kinetic powers. We present a numerical investigation of the effects of varying the jet power on the dynamic and energetic characteristics of the jets for two kinetic power regimes; in the first regime we change the jet density whilst maintaining a fixed velocity, in the second the jet density is held constant while the velocity is varied. We conduct 2D axisymmetric hydrodynamic simulations of bipolar jets propagating through an isothermal cluster atmosphere using the FLASH MHD code in pure hydrodynamics mode. The jets are simulated with kinetic powers ranging between 1045 and 1046 erg/s and internal Mach numbers ranging from 5.6 to 21.5.As the jets begin to propagate into the intracluster medium (ICM), the injected jet energy is converted into the thermal, kinetic and gravitational potential energy components of the jet cocoon and ICM. We explore the temporal evolution of the partitioning of the injected jet energy into the cocoon and the ICM and quantify the importance of entrainment process on the energy partitioning. We investigate the fraction of injected energy transferred to the thermal energy component of the jet-ICM system in the context of heating the cluster environments, noting that the jets simulated display peak thermalisation efficiencies of least 65% and a marked dependence on the jet density. We compare the efficiencies of the energy partitioning between the cocoon and ICM for the two kinetic power regimes and discuss the resulting efficiency-power scaling relations of each regime.

INDICATION OF THE BLACK HOLE POWERED JET IN M87 BY VSOP OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Asada, Keiichi; Nakamura, Masanori; Pu, Hung-Yi, E-mail: asada@asiaa.sinica.edu.tw, E-mail: nakamura@asiaa.sinica.edu.tw, E-mail: hypu@asiaa.sinica.edu.tw [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China)

2016-12-10

In order to study the collimation and acceleration mechanism of relativistic jets, the jet streamline of M87 at milliarcsecond scale is extensively investigated with images from VSOP observations at 1.6 and 5 GHz. Thanks to the higher angular resolution of VSOP, especially in the direction transverse to the jet, we resolved the jet streamline into three ridgelines at the scale of milli arcseconds. While the properties of the outer two ridgelines are in good agreement with those measured in previous observations and can be expressed by one power-law line with a power law index of 1.7, an inner ridgeline is clearly observed for the first time. We compared the measured size with the outermost streamline expected by Blandford and Znajek's parabolic solutions, which are anchored at the event horizon, with different black hole spin parameters. We revealed that the observed inner ridgeline is narrower than the prediction, suggesting the origin of the inner ridgeline to be part of a spine originating from the spinning black hole. The inner ridgeline becomes very dim at large distances from the central engine at 5 GHz. We considered two possible cases for this; Doppler beaming and/or radiative cooling. Either case seems to be reasonable for its explanation, and future multi-frequency observations will discriminate those two possibilities.

Observable Emission Features of Black Hole GRMHD Jets on Event Horizon Scales

Energy Technology Data Exchange (ETDEWEB)

Pu, Hung-Yi [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada); Wu, Kinwah [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Younsi, Ziri; Mizuno, Yosuke [Institut für Theoretische Physik, Max-von-Laue-Straße 1, D-60438 Frankfurt am Main (Germany); Asada, Keiichi; Nakamura, Masanori, E-mail: hpu@perimeterinstitute.ca, E-mail: asada@asiaa.sinica.edu.tw, E-mail: nakamura@asiaa.sinica.edu.tw, E-mail: kinwah.wu@ucl.ac.uk, E-mail: younsi@th.physik.uni-frankfurt.de, E-mail: mizuno@th.physik.uni-frankfurt.de [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No. 1, Taipei 10617, Taiwan (China)

2017-08-20

The general-relativistic magnetohydrodynamical (GRMHD) formulation for black hole-powered jets naturally gives rise to a stagnation surface, where inflows and outflows along magnetic field lines that thread the black hole event horizon originate. We derive a conservative formulation for the transport of energetic electrons, which are initially injected at the stagnation surface and subsequently transported along flow streamlines. With this formulation the energy spectra evolution of the electrons along the flow in the presence of radiative and adiabatic cooling is determined. For flows regulated by synchrotron radiative losses and adiabatic cooling, the effective radio emission region is found to be finite, and geometrically it is more extended along the jet central axis. Moreover, the emission from regions adjacent to the stagnation surface is expected to be the most luminous as this is where the freshly injected energetic electrons are concentrated. An observable stagnation surface is thus a strong prediction of the GRMHD jet model with the prescribed non-thermal electron injection. Future millimeter/submillimeter (mm/sub-mm) very-long-baseline interferometric observations of supermassive black hole candidates, such as the one at the center of M87, can verify this GRMHD jet model and its associated non-thermal electron injection mechanism.

New relativistic particle-in-cell simulation studies of prompt and early afterglows from GRBs

International Nuclear Information System (INIS)

Ken-Ichi Nishikawa

2008-01-01

Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electro-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the collisionless relativistic shock particle acceleration is due to plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electrons' transverse deflection behind the jet head. The '' jitter '' radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. (author)

The jets of 3C120

International Nuclear Information System (INIS)

Axon, D.J.; Pedlar, A.; Unger, S.W.; Meurs, E.J.A.; Ward, M.J.

1989-01-01

Core-dominated radio sources associated with quasars are a manifestation of the most extreme form of activity in galactic nuclei. In general, the morphology of their inner radio structure is in the form of a jet detected on only one side of the core; the larger-scale radio emission is relatively symmetric. Superluminal motion in some sources has led to the suggestion that the ejection of radio-emitting material is relativistic and intrinsically two-sided. The apparent one-sidedness of the jets is then explained by relativistic aberration. This persuasive interpretation has not escaped criticism: both physical and statistical arguments have been advanced in favour of one-sided ejection. However, our new optical observations of 3C120, which reveal the details of the interaction between the radio jet and the quiescent gas in the galaxy, offer significant kinematic evidence in favour of the relativistic-beaming hypothesis. (author)

Rotation and toroidal magnetic field effects on the stability of two-component jets

Science.gov (United States)

Millas, Dimitrios; Keppens, Rony; Meliani, Zakaria

2017-09-01

Several observations of astrophysical jets show evidence of a structure in the direction perpendicular to the jet axis, leading to the development of 'spine and sheath' models of jets. Most studies focus on a two-component jet consisting of a highly relativistic inner jet and a slower - but still relativistic - outer jet surrounded by an unmagnetized environment. These jets are believed to be susceptible to a relativistic Rayleigh-Taylor-type instability, depending on the effective inertia ratio of the two components. We extend previous studies by taking into account the presence of a non-zero toroidal magnetic field. Different values of magnetization are examined to detect possible differences in the evolution and stability of the jet. We find that the toroidal field, above a certain level of magnetization σ, roughly equal to 0.01, can stabilize the jet against the previously mentioned instabilities and that there is a clear trend in the behaviour of the average Lorentz factor and the effective radius of the jet when we continuously increase the magnetization. The simulations are performed using the relativistic MHD module from the open source, parallel, grid adaptive, mpi-amrvac code.

Modeling Polarized Emission from Black Hole Jets: Application to M87 Core Jet

Directory of Open Access Journals (Sweden)

Monika Mościbrodzka

2017-09-01

Full Text Available We combine three-dimensional general-relativistic numerical models of hot, magnetized Advection Dominated Accretion Flows around a supermassive black hole and the corresponding outflows from them with a general relativistic polarized radiative transfer model to produce synthetic radio images and spectra of jet outflows. We apply the model to the underluminous core of M87 galaxy. The assumptions and results of the calculations are discussed in context of millimeter observations of the M87 jet launching zone. Our ab initio polarized emission and rotation measure models allow us to address the constrains on the mass accretion rate onto the M87 supermassive black hole.

Multi-Frequency Blazar Micro-Variability as a Tool to Investigate Relativistic Jets

Directory of Open Access Journals (Sweden)

James R. Webb

2016-08-01

Full Text Available For the past 12 years we have been studying optical micro-variability of a sample of 15 Blazars. We summarize the results of this study and draw some basic conclusions about the characteristics of micro-variability. The intermittency, the stochastic nature, and the similar profile shapes seen in micro-variations at different times and in different objects have led us to a possible model to explain the observed micro-variations. The model is based on a strong shock propagating down a relativistic jet and encountering turbulence which causes density or magnetic field enhancements. We use the theory of Kirk, Reiger, and Mastichiadis (1998 to describe the pulse of synchrotron emission emanating from individual density enhancements energized by the shock. By fitting these “pulses” to micro-variability observations, we obtain excellent fits to actual micro-variations. The model predicts that the spectral index changes as a function of pulse duration. This effect should be observable in multi-frequency micro-variability data. We present the theoretical model, model fits of our micro-variability light curves, and preliminary multi-frequency micro-variability observations that support this model. A further test that has yet to be carried out involves observing polarization changes in different pulses.

Energy distribution of relativistic electrons in the kiloparsec scale jet of M 87 with Chandra

Science.gov (United States)

Sun, Xiao-Na; Yang, Rui-Zhi; Rieger, Frank M.; Liu, Ruo-Yu; Aharonian, Felix

2018-05-01

The X-ray emission from the jets in active galactic nuclei (AGN) carries important information on the distributions of relativistic electrons and magnetic fields on large scales. We reanalysed archival Chandra observations on the jet of M 87 from 2000 to 2016 with a total exposure of 1460 kiloseconds to explore the X-ray emission characteristics along the jet. We investigated the variability behaviours of the nucleus and the inner jet component HST-1, and confirm indications for day-scale X-ray variability in the nucleus contemporaneous to the 2010 high TeV γ-ray state. HST-1 shows a general decline in X-ray flux over the last few years consistent with its synchrotron interpretation. We extracted the X-ray spectra for the nucleus and all knots in the jet, showing that they are compatible with a single power law within the X-ray band. There are indications that the resultant X-ray photon index exhibit a trend, with slight but significant index variations ranging from ≃ 2.2 (e.g. in knot D) to ≃ 2.4-2.6 (in the outer knots F, A, and B). When viewed in a multiwavelength context, a more complex situation can be seen. Fitting the radio to X-ray spectral energy distributions (SEDs) assuming a synchrotron origin, we show that a broken power-law electron spectrum with break energy Eb around 1 (300 μG/B)1/2 TeV allows a satisfactory description of the multiband SEDs for most of the knots. However, in the case of knots B, C, and D we find indications that an additional high-energy component is needed to adequately reproduce the broad-band SEDs. We discuss the implications and suggest that a stratified jet model may account for the differences.

Jet launching radius in low-power radio-loud AGNs in advection-dominated accretion flows

Science.gov (United States)

Le, Truong; Newman, William; Edge, Brinkley

2018-06-01

Using our theory for the production of relativistic outflows, we estimate the jet launching radius and the inferred mass accretion rate for 52 low-power radio-loud AGNs based on the observed jet powers. Our analysis indicates that (1) a significant fraction of the accreted energy is required to convert the accreted mass to relativistic energy particles for the production of the jets near the event horizon, (2) the jet's launching radius moves radially towards the horizon as the mass accretion rate or jet's power increases, and (3) no jet/outflow formation is possible beyond 44 gravitational radii.

Relativistic jets in SS 433

International Nuclear Information System (INIS)

Margon, B.

1982-01-01

The most unusual characteristic of the star SS 433 emerged in the late 1970's when a series of optical spectra showed intense, broad optical emission lines whose profiles and wavelengths changed drastically from night to night. These features are interpreted as strong Doppler-shifted Balmer and HeI lines. The modulation of the Doppler shifts are observed as being cyclic with a period of about 164 days. It was hypothesized that these phenomena were caused by two collimated, colinear, jets which were ejecting in opposite directions from SS 433. Most authors believe that velocity variations of the emission lines are caused by a cyclic rotation of jet axis inclined to line of sight. This rotation being the result of precession, which leads one to suspect SS 433 as a member of a close binary system. This hypothesis has been confirmed from recent optical, radio, and x-ray observations which are discussed in the article. The combination of optical and radio observations of SS 433, described in the article, gives an accurate measure of the Kinematics of the system and some confidence that the Kinematic equations are understood. However, the specific physical processes of this ejection are poorly understood. Some theoretical difficulties regarding this are given

18–22 cm VLBA Observational Evidence for Toroidal B-Field Components in Six AGN Jets

Directory of Open Access Journals (Sweden)

Juliana Cristina Motter

2016-08-01

Full Text Available The formation of relativistic jets in Active Galactic Nuclei (AGN is related to accretion onto their central supermassive black holes, and magnetic (B fields are believed to play a central role in launching, collimating, and accelerating the jet streams from very compact regions out to kiloparsec scales. We present results of Faraday rotation studies based on Very Long Baseline Array (VLBA data obtained at 18–22 cm for six well known AGN (OJ 287, 3C 279, PKS 1510-089, 3C 345, BL Lac, and 3C 454.3, which probe projected distances out to tens of parsecs from the observed cores. We have identified statistically significant, monotonic, transverse Faraday rotation gradients across the jets of all but one of these sources, indicating the presence of toroidal B fields, which may be one component of helical B fields associated with these AGN jets.

Time-dependent inhomogeneous jet models for BL Lac objects

Science.gov (United States)

Marlowe, A. T.; Urry, C. M.; George, I. M.

1992-05-01

Relativistic beaming can explain many of the observed properties of BL Lac objects (e.g., rapid variability, high polarization, etc.). In particular, the broadband radio through X-ray spectra are well modeled by synchrotron-self Compton emission from an inhomogeneous relativistic jet. We have done a uniform analysis on several BL Lac objects using a simple but plausible inhomogeneous jet model. For all objects, we found that the assumed power-law distribution of the magnetic field and the electron density can be adjusted to match the observed BL Lac spectrum. While such models are typically unconstrained, consideration of spectral variability strongly restricts the allowed parameters, although to date the sampling has generally been too sparse to constrain the current models effectively. We investigate the time evolution of the inhomogeneous jet model for a simple perturbation propagating along the jet. The implications of this time evolution model and its relevance to observed data are discussed.

A STUDY OF RADIO POLARIZATION IN PROTOSTELLAR JETS

Energy Technology Data Exchange (ETDEWEB)

Cécere, Mariana [Instituto de Astronomía Teórica y Experimental, Universidad Nacional de Córdoba, X5000BGR, Córdoba (Argentina); Velázquez, Pablo F.; De Colle, Fabio; Esquivel, Alejandro [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apdo. Postal 70-543, CP: 04510, D.F., México (Mexico); Araudo, Anabella T. [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Carrasco-González, Carlos; Rodríguez, Luis F. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72, 58090, Morelia, Michoacán, México (Mexico)

2016-01-10

Synchrotron radiation is commonly observed in connection with shocks of different velocities, ranging from relativistic shocks associated with active galactic nuclei, gamma-ray bursts, or microquasars, to weakly or non-relativistic flows such as those observed in supernova remnants. Recent observations of synchrotron emission in protostellar jets are important not only because they extend the range over which the acceleration process works, but also because they allow us to determine the jet and/or interstellar magnetic field structure, thus giving insights into the jet ejection and collimation mechanisms. In this paper, we compute for the first time polarized (synchrotron) and non-polarized (thermal X-ray) synthetic emission maps from axisymmetrical simulations of magnetized protostellar jets. We consider models with different jet velocities and variability, as well as a toroidal or helical magnetic field. Our simulations show that variable, low-density jets with velocities of ∼1000 km s{sup −1} and ∼10 times lighter than the environment can produce internal knots with significant synchrotron emission and thermal X-rays in the shocked region of the leading bow shock moving in a dense medium. While models with a purely toroidal magnetic field show a very large degree of polarization, models with a helical magnetic field show lower values and a decrease of the degree of polarization, in agreement with observations of protostellar jets.

The γ-rays that accompanied GW170817 and the observational signature of a magnetic jet breaking out of NS merger ejecta

Science.gov (United States)

Bromberg, O.; Tchekhovskoy, A.; Gottlieb, O.; Nakar, E.; Piran, T.

2018-04-01

We present the first relativistic magnetohydrodynamics numerical simulation of a magnetic jet that propagates through and emerges from the dynamical ejecta of a binary neutron star merger. Generated by the magnetized rotation of the merger remnant, the jet propagates through the ejecta and produces an energetic cocoon that expands at mildly relativistic velocities and breaks out of the ejecta. We show that if the ejecta has a low-mass (˜10-7 M⊙) high-velocity (v ˜ 0.85c) tail, the cocoon shock breakout will generate γ-ray emission that is comparable to the observed short GRB170817A that accompanied the recent gravitational wave event GW170817. Thus, we propose that this gamma-ray burst (GRB), which is quite different from all other short GRBs observed before, was produced by a different mechanism. We expect, however, that such events are numerous and many will be detected in coming LIGO-Virgo runs.

DRIVING OUTFLOWS WITH RELATIVISTIC JETS AND THE DEPENDENCE OF ACTIVE GALACTIC NUCLEUS FEEDBACK EFFICIENCY ON INTERSTELLAR MEDIUM INHOMOGENEITY

International Nuclear Information System (INIS)

Wagner, A. Y.; Umemura, M.; Bicknell, G. V.

2012-01-01

We examine the detailed physics of the feedback mechanism by relativistic active galactic nucleus (AGN) jets interacting with a two-phase fractal interstellar medium (ISM) in the kpc-scale core of galaxies using 29 three-dimensional grid-based hydrodynamical simulations. The feedback efficiency, as measured by the amount of cloud dispersal generated by the jet-ISM interactions, is sensitive to the maximum size of clouds in the fractal cloud distribution but not to their volume filling factor. Feedback ceases to be efficient for Eddington ratios P jet /L edd ∼ –4 , although systems with large cloud complexes ∼> 50 pc require jets of Eddington ratio in excess of 10 –2 to disperse the clouds appreciably. Based on measurements of the bubble expansion rates in our simulations, we argue that sub-grid AGN prescriptions resulting in negative feedback in cosmological simulations without a multi-phase treatment of the ISM are good approximations if the volume filling factor of warm-phase material is less than 0.1 and the cloud complexes are smaller than ∼25 pc. We find that the acceleration of the dense embedded clouds is provided by the ram pressure of the high-velocity flow through the porous channels of the warm phase, flow that has fully entrained the shocked hot-phase gas it has swept up, and is additionally mass loaded by ablated cloud material. This mechanism transfers 10% to 40% of the jet energy to the cold and warm gas, accelerating it within a few 10 to 100 Myr to velocities that match those observed in a range of high- and low-redshift radio galaxies hosting powerful radio jets.

ERRATIC JET WOBBLING IN THE BL LACERTAE OBJECT OJ287 REVEALED BY SIXTEEN YEARS OF 7 mm VLBA OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Agudo, Ivan; Gomez, Jose L. [Instituto de Astrofisica de Andalucia, CSIC, Apartado 3004, 18080 Granada (Spain); Marscher, Alan P.; Jorstad, Svetlana G. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Perucho, Manel [Departament d' Astronomia i Astrofisica, Universitat de Valencia, Dr. Moliner 50, E-46100 Burjassot, Valencia (Spain); Piner, B. Glenn [Department of Physics and Astronomy, Whittier College, 13406 East Philadelphia Street, Whittier, CA 90608 (United States); Rioja, Maria [Observatorio Astronomico Nacional, Apdo. 112, E-28803 Alcala de Henares, Madrid (Spain); Dodson, Richard, E-mail: iagudo@iaa.es [ICRAR/University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

2012-03-01

We present the results from an ultra-high-resolution 7 mm Very Long Baseline Array study of the relativistic jet in the BL Lacertae object OJ287 from 1995 to 2011 containing 136 total intensity images. Analysis of the image sequence reveals a sharp jet-position-angle swing by >100 Degree-Sign during [2004,2006], as viewed in the plane of the sky, which we interpret as the crossing of the jet from one side of the line of sight to the other during a softer- and longer-term swing of the inner jet. Modulating such long-term swing, our images also show for the first time a prominent erratic wobbling behavior of the innermost {approx}0.4 mas of the jet with fluctuations in position angle of up to {approx}40 Degree-Sign over timescales {approx}2 yr. This is accompanied by highly superluminal motions along non-radial trajectories, which reflect the remarkable non-ballistic nature of the jet plasma on these scales. The erratic nature and short timescales of the observed behavior rule out scenarios such as binary black hole systems, accretion disk precession, and interaction with the ambient medium as possible origins of the phenomenon on the scales probed by our observations, although such processes may cause longer-term modulation of the jet direction. We propose that variable asymmetric injection of the jet flow, perhaps related to turbulence in the accretion disk, coupled with hydrodynamic instabilities leads to the non-ballistic dynamics that causes the observed non-periodic changes in the direction of the inner jet.

Relativistic jets from active galactic nuclei

CERN Document Server

Harris, D E; Krawczynski

2012-01-01

Written by a carefully selected consortium of researchers working in the field, this book fills the gap for an up-to-date summary of the observational and theoretical status. As such, this monograph includes all used wavelengths, from radio to gamma, the FERMI telescope, a history and theory refresher, and jets from gamma ray bursts. For astronomers, nuclear physicists, and plasmaphysicists.

Relativistic centrifugal instability

Science.gov (United States)

Gourgouliatos, Konstantinos N.; Komissarov, Serguei S.

2018-03-01

Near the central engine, many astrophysical jets are expected to rotate about their axis. Further out they are expected to go through the processes of reconfinement and recollimation. In both these cases, the flow streams along a concave surface and hence, it is subject to the centrifugal force. It is well known that such flows may experience the centrifugal instability (CFI), to which there are many laboratory examples. The recent computer simulations of relativistic jets from active galactic nuclei undergoing the process of reconfinement show that in such jets CFI may dominate over the Kelvin-Helmholtz instability associated with velocity shear (Gourgouliatos & Komissarov). In this letter, we generalize the Rayleigh criterion for CFI in rotating fluids to relativistic flows using a heuristic analysis. We also present the results of computer simulations which support our analytic criterion for the case of an interface separating two uniformly rotating cylindrical flows. We discuss the difference between CFI and the Rayleigh-Taylor instability in flows with curved streamlines.

Particle Acceleration, Magnetic Field Generation in Relativistic Shocks

Science.gov (United States)

Nishikawa, Ken-Ichi; Hardee, P.; Hededal, C. B.; Richardson, G.; Sol, H.; Preece, R.; Fishman, G. J.

2005-01-01

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient parallel magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. New simulations with an ambient perpendicular magnetic field show the strong interaction between the relativistic jet and the magnetic fields. The magnetic fields are piled up by the jet and the jet electrons are bent, which creates currents and displacement currents. At the nonlinear stage, the magnetic fields are reversed by the current and the reconnection may take place. Due to these dynamics the jet and ambient electron are strongly accelerated in both parallel and perpendicular directions.

Polarized Emission from Gamma-Ray Burst Jets

Directory of Open Access Journals (Sweden)

Shiho Kobayashi

2017-11-01

Full Text Available I review how polarization signals have been discussed in the research field of Gamma-Ray Bursts (GRBs. I mainly discuss two subjects in which polarimetry enables us to study the nature of relativistic jets. (1 Jet breaks: Gamma-ray bursts are produced in ultra-relativistic jets. Due to the relativistic beaming effect, the emission can be modeled in a spherical model at early times. However, as the jet gradually slows down, we begin to see the edge of the jet together with polarized signals at some point. (2 Optical flash: later time afterglow is known to be insensitive to the properties of the original ejecta from the GRB central engine. However, a short-lived, reverse shock emission would enable us to study the nature of of GRB jets. I also briefly discuss the recent detection of optical circular polarization in GRB afterglow.

THREE-DIMENSIONAL ADAPTIVE MESH REFINEMENT SIMULATIONS OF LONG-DURATION GAMMA-RAY BURST JETS INSIDE MASSIVE PROGENITOR STARS

Energy Technology Data Exchange (ETDEWEB)

Lopez-Camara, D.; Lazzati, Davide [Department of Physics, NC State University, 2401 Stinson Drive, Raleigh, NC 27695-8202 (United States); Morsony, Brian J. [Department of Astronomy, University of Wisconsin-Madison, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53706-1582 (United States); Begelman, Mitchell C., E-mail: dlopezc@ncsu.edu [JILA, University of Colorado, 440 UCB, Boulder, CO 80309-0440 (United States)

2013-04-10

We present the results of special relativistic, adaptive mesh refinement, 3D simulations of gamma-ray burst jets expanding inside a realistic stellar progenitor. Our simulations confirm that relativistic jets can propagate and break out of the progenitor star while remaining relativistic. This result is independent of the resolution, even though the amount of turbulence and variability observed in the simulations is greater at higher resolutions. We find that the propagation of the jet head inside the progenitor star is slightly faster in 3D simulations compared to 2D ones at the same resolution. This behavior seems to be due to the fact that the jet head in 3D simulations can wobble around the jet axis, finding the spot of least resistance to proceed. Most of the average jet properties, such as density, pressure, and Lorentz factor, are only marginally affected by the dimensionality of the simulations and therefore results from 2D simulations can be considered reliable.

A turbulent radio jet

International Nuclear Information System (INIS)

Kahn, F.D.

1983-01-01

A relativistic plasma flow can explain many of the observations on the one-sided jets, which are associated with radio sources that show superluminal motions in their cores. The pressure from the ambient medium will communicate across the jet in a relatively short distance, typically 30 kpc. The friction between the jet and the external medium then makes the flow go turbulent. As a result the jet dissipates energy and will be brought to rest within a few hundred kpc, if it does not strike an obstacle before. The mean flow in the jet is strongly sheared and stretches the lines of force of any magnetic field frozen into the plasma. The dominant field direction, as seen from the rest frame of the plasma, is therefore parallel to the length of the jet. Polarization measurements have shown that this is in fact the case. (author)

Observation of relativistic antihydrogen atoms

International Nuclear Information System (INIS)

Blanford, Glenn DelFosse

1998-01-01

An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 0 production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e + e - pair creation near a nucleus with the e + being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure

Consequences of Relativistic Neutron Outflow beyond the Accretion Disks of Active Galaxies

Science.gov (United States)

Ekejiuba, I. E.; Okeke, P. N.

1993-05-01

Three channels of relativistic electron injection in the jets of extragalactic radio sources (EGRSs) are discussed. With the assumption that an active galactic nucleus (AGN) is powered by a spinning supermassive black hole of mass ~ 10(8) M_⊙ which sits at the center of the nucleus and ingests matter and energy through an accretion disk, a model for extracting relativistic neutrons from the AGN is forged. In this model, the inelastic proton--proton and proton--photon interactions within the accretion disk, of relativistic protons with background thermal protons and photons, respectively, produce copious amounts of relativistic neutrons. These neutrons travel ballistically for ~ 10(3gamma_n ) seconds and escape from the disk before they decay. The secondary particles produced from the neutron decays then interact with the ambient magnetic field and/or other particles to produce the radio emissions observed in the jets of EGRSs. IEE acknowledges the support of the World Bank and the Federal University of Technology, Yola, Nigeria as well as the hospitality of Georgia State University.

Novel jet observables from machine learning

Science.gov (United States)

Datta, Kaustuv; Larkoski, Andrew J.

2018-03-01

Previous studies have demonstrated the utility and applicability of machine learning techniques to jet physics. In this paper, we construct new observables for the discrimination of jets from different originating particles exclusively from information identified by the machine. The approach we propose is to first organize information in the jet by resolved phase space and determine the effective N -body phase space at which discrimination power saturates. This then allows for the construction of a discrimination observable from the N -body phase space coordinates. A general form of this observable can be expressed with numerous parameters that are chosen so that the observable maximizes the signal vs. background likelihood. Here, we illustrate this technique applied to discrimination of H\\to b\\overline{b} decays from massive g\\to b\\overline{b} splittings. We show that for a simple parametrization, we can construct an observable that has discrimination power comparable to, or better than, widely-used observables motivated from theory considerations. For the case of jets on which modified mass-drop tagger grooming is applied, the observable that the machine learns is essentially the angle of the dominant gluon emission off of the b\\overline{b} pair.

DETECTING RELATIVISTIC X-RAY JETS IN HIGH-REDSHIFT QUASARS

Energy Technology Data Exchange (ETDEWEB)

McKeough, Kathryn [Department of Statistics, Harvard University, Cambridge, MA 02138 (United States); Siemiginowska, Aneta; Kashyap, Vinay L.; Lee, N. P.; Harris, D. E.; Schwartz, D. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Stawarz, Łukasz [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244, Kraków (Poland); Stein, Nathan [Department of Statistics, The Wharton School, University of Pennsylvania, 400 Jon M. Huntsman Hall, 3730 Walnut Street, Philadelphia, PA 19104-6340 (United States); Stampoulis, Vasileios; Dyk, David A. van [Statistics Section, Imperial College London, Huxley Building, South Kensington Campus, London SW7 (United Kingdom); Wardle, J. F. C. [Department of Physics, MS 057, Brandeis University, Waltham, MA 02454 (United States); Donato, Davide [CRESST and Astroparticle Physics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States); Maraschi, Laura; Tavecchio, Fabrizio, E-mail: kathrynmckeough@g.harvard.edu [INAF Osservatorio Astronomico di Brera, via Brera 28, I-20124, Milano (Italy)

2016-12-10

We analyze Chandra X-ray images of a sample of 11 quasars that are known to contain kiloparsec scale radio jets. The sample consists of five high-redshift ( z  ≥ 3.6) flat-spectrum radio quasars, and six intermediate redshift (2.1 <  z  < 2.9) quasars. The data set includes four sources with integrated steep radio spectra and seven with flat radio spectra. A total of 25 radio jet features are present in this sample. We apply a Bayesian multi-scale image reconstruction method to detect and measure the X-ray emission from the jets. We compute deviations from a baseline model that does not include the jet, and compare observed X-ray images with those computed with simulated images where no jet features exist. This allows us to compute p -value upper bounds on the significance that an X-ray jet is detected in a pre-determined region of interest. We detected 12 of the features unambiguously, and an additional six marginally. We also find residual emission in the cores of three quasars and in the background of one quasar that suggest the existence of unresolved X-ray jets. The dependence of the X-ray to radio luminosity ratio on redshift is a potential diagnostic of the emission mechanism, since the inverse Compton scattering of cosmic microwave background photons (IC/CMB) is thought to be redshift dependent, whereas in synchrotron models no clear redshift dependence is expected. We find that the high-redshift jets have X-ray to radio flux ratios that are marginally inconsistent with those from lower redshifts, suggesting that either the X-ray emissions are due to the IC/CMB rather than the synchrotron process, or that high-redshift jets are qualitatively different.

MONITORING THE BIDIRECTIONAL RELATIVISTIC JETS OF THE RADIO GALAXY 1946+708

International Nuclear Information System (INIS)

Taylor, G. B.; Charlot, P.; Vermeulen, R. C.; Pradel, N.

2009-01-01

We report on a multifrequency, multi-epoch campaign of Very Long Baseline Interferometry (VLBI) observations of the radio galaxy 1946+708 using the Very Long Baseline Array and a Global VLBI array. From these high-resolution observations, we deduce the kinematic age of the radio source to be ∼4000 years, comparable with the ages of other Compact Symmetric Objects. Ejections of pairs of jet components appears to take place on time scales of ten years and these components in the jet travel outward at intrinsic velocities between 0.6c and 0.9c. From the constraint that jet components cannot have intrinsic velocities faster than light, we derive H 0 > 57 km s -1 Mpc -1 from the fastest pair of components launched from the core. We provide strong evidence for the ejection of a new pair of components in ∼1997. From the trajectories of the jet components, we deduce that the jet is most likely to be helically confined, rather than being purely ballistic in nature.

A Comprehensive Analysis of Jet Quenching via a Hybrid Strong/Weak Coupling Model for Jet-Medium Interactions

Energy Technology Data Exchange (ETDEWEB)

Casalderrey-Solana, Jorge [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Gulhan, Doga Can [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Milhano, José Guilherme [CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Physics Department, Theory Unit, CERN, CH-1211 Genève 23 (Switzerland); Pablos, Daniel [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rajagopal, Krishna [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2016-12-15

Within a hybrid strong/weak coupling model for jets in strongly coupled plasma, we explore jet modifications in ultra-relativistic heavy ion collisions. Our approach merges the perturbative dynamics of hard jet evolution with the strongly coupled dynamics which dominates the soft exchanges between the fast partons in the jet shower and the strongly coupled plasma itself. We implement this approach in a Monte Carlo, which supplements the DGLAP shower with the energy loss dynamics as dictated by holographic computations, up to a single free parameter that we fit to data. We then augment the model by incorporating the transverse momentum picked up by each parton in the shower as it propagates through the medium, at the expense of adding a second free parameter. We use this model to discuss the influence of the transverse broadening of the partons in a jet on intra-jet observables. In addition, we explore the sensitivity of such observables to the back-reaction of the plasma to the passage of the jet.

Particle Acceleration, Magnetic Field Generation, and Emission in Relativistic Shocks

Science.gov (United States)

Nishikawa, Ken-IchiI.; Hededal, C.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G.

2004-01-01

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (m) code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient parallel magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. New simulations with an ambient perpendicular magnetic field show the strong interaction between the relativistic jet and the magnetic fields. The magnetic fields are piled up by the jet and the jet electrons are bent, which creates currents and displacement currents. At the nonlinear stage, the magnetic fields are reversed by the current and the reconnection may take place. Due to these dynamics the jet and ambient electron are strongly accelerated in both parallel and perpendicular directions.

Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks

Science.gov (United States)

Nishikawa, K.-I.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G. J.

2005-01-01

small- scale magnetic field structure is appropriate to the generation of "jitter" radiation from deflected electrons (positrons) as opposed to synchrotron radiation. The jitter radiation has different properties than synchrotron radiation calculated assuming a uniform magnetic field. The jitter radiation resulting from small-scale magnetic field structures may be important for understanding the complex time structure and spectral evolution observed in gamma-ray bursts or other astrophysical sources containing relativistic jets and relativistic collisionless shocks.

Measurements of jet-related observables at the LHC

Science.gov (United States)

Kokkas, P.

2015-11-01

During the first years of the LHC operation a large amount of jet data was recorded by the ATLAS and CMS experiments. In this review several measurements of jet-related observables are presented, such as multi-jet rates and cross sections, ratios of jet cross sections, jet shapes and event shape observables. All results presented here are based on jet data collected at a centre-of-mass energy of 7 TeV. Data are compared to various Monte Carlo generators, as well as to theoretical next-to-leading-order calculations allowing a test of perturbative Quantum Chromodynamics in a previously unexplored energy region.

Empirical model of the M 87 jet

International Nuclear Information System (INIS)

Shklovskij, I.S.

1984-01-01

The nature of the M87 jet is discussed. Recent observations of the M87 jet in radio, optical and X-ray regions, carried out with a sufficiently high resolving power, have revealed an identity of the brightness distribution at all frequencies. This points to a decisive role of the regular magnetic field variations along the jet for its overall structure. The bright knots of the jet are in the places where the field is enhanced. In the same places, a small fraction of relativistic electrons acquires large pitch-angles due to the interaction with plasma waves, leading to the synchrotron emission of the knots. The velocity of the plasma ejected from the nucleus of M87 should be 0.1 c. Thus, the M87 jet is one-sided

The jet of the Low Luminosity AGN of M81

Directory of Open Access Journals (Sweden)

Alberdi A.

2013-12-01

Full Text Available In this contribution, we summarize our main results of a big campaign of global VLBI observations of the AGN in M81 (M81* phase-referenced to the radio supernova SN 1993J. Thanks to the precise multi-epoch and multi-frequency astrometry, we have determined the normalized core-shift of the relativistic jet of M81* and estimated both the magnetic field and the particle density at the jet base. We have also found evidence of jet precession in M81* coming from the systematic time evolution of the jet orientation correlated with changes in the overall flux density.

Jet measurements in heavy-ion collisions with the ATLAS detector

CERN Document Server

Havener, Laura Brittany; The ATLAS collaboration

2017-01-01

In relativistic heavy-ion collisions, a hot medium with a high density of unscreened colour charges is produced. Jets are produced by parton-parton scatterings in the early stages of the collision, and are observed to be attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. Another manifestation of energy loss is the modification of both dijet transverse energy balance, and a similar modification of photon-jet correlations. Finally, the internal structure of jets is also observed to be modified, from a careful study of fragmentation functions. In this talk, the latest ATLAS results on single jet suppression, dijet suppression, photon-jet correlations, and modification of the jet internal structure in both p+Pb and Pb+Pb collisions, compared to pp, will be presented.

Non-thermal particle acceleration in collisionless relativistic electron-proton reconnection

Science.gov (United States)

Werner, G. R.; Uzdensky, D. A.; Begelman, M. C.; Cerutti, B.; Nalewajko, K.

2018-02-01

Magnetic reconnection in relativistic collisionless plasmas can accelerate particles and power high-energy emission in various astrophysical systems. Whereas most previous studies focused on relativistic reconnection in pair plasmas, less attention has been paid to electron-ion plasma reconnection, expected in black hole accretion flows and relativistic jets. We report a comprehensive particle-in-cell numerical investigation of reconnection in an electron-ion plasma, spanning a wide range of ambient ion magnetizations σi, from the semirelativistic regime (ultrarelativistic electrons but non-relativistic ions, 10-3 ≪ σi ≪ 1) to the fully relativistic regime (both species are ultrarelativistic, σi ≫ 1). We investigate how the reconnection rate, electron and ion plasma flows, electric and magnetic field structures, electron/ion energy partitioning, and non-thermal particle acceleration depend on σi. Our key findings are: (1) the reconnection rate is about 0.1 of the Alfvénic rate across all regimes; (2) electrons can form concentrated moderately relativistic outflows even in the semirelativistic, small-σi regime; (3) while the released magnetic energy is partitioned equally between electrons and ions in the ultrarelativistic limit, the electron energy fraction declines gradually with decreased σi and asymptotes to about 0.25 in the semirelativistic regime; and (4) reconnection leads to efficient non-thermal electron acceleration with a σi-dependent power-law index, p(σ _i)˜eq const+0.7σ _i^{-1/2}. These findings are important for understanding black hole systems and lend support to semirelativistic reconnection models for powering non-thermal emission in blazar jets, offering a natural explanation for the spectral indices observed in these systems.

The collective emission of electromagnetic waves from astrophysical jets - Luminosity gaps, BL Lacertae objects, and efficient energy transport

Science.gov (United States)

Baker, D. N.; Borovsky, Joseph E.; Benford, Gregory; Eilek, Jean A.

1988-01-01

A model of the inner portions of astrophysical jets is constructed in which a relativistic electron beam is injected from the central engine into the jet plasma. This beam drives electrostatic plasma wave turbulence, which leads to the collective emission of electromagnetic waves. The emitted waves are beamed in the direction of the jet axis, so that end-on viewing of the jet yields an extremely bright source (BL Lacertae object). The relativistic electron beam may also drive long-wavelength electromagnetic plasma instabilities (firehose and Kelvin-Helmholtz) that jumble the jet magnetic field lines. After a sufficient distance from the core source, these instabilities will cause the beamed emission to point in random directions and the jet emission can then be observed from any direction relative to the jet axis. This combination of effects may lead to the gap turn-on of astrophysical jets. The collective emission model leads to different estimates for energy transport and the interpretation of radio spectra than the conventional incoherent synchrotron theory.

Dynamics and stability of relativistic gamma-ray-bursts blast waves

Science.gov (United States)

Meliani, Z.; Keppens, R.

2010-09-01

Aims: In gamma-ray-bursts (GRBs), ultra-relativistic blast waves are ejected into the circumburst medium. We analyse in unprecedented detail the deceleration of a self-similar Blandford-McKee blast wave from a Lorentz factor 25 to the nonrelativistic Sedov phase. Our goal is to determine the stability properties of its frontal shock. Methods: We carried out a grid-adaptive relativistic 2D hydro-simulation at extreme resolving power, following the GRB jet during the entire afterglow phase. We investigate the effect of the finite initial jet opening angle on the deceleration of the blast wave, and identify the growth of various instabilities throughout the coasting shock front. Results: We find that during the relativistic phase, the blast wave is subject to pressure-ram pressure instabilities that ripple and fragment the frontal shock. These instabilities manifest themselves in the ultra-relativistic phase alone, remain in full agreement with causality arguments, and decay slowly to finally disappear in the near-Newtonian phase as the shell Lorentz factor drops below 3. From then on, the compression rate decreases to levels predicted to be stable by a linear analysis of the Sedov phase. Our simulations confirm previous findings that the shell also spreads laterally because a rarefaction wave slowly propagates to the jet axis, inducing a clear shell deformation from its initial spherical shape. The blast front becomes meridionally stratified, with decreasing speed from axis to jet edge. In the wings of the jetted flow, Kelvin-Helmholtz instabilities occur, which are of negligible importance from the energetic viewpoint. Conclusions: Relativistic blast waves are subject to hydrodynamical instabilities that can significantly affect their deceleration properties. Future work will quantify their effect on the afterglow light curves.

Chandra Takes on Heavy Jets and Massive Winds in 4U 1630-47

Science.gov (United States)

Neilsen, Joey

2014-11-01

Recently, Díaz Trigo et al. reported the discovery of relativistic baryons in a jet in XMM/ATCA observations of the 2012 outburst of the black hole 4U 1630-47. We present a search for a similarly massive jet earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. Despite a detection of radio emission with ATCA, we find no evidence of a heavy jet in the X-ray spectrum, with tight upper limits on the relativistic emission lines seen by Díaz Trigo eight months later. Instead, we find deep absorption lines from a massive, highly ionized disk wind, whose properties can be probed with detailed photoionization models. We explore several scenarios to explain the two modes of massive outflow in this remarkable black hole system.

ON THE OBSERVATION AND SIMULATION OF SOLAR CORONAL TWIN JETS

Energy Technology Data Exchange (ETDEWEB)

Liu, Jiajia; Wang, Yuming; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, NO. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Fang, Fang [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, CO 80303 (United States); McIntosh, Scott W.; Fan, Yuhong [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

2016-02-01

We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

On the Observation and Simulation of Solar Coronal Twin Jets

Science.gov (United States)

Liu, Jiajia; Fang, Fang; Wang, Yuming; McIntosh, Scott W.; Fan, Yuhong; Zhang, Quanhao

2016-02-01

We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

arXiv Generalized Fragmentation Functions for Fractal Jet Observables

CERN Document Server

Elder, Benjamin T.; Thaler, Jesse; Waalewijn, Wouter J.; Zhou, Kevin

2017-06-15

We introduce a broad class of fractal jet observables that recursively probe the collective properties of hadrons produced in jet fragmentation. To describe these collinear-unsafe observables, we generalize the formalism of fragmentation functions, which are important objects in QCD for calculating cross sections involving identified final-state hadrons. Fragmentation functions are fundamentally nonperturbative, but have a calculable renormalization group evolution. Unlike ordinary fragmentation functions, generalized fragmentation functions exhibit nonlinear evolution, since fractal observables involve correlated subsets of hadrons within a jet. Some special cases of generalized fragmentation functions are reviewed, including jet charge and track functions. We then consider fractal jet observables that are based on hierarchical clustering trees, where the nonlinear evolution equations also exhibit tree-like structure at leading order. We develop a numeric code for performing this evolution and study its phen...

Non-Gaussianities due to relativistic corrections to the observed galaxy bispectrum

International Nuclear Information System (INIS)

Dio, E. Di; Perrier, H.; Durrer, R.; Dizgah, A. Moradinezhad; Riotto, A.; Marozzi, G.; Noreña, J.

2017-01-01

High-precision constraints on primordial non-Gaussianity (PNG) will significantly improve our understanding of the physics of the early universe. Among all the subtleties in using large scale structure observables to constrain PNG, accounting for relativistic corrections to the clustering statistics is particularly important for the upcoming galaxy surveys covering progressively larger fraction of the sky. We focus on relativistic projection effects due to the fact that we observe the galaxies through the light that reaches the telescope on perturbed geodesics. These projection effects can give rise to an effective f NL that can be misinterpreted as the primordial non-Gaussianity signal and hence is a systematic to be carefully computed and accounted for in modelling of the bispectrum. We develop the technique to properly account for relativistic effects in terms of purely observable quantities, namely angles and redshifts. We give some examples by applying this approach to a subset of the contributions to the tree-level bispectrum of the observed galaxy number counts calculated within perturbation theory and estimate the corresponding non-Gaussianity parameter, f NL , for the local, equilateral and orthogonal shapes. For the local shape, we also compute the local non-Gaussianity resulting from terms obtained using the consistency relation for observed number counts. Our goal here is not to give a precise estimate of f NL for each shape but rather we aim to provide a scheme to compute the non-Gaussian contamination due to relativistic projection effects. For the terms considered in this work, we obtain contamination of f NL loc ∼ O(1).

VizieR Online Data Catalog: Radio-loud AGN with relativistic jets (Olguin-Iglesias+, 2016)

Science.gov (United States)

Olguin-Iglesias, A.; Leon-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Anorve, C.; Valdes, J.; Carrasco, L.

2017-11-01

The sample of sources analysed in this work is a sub-sample of variable radio-loud AGN monitored at 7mm (S7mm>1Jy) with the Aalto University Metsahovi Radio Observatory, in Finland (http://metsahovi.aalto.fi/en/) since the last 30 years (Terasranta et al., 1992A&AS...94..121T; Teraesranta et al., 1998, Cat. J/A+AS/132/305; Leon-Tavares et al., 2011A&A...532A.146L; Nieppola et al., 2011, Cat. J/A+A/535/A69). According to the AGN unification scheme (Antonucci, 1993ARA&A..31..473A; Urry & Padovani, 1995PASP..107..803U), FSRQ and BL Lacs are those AGN whose relativistic jets point towards the Earth. Observations were made with the Nordic Optical Telescope (NOT) at La Roque de los Muchachos, La Palma, Canarias, Spain. They were conducted between 2011 May 09 and September 15 using the near-infrared Camera (NOTCam)3 on the NOT. NOTcam field of view is 4'x4' with a pixel scale of 0.234-arcsec/pixel designed to be used in the range from 0.8 to 2.5um in the bands J, H and K. (1 data file).

Non-Gaussianities due to relativistic corrections to the observed galaxy bispectrum

Energy Technology Data Exchange (ETDEWEB)

Dio, E. Di [INAF—Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, Trieste, I-34143 Italy (Italy); Perrier, H.; Durrer, R.; Dizgah, A. Moradinezhad; Riotto, A. [University of Geneva, Department of Theoretical Physics and Center for Astroparticle Physics (CAP), 24 quai E. Ansermet, Geneva 4, CH-1211 Switzerland (Switzerland); Marozzi, G. [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Urca, Rio de Janeiro, CEP 22290-180 Brazil (Brazil); Noreña, J., E-mail: Enea.DiDio@oats.inaf.it, E-mail: Hideki.Perrier@unige.ch, E-mail: Ruth.Durrer@unige.ch, E-mail: Marozzi@cbpf.br, E-mail: amoradinejad@physics.harvard.edu, E-mail: jorge.norena@pucv.cl, E-mail: Antonio.Riotto@unige.ch [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla, Valparaíso, 4059 Chile (Chile)

2017-03-01

High-precision constraints on primordial non-Gaussianity (PNG) will significantly improve our understanding of the physics of the early universe. Among all the subtleties in using large scale structure observables to constrain PNG, accounting for relativistic corrections to the clustering statistics is particularly important for the upcoming galaxy surveys covering progressively larger fraction of the sky. We focus on relativistic projection effects due to the fact that we observe the galaxies through the light that reaches the telescope on perturbed geodesics. These projection effects can give rise to an effective f {sub NL} that can be misinterpreted as the primordial non-Gaussianity signal and hence is a systematic to be carefully computed and accounted for in modelling of the bispectrum. We develop the technique to properly account for relativistic effects in terms of purely observable quantities, namely angles and redshifts. We give some examples by applying this approach to a subset of the contributions to the tree-level bispectrum of the observed galaxy number counts calculated within perturbation theory and estimate the corresponding non-Gaussianity parameter, f {sub NL}, for the local, equilateral and orthogonal shapes. For the local shape, we also compute the local non-Gaussianity resulting from terms obtained using the consistency relation for observed number counts. Our goal here is not to give a precise estimate of f {sub NL} for each shape but rather we aim to provide a scheme to compute the non-Gaussian contamination due to relativistic projection effects. For the terms considered in this work, we obtain contamination of f {sub NL}{sup loc} ∼ O(1).

Stellar signatures of AGN-jet-triggered star formation

International Nuclear Information System (INIS)

Dugan, Zachary; Silk, Joseph; Bryan, Sarah; Gaibler, Volker; Haas, Marcel

2014-01-01

To investigate feedback between relativistic jets emanating from active galactic nuclei and the stellar population of the host galaxy, we analyze the long-term evolution of the orbits of the stars formed in the galaxy-scale simulations by Gaibler et al. of jets in massive, gas-rich galaxies at z ∼ 2-3. We find strong, jet-induced differences in the resulting stellar populations of galaxies that host relativistic jets and galaxies that do not, including correlations in stellar locations, velocities, and ages. Jets are found to generate distributions of increased radial and vertical velocities that persist long enough to effectively augment the stellar structure of the host. The jets cause the formation of bow shocks that move out through the disk, generating rings of star formation within the disk. The bow shock often accelerates pockets of gas in which stars form, yielding populations of stars with significant radial and vertical velocities, some of which have large enough velocities to escape the galaxy. These stellar population signatures can serve to identify past jet activity as well as jet-induced star formation.

Simulations of Gamma-Ray Burst Jets in a Stratified External Medium: Dynamics, Afterglow Light Curves, Jet Breaks, and Radio Calorimetry

Science.gov (United States)

De Colle, Fabio; Ramirez-Ruiz, Enrico; Granot, Jonathan; Lopez-Camara, Diego

2012-05-01

The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with ρextvpropr -k for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle θ0 = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor Γ drops below θ-1 0. For larger k values, however, the lateral expansion is faster at early times (when Γ > θ-1 0) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for θobs <= θ0) than by the slope of the external density profile (for 0 <= k <= 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results in a clear bump-like feature in the light curve. However, for larger k values the jet decelerates more

Observation of the Antimatter Nuclei in Relativistic Heavy Ion Collisions

International Nuclear Information System (INIS)

Yoo, I.-K.

2013-01-01

Recently antimatter hyper-triton nuclei ( 3 Λ¯ H ¯) and antimatter helium nuclei ( 4 2 He ¯ ) are discovered with the Solenoidal Tracker At RHIC detector in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) (STAR Collaboration in Science 328(5974):58-62, 2010; STAR Collaboration in Nature 473:353-356, 2011). In this presentation, discoveries of antimatter particle are historically scanned and the recent observations at RHIC are reported in details as well as potential possibilities of discovery of antimatter nuclei at ALICE. (author)

Assessment of Unusual Gigantic Jets observed during the Monsoon season: First observations from Indian Subcontinent

DEFF Research Database (Denmark)

Singh, Rajesh; Maurya, Ajeet K.; Chanrion, Olivier

2017-01-01

observations. Here we report first observations of Gigantic Jets in Indian subcontinent over the Indo-Gangetic plains during the monsoon season. Two storms each produced two jets with characteristics not documented so far. Jets propagated similar to 37 km up remarkably in similar to 5 ms with velocity...

Predictions for Boson-Jet Observables and Fragmentation Function Ratios from a Hybrid Strong/Weak Coupling Model for Jet Quenching

CERN Document Server

Casalderrey-Solana, Jorge; Milhano, José Guilherme; Pablos, Daniel; Rajagopal, Krishna

2016-01-01

We have previously introduced a hybrid strong/weak coupling model for jet quenching in heavy ion collisions that describes the production and fragmentation of jets at weak coupling, using PYTHIA, and describes the rate at which each parton in the jet shower loses energy as it propagates through the strongly coupled plasma, dE/dx, using an expression computed holographically at strong coupling. The model has a single free parameter that we fit to a single experimental measurement. We then confront our model with experimental data on many other jet observables, focusing here on boson-jet observables, finding that it provides a good description of present jet data. Next, we provide the predictions of our hybrid model for many measurements to come, including those for inclusive jet, dijet, photon-jet and Z-jet observables in heavy ion collisions with energy $\\sqrt{s}=5.02$ ATeV coming soon at the LHC. As the statistical uncertainties on near-future measurements of photon-jet observables are expected to be much sm...

RECONSTRUCTING THREE-DIMENSIONAL JET GEOMETRY FROM TWO-DIMENSIONAL IMAGES

Science.gov (United States)

Avachat, Sayali; Perlman, Eric S.; Li, Kunyang; Kosak, Katie

2018-01-01

Relativistic jets in AGN are one of the most interesting and complex structures in the Universe. Some of the jets can be spread over hundreds of kilo parsecs from the central engine and display various bends, knots and hotspots. Observations of the jets can prove helpful in understanding the emission and particle acceleration processes from sub-arcsec to kilo parsec scales and the role of magnetic field in it. The M87 jet has many bright knots as well as regions of small and large bends. We attempt to model the jet geometry using the observed 2 dimensional structure. The radio and optical images of the jet show evidence of presence of helical magnetic field throughout. Using the observed structure in the sky frame, our goal is to gain an insight into the intrinsic 3 dimensional geometry in the jets frame. The structure of the bends in jet's frame may be quite different than what we see in the sky frame. The knowledge of the intrinsic structure will be helpful in understanding the appearance of the magnetic field and hence polarization morphology. To achieve this, we are using numerical methods to solve the non-linear equations based on the jet geometry. We are using the Log Likelihood method and algorithm based on Markov Chain Monte Carlo (MCMC) simulations.

Dynamical efficiency of collisionless magnetized shocks in relativistic jets

Science.gov (United States)

Aloy, Miguel A.; Mimica, Petar

2011-09-01

The so-called internal shock model aims to explain the light-curves and spectra produced by non-thermal processes originated in the flow of blazars and gamma-ray bursts. A long standing question is whether the tenuous collisionless shocks, driven inside a relativistic flow, are efficient enough to explain the amount of energy observed as compared with the expected kinetic power of the outflow. In this work we study the dynamic efficiency of conversion of kinetic-to-thermal/magnetic energy of internal shocks in relativistic magnetized outflows. We find that the collision between shells with a non-zero relative velocity can yield either two oppositely moving shocks (in the frame where the contact surface is at rest), or a reverse shock and a forward rarefaction. For moderately magnetized shocks (magnetization σ ~= 0.1), the dynamic efficiency in a single two-shell interaction can be as large as 40%. Hence, the dynamic efficiency of moderately magnetized shocks is larger than in the corresponding unmagnetized two-shell interaction. We find that the efficiency is only weakly dependent on the Lorentz factor of the shells and, thus internal shocks in the magnetized flow of blazars and gamma-ray bursts are approximately equally efficient.

Magnetic field, reconnection, and particle acceleration in extragalactic jets

Science.gov (United States)

Romanova, M. M.; Lovelace, R. V. E.

1992-01-01

Extra-galactic radio jets are investigated theoretically taking into account that the jet magnetic field is dragged out from the central rotating source by the jet flow. Thus, magnetohydrodynamic models of jets are considered with zero net poloidal current and flux, and consequently a predominantly toroidal magnetic field. The magnetic field naturally has a cylindrical neutral layer. Collisionless reconnection of the magnetic field in the vicinity of the neutral layer acts to generate a non-axisymmetric radial magnetic field. In turn, axial shear-stretching of reconnected toroidal field gives rise to a significant axial magnetic field if the flow energy-density is larger than the energy-density of the magnetic field. This can lead to jets with an apparent longitudinal magnetic field as observed in the Fanaroff-Riley class II jets. In the opposite limit, where the field energy-density is large, the field remains mainly toroidal as observed in Fanaroff-Riley class I jets. Driven collisionless reconnection at neutral layers may lead to acceleration of electrons to relativistic energies in the weak electrostatic field of the neutral layer. A simple model is discussed for particle acceleration at neutral layers in electron/positron and electron/proton plasmas.

First observations of Gigantic Jets from Monsoon Thunderstorms over India

Science.gov (United States)

Singh, Rajesh; Maurya, Ajeet; Chanrion, Olivier; Neubert, Torsten; Cummer, Steven; Mlynarczyk, Janusz; Bór, József; Siingh, Devendraa; Cohen, Morris; Kumar, Sushil

2016-04-01

Gigantic Jets are electric discharges from thunderstorm cloud tops to the bottom of the ionosphere at ~80 km altitude. After their first discovery in 2001, relatively few observations have been reported. Most of these are from satellites at large distances and a few tens from the ground at higher spatial resolution. Here we report the first Gigantic Jets observed in India from two thunderstorm systems that developed over the land surface from monsoon activity, each storm producing two Gigantic Jets. The jets were recorded by a video camera system at standard video rate (20 ms exposure) at a few hundred km distance. ELF measurements suggest that the jets are of the usual negative polarity and that they develop in less than 40 ms, which is faster than most jets reported in the past. The jets originate from the leading edge of a slowly drifting convective cloud complex close to the highest regions of the clouds and carry ~25 Coulomb of charge to the ionosphere. One jet has a markedly horizontal displacement that we suggest is caused by a combination of close-range cloud electric fields at inception, and longer-range cloud fields at larger distances during full development. The Gigantic Jets are amongst the few that have been observed over land.

Radio Observations of Ultra-Luminous X-Ray Sources ---Microblazars or Intermediate-Mass Black Holes?---

Science.gov (United States)

Körding, E.; Colbert, E.; Falcke, H.

In recent years Ultra-Luminous X-Ray sources (ULXs) received wide attention, however, their true nature is not yet understood. Many explanations have been suggested, including intermediate-mass black holes, super-Eddington accretion flows, anisotropic emission, and relativistic beaming of microquasars. We model the logN-logS distribution of ULXs assuming that each neutron star or black hole XRB can be described by an accretion disk plus jet model, where the jet is relativistically beamed. The distribution can be either fit by intermediate-mass black holes or by stellar mass black holes with mildly relativistic jets. Even though the jet is intrinsically weaker than the accretion disk, relativistic beaming can in the latter approach lead to the high fluxes observed. To further explore the possibility of microblazars contributing to the ULX phenomenon, we have embarked on a radio-monitoring study of ULXs in nearby galaxies with the VLA. However, up to now no radio flare has been detected. Using the radio/X-ray correlation the upper limits on the radio flux can be converted into upper limits for the black hole masses of MBH ≲ 10^3 M⊙.

Imaging of Nuclear Fragmentation in Nuclear Track Emulsion Relativistic Nuclei

International Nuclear Information System (INIS)

Zarubina, I.G. JINR

2011-01-01

The method of nuclear track emulsion provides a uniquely complete observation of multiple fragment systems produced in dissociation of relativistic nuclei. The most valuable events of coherent dissociation of nuclei in narrow jets of light and the lightest nuclei with a net charge as in the initial nucleus, occurring without the production of fragments of the target nuclei and mesons (the so-called w hite s tars), comprise a few percent among the observed interactions. The data on this phenomenon are fragmented, and the interpretation is not offered. The dissociation degree of light O, Ne, Mg and Si, and as well as heavy Au, Pb and U nuclei may reach a complete destruction to light and the lightest nuclei and nucleons, resulting in cluster systems of an unprecedented complexity. Studies with relativistic neutron-deficient nuclei have special advantages due to more complete observations. An extensive collection of macro videos of such interactions in nuclear track emulsion gathered by the Becquerel collaboration is presented

Jetted GRBs, afterglows and SGRs from quark stars birth

CERN Document Server

Dar, Arnon

1999-01-01

Recent studies suggest that when cold nuclear matter is compressed to high nuclear densities, diquarks with spin zero and antisymmetric color wave function Bose condensate into a superfluid/superconducting state that is several times as dense. Various astrophysical phenomena may be explained by gravitational collapse of neutron stars (NSs) to (di)quark stars (QSs) as a result of a first order phase transition in NSs within $\\sim 10^{4}$ years after their birth in supernova explosions, when they cooled and spun down sufficiently (by magnetic braking ?). The gravitational energy release drives an explosion which may eject both highly relativistic narrowly collimated jets and a mildly relativistic ``spherical'' shell. The slow contraction/cooling of the remnant QSs can power soft gamma ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs), without invoking a huge magnetic energy storage. The jets can produce the observed gamma ray bursts (GRBs) in distant galaxies when they happen to point in our direction and...

A Link Between X-ray Emission Lines and Radio Jets in 4U 1630-47?

Science.gov (United States)

Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Lee, Julia C.; Ponti, Gabriele; Tzioumis, A.; Edwards, Phillip; Broderick, Jess

2014-06-01

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. We present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find a strong disk wind but no evidence for any relativistic X-ray emission lines. Indeed, despite ˜5× brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ˜20× weaker than the line observed by Díaz Trigo et al. Thus we can conclusively say that radio emission is not universally associated with relativistically Doppler-shifted emission lines in 4U 1630-47. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby ISM, in which case the X-ray emission lines might be unrelated to the radio emission.

Jet models of X-Ray Flashes

International Nuclear Information System (INIS)

Lamb, D.Q.; Donaghy, T.Q.; Graziani, C.

2005-01-01

One third of all HETE-2-localized bursts are X-Ray Flashes (XRFs), a class of events first identified by Heise in which the fluence in the 2-30 keV energy band exceeds that in the 30-400 keV energy band We summarize recent HETE-2 and other results on the properties of XRFs. These results show that the properties of XRFs, X-ray-rich gamma-ray bursts (GRBs), and GRBs form a continuum, and thus provide evidence that all three kinds of bursts are closely related phenomena. As the most extreme burst population, XRFs provide severe constraints on burst models and unique insights into the structure of GRB jets, the GRB rate, and the nature of Type Ib/Ic supernovae. We briefly mention a number of the physical models that have been proposed to explain XRFs. We then consider two fundamentally different classes of phenomenological jet models: universal jet models, in which it is posited that all GRBs jets are identical and that differences in the observed properties of the bursts are due entirely to differences in the viewing angle; and variable-opening angle jet models, in which it is posited that GRB jets have a distribution of jet opening angles and that differences in the observed properties of the bursts are due to differences in the emissivity and spectra of jets having different opening angles. We consider three shapes far the emissivity as a function of the viewing angle θ ν from the axis of the jet: power law, top hat (or uniform) , and Gaussian (or Fisher). We then discuss the effect of relativistic beaming on each of these models. We show that observations can distinguish between these various models

Di-Jet Conical Correlations Associated with Heavy Quark Jets in anti-de Sitter Space/Conformal Field Theory Correspondence

International Nuclear Information System (INIS)

Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio

2009-01-01

We show that far zone Mach and diffusion wake 'holograms' produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N c →∞ supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium 'neck' zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence

Di-jet conical correlations associated with heavy quark jets in anti-de sitter space/conformal field theory correspondence.

Science.gov (United States)

Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio

2009-03-13

We show that far zone Mach and diffusion wake "holograms" produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N_{c}-->infinity supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium "neck" zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence.

SIMULATIONS OF GAMMA-RAY BURST JETS IN A STRATIFIED EXTERNAL MEDIUM: DYNAMICS, AFTERGLOW LIGHT CURVES, JET BREAKS, AND RADIO CALORIMETRY

International Nuclear Information System (INIS)

De Colle, Fabio; Ramirez-Ruiz, Enrico; Granot, Jonathan; Lopez-Camara, Diego

2012-01-01

The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with ρ ext ∝r –k for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle θ 0 = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor Γ drops below θ –1 0 . For larger k values, however, the lateral expansion is faster at early times (when Γ > θ –1 0 ) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for θ obs ≤ θ 0 ) than by the slope of the external density profile (for 0 ≤ k ≤ 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results in a clear bump-like feature in the light curve. However, for larger k values the jet

SIMULATIONS OF GAMMA-RAY BURST JETS IN A STRATIFIED EXTERNAL MEDIUM: DYNAMICS, AFTERGLOW LIGHT CURVES, JET BREAKS, AND RADIO CALORIMETRY

Energy Technology Data Exchange (ETDEWEB)

De Colle, Fabio; Ramirez-Ruiz, Enrico [TASC, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Granot, Jonathan [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Lopez-Camara, Diego [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ap. 70-543, 04510 D.F. (Mexico)

2012-05-20

The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with {rho}{sub ext}{proportional_to}r{sup -k} for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle {theta}{sub 0} = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor {Gamma} drops below {theta}{sup -1}{sub 0}. For larger k values, however, the lateral expansion is faster at early times (when {Gamma} > {theta}{sup -1}{sub 0}) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for {theta}{sub obs} {<=} {theta}{sub 0}) than by the slope of the external density profile (for 0 {<=} k {<=} 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results

Jet Physics with A Large Ion Collider Experiment at the Large Hadron Collider

CERN Document Server

Klein, Jochen

In the presence of the strongly-interacting medium created in relativistic heavy-ion collisions, highly energetic partons from hard interactions lose energy through scattering and radiating. This effect, referred to as jet quenching, is observed as a suppression of particles with large momenta transverse to the beam axis (high-$p_\\perp$). To study the impact of the medium evolution on the energy loss modelling in the Monte Carlo event generator JEWEL, we compare results obtained for different scenarios of Au-Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200~\\mathrm{GeV}$. For this purpose, JEWEL was extended to use the output of relativistic hydrodynamic calculations in the OSCAR2008H format. We find the modelling of common observables, e.g. the nuclear modification factor, to be rather insensitive to the details of the medium evolution, for which the analytically accessible Bjorken expansion can thus be considered adequate. The OSCAR interface now allows further studies also at LHC energies. Jets of large transve...

Magnetosheath jets: MMS observations of internal structures and jet interactions with ambient plasma

Science.gov (United States)

Plaschke, F.; Karlsson, T.; Hietala, H.; Archer, M. O.; Voros, Z.; Nakamura, R.; Magnes, W.; Baumjohann, W.; Torbert, R. B.; Russell, C. T.; Giles, B. L.

2017-12-01

The dayside magnetosheath downstream of the quasi-parallel bow shock is commonly permeated by high-speed jets. Under low IMF cone angle conditions, large scale jets alone (with cross-sectional diameters of over 2 Earth radii) have been found to impact the subsolar magnetopause once every 6 minutes - smaller scale jets occurring much more frequently. The consequences of jet impacts on the magnetopause can be significant: they may trigger local reconnection and waves, alter radiation belt electron drift paths, disturb the geomagnetic field, and potentially generate diffuse throat aurora at the dayside ionosphere. Although some basic statistical properties of jets are well-established, their internal structure and interactions with the surrounding magnetosheath plasma are rather unknown. We present Magnetospheric Multiscale (MMS) observations which reveal a rich jet-internal structure of high-amplitude plasma moment and magnetic field variations and associated currents. These variations/structures are generally found to be in thermal and magnetic pressure balance; they mostly (but not always) convect with the plasma flow. Small velocity differences between plasma and structures are revealed via four-spacecraft timing analysis. Inside a jet core region, where the plasma velocity maximizes, structures are found to propagate forward (i.e., with the jet), whereas backward propagation is found outside that core region. Although super-magnetosonic flows are detected by MMS in the spacecraft frame of reference, no fast shock is seen as the jet plasma is sub-magnetosonic with respect to the ambient magnetosheath plasma. Instead, the fast jet plasma pushes ambient magnetosheath plasma ahead of the jet out of the way, possibly generating anomalous sunward flows in the vicinity, and modifies the magnetic field aligning it with the direction of jet propagation.

CONFRONTING THREE-DIMENSIONAL TIME-DEPENDENT JET SIMULATIONS WITH HUBBLE SPACE TELESCOPE OBSERVATIONS

International Nuclear Information System (INIS)

Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai

2010-01-01

We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s -1 ) and outer (less than 100 km s -1 ) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.

POPULATION III GAMMA-RAY BURSTS AND BREAKOUT CRITERIA FOR ACCRETION-POWERED JETS

Energy Technology Data Exchange (ETDEWEB)

Nagakura, Hiroki; Suwa, Yudai [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Ioka, Kunihito, E-mail: hiroki@heap.phys.waseda.ac.jp [KEK Theory Center, 1-1 Oho, Tsukuba 305-0801 (Japan)

2012-08-01

We investigate the propagation of accretion-powered jets in various types of massive stars such as Wolf-Rayet stars, light Population III (Pop III) stars, and massive Pop III stars, all of which are the progenitor candidates of gamma-ray bursts (GRBs). We perform two-dimensional axisymmetric simulations of relativistic hydrodynamics, taking into account both the envelope collapse and the jet propagation (i.e., the negative feedback of the jet on the accretion). Based on our hydrodynamic simulations, we show for the first time that the accretion-powered jet can potentially break out relativistically from the outer layers of Pop III progenitors. In our simulations, the accretion rate is estimated by the mass flux going through the inner boundary, and the jet is injected with a fixed accretion-to-jet conversion efficiency {eta}. By varying the efficiency {eta} and opening angle {theta}{sub op} for more than 40 models, we find that the jet can make a relativistic breakout from all types of progenitors for GRBs if a simple condition {eta} {approx}> 10{sup -4}({theta}{sub op}/8 Degree-Sign ){sup 2} is satisfied, which is consistent with analytical estimates. Otherwise no explosion or some failed spherical explosions occur.

THE SPECTACULAR RADIO-NEAR-IR-X-RAY JET OF 3C 111: THE X-RAY EMISSION MECHANISM AND JET KINEMATICS

Energy Technology Data Exchange (ETDEWEB)

Clautice, Devon; Perlman, Eric S. [Department of Physics and Space Sciences, Florida Institute of Technology, 150 W. University Boulevard, Melbourne, FL 32901 (United States); Georganopoulos, Markos [Department of Physics, University of Maryland—Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Lister, Matthew L.; Hogan, Brandon [Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Tombesi, Francesco [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Cara, Mihai [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Marshall, Herman L. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Kazanas, Demos [NASA’s Goddard Space Flight Center, Astrophysics Science Division, Code 663, Greenbelt, MD 20771 (United States)

2016-08-01

Relativistic jets are the most energetic manifestation of the active galactic nucleus (AGN) phenomenon. AGN jets are observed from the radio through gamma-rays and carry copious amounts of matter and energy from the sub-parsec central regions out to the kiloparsec and often megaparsec scale galaxy and cluster environs. While most spatially resolved jets are seen in the radio, an increasing number have been discovered to emit in the optical/near-IR and/or X-ray bands. Here we discuss a spectacular example of this class, the 3C 111 jet, housed in one of the nearest, double-lobed FR II radio galaxies known. We discuss new, deep Chandra and Hubble Space Telescope ( HST ) observations that reveal both near-IR and X-ray emission from several components of the 3C 111 jet, as well as both the northern and southern hotspots. Important differences are seen between the morphologies in the radio, X-ray, and near-IR bands. The long (over 100 kpc on each side), straight nature of this jet makes it an excellent prototype for future, deep observations, as it is one of the longest such features seen in the radio, near-IR/optical, and X-ray bands. Several independent lines of evidence, including the X-ray and broadband spectral shape as well as the implied velocity of the approaching hotspot, lead us to strongly disfavor the EC/CMB model and instead favor a two-component synchrotron model to explain the observed X-ray emission for several jet components. Future observations with NuSTAR , HST , and Chandra will allow us to further constrain the emission mechanisms.

Elastic proton-deuteron backward scattering: relativistic effects and polarization observables

International Nuclear Information System (INIS)

Kaptari, L.P.; Semikh, S.S.

1997-10-01

The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with 000. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, like tensor analyzing power and polarization transfer etc., are investigated in explicit form. Results of numerical calculations for a complete set of polarization observables are presented. (orig.)

The Structure and Dynamics of GRB Jets

Energy Technology Data Exchange (ETDEWEB)

Granot, Jonathan; /KIPAC, Menlo Park

2006-10-25

There are several lines of evidence which suggest that the relativistic outflows in gamma-ray bursts (GRBs) are collimated into narrow jets. The jet structure has important implications for the true energy release and the event rate of GRBs, and can constrain the mechanism responsible for the acceleration and collimation of the jet. Nevertheless, the jet structure and its dynamics as it sweeps up the external medium and decelerates, are not well understood. In this review I discuss our current understanding of GRB jets, stressing their structure and dynamics.

Role of the Kelvin-Helmholtz instability in the evolution of magnetized relativistic sheared plasma flows.

Science.gov (United States)

Hamlin, Nathaniel D; Newman, William I

2013-04-01

We explore, via analytical and numerical methods, the Kelvin-Helmholtz (KH) instability in relativistic magnetized plasmas, with applications to astrophysical jets. We solve the single-fluid relativistic magnetohydrodynamic (RMHD) equations in conservative form using a scheme which is fourth order in space and time. To recover the primitive RMHD variables, we use a highly accurate, rapidly convergent algorithm which improves upon such schemes as the Newton-Raphson method. Although the exact RMHD equations are marginally stable, numerical discretization renders them unstable. We include numerical viscosity to restore numerical stability. In relativistic flows, diffusion can lead to a mathematical anomaly associated with frame transformations. However, in our KH studies, we remain in the rest frame of the system, and therefore do not encounter this anomaly. We use a two-dimensional slab geometry with periodic boundary conditions in both directions. The initial unperturbed velocity peaks along the central axis and vanishes asymptotically at the transverse boundaries. Remaining unperturbed quantities are uniform, with a flow-aligned unperturbed magnetic field. The early evolution in the nonlinear regime corresponds to the formation of counter-rotating vortices, connected by filaments, which persist in the absence of a magnetic field. A magnetic field inhibits the vortices through a series of stages, namely, field amplification, vortex disruption, turbulent breakdown, and an approach to a flow-aligned equilibrium configuration. Similar stages have been discussed in MHD literature. We examine how and to what extent these stages manifest in RMHD for a set of representative field strengths. To characterize field strength, we define a relativistic extension of the Alfvénic Mach number M(A). We observe close complementarity between flow and magnetic field behavior. Weaker fields exhibit more vortex rotation, magnetic reconnection, jet broadening, and intermediate turbulence

Jet physics in ALICE

International Nuclear Information System (INIS)

Loizides, C.A.

2005-01-01

The ALICE experiment is one of the experiments currently prepared for the Large Hadron Collider (LHC) at CERN, Geneva, starting operation end of 2007. ALICE is dedicated to the research on nucleus-nucleus collisions at ultra-relativistic energies, which addresses the properties of strongly interacting matter under varying conditions of high density and temperature. The conditions provided at the LHC allow significant qualitative improvement with respect to previous studies. In particular, energetic probes, light quarks and gluons, will be abundantly produced. These probes might be identified by their fragmentation into correlated particles, so called jets, of high enough energy to allow full reconstruction of jet properties; even in the underlying heavy-ion environment. Understanding the dependence of high-energy jet production and fragmentation influenced by the dense medium created in the collision region is an open field of active research. Generally, one expects energy loss of the probes due to medium-induced gluon radiation. It is suggested that hadronization products of these, rather soft gluons may be contained within the jet emission cone, resulting in a modification of the characteristic jet fragmentation, as observed via longitudinal and transverse momentum distributions with respect to the direction of the initial parton, as well as of the multiplicity distributions arising from the jet fragmentation. Particle momenta parallel to the jet axis are softened (jet quenching), while transverse to it increased (transverse heating). The present thesis studies the capabilities of the ALICE detectors to measure these jets and quantifies obtainable rates and the quality of jet reconstruction, in both proton-proton and lead-lead collisions at the LHC. In particular, it is addressed whether modification of the jet fragmentation can be detected within the high-particle-multiplicity environment of central lead-lead collisions. (orig.)

On the existence of a luminosity threshold of GRB jets in massive stars

Science.gov (United States)

Aloy, M. A.; Cuesta-Martínez, C.; Obergaulinger, M.

2018-05-01

Motivated by the many associations of γ-ray bursts (GRBs) with energetic supernova (SN) explosions, we study the propagation of relativistic jets within the progenitor star in which a SN shock wave may be launched briefly before the jets start to propagate. Based on analytic considerations and verified with an extensive set of 2D axisymmetric relativistic hydrodynamic simulations, we have estimated a threshold intrinsic jet luminosity, L_j^thr, for successfully launching a jet. This threshold depends on the structure of the progenitor and, thus, it is sensitive to its mass and to its metallicity. For a prototype host of cosmological long GRBs, a low-metallicity star of 35 M⊙, it is L_j^thr˜eq 1.35× 10^{49} erg s-1. The observed equivalent isotropic γ-ray luminosity, L_{γ ,iso,BO} ˜eq 4 ɛ _γ L_j θ _BO^{-2}, crucially depends on the jet opening angle after breakout, θBO, and on the efficiency for converting the intrinsic jet luminosity into γ-radiation, ɛγ. Highly energetic jets can produce low-luminosity events if either their opening angle after the breakout is large, which is found in our models, or if the conversion efficiency of kinetic and internal energy into radiation is low enough. Beyond this theoretical analysis, we show how the presence of a SN shock wave may reduce this luminosity threshold by means of numerical simulations. We foresee that the high-energy transients released by jets produced near the luminosity threshold will be more similar to llGRBs or XRFs than to GRBs.

Internal-time observable of classical relativistic systems

International Nuclear Information System (INIS)

Ben-Ya'acov, Uri

2006-01-01

The relativistic framework with its symmetries offers a natural definition for the internal time of classical (non-quantum) physical systems as a Lorentz-invariant observable. The internal-time observable, measuring the system's aging or internal evolution, is identified with the proper time of the system derived from its centre-of-mass (CM) coordinate. For its definition as an observable it is required that the system be symmetric not only under Lorentz-Poincare transformations but also under uniform scaling, with the associated existence of a dilatation function D, and yet that D be a varying-not conserved-quantity. Two alternative definitions are discussed, and it is found that in order to maintain simultaneity of the CM time with the events that define it, it is necessary to split the dilatation function into a CM part and an internal part

The nature of extragalactic radio-jets from high-resolution radio-interferometric observations

OpenAIRE

Perucho, Manel

2014-01-01

Extragalactic jets are a common feature of radio-loud active galaxies. The nature of the observed jets in relation to the bulk flow is still unclear. In particular it is not clear whether the observations of parsec-scale jets using the very long baseline interferometric technique (VLBI) reveal wave-like structures that develop and propagate along the jet, or trace the jet flow itself. In this contribution I review the evidence collected during the last years showing that the ridge-lines of he...

A general relativistic signature in the galaxy bispectrum: the local effects of observing on the lightcone

Energy Technology Data Exchange (ETDEWEB)

Umeh, Obinna; Jolicoeur, Sheean; Maartens, Roy [Department of Physics and Astronomy, University of the Western Cape, Robert Sobukwe Road, Cape Town 7535 (South Africa); Clarkson, Chris, E-mail: umeobinna@gmail.com, E-mail: beautifulheart369@gmail.com, E-mail: roy.maartens@gmail.com, E-mail: chris.clarkson@gmail.com [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

2017-03-01

Next-generation galaxy surveys will increasingly rely on the galaxy bispectrum to improve cosmological constraints, especially on primordial non-Gaussianity. A key theoretical requirement that remains to be developed is the analysis of general relativistic effects on the bispectrum, which arise from observing galaxies on the past lightcone, as well as from relativistic corrections to the dynamics. As an initial step towards a fully relativistic analysis of the galaxy bispectrum, we compute for the first time the local relativistic lightcone effects on the bispectrum, which come from Doppler and gravitational potential contributions. For the galaxy bispectrum, the problem is much more complex than for the power spectrum, since we need the lightcone corrections at second order. Mode-coupling contributions at second order mean that relativistic corrections can be non-negligible at smaller scales than in the case of the power spectrum. In a primordial Gaussian universe, we show that the local lightcone projection effects for squeezed shapes at z ∼ 1 mean that the bispectrum can differ from the Newtonian prediction by ∼> 10% when the short modes are k ∼< (50 Mpc){sup −1}. These relativistic projection effects, if ignored in the analysis of observations, could be mistaken for primordial non-Gaussianity. For upcoming surveys which probe equality scales and beyond, all relativistic lightcone effects and relativistic dynamical corrections should be included for an accurate measurement of primordial non-Gaussianity.

Probing medium-induced jet splitting and energy loss in heavy-ion collisions

Science.gov (United States)

Chang, Ning-Bo; Cao, Shanshan; Qin, Guang-You

2018-06-01

The nuclear modification of jet splitting in relativistic heavy-ion collisions at RHIC and the LHC energies is studied based on the higher twist formalism. Assuming coherent energy loss for the two splitted subjets, a non-monotonic jet energy dependence is found for the nuclear modification of jet splitting function: strongest modification at intermediate jet energies whereas weaker modification for larger or smaller jet energies. Combined with the smaller size and lower density of the QGP medium at RHIC than at the LHC, this helps to understand the groomed jet measurements from CMS and STAR Collaborations: strong modification of the momentum sharing zg distribution at the LHC and no obvious modification of zg distribution at RHIC. In addition, the observed nuclear modification pattern of the groomed jet zg distribution cannot be explained solely by independent energy loss of the two subjets. Our result may be tested in future measurements of groomed jets with lower jet energies at the LHC and larger jet energies at RHIC, for different angular separations between the two subjets.

High-pt and jet physics from RHIC to LHC

International Nuclear Information System (INIS)

Estienne, M.

2008-01-01

The observation of the strong suppression of high-pt hadrons in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) at BNL has motivated a large experimental program using hard probes to characterize the deconfined medium created. However, what can be denoted as 'leading particle' physics accessible at RHIC presents some limitations which motivate at higher energy the study of much more penetrating objects: jets. The gain in center-of-mass energy expected at the Large Hadron Collider (LHC) at CERN will definitively improve our understanding on how the energy is lost in the system, opening a major new window of study: the physics of jets on an event-by-event basis. We will concentrate on the expected performance for jet reconstruction in ALICE using the EMCal calorimeter.

Simulating satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds

OpenAIRE

M. Füllekrug; C. Hanuise; M. Parrot

2010-01-01

Relativistic electron beams above thunderclouds emit 100 kHz radio waves which illuminate the Earth's atmosphere and near-Earth space. This contribution aims to clarify the physical processes which are relevant for the spatial spreading of the radio wave energy below and above the ionosphere and thereby enables simulating satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds. The simulation uses the DEMETER satellite which observes 100 kHz ...

Tidal Control of Jet Eruptions Observed by Cassini ISS

Science.gov (United States)

Hurford, T. A.; Helfenstein, P.; Spitale, J. N.

2012-01-01

Observations by Cassini's Imaging Science Subsystem (ISS) of Enceladus' south polar region at high phase angles has revealed jets of material venting into space. Observations by Cassini's Composite Infrared Spectrometer (CIRS) have also shown that the south polar region is anomalously warm with hotspots associated with geological features called the Tiger Stripes. The Tiger Stripes are large rifts near the south pole of Enceladus, which are typically about 130 km in length, 2 km wide, with a trough 500 m deep, and are l1anked on each side by 100m tall ridges. Preliminary triangulation of jets as viewed at different times and with different viewing geometries in Cassini ISS images taken between 2005 and 2007 have constrained the locations of eight major eruptions of material and found all of them associated with the south polar fractures unofficially the 'Tiger Stripes', and found four of them coincident with the hotspots reported in 2006 by CIRS. While published ISS observations of jet activity suggest that individual eruption sites stay active on the timescale of years, any shorter temporal variability (on timescales of an orbital period, or 1.3 Earth days, for example) is more difficult to establish because of the spotty temporal coverage and the difficulty of visually isolating one jet from the forest of many seen in a typical image. Consequently, it is not known whether individual jets are continuously active, randomly active, or if they erupt on a predictable, periodic schedule. One mechanism that may control the timing of eruptions is diurnal tidal stress, which oscillates between compression/tension as well as right and left lateral shear at any given location throughout Enceladus' orbit and may allow the cracks to open and close regularly. We examine the stresses on the Tiger Stripe regions to see how well diurnal tidal stress caused by Enceladus' orbital eccentricity may possibly correlate with and thus control the observed eruptions. We then identify

Electric Currents along Astrophysical Jets

Directory of Open Access Journals (Sweden)

Ioannis Contopoulos

2017-10-01

Full Text Available Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these fields and their associated electric currents. Several researchers have reported direct evidence for large scale electric currents along astrophysical jets. Quite unexpectedly, their directions are not random as would have been the case if the magnetic field were generated by a magnetohydrodynamic dynamo. Instead, in all kpc-scale detections, the inferred electric currents are found to flow away from the galactic nucleus. This unexpected break of symmetry suggests that a battery mechanism is operating around the central black hole. In the present article, we summarize observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets. We also present recent results of general relativistic radiation magnetohydrodynamic simulations which show the action of the Cosmic Battery in the vicinity of astrophysical black holes.

Constraining sources of ultrahigh energy cosmic rays and shear acceleration mechanism of particles in relativistic jets

Energy Technology Data Exchange (ETDEWEB)

Liu, Ruoyu

2015-06-10

Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.

TV observations of the Barium-GEOS ion jet experiment

International Nuclear Information System (INIS)

Hapgood, M.A.; Collin, H.L.; Rothwell, P.

1980-01-01

The barium jet released by the Barium-GEOS rocket was observed by low light television cameras at Skibotn, Norway and Esrange, Sweden. The release produced a single well-defined jet containing barium ions with initial velocities between 7 and 12 km s -1 systematically slower than the velocities reported in previous experiments. Accurate data on the motion of the jet has been obtained for the first two minutes after release (up to a height of 2000 km). The orientation of the jet was close to that of an IGRF1975 model field line but was significantly different from that predicted by the Barraclough and Olson field model. The motion of the jet across the field lines was southwards with a velocity of about 150 m s -1 . (Auth.)

New ALMA and Fermi /LAT Observations of the Large-scale Jet of PKS 0637−752 Strengthen the Case Against the IC/CMB Model

Energy Technology Data Exchange (ETDEWEB)

Meyer, Eileen T.; Breiding, Peter; Georganopoulos, Markos [University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Oteo, Iván; Ivison, R. J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Zwaan, Martin A.; Laing, Robert [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching-bei-München (Germany); Godfrey, Leith, E-mail: meyer@umbc.edu [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands)

2017-02-01

The Chandra X-ray observatory has discovered several dozen anomalously X-ray-bright jets associated with powerful quasars. A popular explanation for the X-ray flux from the knots in these jets is that relativistic synchrotron-emitting electrons inverse-Compton scatter cosmic microwave background (CMB) photons to X-ray energies (the IC/CMB model). This model predicts a high gamma-ray flux that should be detectable by the Fermi /Large Area Telescope (LAT) for many sources. GeV-band upper limits from Fermi /LAT for the well-known anomalous X-ray jet in PKS 0637−752 were previously shown in Meyer et al. to violate the predictions of the IC/CMB model. Previously, measurements of the jet synchrotron spectrum, important for accurately predicting the gamma-ray flux level, were lacking between radio and infrared wavelengths. Here, we present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the large-scale jet at 100, 233, and 319 GHz, which further constrain the synchrotron spectrum, supporting the previously published empirical model. We also present updated limits from the Fermi /LAT using the new “Pass 8” calibration and approximately 30% more time on source. With these deeper limits, we rule out the IC/CMB model at the 8.7 σ level. Finally, we demonstrate that complete knowledge of the synchrotron SED is critical in evaluating the IC/CMB model.

Observational and theoretical aspects of relativistic astrophysics and cosmology

International Nuclear Information System (INIS)

Sanz, J.L.; Goicoechea, L.J.

1985-01-01

The studies of relativistic astrophysics and cosmology in these proceedings include primordial nucleosynthesis, nonluminous matter, star and galaxy evolution, cosmic microwave background, and general relativistic models of the universe

Identification and rejection of fake reconstructed jets from a fluctuating heavy ion background in ATLAS

International Nuclear Information System (INIS)

Grau, N.

2009-01-01

Full jet reconstruction in relativistic heavy ion collisions provides new and unique insights to the physics of parton energy loss. Because of the large underlying event multiplicity in A+A collisions, random and correlated fluctuations in the background can result in the reconstruction of fake jets. These fake jets must be identified and rejected to obtain the purest jet sample possible. A large but reducible fake rate of jets reconstructed using an iterative cone algorithm on HIJING events is observed. The absolute rate of fake jets exceeds the binary-scaled p+p jet rate below 50 GeV and is not negligible until 100 GeV. The variable Σj T , the sum of the jet constituent's E T perpendicular to the jet axis, is introduced to identify and reject fake jets at by a factor of 100 making it negligible. This variable is shown to not strongly depend on jet energy profiles modified by energy loss. By studying azimuthal correlations of reconstructed di-jets, the fake jet rate can be evaluated in data. (orig.)

Jets as a probe of dense matter at RHIC

International Nuclear Information System (INIS)

Filimonov, Kirill

2004-01-01

Jet quenching in the matter created in high energy nucleus-nucleus collisions provides a tomographic tool to probe the medium properties. Recent experimental results on jet production at the Relativistic Heavy-Ion Collider (RHIC) are reviewed. Jet properties in p+p and d+Au collisions have been measured, establishing the baseline for studying jet modification in heavy-ion collisions. Current progress on detailed studies of high transverse momentum production in Au+Au collisions is discussed, with an emphasis on dihadron correlation measurements

Multi-Frequency VLBA Polarimetry and the Twin-Jet Quasar 0850+581

Directory of Open Access Journals (Sweden)

Evgeniya Kravchenko

2017-11-01

Full Text Available We present the first multi-frequency VLBA study of the quasar 0850+581 which appears to have a two-sided relativistic jet. Apparent velocity in the approaching jet changes from 3.4c to 7c with the separation from the core. The jet-to-counter-jet ratio of about 5 and apparent superluminal velocities suggest that the observing angle of the inner jet is ≤ 17 ∘ . It is likely that this orientation significantly changes downstream due to an interaction of the jet with the surrounding medium; signs of this are seen in polarization. A dense inhomogeneous Faraday screen is detected in the innermost regions of this quasar. We suggest that there is a presence of ionized gas in its nucleus, which might be responsible for the free-free absorption of the synchrotron emission in the jet and counter-jet at frequencies below 8.4 GHz. The experiment makes use of slowly varying instrumental polarisation factors (polarization leakage or D-terms in time. We report application of the “D-term connection” technique for the calibration of an absolute orientation of electric vector position angle (EVPA observed by VLBA at 4.6, 5.0, 8.1, 8.4, 15.4, 22.3, and 43.3 GHz bands during the 2007–2011.

Relativistic magnetic reconnection driven by a moderately intense laser interacting with a micro-plasma-slab

Science.gov (United States)

Yi, Longqing; Shen, Baifei; Pukhov, Alexander; Fülöp, Tünde

2017-10-01

Magnetic reconnection (MR) in the relativistic regime is generally thought to be responsible for powering rapid bursts of non-thermal radiation in astrophysical events. It is therefore of significant importance to study how the field energy is transferred to the plasma to power the observed emission. However, due to the difficulty in making direct measurements in astrophysical systems or achieving relativistic MR in laboratory environments, the particle acceleration is usually studied using fully kinetic PIC simulations. Here we present a numerical study of a readily available (TW-mJ-class) laser interacting with a micro-scale plasma slab. The simulations show when the electron beams excited on both sides of the slab approach the end of the plasma structure, ultrafast relativistic MR occurs. As the field topology changes, the explosive release of magnetic energy results in emission of relativistic electron jets with cut-off energy 12 MeV. The proposed novel scenario can be straightforwardly implemented in experiments, and might significantly improve the understanding of fundamental questions such as field dissipation and particle acceleration in relativistic MR. This work is supported by the Knut and Alice Wallenberg Foundation and the European Research Council (ERC-2014-CoG Grant 64712).

Study of jet quenching in heavy ion collisions at LHC using ATLAS detector

CERN Document Server

Štefko, Pavol

2015-01-01

Quark-Gluon Plasma (QGP) is one of the most extreme states of matter which exists only in extraordinary conditions of heavy-ion collisions that can be achieved at particle accelerators. Interactions between the partons and the hot, dense QGP are expected to cause the loss of the jet energy, which is phenomenon called jet quenching. In this talk we provide an introduction to the problematics of ultra-relativistic heavy ion collisions and we show how the jet quenching can be used to analyze the properties of QGP. We also present some “work in progress” results of the jet analysis done on the data taken by the ATLAS detector during the 2011 heavy-ion run at the LHC. Jets are studied as a function of collision centrality and dijet energy imbalance. Dijets are observed to be increasingly asymmetric with increasing centrality. The study of charged particles indicates an increase of yields of low- p T tracks in events with strongly quenched jets

Measurements of azimuthal correlation between jets and charged particles at LHC-ALICE experiment

CERN Document Server

Sakata, Dousatsu

In the nature around us, quarks and gluons are confined in hadrons due to "confinement of quarks". However, the coupling strength of the QCD between quarks and gluons is to be asymptotically weaker with the increasing their energy. At high temperature the quarks and gluons move freely beyond the boundary of hadrons. Such high energy state is called Quark-Gluon Plasma(QGP). To create such state on the earth, the ultra relativistic heavy ion collision is unique tool. It has been observed several signatures of the QGP formation at the Relativistic Heavy Ion Collider(RHIC). Suppression of high momentum particles is one of the signatures. High momentum particles are known to be produced in characteristic phenomena, jet , where high momentum particle are produced in cluster. The jet is produced when parton in each projectile is scattered with large momentum, followed by fragmentation into many hadrons. It is considered that the cause of the suppression of high momentum particle is due to the characteristic en...

Relativistic Turbulence with Strong Synchrotron and Synchrotron-Self-Compton Cooling

Science.gov (United States)

Uzdensky, D. A.

2018-03-01

Many relativistic plasma environments in high-energy astrophysics, including pulsar wind nebulae, hot accretion flows onto black holes, relativistic jets in active galactic nuclei and gamma-ray bursts, and giant radio lobes, are naturally turbulent. The plasma in these environments is often so hot that synchrotron and inverse-Compton (IC) radiative cooling becomes important. In this paper we investigate the general thermodynamic and radiative properties (and hence the observational appearance) of an optically thin relativistically hot plasma stirred by driven magnetohydrodynamic (MHD) turbulence and cooled by radiation. We find that if the system reaches a statistical equilibrium where turbulent heating is balanced by radiative cooling, the effective electron temperature tends to attain a universal value θ = kT_e/m_e c^2 ˜ 1/√{τ_T}, where τT = neσTL ≪ 1 is the system's Thomson optical depth, essentially independent of the strength of turbulent driving and hence of the magnetic field. This is because both MHD turbulent dissipation and synchrotron cooling are proportional to the magnetic energy density. We also find that synchrotron self-Compton (SSC) cooling and perhaps a few higher-order IC components are automatically comparable to synchrotron in this regime. The overall broadband radiation spectrum then consists of several distinct components (synchrotron, SSC, etc.), well separated in photon energy (by a factor ˜ τ_T^{-1}) and roughly equal in power. The number of IC peaks is checked by Klein-Nishina effects and depends logarithmically on τT and the magnetic field. We also examine the limitations due to synchrotron self-absorption, explore applications to Crab PWN and blazar jets, and discuss links to radiative magnetic reconnection.

From molecular clouds to active galactic nuclei - The universality of the jet phenomenon

International Nuclear Information System (INIS)

Konigl, A.

1986-01-01

Jets are among the most remarkable astrophysical phenomena explored in recent years. The term ''jets'' was originally coined to describe the narrow, elongated features that had been discovered in radio maps (and, in some cases, also by X-ray and optical observations) of extragalactic sources. Similar features have subsequently been found, however, also in our own galaxy, with the relativistic beams of SS433 being probably the most celebrated example. While the SS433 beams are still unique, there is now mounting evidence that oppositely directed jets are very frequently associated with nascent stars embedded in dense molecular clouds. The purpose of this article is, in essence, to ''bridge the gap'' between these smallest-scale jets and their enormously larger extragalactic counterparts. By concentrating on the similarities between molecular-cloud and extragalactic jets, the author shall try to extract some of the basic dynamical principles that could account for the apparent universality of this phenomenon. Following an observational overview, he considers the general hydrodynamic and magnetohydrodynamic (MHD) aspects of the production, the collimation, and the propagation of jets in protostellar and in active-galactic-nuclei (AGN) environments

A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

Energy Technology Data Exchange (ETDEWEB)

Neilsen, Joseph [Department of Astronomy, Boston University, Boston, MA 02215 (United States); Coriat, Mickaël [Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Fender, Rob; Broderick, Jess W. [Department of Physics, Oxford University, Oxford OX1 3RH (United Kingdom); Lee, Julia C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max Planck Institute fur Extraterrestriche Physik, D-85748 Garching (Germany); Tzioumis, Anastasios K.; Edwards, Philip G., E-mail: neilsenj@bu.edu [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

2014-03-20

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission.

A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

International Nuclear Information System (INIS)

Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Broderick, Jess W.; Lee, Julia C.; Ponti, Gabriele; Tzioumis, Anastasios K.; Edwards, Philip G.

2014-01-01

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission

Jet suppression measurement with the ATLAS detector

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00443411; The ATLAS collaboration

2016-01-01

A hot medium with a high density of unscreened color charges is produced in relativistic heavy ion collisions. Jets are produced at the early stages of this collision and are known to become attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. Another manifestation of the energy loss is the modification of the dijet balance and the modification of fragmentation functions. In these proceedings, the latest ATLAS results on single jet suppression, dijet suppression, and modification of the jet internal structure in \\PbPb~collisions are presented.

Soft functions for generic jet algorithms and observables at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Bertolini, Daniele [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Theoretical Physics Group; California Univ., Berkeley, CA (United States). Berkeley Center for Theoretical Physics; Kolodrubetz, Daniel; Stewart, Iain W. [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Duff, Neill [Los Alamos National Laboratory, NM (United States). Theoretical Div.; Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Pietrulewicz, Piotr; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Waalewijn, Wouter J. [NIKHEF, Amsterdam (Netherlands). Theory Group; Amsterdam Univ. (Netherlands). Inst. for Theoretical Physics Amsterdam and Delta Inst. for Theoretical Physics

2017-07-15

We introduce a method to compute one-loop soft functions for exclusive N-jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the N-jettiness hemisphere decomposition of T. T. Joutennus et al. (2011) in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti-k{sub T}, XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet mass and jet broadening, in pp→L+1 jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius R. We find that the small-R results, including corrections up to O(R{sup 2}), accurately capture the full behavior over a large range of R.

Jet emission in young radio sources: A Fermi large area telescope gamma-ray view

Energy Technology Data Exchange (ETDEWEB)

Migliori, G.; Siemiginowska, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kelly, B. C. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93107 (United States); Stawarz, Ł. [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Celotti, A. [Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea, 265-34136 Trieste (Italy); Begelman, M. C., E-mail: migliori@cfa.harvard.edu [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440 (United States)

2014-01-10

We investigate the contribution of the beamed jet component to the high-energy emission in young and compact extragalactic radio sources, focusing for the first time on the γ-ray band. We derive predictions on the γ-ray luminosities associated with the relativistic jet assuming a leptonic radiative model. The high-energy emission is produced via Compton scattering by the relativistic electrons in a spherical region at the considered scales (≲10 kpc). Simulations show a wide range of γ-ray luminosities, with intensities up to ∼10{sup 46}-10{sup 48} erg s{sup –1} depending on the assumed jet parameters. We find a highly linear relation between the simulated X-ray and γ-ray luminosities that can be used to select candidates for γ-ray detection. We compare the simulated luminosity distributions in the radio, X-ray, and γ-ray regimes with observations for the largest sample of X-ray-detected young radio quasars. Our analysis of ∼4-yr Fermi Large Area Telescope (LAT) data does not yield any statistically significant detections. However, the majority of the model-predicted γ-ray fluxes for the sample are near or below the current Fermi-LAT flux threshold and compatible with the derived upper limits. Our study gives constraints on the minimum jet power (L {sub jet,} {sub kin}/L {sub disk} > 0.01) of a potential jet contribution to the X-ray emission in the most compact sources (≲ 1 kpc) and on the particle-to-magnetic field energy density ratio that are in broad agreement with equipartition assumptions.

Oscillations in solar jets observed with the SOT of Hinode: viscous effects during reconnection

Science.gov (United States)

Tavabi, E.; Koutchmy, S.

2014-07-01

Transverse oscillatory motions and recurrence behavior in the chromospheric jets observed by Hinode/SOT are studied. A comparison is considered with the behavior that was noticed in coronal X-ray jets observed by Hinode/XRT. A jet like bundle observed at the limb in Ca II H line appears to show a magnetic topology that is similar to X-ray jets (i.e., the Eiffel tower shape). The appearance of such magnetic topology is usually assumed to be caused by magnetic reconnection near a null point. Transverse motions of the jet axis are recorded but no clear evidence of twist is appearing from the highly processed movie. The aim is to investigate the dynamical behavior of an incompressible magnetic X-point occurring during the magnetic reconnection in the jet formation region. The viscous effect is specially considered in the closed line-tied magnetic X-shape nulls. We perform the MHD numerical simulation in 2-D by solving the visco-resistive MHD equations with the tracing of velocity and magnetic field. A qualitative agreement with Hinode observations is found for the oscillatory and non-oscillatory behaviors of the observed solar jets in both the chromosphere and the corona. Our results suggest that the viscous effect contributes to the excitation of the magnetic reconnection by generating oscillations that we observed at least inside this Ca II H line cool solar jet bundle.

Observation of medium induced modifications of jet fragmentation in PbPb collisions using isolated-photon-tagged jets

CERN Document Server

Sirunyan, Albert M; CMS Collaboration; Adam, Wolfgang; Ambrogi, Federico; Asilar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Escalante Del Valle, Alberto; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Grossmann, Johannes; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krammer, Natascha; Krätschmer, Ilse; Liko, Dietrich; Madlener, Thomas; Mikulec, Ivan; Pree, Elias; Rad, Navid; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Spanring, Markus; Spitzbart, Daniel; Taurok, Anton; Waltenberger, Wolfgang; Wittmann, Johannes; Wulz, Claudia-Elisabeth; Zarucki, Mateusz; Chekhovsky, Vladimir; Mossolov, Vladimir; Suarez Gonzalez, Juan; De Wolf, Eddi A; Di Croce, Davide; Janssen, Xavier; Lauwers, Jasper; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; De Bruyn, Isabelle; De Clercq, Jarne; Deroover, Kevin; Flouris, Giannis; Lontkovskyi, Denys; Lowette, Steven; Marchesini, Ivan; Moortgat, Seth; Moreels, Lieselotte; Python, Quentin; Skovpen, Kirill; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Parijs, Isis; Beghin, Diego; Bilin, Bugra; Brun, Hugues; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Dorney, Brian; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Kalsi, Amandeep Kaur; Lenzi, Thomas; Luetic, Jelena; Maerschalk, Thierry; Marinov, Andrey; Seva, Tomislav; Starling, Elizabeth; Vander Velde, Catherine; Vanlaer, Pascal; Vannerom, David; Yonamine, Ryo; Zenoni, Florian; Cornelis, Tom; Dobur, Didar; Fagot, Alexis; Gul, Muhammad; Khvastunov, Illia; Poyraz, Deniz; Roskas, Christos; Salva Diblen, Sinem; Trocino, Daniele; Tytgat, Michael; Verbeke, Willem; Vit, Martina; Zaganidis, Nicolas; Bakhshiansohi, Hamed; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caputo, Claudio; Caudron, Adrien; David, Pieter; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Francois, Brieuc; Giammanco, Andrea; Komm, Matthias; Krintiras, Georgios; Lemaitre, Vincent; Magitteri, Alessio; Mertens, Alexandre; Musich, Marco; Piotrzkowski, Krzysztof; Quertenmont, Loic; Saggio, Alessia; Vidal Marono, Miguel; Wertz, Sébastien; Zobec, Joze; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correia Silva, Gilson; Hensel, Carsten; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Coelho, Eduardo; Melo Da Costa, Eliza; Da Silveira, Gustavo Gil; De Jesus Damiao, Dilson; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Melo De Almeida, Miqueias; Mora Herrera, Clemencia; Mundim, Luiz; Nogima, Helio; Sanchez Rosas, Luis Junior; Santoro, Alberto; Sznajder, Andre; Thiel, Mauricio; Tonelli Manganote, Edmilson José; Torres Da Silva De Araujo, Felipe; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Misheva, Milena; Rodozov, Mircho; Shopova, Mariana; Sultanov, Georgi; Dimitrov, Anton; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Gao, Xuyang; Yuan, Li; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Chen, Ye; Jiang, Chun-Hua; Leggat, Duncan; Liao, Hongbo; Liu, Zhenan; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Yazgan, Efe; Zhang, Huaqiao; Zhao, Jingzhou; Ban, Yong; Chen, Geng; Li, Jing; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Zhang, Fengwangdong; Wang, Yi; Avila, Carlos; Cabrera, Andrés; Carrillo Montoya, Camilo Andres; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; González Hernández, Carlos Felipe; Ruiz Alvarez, José David; Segura Delgado, Manuel Alejandro; Courbon, Benoit; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Sculac, Toni; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Ferencek, Dinko; Kadija, Kreso; Mesic, Benjamin; Starodumov, Andrei; Susa, Tatjana; Ather, Mohsan Waseem; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Finger, Miroslav; Finger Jr, Michael; Carrera Jarrin, Edgar; El-khateeb, Esraa; Ellithi Kamel, Ali; Mahmoud, Mohammed; Bhowmik, Sandeep; Dewanjee, Ram Krishna; Kadastik, Mario; Perrini, Lucia; Raidal, Martti; Veelken, Christian; Eerola, Paula; Kirschenmann, Henning; Pekkanen, Juska; Voutilainen, Mikko; Havukainen, Joona; Heikkilä, Jaana Kristiina; Jarvinen, Terhi; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Laurila, Santeri; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Siikonen, Hannu; Tuominen, Eija; Tuominiemi, Jorma; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Ghosh, Saranya; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Leloup, Clément; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Negro, Giulia; Rander, John; Rosowsky, André; Sahin, Mehmet Özgür; Titov, Maksym; Abdulsalam, Abdulla; Amendola, Chiara; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Charlot, Claude; Granier de Cassagnac, Raphael; Jo, Mihee; Kucher, Inna; Lisniak, Stanislav; Lobanov, Artur; Martin Blanco, Javier; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Stahl Leiton, Andre Govinda; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Zghiche, Amina; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Coubez, Xavier; Drouhin, Frédéric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Jansová, Markéta; Juillot, Pierre; Le Bihan, Anne-Catherine; Tonon, Nicolas; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Chanon, Nicolas; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Finco, Linda; Gascon, Susan; Gouzevitch, Maxime; Grenier, Gérald; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Popov, Andrey; Sordini, Viola; Vander Donckt, Muriel; Viret, Sébastien; Zhang, Sijing; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Feld, Lutz; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Preuten, Marius; Schomakers, Christian; Schulz, Johannes; Teroerde, Marius; Wittmer, Bruno; Zhukov, Valery; Albert, Andreas; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Mukherjee, Swagata; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Teyssier, Daniel; Thüer, Sebastian; Flügge, Günter; Kargoll, Bastian; Kress, Thomas; Künsken, Andreas; Müller, Thomas; Nehrkorn, Alexander; Nowack, Andreas; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Arndt, Till; Asawatangtrakuldee, Chayanit; Beernaert, Kelly; Behnke, Olaf; Behrens, Ulf; Bermúdez Martínez, Armando; Bin Anuar, Afiq Aizuddin; Borras, Kerstin; Botta, Valeria; Campbell, Alan; Connor, Patrick; Contreras-Campana, Christian; Costanza, Francesco; Diez Pardos, Carmen; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Eren, Engin; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Grados Luyando, Juan Manuel; Grohsjean, Alexander; Gunnellini, Paolo; Guthoff, Moritz; Harb, Ali; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kasemann, Matthias; Keaveney, James; Kleinwort, Claus; Korol, Ievgen; Krücker, Dirk; Lange, Wolfgang; Lelek, Aleksandra; Lenz, Teresa; Lipka, Katerina; Lohmann, Wolfgang; Mankel, Rainer; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Missiroli, Marino; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Ntomari, Eleni; Pitzl, Daniel; Raspereza, Alexei; Savitskyi, Mykola; Saxena, Pooja; Shevchenko, Rostyslav; Stefaniuk, Nazar; Van Onsem, Gerrit Patrick; Walsh, Roberval; Wen, Yiwen; Wichmann, Katarzyna; Wissing, Christoph; Zenaiev, Oleksandr; Aggleton, Robin; Bein, Samuel; Blobel, Volker; Centis Vignali, Matteo; Dreyer, Torben; Garutti, Erika; Gonzalez, Daniel; Haller, Johannes; Hinzmann, Andreas; Hoffmann, Malte; Karavdina, Anastasia; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Kurz, Simon; Marconi, Daniele; Meyer, Mareike; Niedziela, Marek; Nowatschin, Dominik; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Scharf, Christian; Schleper, Peter; Schmidt, Alexander; Schumann, Svenja; Schwandt, Joern; Sonneveld, Jory; Stadie, Hartmut; Steinbrück, Georg; Stober, Fred-Markus Helmut; Stöver, Marc; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baselga, Marta; Baur, Sebastian; Butz, Erik; Caspart, René; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Dierlamm, Alexander; Faltermann, Nils; Freund, Benedikt; Friese, Raphael; Giffels, Manuel; Harrendorf, Marco Alexander; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Kassel, Florian; Kudella, Simon; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Schröder, Matthias; Shvetsov, Ivan; Sieber, Georg; Simonis, Hans-Jürgen; Ulrich, Ralf; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Williamson, Shawn; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Kyriakis, Aristotelis; Loukas, Demetrios; Topsis-Giotis, Iasonas; Karathanasis, George; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Kousouris, Konstantinos; Evangelou, Ioannis; Foudas, Costas; Gianneios, Paraskevas; Katsoulis, Panagiotis; Kokkas, Panagiotis; Mallios, Stavros; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Triantis, Frixos A; Tsitsonis, Dimitrios; Csanad, Mate; Filipovic, Nicolas; Pasztor, Gabriella; Surányi, Olivér; Veres, Gabor Istvan; Bencze, Gyorgy; Hajdu, Csaba; Horvath, Dezso; Hunyadi, Ádám; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Beni, Noemi; Czellar, Sandor; Karancsi, János; Makovec, Alajos; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Choudhury, Somnath; Komaragiri, Jyothsna Rani; Bahinipati, Seema; Mal, Prolay; Mandal, Koushik; Nayak, Aruna; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Dhingra, Nitish; Kaur, Anterpreet; Kaur, Manjit; Kaur, Sandeep; Kumar, Ramandeep; Kumari, Priyanka; Mehta, Ankita; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Shah, Aashaq; Bhardwaj, Ashutosh; Chauhan, Sushil; Choudhary, Brajesh C; Garg, Rocky Bala; Keshri, Sumit; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Ramkrishna; Bhardwaj, Rishika; Bhattacharya, Rajarshi; Bhattacharya, Satyaki; Bhawandeep, Bhawandeep; Bhowmik, Debabrata; Dey, Sourav; Dutt, Suneel; Dutta, Suchandra; Ghosh, Shamik; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukhopadhyay, Supratik; Nandan, Saswati; Purohit, Arnab; Rout, Prasant Kumar; Roy, Ashim; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Singh, Bipen; Thakur, Shalini; Behera, Prafulla Kumar; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Netrakanti, Pawan Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Dugad, Shashikant; Mahakud, Bibhuprasad; Mitra, Soureek; Mohanty, Gagan Bihari; Sur, Nairit; Sutar, Bajrang; Banerjee, Sudeshna; Bhattacharya, Soham; Chatterjee, Suman; Das, Pallabi; Guchait, Monoranjan; Jain, Sandhya; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Sarkar, Tanmay; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Hegde, Vinay; Kapoor, Anshul; Kothekar, Kunal; Pandey, Shubham; Rane, Aditee; Sharma, Seema; Chenarani, Shirin; Eskandari Tadavani, Esmaeel; Etesami, Seyed Mohsen; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Errico, Filippo; Fiore, Luigi; Iaselli, Giuseppe; Lezki, Samet; Maggi, Giorgio; Maggi, Marcello; Marangelli, Bartolomeo; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Sharma, Archana; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Zito, Giuseppe; Abbiendi, Giovanni; Battilana, Carlo; Bonacorsi, Daniele; Borgonovi, Lisa; Braibant-Giacomelli, Sylvie; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Iemmi, Fabio; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Albergo, Sebastiano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Chatterjee, Kalyanmoy; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Russo, Lorenzo; Sguazzoni, Giacomo; Strom, Derek; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Ravera, Fabio; Robutti, Enrico; Tosi, Silvano; Benaglia, Andrea; Beschi, Andrea; Brianza, Luca; Brivio, Francesco; Ciriolo, Vincenzo; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Govoni, Pietro; Malberti, Martina; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pauwels, Kristof; Pedrini, Daniele; Pigazzini, Simone; Ragazzi, Stefano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Fienga, Francesco; Iorio, Alberto Orso Maria; Khan, Wajid Ali; Lista, Luca; Meola, Sabino; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; De Castro Manzano, Pablo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Lujan, Paul; Margoni, Martino; Meneguzzo, Anna Teresa; Pozzobon, Nicola; Ronchese, Paolo; Rossin, Roberto; Simonetto, Franco; Tiko, Andres; Torassa, Ezio; Zanetti, Marco; Zotto, Pierluigi; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Ressegotti, Martina; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Biasini, Maurizio; Bilei, Gian Mario; Cecchi, Claudia; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Leonardi, Roberto; Manoni, Elisa; Mantovani, Giancarlo; Mariani, Valentina; Menichelli, Mauro; Rossi, Alessandro; Santocchia, Attilio; Spiga, Daniele; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bianchini, Lorenzo; Boccali, Tommaso; Borrello, Laura; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Fedi, Giacomo; Giannini, Leonardo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Manca, Elisabetta; Mandorli, Giulio; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Cipriani, Marco; Daci, Nadir; Del Re, Daniele; Di Marco, Emanuele; Diemoz, Marcella; Gelli, Simone; Longo, Egidio; Margaroli, Fabrizio; Marzocchi, Badder; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bartosik, Nazar; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Cenna, Francesca; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Monteno, Marco; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Shchelina, Ksenia; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Traczyk, Piotr; Belforte, Stefano; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Zanetti, Anna; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Lee, Jeongeun; Lee, Sangeun; Lee, Seh Wook; Moon, Chang-Seong; Oh, Young Do; Sekmen, Sezen; Son, Dong-Chul; Yang, Yu Chul; Kim, Hyunchul; Moon, Dong Ho; Oh, Geonhee; Brochero Cifuentes, Javier Andres; Goh, Junghwan; Kim, Tae Jeong; Cho, Sungwoong; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Ha, Seungkyu; Hong, Byung-Sik; Jo, Youngkwon; Kim, Yongsun; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Lim, Jaehoon; Park, Sung Keun; Roh, Youn; Almond, John; Kim, Junho; Kim, Jae Sung; Lee, Haneol; Lee, Kyeongpil; Nam, Kyungwook; Oh, Sung Bin; Radburn-Smith, Benjamin Charles; Seo, Seon-hee; Yang, Unki; Yoo, Hwi Dong; Yu, Geum Bong; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Choi, Young-Il; Hwang, Chanwook; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Zolkapli, Zukhaimira; Reyes-Almanza, Rogelio; Ramirez-Sanchez, Gabriel; Duran-Osuna, Cecilia; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Rabadán-Trejo, Raúl Iraq; Lopez-Fernandez, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Oropeza Barrera, Cristina; Vazquez Valencia, Fabiola; Eysermans, Jan; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Uribe Estrada, Cecilia; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Saddique, Asif; Shah, Mehar Ali; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bozena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Szleper, Michal; Zalewski, Piotr; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Pyskir, Andrzej; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Galinhas, Bruno; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Seixas, Joao; Strong, Giles; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Voytishin, Nikolay; Zarubin, Anatoli; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sosnov, Dmitry; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Stepennov, Anton; Stolin, Viatcheslav; Toms, Maria; Vlasov, Evgueni; Zhokin, Alexander; Aushev, Tagir; Bylinkin, Alexander; Chadeeva, Marina; Parygin, Pavel; Philippov, Dmitry; Polikarpov, Sergey; Popova, Elena; Rusinov, Vladimir; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Rusakov, Sergey V; Terkulov, Adel; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Demiyanov, Andrey; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Vardanyan, Irina; Blinov, Vladimir; Shtol, Dmitry; Skovpen, Yuri; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Elumakhov, Dmitry; Godizov, Anton; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Mandrik, Petr; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Babaev, Anton; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Dordevic, Milos; Milosevic, Jovan; Alcaraz Maestre, Juan; Bachiller, Irene; Barrio Luna, Mar; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Moran, Dermot; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; Triossi, Andrea; Álvarez Fernández, Adrian; Albajar, Carmen; de Trocóniz, Jorge F; Cuevas, Javier; Erice, Carlos; Fernandez Menendez, Javier; Gonzalez Caballero, Isidro; González Fernández, Juan Rodrigo; Palencia Cortezon, Enrique; Sanchez Cruz, Sergio; Vischia, Pietro; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Chazin Quero, Barbara; Duarte Campderros, Jordi; Fernandez, Marcos; Fernández Manteca, Pedro José; Garcia-Ferrero, Juan; García Alonso, Andrea; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Martinez Rivero, Celso; Martinez Ruiz del Arbol, Pablo; Matorras, Francisco; Piedra Gomez, Jonatan; Prieels, Cédric; Rodrigo, Teresa; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Akgun, Bora; Auffray, Etiennette; Baillon, Paul; Ball, Austin; Barney, David; Bendavid, Joshua; Bianco, Michele; Bocci, Andrea; Botta, Cristina; Camporesi, Tiziano; Castello, Roberto; Cepeda, Maria; Cerminara, Gianluca; Chapon, Emilien; Chen, Yi; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Roeck, Albert; Deelen, Nikkie; Dobson, Marc; Du Pree, Tristan; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Everaerts, Pieter; Fallavollita, Francesco; Franzoni, Giovanni; Fulcher, Jonathan; Funk, Wolfgang; Gigi, Dominique; Gilbert, Andrew; Gill, Karl; Glege, Frank; Gulhan, Doga; Hegeman, Jeroen; Innocente, Vincenzo; Jafari, Abideh; Janot, Patrick; Karacheban, Olena; Kieseler, Jan; Knünz, Valentin; Kornmayer, Andreas; Kortelainen, Matti J; Krammer, Manfred; Lange, Clemens; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Meijers, Frans; Merlin, Jeremie Alexandre; Mersi, Stefano; Meschi, Emilio; Milenovic, Predrag; Moortgat, Filip; Mulders, Martijn; Neugebauer, Hannes; Ngadiuba, Jennifer; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuel; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Pitters, Florian Michael; Rabady, Dinyar; Racz, Attila; Reis, Thomas; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Selvaggi, Michele; Sharma, Archana; Silva, Pedro; Sphicas, Paraskevas; Stakia, Anna; Steggemann, Jan; Stoye, Markus; Tosi, Mia; Treille, Daniel; Tsirou, Andromachi; Veckalns, Viesturs; Verweij, Marta; Zeuner, Wolfram Dietrich; Bertl, Willi; Caminada, Lea; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Rohe, Tilman; Wiederkehr, Stephan Albert; Backhaus, Malte; Bäni, Lukas; Berger, Pirmin; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dorfer, Christian; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Klijnsma, Thomas; Lustermann, Werner; Mangano, Boris; Marionneau, Matthieu; Meinhard, Maren Tabea; Meister, Daniel; Micheli, Francesco; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrin, Gaël; Perrozzi, Luca; Quittnat, Milena; Reichmann, Michael; Sanz Becerra, Diego Alejandro; Schönenberger, Myriam; Shchutska, Lesya; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Vesterbacka Olsson, Minna Leonora; Wallny, Rainer; Zhu, De Hua; Aarrestad, Thea Klaeboe; Amsler, Claude; Canelli, Maria Florencia; De Cosa, Annapaola; Del Burgo, Riccardo; Donato, Silvio; Galloni, Camilla; Hreus, Tomas; Kilminster, Benjamin; Pinna, Deborah; Rauco, Giorgia; Robmann, Peter; Salerno, Daniel; Schweiger, Korbinian; Seitz, Claudia; Takahashi, Yuta; Zucchetta, Alberto; Candelise, Vieri; Chang, Yu-Hsiang; Cheng, Kai-yu; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Kuo, Chia-Ming; Lin, Willis; Pozdnyakov, Andrey; Yu, Shin-Shan; Kumar, Arun; Chang, Paoti; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Fiori, Francesco; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Paganis, Efstathios; Psallidas, Andreas; Steen, Arnaud; Tsai, Jui-fa; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Bakirci, Mustafa Numan; Bat, Ayse; Boran, Fatma; Damarseckin, Serdal; Demiroglu, Zuhal Seyma; Dozen, Candan; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Hos, Ilknur; Kangal, Evrim Ersin; Kara, Ozgun; Kiminsu, Ugur; Oglakci, Mehmet; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sunar Cerci, Deniz; Tok, Ufuk Guney; Turkcapar, Semra; Zorbakir, Ibrahim Soner; Zorbilmez, Caglar; Karapinar, Guler; Ocalan, Kadir; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Tekten, Sevgi; Yetkin, Elif Asli; Agaras, Merve Nazlim; Atay, Serhat; Cakir, Altan; Cankocak, Kerem; Komurcu, Yildiray; Grynyov, Boris; Levchuk, Leonid; Ball, Fionn; Beck, Lana; Brooke, James John; Burns, Douglas; Clement, Emyr; Cussans, David; Davignon, Olivier; Flacher, Henning; Goldstein, Joel; Heath, Greg P; Heath, Helen F; Kreczko, Lukasz; Newbold, Dave M; Paramesvaran, Sudarshan; Sakuma, Tai; Seif El Nasr-storey, Sarah; Smith, Dominic; Smith, Vincent J; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; 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Khan, Akram; Kyberd, Paul; Morton, Alexander; Reid, Ivan; Teodorescu, Liliana; Zahid, Sema; Borzou, Ahmad; Call, Kenneth; Dittmann, Jay; Hatakeyama, Kenichi; Liu, Hongxuan; Pastika, Nathaniel; Smith, Caleb; Bartek, Rachel; Dominguez, Aaron; Buccilli, Andrew; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; West, Christopher; Arcaro, Daniel; Avetisyan, Aram; Bose, Tulika; Gastler, Daniel; Rankin, Dylan; Richardson, Clint; Rohlf, James; Sulak, Lawrence; Zou, David; Benelli, Gabriele; Cutts, David; Hadley, Mary; Hakala, John; Heintz, Ulrich; Hogan, Julie Managan; Kwok, Ka Hei Martin; Laird, Edward; Landsberg, Greg; Lee, Jangbae; Mao, Zaixing; Narain, Meenakshi; Pazzini, Jacopo; Piperov, Stefan; Sagir, Sinan; Syarif, Rizki; Yu, David; Band, Reyer; Brainerd, Christopher; Breedon, Richard; Burns, Dustin; Calderon De La Barca Sanchez, Manuel; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Flores, Chad; Funk, Garrett; Ko, Winston; Lander, Richard; Mclean, Christine; 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Chu, Jennifer; Dittmer, Susan; Mcdermott, Kevin; Mirman, Nathan; Patterson, Juliet Ritchie; Quach, Dan; Rinkevicius, Aurelijus; Ryd, Anders; Skinnari, Louise; Soffi, Livia; Tan, Shao Min; Tao, Zhengcheng; Thom, Julia; Tucker, Jordan; Wittich, Peter; Zientek, Margaret; Abdullin, Salavat; Albrow, Michael; Alyari, Maral; Apollinari, Giorgio; Apresyan, Artur; Apyan, Aram; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Canepa, Anadi; Cerati, Giuseppe Benedetto; Cheung, Harry; Chlebana, Frank; Cremonesi, Matteo; Duarte, Javier; Elvira, Victor Daniel; Freeman, Jim; Gecse, Zoltan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Lincoln, Don; Lipton, Ron; Liu, Miaoyuan; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Magini, Nicolo; Marraffino, John Michael; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Ristori, Luciano; Savoy-Navarro, Aurore; Schneider, Basil; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strait, James; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Wang, Michael; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Wu, Weimin; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Brinkerhoff, Andrew; Carnes, Andrew; Carver, Matthew; Curry, David; Field, Richard D; Furic, Ivan-Kresimir; Gleyzer, Sergei V; Joshi, Bhargav Madhusudan; Konigsberg, Jacobo; Korytov, Andrey; Kotov, Khristian; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Mitselmakher, Guenakh; Shi, Kun; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Joshi, Yagya Raj; Linn, Stephan; Markowitz, Pete; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Todd; Askew, Andrew; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Kolberg, Ted; Martinez, German; Perry, Thomas; Prosper, Harrison; Saha, Anirban; Santra, Arka; Sharma, Varun; Yohay, Rachel; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Cavanaugh, Richard; Chen, Xuan; Evdokimov, Olga; Gerber, Cecilia Elena; Hangal, Dhanush Anil; Hofman, David Jonathan; Jung, Kurt; Kamin, Jason; Sandoval Gonzalez, Irving Daniel; Tonjes, Marguerite; Trauger, Hallie; Varelas, Nikos; Wang, Hui; Wu, Zhenbin; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; You, Can; Al-bataineh, Ayman; Baringer, Philip; Bean, Alice; Boren, Samuel; Bowen, James; Castle, James; Khalil, Sadia; Kropivnitskaya, Anna; Majumder, Devdatta; Mcbrayer, William; Murray, Michael; Rogan, Christopher; Royon, Christophe; Sanders, Stephen; Schmitz, Erich; Tapia Takaki, Daniel; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Baron, Owen; Belloni, Alberto; Eno, Sarah Catherine; Feng, Yongbin; Ferraioli, Charles; Hadley, Nicholas John; Jabeen, Shabnam; Jeng, Geng-Yuan; Kellogg, Richard G; Kunkle, Joshua; Mignerey, Alice; Ricci-Tam, Francesca; Shin, Young Ho; Skuja, Andris; Tonwar, Suresh C; Abercrombie, Daniel; Allen, Brandon; Azzolini, Virginia; Barbieri, Richard; Baty, Austin; Bauer, Gerry; Bi, Ran; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; D'Alfonso, Mariarosaria; Demiragli, Zeynep; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Harris, Philip; Hsu, Dylan; Hu, Miao; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Maier, Benedikt; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Tatar, Kaya; Velicanu, Dragos; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Benvenuti, Alberto; Chatterjee, Rajdeep Mohan; Evans, Andrew; Hansen, Peter; Hiltbrand, Joshua; Kalafut, Sean; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Turkewitz, Jared; Wadud, Mohammad Abrar; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Claes, Daniel R; Fangmeier, Caleb; Golf, Frank; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Kravchenko, Ilya; Monroy, Jose; Siado, Joaquin Emilo; Snow, Gregory R; Stieger, Benjamin; Dolen, James; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Nguyen, Duong; Parker, Ashley; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Freer, Chad; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Orimoto, Toyoko; Teixeira De Lima, Rafael; Wamorkar, Tanvi; Wang, Bingran; Wisecarver, Andrew; Wood, Darien; Bhattacharya, Saptaparna; Charaf, Otman; Hahn, Kristan Allan; Mucia, Nicholas; Odell, Nathaniel; Schmitt, Michael Henry; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Bucci, Rachael; Dev, Nabarun; Hildreth, Michael; Hurtado Anampa, Kenyi; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Li, Wenzhao; 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Qiu, Hao; Schulte, Jan-Frederik; Sun, Jian; Wang, Fuqiang; Xiao, Rui; Xie, Wei; Cheng, Tongguang; Parashar, Neeti; Stupak, John; Chen, Zhenyu; Ecklund, Karl Matthew; Freed, Sarah; Geurts, Frank JM; Guilbaud, Maxime; Kilpatrick, Matthew; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Roberts, Jay; Rorie, Jamal; Shi, Wei; Tu, Zhoudunming; Zabel, James; Zhang, Aobo; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Duh, Yi-ting; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Hindrichs, Otto; Khukhunaishvili, Aleko; Lo, Kin Ho; Tan, Ping; Verzetti, Mauro; Ciesielski, Robert; Goulianos, Konstantin; Mesropian, Christina; Agapitos, Antonis; Chou, John Paul; Gershtein, Yuri; Gómez Espinosa, Tirso Alejandro; Halkiadakis, Eva; Heindl, Maximilian; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Kyriacou, Savvas; Lath, Amitabh; Montalvo, Roy; Nash, Kevin; Osherson, Marc; Saka, Halil; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Delannoy, Andrés G; Heideman, Joseph; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Kamon, Teruki; Mueller, Ryan; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Perniè, Luca; Rathjens, Denis; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Damgov, Jordan; De Guio, Federico; Dudero, Phillip Russell; Faulkner, James; Gurpinar, Emine; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Mengke, Tielige; Muthumuni, Samila; Peltola, Timo; Undleeb, Sonaina; Volobouev, Igor; Wang, Zhixing; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Melo, Andrew; Ni, Hong; Padeken, Klaas; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Barria, Patrizia; Cox, Bradley; Hirosky, Robert; Joyce, Matthew; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Wang, Yanchu; Wolfe, Evan; Xia, Fan; Harr, Robert; Karchin, Paul Edmund; Poudyal, Nabin; Sturdy, Jared; Thapa, Prakash; Zaleski, Shawn; Brodski, Michael; Buchanan, James; Caillol, Cécile; Carlsmith, Duncan; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Hussain, Usama; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Rekovic, Vladimir; Ruggles, Tyler; Savin, Alexander; Smith, Nicholas; Smith, Wesley H; Woods, Nathaniel

2018-01-01

Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and PbPb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with ${p_{\\mathrm{T}}}^{\\text{jet}} > $ 30 GeV/$c$ in events containing an isolated photon with ${p_{\\mathrm{T}}}^{\\gamma} > $ 60 GeV/$c$, using charged tracks with transverse momentum $ {p_{\\mathrm{T}}}^{\\text{trk}} > $ 1 GeV/$c$ in a cone around the jet axis. The association with an isolated photon constrains the initial ${p_{\\mathrm{T}}}$ and azimuthal angle of the parton whose shower produced the jet. For central PbPb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50\\% most peripheral collisions. Jets in central PbPb events show an excess (depletion) of low (high) $ {p_...

Observation of medium induced modifications of jet fragmentation in PbPb collisions using isolated-photon-tagged jets

Energy Technology Data Exchange (ETDEWEB)

Sirunyan, Albert M; et al.

2018-01-15

Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and PbPb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with p$_\\mathrm{T}^\\text{jet} >$ 30 GeV in events containing an isolated photon with p$_\\mathrm{T}^\\gamma>$ 60 GeV, using charged tracks with transverse momentum p$_\\mathrm{T}^\\text{trk} >$ 1 GeV in a cone around the jet axis. The association with an isolated photon constrains the initial p$_\\mathrm{T}$ and azimuthal angle of the parton whose shower produced the jet. For central PbPb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50% most peripheral collisions. Jets in central PbPb events show an excess (depletion) of low (high) p$_\\mathrm{T}$ particles, with a transition around 3 GeV.

Jets in Active Galaxies

Indian Academy of Sciences (India)

which are rapidly rotating neutron stars emitting narrow beams of radiation. Images of ... rized into starburst galaxies and AGN powered by SMBHs. The ..... swer lies in the relativistic motion of the jets which boosts the flux density of .... radio cores, detection of ... to as synchrotron self-Compton or SSC, or those of the cosmic.

Relativistic Electrons Produced by Foreshock Disturbances Observed Upstream of Earth's Bow Shock

Science.gov (United States)

Wilson, L. B., III; Sibeck, D. G.; Turner, D. L.; Osmane, A.; Caprioli, D.; Angelopoulos, V.

2016-01-01

Charged particles can be reflected and accelerated by strong (i.e., high Mach number) astrophysical collisionless shock waves, streaming away to form a foreshock region in communication with the shock. Foreshocks are primarily populated by suprathermal ions that can generate foreshock disturbances-largescale (i.e., tens to thousands of thermal ion Larmor radii), transient (approximately 5-10 per day) structures. They have recently been found to accelerate ions to energies of several keV. Although electrons in Saturn's high Mach number (M > 40) bow shock can be accelerated to relativistic energies (nearly 1000 keV), it has hitherto been thought impossible to accelerate electrons beyond a few tens of keV at Earth's low Mach number (1 =M foreshock disturbances to energies up to at least approximately 300 keV. Although such energetic electrons have been previously observed, their presence has been attributed to escaping magnetospheric particles or solar events. These relativistic electrons are not associated with any solar or magnetospheric activity. Further, due to their relatively small Larmor radii (compared to magnetic gradient scale lengths) and large thermal speeds (compared to shock speeds), no known shock acceleration mechanism can energize thermal electrons up to relativistic energies. The discovery of relativistic electrons associated with foreshock structures commonly generated in astrophysical shocks could provide a new paradigm for electron injections and acceleration in collisionless plasmas.

Jet and electromagnetic tomography (JET) of extreme phases of matter in heavy-ion collisions

Energy Technology Data Exchange (ETDEWEB)

Heinz, Ulrich [The Ohio State Univ., Columbus, OH (United States)

2015-08-31

The Ohio State University (OSU) group contributed to the deliverables of the JET Collaboration three major products: 1. The code package iEBE-VISHNU for modeling the dynamical evolution of the soft medium created in relativistic heavy-ion collisions, from its creation all the way to final freeze-out using a hybrid approach that interfaces a free-streaming partonic pre-equilbrium stage with a (2+1)-dimensional viscous relativistic fluid dynamical stage for the quark-gluon plasma (QGP) phase and the microscopic hadron cascade UrQMD for the hadronic rescattering and freeze-out stage. Except for UrQMD, all dynamical evolution components and interfaces were developed at OSU and tested and implemented in collaboration with the Duke University group. 2. An electromagnetic radiation module for the calculation of thermal photon emission from the QGP and hadron resonance gas stages of a heavy-ion collision, with emission rates that have been corrected for viscous effects in the expanding medium consistent with the bulk evolution. The electromagnetic radiation module was developed under OSU leadership in collaboration with the McGill group and has been integrated in the iEBE-VISHNU code package. 3. An interface between the Monte Carlo jet shower evolution and hadronization codes developed by the Wayne State University (WSU), McGill and Texas A&M groups and the iEBE-VISHNU bulk evolution code, for performing jet quenching and jet shape modification studies in a realistically modeled evolving medium that was tuned to measured soft hadron data. Building on work performed at OSU for the theoretical framework used to describe the interaction of jets with the medium, initial work on the jet shower Monte Carlo was started at OSU and moved to WSU when OSU Visiting Assistant Professor Abhijit Majumder accepted a tenure track faculty position at WSU in September 2011. The jet-hydro interface was developed at OSU and WSU and tested and implemented in collaboration with the McGill, Texas

FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Caliandro, G. A.; Bruel, P.

2009-01-01

We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) ∼1500 km s -1 ), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti and Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

Fractal based observables to probe jet substructure of quarks and gluons

Science.gov (United States)

Davighi, Joe; Harris, Philip

2018-04-01

New jet observables are defined which characterize both fractal and scale-dependent contributions to the distribution of hadrons in a jet. These infrared safe observables, named Extended Fractal Observables (EFOs), have been applied to quark-gluon discrimination to demonstrate their potential utility. The EFOs are found to be individually discriminating and only weakly correlated to variables used in existing discriminators. Consequently, their inclusion improves discriminator performance, as here demonstrated with particle level simulation from the parton shower.

A Precessing Jet in the CH Cyg Symbiotic System

Science.gov (United States)

Karovska, Margarita; Gaetz, Terrance J.; Carilli, Christopher L.; Hack, Warren; Raymond, John C.; Lee, Nicholas P.

2010-02-01

Jets have been detected in only a few symbiotic binaries to date, and CH Cyg is one of them. In 2001, a non-relativistic jet was detected in CH Cyg for the first time in X-rays. We carried out coordinated Chandra, Hubble Space Telescope (HST), and VLA observations in 2008 to study the propagation of this jet and its interaction with the circumbinary medium. We detected the jet with Chandra and HST and determined that the apex has expanded to the south from ~300 AU to ~1400 AU, with the shock front propagating with velocity <100 km s-1. The shock front has significantly slowed down since 2001. Unexpectedly, we also discovered a powerful jet in the NE-SW direction, in the X-ray, optical and radio. This jet has a multi-component structure, including an inner jet and a counterjet at ~170 AU, and a SW component ending in several clumps extending out to ~750 AU. The structure of the jet and the curvature of the outer portion of the SW jet suggest an episodically powered precessing jet or a continuous precessing jet with occasional mass ejections or pulses. We carried out detailed spatial mapping of the X-ray emission and correlation with the optical and radio emission. X-ray spectra were extracted from the central source, inner NE counterjet, and the brightest clump at a distance of ~500 AU from the central source. We discuss the initial results of our analyses, including the multi-component spectral fitting of the jet components and of the central source.

A PRECESSING JET IN THE CH Cyg SYMBIOTIC SYSTEM

International Nuclear Information System (INIS)

Karovska, Margarita; Gaetz, Terrance J.; Raymond, John C.; Lee, Nicholas P.; Carilli, Christopher L.; Hack, Warren

2010-01-01

Jets have been detected in only a few symbiotic binaries to date, and CH Cyg is one of them. In 2001, a non-relativistic jet was detected in CH Cyg for the first time in X-rays. We carried out coordinated Chandra, Hubble Space Telescope (HST), and VLA observations in 2008 to study the propagation of this jet and its interaction with the circumbinary medium. We detected the jet with Chandra and HST and determined that the apex has expanded to the south from ∼300 AU to ∼1400 AU, with the shock front propagating with velocity -1 . The shock front has significantly slowed down since 2001. Unexpectedly, we also discovered a powerful jet in the NE-SW direction, in the X-ray, optical and radio. This jet has a multi-component structure, including an inner jet and a counterjet at ∼170 AU, and a SW component ending in several clumps extending out to ∼750 AU. The structure of the jet and the curvature of the outer portion of the SW jet suggest an episodically powered precessing jet or a continuous precessing jet with occasional mass ejections or pulses. We carried out detailed spatial mapping of the X-ray emission and correlation with the optical and radio emission. X-ray spectra were extracted from the central source, inner NE counterjet, and the brightest clump at a distance of ∼500 AU from the central source. We discuss the initial results of our analyses, including the multi-component spectral fitting of the jet components and of the central source.

Radio Loud AGN Unification: Connecting Jets and Accretion

Directory of Open Access Journals (Sweden)

Meyer Eileen T.

2013-12-01

Full Text Available While only a fraction of Active Galactic Nuclei are observed to host a powerful relativistic jet, a cohesive picture is emerging that radio-loud AGN may represent an important phase in the evolution of galaxies and the growth of the central super-massive black hole. I will review my own recent observational work in radio-loud AGN unification in the context of understanding how and why jets form and their the connection to different kinds of accretion and growing the black hole, along with a brief discussion of possible connections to recent modeling work in jet formation. Starting from the significant observational advances in our understanding of jetted AGN as a population over the last decade thanks to new, more sensitive instruments such as Fermi and Swift as well as all-sky surveys at all frequencies, I will lay out the case for a dichotomy in the jetted AGN population connected to accretion mode onto the black hole. In recent work, we have identified two sub-populations of radio-loud AGN which appear to be distinguished by jet structure, where low-efficiency accreting systems produce ‘weak’ jets which decelerate more rapidly than the ’strong’ jets of black holes accreting near the Eddington limit. The two classes are comprised of: (1The weak jet sources, corresponding to the less collimated, edge-darkened FR Is, with a decelerating or spine-sheath jet with velocity gradients, and (2 The strong jet sources, having fast, collimated jets, and typically displaying strong emission lines. The dichotomy in the vp-Lp plane can be understood as a "broken power sequence" in which jets exist on one branch or the other based on the particular accretion mode (Georganopolous 2011.We suggest that the intrinsic kinetic power (as measured by low-frequency, isotropic radio emission, the orientation, and the accretion rate of the SMBH system are the the fundamental axes needed for unification of radio-loud AGN by studying a well-characterized sample

Ooishi's Observation: Viewed in the Context of Jet Stream Discovery.

Science.gov (United States)

Lewis, John M.

2003-03-01

Although aircraft encounters with strong westerly winds during World War II provided the stimulus for postwar research on the jet stream, Wasaburo Ooishi observed these winds in the 1920s. Ooishi's work is reviewed in the context of earlier work in upperair observation and postwar work on the jet stream. An effort is made to reconstruct Ooishi's path to the directorship of Japan's first upper-air observatory by reliance on historical studies and memoirs from the Central Meteorological Observatory.Archival records from Japan's Aerological Observatory have been used to document Ooishi's upperair observations. The first official report from the observatory (written in 1926 and in the auxiliary language of Esperanto) assumes a central role in the study. In this report, data are stratified by season and used to produce the mean seasonal wind profiles. The profile for winter gives the first known evidence of the persistent strong westerlies over Japan that would later become known as the jet stream.

The Properties of Short Gamma-Ray Burst Jets Triggered by Neutron Star Mergers

Energy Technology Data Exchange (ETDEWEB)

Murguia-Berthier, Ariadna; Ramirez-Ruiz, Enrico; Montes, Gabriela [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); De Colle, Fabio [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A. P. 70-543 04510 D. F. (Mexico); Rezzolla, Luciano; Takami, Kentaro [Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Rosswog, Stephan [Astronomy and Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Perego, Albino [Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Lee, William H. [Instituto de Astronomía, Universidad Nacional Autónoma de México, A. P. 70-264 04510 D. F. (Mexico)

2017-02-01

The most popular model for short gamma-ray bursts (sGRBs) involves the coalescence of binary neutron stars. Because the progenitor is actually hidden from view, we must consider under which circumstances such merging systems are capable of producing a successful sGRB. Soon after coalescence, winds are launched from the merger remnant. In this paper, we use realistic wind profiles derived from global merger simulations in order to investigate the interaction of sGRB jets with these winds using numerical simulations. We analyze the conditions for which these axisymmetric winds permit relativistic jets to break out and produce an sGRB. We find that jets with luminosities comparable to those observed in sGRBs are only successful when their half-opening angles are below ≈20°. This jet collimation mechanism leads to a simple physical interpretation of the luminosities and opening angles inferred for sGRBs. If wide, low-luminosity jets are observed, they might be indicative of a different progenitor avenue such as the merger of a neutron star with a black hole. We also use the observed durations of sGRB to place constraints on the lifetime of the wind phase, which is determined by the time it takes the jet to break out. In all cases we find that the derived limits argue against completely stable remnants for binary neutron star mergers that produce sGRBs.

Observer dependence of quantum states in relativistic quantum field theories

International Nuclear Information System (INIS)

Malin, S.

1982-01-01

Quantum states can be understood as either (i) describing quantum systems or (ii) representing observers' knowledge about quantum systems. These different meanings are shown to imply different transformation properties in relativistic field theories. The rules for the reduction of quantum states and the transformation properties of quantum states under Lorentz transformations are derived for case (ii). The results obtained are applied to a quantum system recently presented and analyzed by Aharonov and Albert. It is shown that the present results, combined with Aharonov and Albert's, amount to a proof of Bohr's view that quantum states represent observers' knowledge about quantum systems

General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes

Energy Technology Data Exchange (ETDEWEB)

McKinney, Jonathan C.; Tchekhovskoy, Alexander; Blandford, Roger D.

2012-04-26

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H to cylindrical radius R ratio of |H/R| {approx} 0.2-1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally-dominated ({phi}-directed) and poloidally-dominated (R-z directed) magnetic fields. Firstly, for toroidal field models and BHs with high enough |a/M|, coherent large-scale (i.e. >> H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Secondly, for poloidal field models, poloidal magnetic flux readily accretes through the disk from large radii and builds-up to a natural saturation point near the BH. While models with |H/R| {approx} 1 and |a/M| {le} 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non-axisymmetric 'magnetically choked accretion flow' (MCAF) within which the standard linear magneto-rotational instability is suppressed. The condition of a highly-magnetized state over most of the horizon is optimal for the Blandford-Znajek mechanism that generates persistent relativistic jets with and 100% efficiency for |a/M| {approx}> 0.9. A magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface forms between the compressed inflow and bulging jet magnetosphere, which drives a new jet-disk oscillation (JDO) type of quasi-periodic oscillation (QPO) mechanism. The high-frequency QPO has spherical harmonic |m| = 1 mode period of {tau} {approx} 70GM/c{sup 3} for a/M {approx} 0.9 with coherence quality factors Q {approx}> 10. Overall, our models are qualitatively distinct from most prior MHD simulations (typically, |H/R| << 1 and poloidal flux is

Gamma-ray burst jet dynamics and their interaction with the progenitor star.

Science.gov (United States)

Lazzati, Davide; Morsony, Brian J; Begelman, Mitchell C

2007-05-15

The association of at least some long gamma-ray bursts with type Ic supernova explosions has been established beyond reasonable doubt. Theoretically, the challenge is to explain the presence of a light hyper-relativistic flow propagating through a massive stellar core without losing those properties. We discuss the role of the jet-star interaction in shaping the properties of the outflow emerging on the surface of the star. We show that the nature of the inner engine is hidden from the observer for most of the evolution, well beyond the time of the jet breakout on the stellar surface. The discussion is based on analytical considerations as well as high resolution numerical simulations. Finally, the observational consequences of the scenario are addressed in light of the present capabilities.

Rarefaction acceleration in magnetized gamma-ray burst jets

Science.gov (United States)

Sapountzis, Konstantinos; Vlahakis, Nektarios

2013-09-01

Relativistic jets associated with long/soft gamma-ray bursts are formed and initially propagate in the interior of the progenitor star. Because of the subsequent loss of their external pressure support after they cross the stellar surface, these flows can be modelled as moving around a corner. A strong steady-state rarefaction wave is formed, and the sideways expansion is accompanied by a rarefaction acceleration. We investigate the efficiency and the general characteristics of this mechanism by integrating the steady-state, special relativistic, magnetohydrodynamic equations, using a special set of partial exact solutions in planar geometry (r self-similar with respect to the `corner'). We also derive analytical approximate scalings in the ultrarelativistic cold/magnetized, and hydrodynamic limits. The mechanism is more effective in magnetized than in purely hydrodynamic flows. It substantially increases the Lorentz factor without much affecting the opening of the jet; the resulting values of their product can be much greater than unity, allowing for possible breaks in the afterglow light curves. These findings are similar to the ones from numerical simulations of axisymmetric jets by Komissarov et al. and Tchekhovskoy et al., although in our approach we describe the rarefaction as a steady-state simple wave and self-consistently calculate the opening of the jet that corresponds to zero external pressure.

Jets and beams in powerful extragalatic radio sources

International Nuclear Information System (INIS)

Pelletier, G.; Roland, J.; Asseo, E.

1989-01-01

The simplest, but the most constraining assumption for jet modeling powerfull extragalatic radio sources is to consider a single relativistic plasma with relativistic motion from short distances (few pc) to large distances (few 100 kpc) from the nucleus. We argue that it is worth introducing more ingredients in the model. Besides the interest in developing plasma physics motivated by these objects, there are two reasons for enriching the physics. First, the interpretation of hot spots as resulting from shocks with diffusive acceleration in a thermal classical plasma with a tenuous relativistic component is consistent with data and constrain the parameters. Second, the interpretation of relativistic motions on parsec scales as resulting from a core beam relaxing in a collimated wind is consistent with data and avoid several difficulties. (author). 14 refs

Splitter target for controlling magnetic reconnection in relativistic laser plasma interactions

Science.gov (United States)

Gu, Y. J.; Bulanov, S. S.; Korn, G.; Bulanov, S. V.

2018-04-01

The utilization of a conical target irradiated by a high power laser is proposed to study fast magnetic reconnection in relativistic plasma interactions. Such target, placed in front of the near critical density gas jet, splits the laser pulse, forming two parallel laser pulses in the 2D case and a donut shaped pulse in the 3D case. The magnetic annihilation and reconnection occur in the density downramp region of the subsequent gas jet. The magnetic field energy is converted into the particle kinetic energy. As a result, a backward accelerated electron beam is obtained as a signature of reconnection. The above mechanisms are demonstrated using particle-in-cell simulations in both 2D and 3D cases. Facilitating the synchronization of two laser beams, the proposed approach can be used in designing the corresponding experiments on studying fundamental problems of relativistic plasma physics.

Relativistic Descriptions of Few-Body Systems

International Nuclear Information System (INIS)

Karmanov, V. A.

2011-01-01

A brief review of relativistic effects in few-body systems, of theoretical approaches, recent developments and applications is given. Manifestations of relativistic effects in the binding energies, in the electromagnetic form factors and in three-body observables are demonstrated. The three-body forces of relativistic origin are also discussed. We conclude that relativistic effects in nuclei can be important in spite of small binding energy. At high momenta they clearly manifest themselves and are necessary to describe the deuteron e.m. form factors. At the same time, there is still a discrepancy in three-body observables which might be a result of less clarity in understanding the corresponding relativistic effects, the relativistic NN kernel and the three-body forces. Relativistic few-body physics remains to be a field of very intensive and fruitful researches. (author)

GRB 170817A as a jet counterpart to gravitational wave trigger GW 170817

Science.gov (United States)

Lamb, Gavin P.; Kobayashi, Shiho

2018-05-01

Fermi/GBM (Gamma-ray Burst Monitor) and INTEGRAL (the International Gamma-ray Astrophysics Laboratory) reported the detection of the γ-ray counterpart, GRB 170817A, to the LIGO (Light Interferometer Gravitational-wave Observatory)/Virgo gravitational wave detected binary neutron star merger, GW 170817. GRB 170817A is likely to have an internal jet or another origin such as cocoon emission, shock-breakout, or a flare from a viscous disc. In this paper we assume that the γ-ray emission is caused by energy dissipation within a relativistic jet and we model the afterglow synchrotron emission from a reverse- and forward-shock in the outflow. We show the afterglow for a low-luminosity γ-ray burst (GRB) jet with a high Lorentz-factor (Γ); a low-Γ and low-kinetic energy jet; a low-Γ, high kinetic energy jet; structured jets viewed at an inclination within the jet-half-opening angle; and an off-axis `typical' GRB jet. All jet models will produce observable afterglows on various timescales. The late-time afterglow from 10-110 days can be fit by a Gaussian structured jet viewed at a moderate inclination, however the GRB is not directly reproduced by this model. These jet afterglow models can be used for future GW detected NS merger counterparts with a jet afterglow origin.

Spatial stability of jets - the nonaxisymmetric fundamental and reflection modes

International Nuclear Information System (INIS)

Hardee, P.E.

1987-01-01

A spatial stability analysis of the relativistic dispersion relation governing the growth and propagation of harmonic components comprising a perturbation to the surface of a cylindrical jet is performed. The spatial growth of harmonic components associated with the nonaxisymmetric fundamental solution and reflection solutions of several Fourier modes are analyzed. Approximate analytical expressions describing resonant frequencies and wavelengths, and maximum growth rates at resonance applicable to relativistic jets are found from the dispersion relation, and the nature of the resonances is explored. On transonic jets there is only a fundamental solution for each Fourier mode with no resonance or maximum growth rate. On supersonic jets there is a fundamental solution and reflection solutions for each Fourier mode, and each solution contains a resonance at which the growth rate is a maximum. A numerical analysis of the fundamental and first three reflection solutions of the axisymmetric and first three nonaxisymmetric Fourier modes is performed. The numerical analysis is restricted to nonrelativistic flows but otherwise covers a broad range of Mach numbers and jet densities. The numerical results are used along with the analytical results to obtain accurate expressions for resonant frequencies, wavelengths, and growth rates as a function of Mach numnber and jet density. In all cases the fastest spatial growth rate at a given frequency is of harmonic components associated with the fundamental solution of one of the nonaxisymmetric Fourier modes. The application of these results to jet structure and implication of these results for jet structure in extragalactic radio sources are considered. 23 references

Jets and Jet-like Correlations in Heavy Ion and p+p Collisions at PHENIX

International Nuclear Information System (INIS)

2010-01-01

Jets from heavy ion collisions provide a measurement of the medium-induced parton energy loss and the in-medium fragmentation properties. The medium modification effects are determined by comparing to a p+p baseline measurement, but the high multiplicity background in a heavy ion collision inhibits the direct application of traditional jet reconstruction techniques and novel approaches are needed to deal with this environment. Alternatively, angular correlations between the hadronic fragments of energetic partons can be used to understand the hot dense matter produced in relativistic heavy ion collisions. The yield and shape modifications of the away side peaks as function of transverse momentum compared to p+p has been interpreted as a medium response to parton energy loss. Direct photon-hadron correlations are another excellent channel to study jets from heavy ion collisions. Photons do not interact strongly with the medium and thus the photon approximately balances the momentum of the opposing jet, allowing the measurement of the effective modification to the fragmentation function through jet energy loss in the medium.

PROPER MOTIONS OF THE OUTER KNOTS OF THE HH 80/81/80N RADIO-JET

Energy Technology Data Exchange (ETDEWEB)

Masqué, Josep M.; Rodriguez, Luis F.; Carrasco-González, Carlos [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58089, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Estalella, Robert [Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos (IEEC-UB), Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Catalunya (Spain); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E-18080 Granada (Spain); Girart, Josep M. [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193 Cerdanyola del Vallès, Catalunya (Spain)

2015-11-20

The radio-knots of the Herbig–Haro (HH) 80/81/80N jet extend from the HH 80 object to the recently discovered Source 34 and has a total projected jet size of 10.3 pc, constituting the largest collimated radio-jet system known so far. It is powered by the bright infrared source IRAS 18162−2048 associated with a massive young stellar object. We report 6 cm JVLA observations that, compared with previous 6 cm VLA observations carried out in 1989, allow us to derive proper motions of the HH 80, HH 81, and HH 80N radio knots located about 2.5 pc away in projection from the powering source. For the first time, we measure proper motions of the optically obscured HH 80N object providing evidence that this knot, along with HH 81 and HH 80 are associated with the same radio-jet. We also confirm the presence of Source 34, located further north of HH 80N, previously proposed to belong to the jet.We derived that the tangential velocity of HH 80N is 260 km s{sup −1} and has a direction in agreement with the expected direction of a ballistic precessing jet. The HH 80 and HH 81 objects have tangential velocities of 350 and 220 km s{sup −1}, respectively, but their directions are somewhat deviated from the expected jet path. The velocities of the HH objects studied in this work are significantly lower than those derived for the radio knots of the jet close to the powering source (600–1400 km s{sup −1}) suggesting that the jet is slowing down due to a strong interaction with the ambient medium. As a result, since HH 80 and HH 81 are located near the edge of the cloud, the inhomogeneous and low density medium may contribute to skew the direction of their determined proper motions. The HH 80 and HH 80N emission at 6 cm is, at least in part, probably synchrotron radiation produced by relativistic electrons in a magnetic field of 1 mG. If these electrons are accelerated in a reverse adiabatic shock, we estimate a jet total density of ≲1000 cm{sup −3}. All of these

On the physics of runaway particles in JET and MAST

International Nuclear Information System (INIS)

Helander, P.; Akers, R.J.; Gimblett, C.G.; Tournianski, M.R.; Byrom, C.; Eriksson, L.-G.; Andersson, F.

2003-01-01

This paper explores the physics of runaway particles observed in MAST and JET. During internal reconnection events in MAST, it is observed that the ion distribution function, as measured by a neutral-particle analyser, develops a high-energy tail, which subsequently decays on the time scale of collisional slowing down. These observations are explained in terms of runaway ion acceleration in the electric field induced by the reconnection - a phenomenon predicted theoretically by Furth and Rutherford in 1972 but not commonly noted in tokamaks. In JET, long-lived post-disruption currents carried by runaway electrons have been observed to decay on a time scale of 1-2 s. A relativistic kinetic theory is developed to explain this decay as a consequence of the combined action of Coulomb collisions and synchrotron radiation emission. It is also pointed out that substantial electron-positron pair production should occur in such discharges, which have also been made more recently on JT-60U. In fact, tokamaks may be the largest positron repositories made by man. (author)

Measurements of jet fragmentation and the angular distributions of charged particles within and around jets in $pp$ and Pb+Pb with ATLAS

CERN Document Server

Rybar, Martin; The ATLAS collaboration

2018-01-01

Highly energetic jets produced in ultra-relativistic nuclear collisions are considered to be direct probes to study the properties of the hot and dense QCD matter created in these collisions. The measurement of the fragmentation functions of jets into charged particles in Pb+Pb collisions is sensitive to the strength and mechanism of jet quenching. In this talk, we present the latest measurement of the internal structure of jets and the angular distributions of charged particles within and around jets performed with the ATLAS detector. Fragmentation functions in Pb+Pb collisions and distributions of the transverse momentum of charged particles are compared to the same quantities measured in pp collisions at the same collision energy. Measurements are presented as a function of collision centrality, jet transverse momentum, and jet rapidity at 2.76 and 5.02 TeV. Furthermore, a new measurement of the angular distributions of charged-particles with respect to jet axis extended to distances outside the jet radius...

Relativistic motion of spinning particles in a gravitational field

International Nuclear Information System (INIS)

Chicone, C.; Mashhoon, B.; Punsly, B.

2005-01-01

The relative motion of a classical relativistic spinning test particle is studied with respect to a nearby free test particle in the gravitational field of a rotating source. The effects of the spin-curvature coupling force are elucidated and the implications of the results for the motion of rotating plasma clumps in astrophysical jets are discussed

INVESTIGATING PARTICLE ACCELERATION IN PROTOSTELLAR JETS: THE TRIPLE RADIO CONTINUUM SOURCE IN SERPENS

Energy Technology Data Exchange (ETDEWEB)

Rodríguez-Kamenetzky, Adriana; Valotto, Carlos [Instituto de Astronomía Teórica y Experimental, (IATE-UNC), X5000BGR Córdoba (Argentina); Carrasco-González, Carlos; Rodríguez, Luis F. [Instituto de Radioastronomía y Astrofísica (IRyA-UNAM), 58089 Morelia, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Torrelles, José M. [Institut de Ciències de l’Espai (CSIC-IEEC) and Institut de Ciències del Cosmos (UB-IEEC), Martí i Franquès 1, E-08028 Barcelona (Spain); Anglada, Guillem [Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain); Martí, Josep [Dept. de Física, EPS de Jaén, Universidad de Jaén, Campus Las Lagunillas s/n, A3-402, E-23071 Jaén (Spain)

2016-02-10

While most protostellar jets present free–free emission at radio wavelengths, synchrotron emission has also been proposed to be present in a handful of these objects. The presence of nonthermal emission has been inferred by negative spectral indices at centimeter wavelengths. In one case (the HH 80-81 jet arising from a massive protostar), its synchrotron nature was confirmed by the detection of linearly polarized radio emission. One of the main consequences of these results is that synchrotron emission implies the presence of relativistic particles among the nonrelativistic material of these jets. Therefore, an acceleration mechanism should be taking place. The most probable scenario is that particles are accelerated when the jets strongly impact against the dense envelope surrounding the protostar. Here we present an analysis of radio observations obtained with the Very Large Array of the triple radio source in the Serpens star-forming region. This object is known to be a radio jet arising from an intermediate-mass protostar. It is also one of the first protostellar jets where the presence of nonthermal emission was proposed. We analyze the dynamics of the jet and the nature of the emission and discuss these issues in the context of the physical parameters of the jet and the particle acceleration phenomenon.

Transverse momentum dependent fragmenting jet functions with applications to quarkonium production

Energy Technology Data Exchange (ETDEWEB)

Bain, Reggie; Makris, Yiannis; Mehen, Thomas [Department of Physics, Duke University,Science Dr., Box 90305, Durham, NC 27708 (United States)

2016-11-23

We introduce the transverse momentum dependent fragmenting jet function (TMDFJF), which appears in factorization theorems for cross sections for jets with an identified hadron. These are functions of z, the hadron’s longitudinal momentum fraction, and transverse momentum, p{sub ⊥}, relative to the jet axis. In the framework of Soft-Collinear Effective Theory (SCET) we derive the TMDFJF from both a factorized SCET cross section and the TMD fragmentation function defined in the literature. The TMDFJFs are factorized into distinct collinear and soft-collinear modes by matching onto SCET{sub +}. As TMD calculations contain rapidity divergences, both the renormalization group (RG) and rapidity renormalization group (RRG) must be used to provide resummed calculations with next-to-leading-logarithm prime (NLL’) accuracy. We apply our formalism to the production of J/ψ within jets initiated by gluons. In this case the TMDFJF can be calculated in terms of NRQCD (Non-relativistic quantum chromodynamics) fragmentation functions. We find that when the J/ψ carries a significant fraction of the jet energy, the p{sub T} and z distributions differ for different NRQCD production mechanisms. Another observable with discriminating power is the average angle that the J/ψ makes with the jet axis.

Cloud Ablation by a Relativistic Jet and the Extended Flare in CTA 102 in 2016 and 2017

Science.gov (United States)

Zacharias, M.; Böttcher, M.; Jankowsky, F.; Lenain, J.-P.; Wagner, S. J.; Wierzcholska, A.

2017-12-01

In late 2016 and early 2017, the flat spectrum radio quasar CTA 102 exhibited a very strong and long-lasting outburst. The event can be described by a roughly two-month long increase of the baseline flux in the monitored energy bands (optical to γ-rays) by a factor 8, and a subsequent decrease over another two months back to pre-flare levels. The long-term trend was superseded by short but very strong flares, resulting in a peak flux that was a factor 50 above pre-flare levels in the γ-ray domain and almost a factor 100 above pre-flare levels in the optical domain. In this paper, we explain the long-term evolution of the outburst by the ablation of a gas cloud penetrating the relativistic jet. The slice-by-slice ablation results in a gradual increase of the particle injection until the center of the cloud is reached, after which the injected number of particles decreases again. With reasonable cloud parameters, we obtain excellent fits of the long-term trend.

Observation of jet production in deep inelastic scattering with a large rapidity gap at HERA

International Nuclear Information System (INIS)

Doeker, T.

1994-01-01

Events with a large rapidity gap in deep inelastic scattering with Q 2 ≥ 10 GeV 2 have been studied in the ZEUS detector. The properties of these events with W > 140 GeV are consistent with a leading twist diffractive production mechanism. In the laboratory frame, with E jet t ≥ 4 GeV, 159% of the events are of the 1-jet type with negligible 2-jet production. The single jet is back-to-back in azimuth with the scattered electron. No energy now is observed between the jet and the proton direction. With a lower jet transverse energy cut 2-jet production is observed both in the laboratory and the γ * P centre-of-mass systems, demonstrating the presence of hard scattering in the virtual photon proton interactions that give rise to large rapidity gap events

Observation of jet production in deep inelastic scattering with a large rapidity gap a HERA

International Nuclear Information System (INIS)

Derrick, M.; Krakauer, D.; Magill, S.

1994-04-01

Events with a large rapidity gap in deep inelastic scattering with Q 2 ≥10 GeV 2 have been studied in the ZEUS detector. The properties of these events with W>140 GeV are consistent with a leading twist diffractive mechanism. In the laboratory frame, with E T jet ≥4 GeV, 15% of the events are of the 1-jet type with negligible 2-jet production. The single jet is back-to-back in azimuth with the scattered electron. No energy flow is observed between the jet and the proton direction. With a lower jet transverse energy cut 2-jet production is observed both in the laboratory and the γ * p centre-of-mass systems demonstrating the presence of hard scattering in the virtual photon interactions that give rise to large rapidity gap events. (orig.)

HIGH ENERGY NEUTRINOS PRODUCED IN THE ACCRETION DISKS BY NEUTRONS FROM NUCLEI DISINTEGRATED IN THE AGN JETS

Energy Technology Data Exchange (ETDEWEB)

Bednarek, W., E-mail: bednar@uni.lodz.pl [Department of Astrophysics, The University of Lodz, 90-236 Lodz, ul. Pomorska 149/153 (Poland)

2016-12-20

We investigate the consequences of acceleration of nuclei in jets of active galaxies not far from the surface of an accretion disk. The nuclei can be accelerated in the re-connection regions in the jet and/or at the jet boundary, between the relativistic jet and its cocoon. It is shown that the relativistic nuclei can efficiently fragment onto specific nucleons in collisions with the disk radiation. Neutrons, directed toward the accretion disk, take a significant part of energy from the relativistic nuclei. These neutrons develop a cascade in the dense accretion disk. We calculate the neutrino spectra produced in such a hadronic cascade within the accretion disk. We propose that the neutrinos produced in such a scenario, from the whole population of super-massive black holes in active galaxies, can explain the extragalactic neutrino background recently measured by the IceCube neutrino detector, provided that a 5% fraction of galaxies have an active galactic nucleus and a few percent of neutrons reach the accretion disk. We predict that the neutrino signals in the present neutrino detectors, produced in terms of such a model, will not be detectable even from the nearby radio galaxies similar to M87.

Strangeness Production in Jets with ALICE at the LHC

Science.gov (United States)

Smith, Chrismond; Harton, Austin; Garcia, Edmundo; Alice Collaboration

2016-03-01

The study of strange particle production is an important tool for understanding the properties of the hot and dense QCD medium created in heavy-ion collisions at ultra-relativistic energies. The study of strange particles in these collisions provides information on parton fragmentation, a fundamental QCD process. While measurements at low and intermediate pT, are already in progress at the LHC, the study of high momentum observables is equally important for a complete understanding of the QCD matter, this can be achieved by studying jet interactions. We propose the measurement of the characteristics of the jets containing strange particles. Starting with proton-proton collisions, we have calculated the inclusive pTJet spectra and the spectra for jets containing strange particles (K-short or lambda), and we are extending this analysis to lead-lead collisions. In this talk the ALICE experiment will be described, the methodology used for the data analysis and the available results will be discussed. This material is based upon work supported by the National Science Foundation under Grants PHY-1305280 and PHY-1407051.

Constraining the radio jet proper motion of the high-redshift quasar J2134-0419 at z = 4.3

Science.gov (United States)

Perger, Krisztina; Frey, Sándor; Gabányi, Krisztina É.; An, Tao; Britzen, Silke; Cao, Hong-Min; Cseh, Dávid; Dennett-Thorpe, Jane; Gurvits, Leonid I.; Hong, Xiao-Yu; Hook, Isobel M.; Paragi, Zsolt; Schilizzi, Richard T.; Yang, Jun; Zhang, Yingkang

2018-06-01

To date, PMN J2134-0419 (at a redshift z = 4.33) is the second most distant quasar known with a milliarcsecond-scale morphology permitting direct estimates of the jet proper motion. Based on two-epoch observations, we constrained its radio jet proper motion using the very long baseline interferometry (VLBI) technique. The observations were conducted with the European VLBI Network (EVN) at 5 GHz on 1999 November 26 and 2015 October 6. We imaged the central 10-pc scale radio jet emission and modelled its brightness distribution. By identifying a jet component at both epochs separated by 15.86 yr, a proper motion of μ = 0.035 ± 0.023 mas yr-1 is found. It corresponds to an apparent superluminal speed of βa = 4.1 ± 2.7 c. Relativistic beaming at both epochs suggests that the jet viewing angle with respect to the line of sight is smaller than 20°, with a minimum bulk Lorentz factor Γ = 4.3. The small value of the proper motion is in good agreement with the expectations from the cosmological interpretation of the redshift and the current cosmological model. Additionally we analysed archival Very Large Array observations of J2143-0419 and found indication of a bent jet extending to ˜30 kpc.

Polarization Signatures of Kink Instabilities in the Blazar Emission Region from Relativistic Magnetohydrodynamic Simulations

International Nuclear Information System (INIS)

Zhang, Haocheng; Taylor, Greg; Li, Hui; Guo, Fan

2017-01-01

Kink instabilities are likely to occur in the current-carrying magnetized plasma jets. Recent observations of the blazar radiation and polarization signatures suggest that the blazar emission region may be considerably magnetized. While the kink instability has been studied with first-principle magnetohydrodynamic (MHD) simulations, the corresponding time-dependent radiation and polarization signatures have not been investigated. In this paper, we perform comprehensive polarization-dependent radiation modeling of the kink instability in the blazar emission region based on relativistic MHD (RMHD) simulations. We find that the kink instability may give rise to strong flares with polarization angle (PA) swings or weak flares with polarization fluctuations, depending on the initial magnetic topology and magnetization. These findings are consistent with observations. Compared with the shock model, the kink model generates polarization signatures that are in better agreement with the general polarization observations. Therefore, we suggest that kink instabilities may widely exist in the jet environment and provide an efficient way to convert the magnetic energy and produce multiwavelength flares and polarization variations.

Polarization Signatures of Kink Instabilities in the Blazar Emission Region from Relativistic Magnetohydrodynamic Simulations

Energy Technology Data Exchange (ETDEWEB)

Zhang, Haocheng; Taylor, Greg [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Li, Hui; Guo, Fan [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-02-01

Kink instabilities are likely to occur in the current-carrying magnetized plasma jets. Recent observations of the blazar radiation and polarization signatures suggest that the blazar emission region may be considerably magnetized. While the kink instability has been studied with first-principle magnetohydrodynamic (MHD) simulations, the corresponding time-dependent radiation and polarization signatures have not been investigated. In this paper, we perform comprehensive polarization-dependent radiation modeling of the kink instability in the blazar emission region based on relativistic MHD (RMHD) simulations. We find that the kink instability may give rise to strong flares with polarization angle (PA) swings or weak flares with polarization fluctuations, depending on the initial magnetic topology and magnetization. These findings are consistent with observations. Compared with the shock model, the kink model generates polarization signatures that are in better agreement with the general polarization observations. Therefore, we suggest that kink instabilities may widely exist in the jet environment and provide an efficient way to convert the magnetic energy and produce multiwavelength flares and polarization variations.

Misaligned Accretion and Jet Production

Science.gov (United States)

King, Andrew; Nixon, Chris

2018-04-01

Disk accretion onto a black hole is often misaligned from its spin axis. If the disk maintains a significant magnetic field normal to its local plane, we show that dipole radiation from Lense–Thirring precessing disk annuli can extract a significant fraction of the accretion energy, sharply peaked toward small disk radii R (as R ‑17/2 for fields with constant equipartition ratio). This low-frequency emission is immediately absorbed by surrounding matter or refracted toward the regions of lowest density. The resultant mechanical pressure, dipole angular pattern, and much lower matter density toward the rotational poles create a strong tendency to drive jets along the black hole spin axis, similar to the spin-axis jets of radio pulsars, also strong dipole emitters. The coherent primary emission may explain the high brightness temperatures seen in jets. The intrinsic disk emission is modulated at Lense–Thirring frequencies near the inner edge, providing a physical mechanism for low-frequency quasi-periodic oscillations (QPOs). Dipole emission requires nonzero hole spin, but uses only disk accretion energy. No spin energy is extracted, unlike the Blandford–Znajek process. Magnetohydrodynamic/general-relativistic magnetohydrodynamic (MHD/GRMHD) formulations do not directly give radiation fields, but can be checked post-process for dipole emission and therefore self-consistency, given sufficient resolution. Jets driven by dipole radiation should be more common in active galactic nuclei (AGN) than in X-ray binaries, and in low accretion-rate states than high, agreeing with observation. In non-black hole accretion, misaligned disk annuli precess because of the accretor’s mass quadrupole moment, similarly producing jets and QPOs.

Four-dimensional jets of hadrons: universal characteristics of multiple production of particles

International Nuclear Information System (INIS)

Baldin, A.M.; Batyunya, B.V.; Gramenitskii, I.M.; Grishin, V.G.; Didenko, L.A.; Kuznetsov, A.A.; Metreveli, Z.V.

1986-01-01

In a new relativistically invariant approach, data on multiple production of particles are analyzed in pp, p-barp, π - p, π - C, pC, and pTa interactions in the momentum range from 6 to 205 GeV/c. Distributions of hadrons (π - , K 0 /sub S/, Λ) in the square of the 4-velocity (b/sub k/) relative to the jet axis are obtained. It is shown that at a momentum p/sub lab/ ≥22 GeV/c these distributions do not depend on energy and are identical for hadronization of quarks and of multiquark systems. The observed universal properties of 4-dimensional jets of hadrons apparently are fundamental characteristics of interactions of color charges with the vacuum

Observations of Seven Blue/Gigantic Jets above One Storm over the Atlantic Ocean

Science.gov (United States)

Liu, N.; Spiva, N.; Dwyer, J. R.; Rassoul, H.; Free, D. L.; Cummer, S. A.

2013-12-01

Blue/gigantic jets are electrical discharges developing from thundercloud tops and propagating to the upper atmosphere [e.g., Pasko et al., Nature, 416, 152, 2002; Su et al., Nature, 423, 973, 2003]. Not just producing an impressive display, gigantic jets establish a direct path of electrical contact between the upper troposphere and the lower ionosphere, capable of transferring a large amount of charge between them [Cummer et al., Nat. Geosci., 2, 617, 2009]. It has been suggested that they may play an important role in the earth's electrical environment [e. g., Pasko, Nature, 423, 927, 2003]. Upward discharges from thunderstorms like blue/gigantic jets are believed to originate from lightning leaders escaping from thunderclouds when the cloud's charges of different polarities are not balanced [Krehbiel et al., Nat. Geosci., 1, 233, 2008; Riousset et al., JGR, 115, A00E10, 2010]. On the evening of August 2, 2013, 4 gigantic jets, 2 blue jets and 1 blue starter were recorded within 26 min above a storm over the Atlantic Ocean by a low light level camera from the campus of Florida Institute of Technology. The events were also captured by two all-sky cameras: one again from the Florida Tech campus and the other from a nearby location. According to the NLDN data, positive intra-cloud flashes preceded all events except one gigantic jet. The distance between the observation site to the locations of the NLDN lightning discharges varies from 77 to 82 km. Optical signatures of intra-cloud discharge activities accompanied the events are clearly visible in the videos. The duration of each jet varies from about 300 ms to 1.2 s, and the 1.2 s duration is probably the longest that has been reported to date for jets. Rebrightening of gigantic jet structures occurs for at least two of the events. The upper terminal altitude of the 4 gigantic jets is greater than 76-81 km, the 2 blue jets reach about 48 and 51 km altitude, respectively, and the blue starter reaches 24 km altitude

A Reconnection Switch to Trigger gamma-Ray Burst Jet Dissipation

International Nuclear Information System (INIS)

McKinney, Jonathan

2012-01-01

Prompt gamma-ray burst (GRB) emission requires some mechanism to dissipate an ultrarelativistic jet. Internal shocks or some form of electromagnetic dissipation are candidate mechanisms. Any mechanism needs to answer basic questions, such as what is the origin of variability, what radius does dissipation occur at, and how does efficient prompt emission occur. These mechanisms also need to be consistent with how ultrarelativistic jets form and stay baryon pure despite turbulence and electromagnetic reconnection near the compact object and despite stellar entrainment within the collapsar model. We use the latest magnetohydrodynamical models of ultrarelativistic jets to explore some of these questions in the context of electromagnetic dissipation due to the slow collisional and fast collisionless reconnection mechanisms, as often associated with Sweet-Parker and Petschek reconnection, respectively. For a highly magnetized ultrarelativistic jet and typical collapsar parameters, we find that significant electromagnetic dissipation may be avoided until it proceeds catastrophically near the jet photosphere at large radii (r ∼ 10 13 -10 14 cm), by which the jet obtains a high Lorentz factor (γ ∼ 100-1000), has a luminosity of L j ∼ 10 50 -10 51 erg s -1 , has observer variability timescales of order 1s (ranging from 0.001-10s), achieves γθ j ∼ 10-20 (for opening half-angle θ j ) and so is able to produce jet breaks, and has comparable energy available for both prompt and afterglow emission. A range of model parameters are investigated and simplified scaling laws are derived. This reconnection switch mechanism allows for highly efficient conversion of electromagnetic energy into prompt emission and associates the observed prompt GRB pulse temporal structure with dissipation timescales of some number of reconnecting current sheets embedded in the jet. We hope this work helps motivate the development of self-consistent radiative compressible relativistic

Observation of two-jet production in deep inelastic scattering at HERA

Science.gov (United States)

Derrick, M.; Krakauer, D.; Magill, S.; Musgrave, B.; Repond, J.; Repond, S.; Stanek, R.; Talaga, R. L.; Thron, J.; Arzarello, F.; Ayad, R.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Bruni, P.; Cara Romeo, G.; Castellini, G.; Chiarini, M.; Cifarelli, L.; Cindolo, F.; Ciralli, F.; Contin, A.; D'Auria, S.; Del Papa, C.; Frasconi, F.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Lin, Q.; Lisowski, B.; Maccarrone, G.; Margotti, A.; Massam, T.; Nania, R.; Nemoz, C.; Palmonari, F.; Sartorelli, G.; Timellini, R.; Zamora Garcia, Y.; Zichichi, A.; Bargende, A.; Crittenden, J.; Dabbous, H.; Desch, K.; Diekmann, B.; Doeker, T.; Geerts, M.; Geitz, G.; Gutjahr, B.; Hartmann, H.; Haun, D.; Heinloth, K.; Hilger, E.; Jakob, H.-P.; Kramarczyk, S.; Kückes, M.; Mass, A.; Mengel, S.; Mollen, J.; Monaldi, D.; Müsch, H.; Paul, E.; Schattevoy, R.; Schneider, J.-L.; Wedemeyer, R.; Cassidy, A.; Cussans, D. G.; Dyce, N.; Fawcett, H. F.; Foster, B.; Gilmore, R.; Heath, G. P.; Lancaster, M.; Llewellyn, T. J.; Malos, J.; Morgado, C. J. S.; Tapper, R. J.; Wilson, S. S.; Rau, R. R.; Arneodo, M.; Barillari, T.; Schioppa, M.; Susinno, G.; Bernstein, A.; Caldwell, A.; Gialas, I.; Parsons, J. A.; Ritz, S.; Sciulli, F.; Straub, P. B.; Wai, L.; Yang, S.; Chwastowski, J.; Dwuraźny, A.; Eskreys, A.; Jakubowski, Z.; Niziom̵, B.; Piotrzkowski, K.; Zachara, M.; Zawiejski, L.; Bednarek, B.; Borzemski, P.; Eskreys, K.; Jeleń, K.; Kisielewska, D.; Kowalski, T.; Rulikowska-Zarȩbska, E.; Suszycki, L.; Zajaç, J.; Kȩdzierski, T.; Kotański, A.; Przybycień, M.; Bauerdick, L. A. T.; Behrens, U.; Bienlein, J. K.; Coldewey, C.; Dannemann, A.; Drews, G.; Erhard, P.; Flasiński, M.; Fleck, I.; Gläser, R.; Göttlicher, P.; Haas, T.; Hagge, L.; Hain, W.; Hasell, D.; Hultschig, H.; Jahnen, G.; Joos, P.; Kasemann, M.; Klanner, R.; Koch, W.; Kötz, U.; Kowalski, H.; Krüger, J.; Labs, J.; Ladage, A.; Löhr, B.; Löwe, M.; Lüke, D.; Mainusch, J.; Manczak, O.; Momayezi, M.; Ng, J. S. T.; Nickel, S.; Notz, D.; Park, I. H.; Pösnecker, K.-U.; Rohde, M.; Roldán, J.; Ros, E.; Schneekloth, U.; Schroeder, J.; Schulz, W.; Selonke, F.; Stiliaris, E.; Tscheslog, E.; Tsurugai, T.; Turkot, F.; Vogel, W.; Wolf, G.; Youngman, C.; Grabosch, H. J.; Leich, A.; Meyer, A.; Rethfeldt, C.; Schlenstedt, S.; Barbagli, G.; Francescato, A.; Nuti, M.; Pelfer, P.; Anzivino, G.; Casaccia, R.; De Pasquale, S.; Qian, S.; Votano, L.; Bamberger, A.; Freidhof, A.; Poser, T.; Söldner-Rembold, S.; Theisen, G.; Trefzger, T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; Forbes, J. R.; Jamieson, V. A.; Raine, C.; Saxon, D. H.; Brückmann, H.; Gloth, G.; Holm, U.; Kammerlocher, H.; Krebs, B.; Neumann, T.; Wick, K.; Fürtjes, A.; Kröger, W.; Lohrmann, E.; Milewski, J.; Nakahata, M.; Pavel, N.; Poelz, G.; Seidman, A.; Schott, W.; Terron, J.; Wiik, B. H.; Zetsche, F.; Bacon, T. C.; Butterworth, I.; Markou, C.; McQuillan, D.; Miller, D. B.; Mobayyen, M. M.; Prinias, A.; Vorvolakos, A.; Bienz, T.; Kreutzmann, H.; Mallik, U.; McCliment, E.; Roco, M.; Wang, M. Z.; Cloth, P.; Filges, D.; Chen, L.; Imlay, R.; Kartik, S.; Kim, H.-J.; McNeil, R. R.; Metcalf, W.; Barreiro, F.; Cases, G.; Hervás, L.; Labarga, L.; del Peso, J.; de Trocóniz, J. F.; Ikraiam, F.; Mayer, J. K.; Smith, G. R.; Corriveau, F.; Gilkinson, D. J.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Lim, J. N.; Meijer Drees, R.; Mitchell, J. W.; Patel, P. M.; Sinclair, L. E.; Stairs, D. G.; Ullmann, R.; Bashindzhagyan, G. L.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Y. A.; Kuzmin, V. A.; Kuznetsov, E. N.; Savin, A. A.; Voronin, A. G.; Zotov, N. P.; Bentvelsen, S.; Botje, M.; Dake, A.; Engelen, J.; de Jong, P.; de Kamps, M.; Kooijman, P.; Kruse, A.; van der Lugt, H.; O'Dell, V.; Tenner, A.; Tiecke, H.; Uijterwaal, H.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; van Woudenberg, R.; Yoshida, R.; Bylsma, B.; Durkin, L. S.; Honscheid, K.; Li, C.; Ling, T. Y.; McLean, K. W.; Murray, W. N.; Park, S. K.; Romanowski, T. A.; Seidlein, R.; Blair, G. A.; Byrne, A.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Gingrich, D. M.; Hallam-Baker, P. M.; Harnew, N.; Khatri, T.; Long, K. R.; Luffman, P.; McArthur, I.; Morawitz, P.; Nash, J.; Smith, S. J. P.; Roocroft, N. C.; Wilson, F. F.; Abbiendi, G.; Brugnera, R.; Carlin, R.; Dal Corso, F.; De Giorgi, M.; Dosselli, U.; Gasparini, F.; Limentani, S.; Morandin, M.; Posocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Butterworth, J. M.; Bulmahn, J.; Field, G.; Oh, B. Y.; Whitmore, J.; Contino, U.; D'Agostini, G.; Guida, M.; Iori, M.; Mari, S. M.; Marini, G.; Mattioli, M.; Nigro, A.; Hart, J. C.; McCubbin, N. A.; Prytz, K.; Shah, T. P.; Short, T. L.; Barberis, E.; Cartiglia, N.; Heusch, C.; Hubbard, B.; Leslie, J.; Lockman, W.; O'Shaughnessy, K.; Sadrozinski, H. F.; Seiden, A.; Badura, E.; Biltzinger, J.; Chaves, H.; Rost, M.; Seifert, R. J.; Walenta, A. H.; Weihs, W.; Zech, G.; Dagan, S.; Levy, A.; Zer-Zion, D.; Hasegawa, T.; Hazumi, M.; Ishii, T.; Kasai, S.; Kuze, M.; Nagasawa, Y.; Nakao, M.; Okuno, H.; Tokushuku, K.; Watanabe, T.; Yamada, S.; Chiba, M.; Hamatsu, R.; Hirose, T.; Kitamura, S.; Nagayama, S.; Nakamitsu, Y.; Cirio, R.; Costa, M.; Ferrero, M. I.; Lamberti, L.; Maselli, S.; Peroni, C.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Bandyopadhyay, D.; Benard, F.; Bhadra, S.; Brkic, M.; Burow, B. D.; Chlebana, F. S.; Crombie, M. B.; Hartner, G. F.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Prentice, J. D.; Sampson, C. R.; Stairs, G. G.; Teuscher, R. J.; Yoon, T.-S.; Bullock, F. W.; Catterall, C. D.; Giddings, J. C.; Jones, T. W.; Khan, A. M.; Lane, J. B.; Makkar, P. L.; Shaw, D.; Shulman, J.; Blankenship, K.; Gibaut, D. B.; Kochocki, J.; Lu, B.; Mo, L. W.; Charchum̵a, K.; Ciborowski, J.; Gajewski, J.; Grzelak, G.; Kasprzak, M.; Krzyżanowski, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Stopczyński, A.; Tymieniecka, T.; Walczak, R.; Wróblewski, A. K.; Zakrzewski, J. A.; Żarnecki, A. F.; Adamus, M.; Abramowicz, H.; Eisenberg, Y.; Glasman, C.; Karshon, U.; Montag, A.; Revel, D.; Shapira, A.; Foudas, C.; Fordham, C.; Loveless, R. J.; Goussiou, A.; Ali, I.; Behrens, B.; Dasu, S.; Reeder, D. D.; Smith, W. H.; Silverstein, S.; Frisken, W. R.; Furutani, K. M.; Iga, Y.; ZEUS Collaboration

1993-05-01

A sample of events with two distinct jets, in addition to the proton remnant, has been identified in deep inelastic, neutral current ep interactions recorded at HERA by the ZEUS experiment. For these events, the mass of the hadronic system ranges from 40 to 260 GeV. The salient features of the observed jet production agree with the predictions of higher order QCD.

CUSP-SHAPED STRUCTURE OF A JET OBSERVED BY IRIS AND SDO

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuzong; Zhang, Jun, E-mail: yuzong@nao.cas.cn, E-mail: zjun@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2017-01-01

On 2014 August 29, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 Å by the Interface Region Imaging Spectrograph . At first, two neighboring mini-prominences arose in turn from the low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences lead to the blowout, and then a cusp-shaped jet formed with a spire and an arch-base. In the spire, many brightening blobs originating from the junction between the spire and the arch-base moved upward in a rotating manner and then in a straight line in the late phase of the jet. In the arch-base, dark and bright material simultaneously tracked in a fan-like structure, and the majority of the material moved along the fan's threads. At the later phase of the jet's evolution, bidirectional flows emptied the arch-base, while downflows emptied the spire, thus making the jet entirely vanish. The extremely detailed observations in this study shed new light on how magnetic reconnection alters the inner topological structure of a jet and provides a beneficial complement for understanding current jet models.

Experimental simulation of satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds

OpenAIRE

Fullekrug, Martin; Hanuise, C; Parrot, M

2011-01-01

Relativistic electron beams above thunderclouds emit 100 kHz radio waves which illuminate the Earth's atmosphere and near-Earth space. This contribution aims to clarify the physical processes which are relevant for the spatial spreading of the radio wave energy below and above the ionosphere and thereby enables an experimental simulation of satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds. The simulation uses the DEMETER satellite which...

Modeling of the Enceladus water vapor jets for interpreting UVIS star and solar occultation observations

Science.gov (United States)

Portyankina, Ganna; Esposito, Larry W.; Aye, Klaus-Michael; Hansen, Candice J.

2015-11-01

One of the most spectacular discoveries of the Cassini mission is jets emitting from the southern pole of Saturn’s moon Enceladus. The composition of the jets is water vapor and salty ice grains with traces of organic compounds. Jets, merging into a wide plume at a distance, are observed by multiple instruments on Cassini. Recent observations of the visible dust plume by the Cassini Imaging Science Subsystem (ISS) identified as many as 98 jet sources located along “tiger stripes” [Porco et al. 2014]. There is a recent controversy on the question if some of these jets are “optical illusion” caused by geometrical overlap of continuous source eruptions along the “tiger stripes” in the field of view of ISS [Spitale et al. 2015]. The Cassini’s Ultraviolet Imaging Spectrograph (UVIS) observed occultations of several stars and the Sun by the water vapor plume of Enceladus. During the solar occultation separate collimated gas jets were detected inside the background plume [Hansen et al., 2006 and 2011]. These observations directly provide data about water vapor column densities along the line of sight of the UVIS instrument and could help distinguish between the presence of only localized or also continuous sources. We use Monte Carlo simulations and Direct Simulation Monte Carlo (DSMC) to model the plume of Enceladus with multiple (or continuous) jet sources. The models account for molecular collisions, gravitational and Coriolis forces. The models result in the 3-D distribution of water vapor density and surface deposition patterns. Comparison between the simulation results and column densities derived from UVIS observations provide constraints on the physical characteristics of the plume and jets. The specific geometry of the UVIS observations helps to estimate the production rates and velocity distribution of the water molecules emitted by the individual jets.Hansen, C. J. et al., Science 311:1422-1425 (2006); Hansen, C. J. et al, GRL 38:L11202 (2011

Blazar Variability from Turbulence in Jets Launched by Magnetically Arrested Accretion Flows

International Nuclear Information System (INIS)

Riordan, Michael O’; Pe’er, Asaf; McKinney, Jonathan C.

2017-01-01

Blazars show variability on timescales ranging from minutes to years, the former being comparable to and in some cases even shorter than the light-crossing time of the central black hole. The observed γ -ray light curves can be described by a power-law power density spectrum (PDS), with a similar index for both BL Lacs and flat-spectrum radio quasars. We show that this variability can be produced by turbulence in relativistic jets launched by magnetically arrested accretion flows (MADs). We perform radiative transport calculations on the turbulent, highly magnetized jet launching region of a MAD with a rapidly rotating supermassive black hole. The resulting synchrotron and synchrotron self-Compton emission, originating from close to the black hole horizon, is highly variable. This variability is characterized by PDS, which is remarkably similar to the observed power-law spectrum at frequencies less than a few per day. Furthermore, turbulence in the jet launching region naturally produces fluctuations in the plasma on scales much smaller than the horizon radius. We speculate that similar turbulent processes, operating in the jet at large radii (and therefore a high bulk Lorentz factor), are responsible for blazar variability over many decades in frequency, including on minute timescales.

Blazar Variability from Turbulence in Jets Launched by Magnetically Arrested Accretion Flows

Energy Technology Data Exchange (ETDEWEB)

Riordan, Michael O’; Pe’er, Asaf [Physics Department, University College Cork, Cork (Ireland); McKinney, Jonathan C., E-mail: michael_oriordan@umail.ucc.ie [Department of Physics and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

2017-07-10

Blazars show variability on timescales ranging from minutes to years, the former being comparable to and in some cases even shorter than the light-crossing time of the central black hole. The observed γ -ray light curves can be described by a power-law power density spectrum (PDS), with a similar index for both BL Lacs and flat-spectrum radio quasars. We show that this variability can be produced by turbulence in relativistic jets launched by magnetically arrested accretion flows (MADs). We perform radiative transport calculations on the turbulent, highly magnetized jet launching region of a MAD with a rapidly rotating supermassive black hole. The resulting synchrotron and synchrotron self-Compton emission, originating from close to the black hole horizon, is highly variable. This variability is characterized by PDS, which is remarkably similar to the observed power-law spectrum at frequencies less than a few per day. Furthermore, turbulence in the jet launching region naturally produces fluctuations in the plasma on scales much smaller than the horizon radius. We speculate that similar turbulent processes, operating in the jet at large radii (and therefore a high bulk Lorentz factor), are responsible for blazar variability over many decades in frequency, including on minute timescales.

Time dependent approach of TeV blazars based on a model of inhomogeneous stratified jet

International Nuclear Information System (INIS)

Boutelier, T.

2009-05-01

The study of the emission and variability mechanisms of TeV blazars has been the subject of intensive research for years. The homogeneous one-zone model commonly used is puzzling since it yields very high Lorentz factor, in contradiction with other observational evidences. In this work, I describe a new time dependent multi-zone approach, in the framework of the two-flow model. I compute the emission of a full jet, where relativistic electron-positron pairs distributed in pileup propagate. The evolution and the emission of the plasma is computed taking into account a turbulent heating term, some radiative cooling, and a pair production term due to photo-annihilation process. Applied to PKS 2155-304, the model allows the reproduction of the full spectra, as well as the simultaneous multi wavelength variability, with a relatively small Lorentz factor. The variability is explained by the instability of the pair creation process. Nonetheless, the value is still high to agree with other observational evidences in radio. Hence, I show in the last part of this work how to conciliate high Lorentz factor with the absence of apparent superluminal movement in radio, by taking into account the effect of the opening angle on the appearance of relativistic jets. (author)

CENTIMETER CONTINUUM OBSERVATIONS OF THE NORTHERN HEAD OF THE HH 80/81/80N JET: REVISING THE ACTUAL DIMENSIONS OF A PARSEC-SCALE JET

Energy Technology Data Exchange (ETDEWEB)

Masque, Josep M.; Estalella, Robert [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona, Catalunya (Spain); Girart, Josep M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico); Beltran, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

2012-10-10

We present 6 and 20 cm Jansky Very Large Array/Very Large Array observations of the northern head of the HH 80/81/80N jet, one of the largest collimated jet systems known so far, aimed to look for knots farther than HH 80N, the northern head of the jet. Aligned with the jet and 10' northeast of HH 80N, we found a radio source not reported before, with a negative spectral index similar to that of HH 80, HH 81, and HH 80N. The fit of a precessing jet model to the knots of the HH 80/81/80N jet, including the new source, shows that the position of this source is close to the jet path resulting from the modeling. If the new source belongs to the HH 80/81/80N jet, its derived size and dynamical age are 18.4 pc and >9 Multiplication-Sign 10{sup 3} yr, respectively. If the jet is symmetric, its southern lobe would expand beyond the cloud edge resulting in an asymmetric appearance of the jet. Based on the updated dynamical age, we speculate on the possibility that the HH 80/81/80N jet triggered the star formation observed in a dense core found ahead of HH 80N, which shows signposts of interaction with the jet. These results indicate that parsec-scale radio jets can play a role in the stability of dense clumps and the regulation of star formation in the molecular cloud.

Measurements of Relativistic Effects in Collective Thomson Scattering at Electron Temperatures less than 1 keV

Energy Technology Data Exchange (ETDEWEB)

Ross, James Steven [Univ. of California, San Diego, CA (United States)

2010-01-01

Simultaneous scattering from electron-plasma waves and ion-acoustic waves is used to measure local laser-produced plasma parameters with high spatiotemporal resolution including electron temperature and density, average charge state, plasma flow velocity, and ion temperature. In addition, the first measurements of relativistic modifications in the collective Thomson scattering spectrum from thermal electron-plasma fluctuations are presented [1]. Due to the high phase velocity of electron-plasma fluctuations, relativistic effects are important even at low electron temperatures (T_e < 1 keV). These effects have been observed experimentally and agree well with a relativistic treatment of the Thomson scattering form factor [2]. The results are important for the interpretation of scattering measurements from laser produced plasmas. Thomson scattering measurements are used to characterize the hydrodynamics of a gas jet plasma which is the foundation for a broad series of laser-plasma interaction studies [3, 4, 5, 6]. The temporal evolution of the electron temperature, density and ion temperature are measured. The measured electron density evolution shows excellent agreement with a simple adiabatic expansion model. The effects of high temperatures on coupling to hohlraum targets is discussed [7]. A peak electron temperature of 12 keV at a density of 4.7 × 10²⁰cm^-3 are measured 200 μm outside the laser entrance hole using a two-color Thomson scattering method we developed in gas jet plasmas [8]. These measurements are used to assess laser-plasma interactions that reduce laser hohlraum coupling and can significantly reduce the hohlraum radiation temperature.

Solar Coronal Jets: Observations, Theory, and Modeling

Science.gov (United States)

Raouafi, N. E.; Patsourakos, S.; Pariat, E.; Young, P. R.; Sterling, A.; Savcheva, A.; Shimojo, M.; Moreno-Insertis, F.; Devore, C. R.; Archontis, V.;

Tidal Control of Jet Eruptions on Enceladus as Observed by Cassini ISS between 2005 and 2007

Science.gov (United States)

Hurford, T. A.; Helfenstein, P.; Spitale, J. N.

2012-01-01

Observations of Enceladus have revealed active jets of material erupting from cracks on its south polar surface. It has previously been proposed that diurnal tidal stress, driven by Enceladus' orbital eccentricity, may actively produce surface movement along these cracks daily and thus may regulate when eruptions occur. Our analysis of the stress on jet source regions identified in Cassini ISS images reveals tidal stress as a plausible controlling mechanism of jet activity. However, the evidence available in the published and preliminary observations of jet activity between 2005 and 2007 may not be able to solidify the link between tidal stress and eruptions from fissures. Ongoing, far more comprehensive analyses based on recent, much higher resolution jetting observations have the potential to prove otherwise.

Gamma-Ray Burst Dynamics and Afterglow Radiation from Adaptive Mesh Refinement, Special Relativistic Hydrodynamic Simulations

Science.gov (United States)

De Colle, Fabio; Granot, Jonathan; López-Cámara, Diego; Ramirez-Ruiz, Enrico

2012-02-01

We report on the development of Mezcal-SRHD, a new adaptive mesh refinement, special relativistic hydrodynamics (SRHD) code, developed with the aim of studying the highly relativistic flows in gamma-ray burst sources. The SRHD equations are solved using finite-volume conservative solvers, with second-order interpolation in space and time. The correct implementation of the algorithms is verified by one-dimensional (1D) and multi-dimensional tests. The code is then applied to study the propagation of 1D spherical impulsive blast waves expanding in a stratified medium with ρvpropr -k , bridging between the relativistic and Newtonian phases (which are described by the Blandford-McKee and Sedov-Taylor self-similar solutions, respectively), as well as to a two-dimensional (2D) cylindrically symmetric impulsive jet propagating in a constant density medium. It is shown that the deceleration to nonrelativistic speeds in one dimension occurs on scales significantly larger than the Sedov length. This transition is further delayed with respect to the Sedov length as the degree of stratification of the ambient medium is increased. This result, together with the scaling of position, Lorentz factor, and the shock velocity as a function of time and shock radius, is explained here using a simple analytical model based on energy conservation. The method used for calculating the afterglow radiation by post-processing the results of the simulations is described in detail. The light curves computed using the results of 1D numerical simulations during the relativistic stage correctly reproduce those calculated assuming the self-similar Blandford-McKee solution for the evolution of the flow. The jet dynamics from our 2D simulations and the resulting afterglow light curves, including the jet break, are in good agreement with those presented in previous works. Finally, we show how the details of the dynamics critically depend on properly resolving the structure of the relativistic flow.

GAMMA-RAY BURST DYNAMICS AND AFTERGLOW RADIATION FROM ADAPTIVE MESH REFINEMENT, SPECIAL RELATIVISTIC HYDRODYNAMIC SIMULATIONS

International Nuclear Information System (INIS)

De Colle, Fabio; Ramirez-Ruiz, Enrico; Granot, Jonathan; López-Cámara, Diego

2012-01-01

We report on the development of Mezcal-SRHD, a new adaptive mesh refinement, special relativistic hydrodynamics (SRHD) code, developed with the aim of studying the highly relativistic flows in gamma-ray burst sources. The SRHD equations are solved using finite-volume conservative solvers, with second-order interpolation in space and time. The correct implementation of the algorithms is verified by one-dimensional (1D) and multi-dimensional tests. The code is then applied to study the propagation of 1D spherical impulsive blast waves expanding in a stratified medium with ρ∝r –k , bridging between the relativistic and Newtonian phases (which are described by the Blandford-McKee and Sedov-Taylor self-similar solutions, respectively), as well as to a two-dimensional (2D) cylindrically symmetric impulsive jet propagating in a constant density medium. It is shown that the deceleration to nonrelativistic speeds in one dimension occurs on scales significantly larger than the Sedov length. This transition is further delayed with respect to the Sedov length as the degree of stratification of the ambient medium is increased. This result, together with the scaling of position, Lorentz factor, and the shock velocity as a function of time and shock radius, is explained here using a simple analytical model based on energy conservation. The method used for calculating the afterglow radiation by post-processing the results of the simulations is described in detail. The light curves computed using the results of 1D numerical simulations during the relativistic stage correctly reproduce those calculated assuming the self-similar Blandford-McKee solution for the evolution of the flow. The jet dynamics from our 2D simulations and the resulting afterglow light curves, including the jet break, are in good agreement with those presented in previous works. Finally, we show how the details of the dynamics critically depend on properly resolving the structure of the relativistic flow.

GAMMA-RAY BURST DYNAMICS AND AFTERGLOW RADIATION FROM ADAPTIVE MESH REFINEMENT, SPECIAL RELATIVISTIC HYDRODYNAMIC SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

De Colle, Fabio; Ramirez-Ruiz, Enrico [Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064 (United States); Granot, Jonathan [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Lopez-Camara, Diego [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ap. 70-543, 04510 D.F. (Mexico)

2012-02-20

We report on the development of Mezcal-SRHD, a new adaptive mesh refinement, special relativistic hydrodynamics (SRHD) code, developed with the aim of studying the highly relativistic flows in gamma-ray burst sources. The SRHD equations are solved using finite-volume conservative solvers, with second-order interpolation in space and time. The correct implementation of the algorithms is verified by one-dimensional (1D) and multi-dimensional tests. The code is then applied to study the propagation of 1D spherical impulsive blast waves expanding in a stratified medium with {rho}{proportional_to}r{sup -k}, bridging between the relativistic and Newtonian phases (which are described by the Blandford-McKee and Sedov-Taylor self-similar solutions, respectively), as well as to a two-dimensional (2D) cylindrically symmetric impulsive jet propagating in a constant density medium. It is shown that the deceleration to nonrelativistic speeds in one dimension occurs on scales significantly larger than the Sedov length. This transition is further delayed with respect to the Sedov length as the degree of stratification of the ambient medium is increased. This result, together with the scaling of position, Lorentz factor, and the shock velocity as a function of time and shock radius, is explained here using a simple analytical model based on energy conservation. The method used for calculating the afterglow radiation by post-processing the results of the simulations is described in detail. The light curves computed using the results of 1D numerical simulations during the relativistic stage correctly reproduce those calculated assuming the self-similar Blandford-McKee solution for the evolution of the flow. The jet dynamics from our 2D simulations and the resulting afterglow light curves, including the jet break, are in good agreement with those presented in previous works. Finally, we show how the details of the dynamics critically depend on properly resolving the structure of the

Measurement of jet fragmentation in Pb+Pb and $pp$ collisions at $\\sqrt{s_{NN}} = 5.02$ TeV with the ATLAS detector

CERN Document Server

Aaboud, Morad; ATLAS Collaboration; Abbott, Brad; Abdinov, Ovsat; Abeloos, Baptiste; Abhayasinghe, Deshan Kavishka; Abidi, Syed Haider; Abouzeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adachi, Shunsuke; Adamczyk, Leszek; Adelman, Jahred; Adersberger, Michael; Adiguzel, Aytul; Adye, Tim; Affolder, Tony; Afik, Yoav; Agheorghiesei, Catalin; Aguilar Saavedra, Juan Antonio; Ahmadov, Faig; Aielli, Giulio; Akatsuka, Shunichi; Akesson, Torsten Paul Ake; Akilli, Ece; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albicocco, Pietro; Alconada Verzini, Maria Josefina; Alderweireldt, Sara Caroline; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexopoulos, Theodoros; Alhroob, Muhammad; Ali, Babar; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allaire, Corentin; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alshehri, Azzah Aziz; Alstaty, Mahmoud; Alvarez Gonzalez, Barbara; Alvarez Piqueras, Damian; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amaral Coutinho, Yara; Ambroz, Luca; Amelung, Christoph; Amidei, Dante Eric; Amor Dos Santos, Susana Patricia; Amoroso, Simone; Amrouche, Cherifa Sabrina; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anelli, Christopher Ryan; Angelidakis, Stylianos; Angelozzi, Ivan; Angerami, Aaron; Anisenkov, Alexey; Annovi, Alberto; Antel, Claire; Anthony, Matthew Thomas; Antonelli, Mario; Antrim, Daniel Joseph; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Araque Espinosa, Juan Pedro; Araujo Ferraz, Victor; Araujo Pereira, Rodrigo; Arce, Ayana; Ardell, Rose Elisabeth; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Armbruster, Aaron James; Armitage, Lewis James; Armstrong, Alexander Iii; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Asimakopoulou, Eleni Myrto; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkin, Ryan Justin; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Avramidou, Rachel Maria; Ayoub, Mohamad Kassem; Azuelos, Georges; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Bagnaia, Paolo; Bahmani, Marzieh; Baluch Bahrasemani, Sina; Bailey, Adam; Baines, John; Bajic, Milena; Bakalis, Christos; Baker, Keith; Bakker, Pepijn Johannes; Bakshi Gupta, Debottam; Baldin, Evgenii; Balek, Petr; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Bandyopadhyay, Anjishnu; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barbe, William Mickael; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisits, Martin-Stefan; Barkeloo, Jason Tylor Colt; Barklow, Timothy; Barlow, Nick; Barnea, Rotem; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Blenessy, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimaraes da Costa, Joao; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Bates, Richard; Batista, Santiago Juan; Batlamous, Souad; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bauer, Kevin Thomas; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Helge Christoph; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Maurice; Becot, Cyril; Beddall, Ayda; Beddall, Andrew; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beermann, Thomas Alfons; Begalli, Marcia; Begel, Michael; Behera, Arabinda; Behr, Katharina; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Bellos, Panagiotis; Belotskiy, Konstantin; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Bergsten, Laura Jean; Beringer, Juerg; Berlendis, Simon Paul; Bernard, Nathan Rogers; Bernardi, Gregorio; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertram, Iain Alexander; Besjes, Geert-jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Bethani, Agni; Bethke, Siegfried; Betti, Alessandra; Bevan, Adrian John; Beyer, Julien-christopher; Bianchi, Riccardo-Maria; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Bierwagen, Katharina; Biesuz, Nicolo Vladi; Biglietti, Michela; Billoud, Thomas Remy Victor; Bindi, Marcello; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Birman, Mattias; Bisanz, Tobias; Biswal, Jyoti Prakash; Bittrich, Carsten; Bjergaard, David Martin; Black, James; Black, Kevin; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blue, Andrew; Blumenschein, Ulrike; Blunier, Sylvain; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boerner, Daniela; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bokan, Petar; Bold, Tomasz; Boldyrev, Alexey; Bolz, Arthur Eugen; Bomben, Marco; Bona, Marcella; Bonilla, Johan Sebastian; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Bortfeldt, Jonathan; Bortoletto, Daniela; Bortolotto, Valerio; Boscherini, Davide; Bosman, Martine; Bossio Sola, Jonathan David; Bouaouda, Khalil; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozson, Adam James; Bracinik, Juraj; Brahimi, Nihal; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Braren, Frued; Bratzler, Uwe; Brau, Benjamin; Brau, James; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Brickwedde, Bernard; Briglin, Daniel Lawrence; Britton, Dave; Britzger, Daniel Andreas; Brock, Ian; Brock, Raymond; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brost, Elizabeth; Broughton, James; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruni, Alessia; Bruni, Graziano; Bruni, Lucrezia Stella; Bruno, Salvatore; Brunt, Benjamin Hylton; Bruschi, Marco; Bruscino, Nello; Bryant, Patrick; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Buehrer, Felix; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burch, Tyler James; Burdin, Sergey; Burgard, Carsten Daniel; Burger, Angela Maria; Burghgrave, Blake; Burka, Klaudia; Burke, Stephen; Burmeister, Ingo; Burr, Jonathan Thomas; Buescher, Daniel; Buescher, Volker; Buschmann, Eric; Bussey, Peter; Butler, John; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabras, Grazia; Cabrera Urban, Susana; Caforio, Davide; Cai, Huacheng; Cairo, Valentina Maria; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Callea, Giuseppe; Caloba, Luiz; Calvente Lopez, Sergio; Calvet, David; Calvet, Samuel; Calvet, Thomas Philippe; Calvetti, Milene; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Camincher, Clement; Campana, Simone; Campanelli, Mario; Camplani, Alessandra; Campoverde, Angel; Canale, Vincenzo; Cano Bret, Marc; Cantero, Josu; Cao, Tingting; Cao, Yumeng; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Carbone, Ryne Michael; Cardarelli, Roberto; Cardillo, Fabio; Carli, Ina; Carli, Tancredi; Carlino, Gianpaolo; Carlson, Benjamin Taylor; Carminati, Leonardo; Carney, Rebecca; Caron, Sascha; Carquin, Edson; Carra, Sonia; Carrillo Montoya, German David; Casadei, Diego; Casado, Maria Pilar; Casha, Albert Francis; Casolino, Mirkoantonio; Casper, David William; Castelijn, Remco; Castillo, Florencia Luciana; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavallaro, Emanuele; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Celebi, Emre; Ceradini, Filippo; Cerda Alberich, Leonor; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Stephen Kam-wah; Chan, Wing Sheung; Chan, Yat Long; Chapman, John Derek; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Che, Siinn; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Cheng; Chen, Chunhui; Chen, Hucheng; Chen, Jing; Chen, Jue; Chen, Shion; Chen, Shenjian; Chen, Xin; Chen, Ye; Chen, Yu-heng; Cheng, Hok Chuen; Cheng, Huajie; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Cheu, Elliott; Cheung, Kingman; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chitan, Adrian; Chiu, I-huan; Chiu, Yu Him Justin; Chizhov, Mihail; Choi, Kyungeon; Chomont, Arthur Rene; Chouridou, Sofia; Chow, Yun Sang; Christodoulou, Valentinos; Chu, Ming Chung; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Citterio, Mauro; Clark, Allan G; Clark, Michael Ryan; Clark, Philip James; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coimbra, Artur Cardoso; Colasurdo, Luca; Cole, Brian; Colijn, Auke-Pieter; Collot, Johann; Conde Muino, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Constantinescu, Serban; Conventi, Francesco; Cooper-Sarkar, Amanda; Cormier, Felix; Cormier, Kyle James Read; Corradi, Massimo; Corrigan, Eric Edward; Corriveau, Francois; Cortes-Gonzalez, Arely; Costa, Maria Jose; Costanzo, Davide; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Crane, Jonathan; Cranmer, Kyle; Crawley, Samuel Joseph; Creager, Rachael Ann; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cristinziani, Markus; Croft, Vincent; Crosetti, Giovanni; Cueto Gomez, Ana Rosario; Cuhadar Donszelmann, Tulay; Cukierman, Aviv Ruben; Cuth, Jakub; Czekierda, Sabina; Czodrowski, Patrick; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dado, Tomas; Dahbi, Salah-eddine; Dai, Tiesheng; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; D'amen, Gabriele; Damp, Johannes Frederic; Dandoy, Jeffrey Rogers; Daneri, Maria Florencia; Dang, Nguyen Phuong; Dann, Nicholas Stuart; Danninger, Matthias; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dartsi, Olympia; Dattagupta, Aparajita; Daubney, Thomas; D'Auria, Saverio; Davey, Will; David, Claire; Davidek, Tomas; Davis, Douglas; Dawe, Edmund; Dawson, Ian; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Beurs, Marcus; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Maria, Antonio; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vasconcelos Corga, Kevin; De Vivie De Regie, Jean-Baptiste; Debenedetti, Chiara; Dedovich, Dmitri; Dehghanian, Nooshin; Del Gaudio, Michela; Del Peso, Jose; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Della Pietra, Massimo; della Volpe, Domenico; Dell'Acqua, Andrea; Dell'Asta, Lidia; Delmastro, Marco; Delporte, Charles; Delsart, Pierre-Antoine; Demarco, David; Demers, Sarah; Demichev, Mikhail; Denisov, Sergey; Denysiuk, Denys; D'eramo, Louis; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Dette, Karola; Devesa, Maria Roberta; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Bello, Francesco Armando; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Clemente, William Kennedy; Di Donato, Camilla; Di Girolamo, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Petrillo, Karri Folan; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; De Almeida Dias, Flavia; Dias do vale, Tiago; Diaz, Marco Aurelio; Dickinson, Jennet; Diehl, Edward; Dietrich, Janet; Díez Cornell, Sergio; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dittus, Fido; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Dobre, Monica; Dodsworth, David; Doglioni, Caterina; Dolejsi, Jiri; Dolezal, Zdenek; Donadelli, Marisilvia; Donini, Julien; D'onofrio, Adelina; D'Onofrio, Monica; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dreyer, Etienne; Dreyer, Timo; Du, Yanyan; Duarte Campderros, Jorge; Dubinin, Filipp; Dubovsky, Michal; Dubreuil, Arnaud; Duchovni, Ehud; Duckeck, Guenter; Ducourthial, Audrey; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudder, Andreas Christian; Duffield, Emily Marie; Duflot, Laurent; Duehrssen, Michael; Dulsen, Carsten; Dumancic, Mirta; Dumitriu, Ana Elena; Duncan, Anna Kathryn; Dunford, Monica; Duperrin, Arnaud; Duran Yildiz, Hatice; Dueren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dutta, Baishali; Duvnjak, Damir; Dyndal, Mateusz; Dysch, Samuel; Dziedzic, Bartosz Sebastian; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; El Kosseifi, Rima; Ellajosyula, Venugopal; Ellert, Mattias; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Ennis, Joseph Stanford; Epland, Matthew Berg; Erdmann, Johannes; Ereditato, Antonio; Errede, Steven; Escalier, Marc; Escobar, Carlos; Estrada Pastor, Oscar; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Ezzi, Mohammed; Fabbri, Federica; Fabbri, Laura; Fabiani, Veronica; Facini, Gabriel John; Faisca Rodrigues Pereira, Rui Miguel; Fakhrutdinov, Rinat; Falciano, Speranza; Falke, Peter Johannes; Falke, Saskia; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farina, Edoardo Maria; Farooque, Trisha; FARRELL, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fawcett, William James; Fayard, Louis; Fedin, Oleg; Fedorko, Woiciech; Feickert, Matthew; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Minyu; Fenton, Michael James; Fenyuk, Alexander; Feremenga, Last; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Fiedler, Frank; Filipcic, Andrej; Filthaut, Frank; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Fischer, Cora; Fisher, Wade Cameron; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fletcher, Rob Roy Mac Gregor; Flick, Tobias; Flierl, Bernhard Matthias; Flores, Lucas Macrorie; Flores Castillo, Luis; Fomin, Nikolai; Forcolin, Giulio Tiziano; Formica, Andrea; Foerster, Fabian Alexander; Forti, Alessandra; Foster, Andrew Geoffrey; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; Fressard-Batraneanu, Silvia Maria; Freund, Benjamin; Spolidoro Freund, Werner; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fusayasu, Takahiro; Fuster, Juan; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz Pawel; Gadatsch, Stefan; Gadow, Paul Philipp; Gagliardi, Guido; Gagnon, Louis Guillaume; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram; Gamboa Goni, Rodrigo; Gan, KK; Ganguly, Sanmay; Gao, Yanyan; Gao, Yongsheng; García, Carmen; García Navarro, José Enrique; Garcia Pascual, Juan Antonio; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gasnikova, Ksenia; Gaudiello, Andrea; Gaudio, Gabriella; Gavrilenko, Igor; Gavrilyuk, Alexander; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Gee, Norman; Geisen, Jannik; Geisen, Marc; Geisler, Manuel Patrice; Gellerstedt, Karl; Gemme, Claudia; Genest, Marie-Helene; Geng, Cong; Gentile, Simonetta; Gentsos, Christos; George, Simon; Gerbaudo, Davide; Gessner, Gregor; Ghasemi, Sara; Ghasemi Bostanabad, Meisam; Ghneimat, Mazuza; Giacobbe, Benedetto; Giagu, Stefano; Giangiacomi, Nico; Giannetti, Paola; Giannini, Antonio; Gibson, Stephen; Gignac, Matthew; Gillberg, Dag Ingemar; Gilles, Geoffrey; Gingrich, Douglas; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giraud, Pierre-Francois; Giromini, Paolo; Giugliarelli, Gilberto; Giugni, Danilo; Giuli, Francesco; Giulini, Maddalena; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos; Gkountoumis, Panagiotis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian Maximilian Volker; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Goncalo, Ricardo; Goncalves Gama, Rafael; Gonella, Giulia; Gonella, Laura; Gongadze, Alexi; Gonnella, Francesco; Gonski, Julia Lynne; Gonzalez de la Hoz, Santiago; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorini, Benedetto; Gorini, Edoardo; Gorisek, Andrej; Goshaw, Alfred; Goessling, Claus; Gostkin, Mikhail Ivanovitch; Gottardo, Carlo Alberto; Goudet, Christophe Raymond; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Goy, Corinne; Gozani, Eitan; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Graham, Emily Charlotte; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gravila, Paul Mircea; Gray, Chloe; Gray, Heather; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Grevtsov, Kirill; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Groh, Sabrina; Gross, Eilam; Grosse-Knetter, Jorn; Grossi, Giulio Cornelio; Grout, Zara Jane; Grud, Christopher; Grummer, Aidan; Guan, Liang; Guan, Wen; Guenther, Jaroslav; Guerguichon, Antinea; Guescini, Francesco; Guest, Daniel; Gugel, Ralf; Gui, Bin; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Wen; Guo, Yicheng; Guo, Ziyu; Gupta, Ruchi; Gurbuz, Saime; Gustavino, Giuliano; Gutelman, Benjamin Jacque; Gutierrez, Phillip; Gutschow, Christian; Guyot, Claude; Guzik, Marcin Pawel; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Hadef, Asma; Hageboeck, Stephan; Hagihara, Mutsuto; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Han, Kunlin; Han, Liang; Han, Shuo; Hanagaki, Kazunori; Hance, Michael; Handl, David Michael; Haney, Bijan; Hankache, Robert; Hanke, Paul; Hansen, Eva; Hansen, Jorgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew Straiton; Harenberg, Torsten; Harkusha, Siarhei; Harrison, Paul Fraser; Hartmann, Nikolai Marcel; Hasegawa, Yoji; Hasib, Ahmed; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havener, Laura Brittany; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard; Hayden, Daniel; Hayes, Christopher; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Heath, Matthew Peter; Hedberg, Vincent; Heelan, Louise; Heer, Sebastian; Heidegger, Kim Katrin; Heilman, Jesse; Heim, Sarah; Heim, Timon Frank-thomas; Heinemann, Beate; Heinrich, Jochen Jens; Heinrich, Lukas; Heinz, Christian; Hejbal, Jiri; Helary, Louis; Held, Alexander; Hellesund, Simen; Hellman, Sten; Helsens, Clement; Henderson, Robert; Heng, Yang; Henkelmann, Steffen; Henriques Correia, Ana Maria; Herbert, Geoffrey Henry; Herde, Hannah; Herget, Verena; Hernandez Jimenez, Yesenia; Herr, Holger; Herrmann, Maximilian Georg; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Herwig, Theodor Christian; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Higashino, Satoshi; Higon-Rodriguez, Emilio; Hildebrand, Kevin; Hill, Ewan; Hill, John; Hill, Kurt Keys; Hiller, Karl Heinz; Hillier, Stephen; Hils, Maximilian; Hinchliffe, Ian; Hirose, Minoru; Hirschbuehl, Dominic; Hiti, Bojan; Hladik, Ondrej; Hlaluku, Dingane Reward; Hoad, Xanthe; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohn, David; Hohov, Dmytro; Holmes, Tova Ray; Holzbock, Michael; Homann, Michael; Honda, Shunsuke; Honda, Takuya; Hong, Tae Min; Honle, Andreas; Hooberman, Benjamin Henry; Hopkins, Walter Howard; Horii, Yasuyuki; Horn, Philipp; Horton, Arthur James; Horyn, Lesya Anna; Hostachy, Jean-Yves; Hostiuc, Alexandru; Hou, Suen; Hoummada, Abdeslam; Howarth, James; Hoya, Joaquin; Hrabovsky, Miroslav; Hrdinka, Julia; Hristova, Ivana; Hrivnac, Julius; Hrynevich, Aliaksei; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Qipeng; Hu, Shuyang; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huebner, Michael; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Huhtinen, Mika; Hunter, Robert Francis; Huo, Peng; Hupe, Andre Marc; Huseynov, Nazim; Huston, Joey; Huth, John; Hyneman, Rachel; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idrissi, Zineb; Iengo, Paolo; Ignazzi, Rosanna; Igonkina, Olga; Iguchi, Ryunosuke; Iizawa, Tomoya; Ikegami, Yoichi; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Iltzsche Speiser, Franziska; Introzzi, Gianluca; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Isacson, Max Fredrik; Ishijima, Naoki; Ishino, Masaya; Ishitsuka, Masaki; Islam, Wasikul; Issever, Cigdem; Istin, Serhat; Ito, Fumiaki; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivina, Anna; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jacka, Petr; Jackson, Paul; Jacobs, Ruth Magdalena; Jain, Vivek; Jakel, Gunnar; Jakobi, Katharina Bianca; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jamin, David Olivier; Jana, Dilip; Jansky, Roland; Janssen, Jens; Janus, Michel; Janus, Piotr Andrzej; Jarlskog, Goeran; Javadov, Namig; Javurek, Tomas; Javurkova, Martina; Jeanneau, Fabien; Jeanty, Laura; Jejelava, Juansher; Jelinskas, Adomas; Jenni, Peter; Jeong, Jihyun; Jezequel, Stephane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Hai; Jiang, Yi; Jiang, Zihao; Jiggins, Stephen; Jimenez Morales, Fabricio Andres; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Jivan, Harshna; Johansson, Per; Johns, Kenneth; Johnson, Christian; Johnson, William Joseph; Jon-And, Kerstin; Jones, Roger; Jones, Samuel David; Jones, Sarah; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Jovicevic, Jelena; Ju, Xiangyang; Junggeburth, Johannes Josef; Juste Rozas, Aurelio; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaji, Toshiaki; Kajomovitz, Enrique; Kalderon, Charles William; Kaluza, Adam; Kama, Sami; Kamenshchikov, Andrey; Kanjir, Luka; Kano, Yuya; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kar, Deepak; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karpov, Sergey; Karpova, Zoya; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kasahara, Kota; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katzy, Judith; Kawade, Kentaro; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kay, Ellis Fawn; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John Stakely; Kellermann, Edgar; Kempster, Jacob Julian; Kendrick, James Andrew; Kepka, Oldrich; Kersten, Susanne; Kersevan, Borut Paul; Keyes, Robert; Khader, Mazin; Khalil-zada, Farkhad; Khanov, Alexander; Kharlamov, Alexey; Kharlamova, Tatyana; Khodinov, Alexander; Khoo, Teng Jian; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kiehn, Moritz; Kilby, Callum Robert; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver; King, Barry; Kirchmeier, David; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kitali, Vincent; Kivernyk, Oleh; Kladiva, Eduard; Klapdor-kleingrothaus, Thorwald; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klingl, Tobias; Klioutchnikova, Tatiana; Klitzner, Felix Fidelio; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith B F G; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Koehler, Nicolas Maximilian; Koi, Tatsumi; Kolb, Mathis; Koletsou, Iro; Kondo, Takahiko; Kondrashova, Natalia; Koeneke, Karsten; Koenig, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinides, Vasilis; Konstantinidis, Nikolaos; Konya, Balazs; Kopeliansky, Revital; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Konstantinos; Korn, Andreas; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotwal, Ashutosh; Koulouris, Aimilianos; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kourlitis, Evangelos; Kouskoura, Vasiliki; Kowalewska, Anna Bozena; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozakai, Chihiro; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitrii; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Krauss, Dominik; Kremer, Jakub Andrzej; Kretzschmar, Jan; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Jiri; Kroll, Joe; Krstic, Jelena; Kruchonak, Uladzimir; Krueger, Hans; Krumnack, Nils; Kruse, Mark; Kubota, Takashi; Kuday, Sinan; Kuechler, Jan Thomas; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kulinich, Yakov Petrovich; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kupfer, Tobias; Kuprash, Oleg; Kurashige, Hisaya; Kurchaninov, Leonid; Kurochkin, Yurii; Kurth, Matthew Glenn; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; La Ruffa, Francesco; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lack, David Philip John; Lacker, Heiko; Lacour, Didier; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lammers, Sabine; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lanfermann, Marie Christine; Lang, Valerie Susanne; Lange, Joern Christian; Langenberg, Robert Johannes; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Lapertosa, Alessandro; Laplace, Sandrine; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Lau, Tak Shun; Laudrain, Antoine; Lavorgna, Marco; Law, Alexander Thomas; Laycock, Paul; Lazzaroni, Massimo; Le, Brian; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Quilleuc, Eloi Paul; Leblanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne; Lee, Claire Alexandra; Lee, Graham Richard; Lee JR, Lawrence; Lee, Shih-Chang; Lefebvre, Benoit; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehmann, Niklaus; Lehmann Miotto, Giovanna; Leight, William Axel; Leisos, Antonios; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Lerner, Giuseppe; Leroy, Claude; Les, Robert; Lesage, Arthur; Lester, Christopher; Levchenko, Mikhail; Leveque, Jessica; Levin, Daniel; Levinson, Lorne; Lewis, Dave; Li, Bing; Li, Changqiao; Li, Haifeng; Li, Liang; Li, Qi; Li, Quanyin; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liberti, Barbara; Liblong, Aaron; Lie, Ki; Liem Arvidsson, Sebastian; Limosani, Antonio; Lin, Chiao-ying; Lin, Kuan-yu; Lin, Tai-hua; Linck, Rebecca Anne; Lindquist, Brian Edward; Lionti, Anthony Eric; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lister, Alison; Litke, Alan; Little, Jared David; Liu, Bo; Liu, Bingxuan; Liu, Hongbin; Liu, Hao; Liu, Jianbei; Liu, Jesse Kar Kee; Liu, Kun; Liu, Minghui; Liu, Peilian; Liu, Yanwen; Liu, Yang; Liu, Yanlin; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo, Cheuk Yee; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Loesle, Alena; Loew, Kevin Michael; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan; Long, Robin Eamonn; Longo, Luigi; Looper, Kristina Anne; Lopez Lopez, Jorge Andres; Lopez Paz, Ivan; Lopez Solis, Alvaro; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Losel, Philipp Jonathan; Lou, Xuanhong; Lou, Xinchou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lozano Bahilo, Jose Julio; Lu, Haonan; Lu, Miaoran; Lu, Nan; Lu, Yun-Ju; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luedtke, Christian; Luehring, Fred; Luise, Ilaria; Lukas, Wolfgang; Luminari, Lamberto; Lund-Jensen, Bengt; Lutz, Margaret Susan; Luzi, Pierre Marc; Lynn, David; Lysak, Roman; Lytken, Else; Lyu, Feng; Lyubushkin, Vladimir; Ma, Hong; Ma, LianLiang; Ma, Yanhui; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Machado Miguens, Joana; Madaffari, Daniele; Madar, Romain; Mader, Wolfgang; Madsen, Alexander; Madysa, Nico; Maeda, Jumpei; Maekawa, Koki; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magerl, Veronika; Maidantchik, Carmen; Maier, Thomas; Maio, Amelia; Majersky, Oliver; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Claire; Maltezos, Stavros; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandic, Igor; Maneira, Jose; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mankinen, Katja Hannele; Mann, Alexander; Manousos, Athanasios; Mansoulie, Bruno; Mansour, Jason Dhia; Mantoani, Matteo; Manzoni, Stefano; Marceca, Gino; March Ruiz, Luis; Marchese, Luigi; Marchiori, Giovanni; Marcisovsky, Michal; Marin Tobon, Cesar Augusto; Marjanovic, Marija; Marley, Daniel Edison; Marroquim, Fernando; Marshall, Zach; Martensson, Ulf Fredrik Mikael; Marti i Garcia, Salvador; Martin, Christopher Blake; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez Perez, Mario; Martinez Outschoorn, Verena; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Mason, Lara Hannan; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Maettig, Peter; Maurer, Julien; Macek, Bostjan; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Maznas, Ioannis; Mazza, Simone Michele; Mc Fadden, Neil Christopher; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Tom; McClymont, Laurie Iain; McDonald, Emily; Mcfayden, Joshua Angus; Mchedlidze, Gvantsa; McKay, Madalyn Ann; McLean, Kayla Dawn; McMahon, Steve; Mcnamara, Peter Charles; Mcnicol, Christopher John; McPherson, Robert; Mdhluli, Joyful Elma; Meadows, Zachary Alden; Meehan, Samuel; Megy, Theo Jean; Mehlhase, Sascha; Mehta, Andrew; Meideck, Thomas; Meirose, Bernhard; Melini, Davide; Mellado Garcia, Bruce Rafael; Mellenthin, Johannes Donatus; Melo, Matej; Meloni, Federico; Melzer, Alexander; Menary, Stephen Burns; Mendes Gouveia, Emanuel Demetrio; Meng, Lingxin; Meng, Xiangting; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mergelmeyer, Sebastian; Merlassino, Claudia; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Christopher; Meyer, Jochen; Meyer, Jean-Pierre; Meyer Zu Theenhausen, Hanno; Miano, Fabrizio; Middleton, Robin; Mijovic, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuz, Marko; Milesi, Marco; Milic, Adriana; Millar, Declan Andrew; Miller, David; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Minegishi, Yuji; Ming, Yao; Mir, Lluisa-Maria; Mirto, Alessandro; Mistry, Khilesh Pradip; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mizukami, Atsushi; Mjoernmark, Jan-Ulf; Mkrtchyan, Tigran; Mlynarikova, Michaela; Moa, Torbjoern; Mochizuki, Kazuya; Mogg, Philipp; Mohapatra, Soumya; Molander, Simon; Moles-Valls, Regina; Mondragon, Matthew Craig; Moenig, Klaus; Monk, James; Monnier, Emmanuel; Montalbano, Alyssa; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llacer, Maria; Morettini, Paolo; Morgenstern, Marcus; Morgenstern, Stefanie; Mori, Daniel; Mori, Tatsuya; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, Alice Polyxeni; Morris, John; Morvaj, Ljiljana; Moschovakos, Paraschos; Mosidze, Maia; Moss, Harry James; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Moyse, Edward; Muanza, Steve; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey Andre; Munoz Sanchez, Francisca Javiela; Murin, Pavel; Murray, Bill; Murrone, Alessia; Muskinja, Miha; Mwewa, Chilufya; Myagkov, Alexey; Myers, John; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanjo, Hajime; Napolitano, Fabrizio; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naryshkin, Iouri; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Michael Edward; Nemecek, Stanislav; Nemethy, Peter; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Newman, Paul; Ng, Tsz Yu; Ng, Yan Wing; Nguyen, Hoang Dai Nghia; Nguyen Manh, Tuan; Nibigira, Emery; Nickerson, Richard; Nicolaidou, Rosy; Nielsen, Jason; Nikiforou, Nikiforos; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishu, Nishu; Nisius, Richard; Nitsche, Isabel; Nitta, Tatsumi; Nobe, Takuya; Noguchi, Yohei; Nomachi, Masaharu; Nomidis, Ioannis; Nomura, Marcelo Ayumu; Nooney, Tamsin; Nordberg, Markus; BIN NORJOHARUDDEEN, Nurfikri; Novak, Tadej; Novgorodova, Olga; Novotny, Radek; Nozka, Libor; Ntekas, Konstantinos; Nurse, Emily; Nuti, Francesco; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Abreu Juliao Ochoa De Castro, Maria Ines; Ochoa, Jean-pierre; O'Connor, Kelsey; Oda, Susumu; Odaka, Shigeru; Oerdek, Serhat; Oh, Alexander; Oh, Seog; Ohm, Christian; Oide, Hideyuki; Okawa, Hideki; Okazaki, Yuta; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Oleiro Seabra, Luis Filipe; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver, Jason Lea; Olsson, Mats Joakim Robert; Olszewski, Andrzej; Olszowska, Jolanta; O'Neil, Dugan; Onofre, Antonio; Onogi, Kouta; Onyisi, Peter; Oppen, Henrik; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orgill, Emily Claire; Orlando, Nicola; O'Rourke, Abigail Alexandra; Orr, Robert; Osculati, Bianca; O'Shea, Val; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacalt, Josef; Pacey, Holly Ann; Pachal, Katherine; Pacheco Pages, Andres; Pacheco Rodriguez, Laura; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganini, Michela; Palacino, Gabriel; Palazzo, Serena; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Panagoulias, Ilias; Pandini, Carlo Enrico; Panduro Vazquez, Jose Guillermo; Pani, Priscilla; Panizzo, Giancarlo; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Paredes Saenz, Santiago Rafael; Parida, Bibhuti; Parker, Adam Jackson; Parker, Kerry Ann; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pascuzzi, Vincent; Pasner, Jacob Martin; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Francesca; Pasuwan, Patrawan; Pataraia, Sophio; Pater, Joleen; Pathak, Atanu; Pauly, Thilo; Pearson, Benjamin; Pedersen, Maiken; Pedraza Diaz, Lucia; Costa Batalha Pedro, Rute; Peleganchuk, Sergey; Penc, Ondrej; Peng, Cong; Peng, Haiping; Sotto-Maior Peralva, Bernardo; Perego, Marta Maria; Pereira Peixoto, Ana Paula; Perepelitsa, Dennis; Peri, Francesco; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Reinhild; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrov, Mariyan; Petrucci, Fabrizio; Pettee, Mariel Nelson; Pettersson, Nora Emilia; Peyaud, Alan; Pezoa, Raquel; Pham, Thu; Phillips, Forrest Hays; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Pickering, Mark Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pinamonti, Michele; Pinfold, James; Pitt, Michael; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Pluth, Daniel; Podberezko, Pavel; Poettgen, Ruth; Poggi, Riccardo; Poggioli, Luc; Pogrebnyak, Ivan; Pohl, David-leon; Pokharel, Ishan; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Ponomarenko, Daniil; Pontecorvo, Ludovico; Popeneciu, Gabriel Alexandru; Portillo Quintero, Dilia Maria; Pospisil, Stanislav; Potamianos, Karolos Jozef; Potrap, Igor; Potter, Christina; Potti, Harish; Poulsen, Trine; Poveda, Joaquin; Powell, Thomas Dennis; Pozo Astigarraga, Mikel Eukeni; Pralavorio, Pascal; Prell, Soeren; Price, Darren; Primavera, Margherita; Prince, Sebastien; Proklova, Nadezda; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Puri, Akshat; Puzo, Patrick; Qian, Jianming; Qin, Yang; Quadt, Arnulf; Queitsch-maitland, Michaela; Qureshi, Anum; Rados, Petar Kevin; Ragusa, Francesco; Rahal, Ghita; Raine, John Andrew; Rajagopalan, Srinivasan; Rashid, Tasneem; Raspopov, Sergii; Ratti, Maria Giulia; Rauch, Daniel Mauricio; Rauscher, Felix; Rave, Stefan; Ravina, Baptiste; Ravinovich, Ilia; Rawling, Jacob Henry; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Reale, Marilea; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reed, Robert; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reiss, Andreas; Rembser, Christoph; Ren, Huan; Rescigno, Marco; Resconi, Silvia; Resseguie, Elodie Deborah; Rettie, Sebastien; Reynolds, Elliot; Rezanova, Olga; Reznicek, Pavel; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rimoldi, Marco; Rinaldi, Lorenzo; Ripellino, Giulia; Ristic, Branislav; Ritsch, Elmar; Riu, Imma; Rivera Vergara, Juan Cristobal; Rizatdinova, Flera; Rizvi, Eram; Rizzi, Chiara; Roberts, Rhys Thomas; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocco, Elena; Roda, Chiara; Rodina, Yulia; Rodriguez Bosca, Sergi; Rodriguez Perez, Andrea; Rodriguez Rodriguez, Daniel; Rodriguez Vera, Ana Maria; Roe, Shaun; Rogan, Christopher Sean; Rohne, Ole; Roehrig, Rainer; Roland, Christophe Pol A; Roloff, Jennifer Kathryn; Romaniouk, Anatoli; Romano, Marino; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosien, Nils-arne; Rossi, Elvira; Rossi, Leonardo Paolo; Rossini, Lorenzo; Rosten, Jonatan Hans; Rosten, Rachel; Rotaru, Marina; Rothberg, Joseph; Rousseau, David; Roy, Debarati; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Ruehr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Russell, Heather Lynn; Rutherfoord, John; Ruttinger, Elias Michael; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryu, Soo; Ryzhov, Andrey; Rzehorz, Gerhard Ferdinand; Sabatini, Paolo; Sabato, Gabriele; Sacerdoti, Sabrina; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saha, Puja; Sahinsoy, Merve; Sahu, Arunika; Saimpert, Matthias; Saito, Masahiko; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakharov, Alexander; Salamani, Dalila; Salamanna, Giuseppe; Salazar Loyola, Javier Esteban; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Samarati, Jerome; Sammel, Dirk; Sampsonidis, Dimitrios; Sampsonidou, Despoina; Sánchez, Javier; Sanchez Pineda, Arturo Rodolfo; Sandaker, Heidi; Sander, Christian Oliver; Sandhoff, Marisa; Sandoval Usme, Carlos; Sankey, Dave; Sannino, Mario; Sano, Yuta; Sansoni, Andrea; Santoni, Claudio; Santos, Helena; Santoyo Castillo, Itzebelt; Sapronov, Andrey; Saraiva, Joao; Sasaki, Osamu; Sato, Koji; Sauvan, Emmanuel; Savard, Pierre; Savic, Natascha; Sawada, Ryu; Sawyer, Craig; Sawyer, Lee; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Timothy Paul; Schaarschmidt, Jana; Schacht, Peter; Schachtner, Balthasar Maria; Schaefer, Douglas; Schaefer, Leigh; Schaeffer, Jan; Schaepe, Steffen; Schaefer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharmberg, Nicolas; Schegelsky, Valery; Scheirich, Daniel; Schenck, Ferdinand; Schernau, Michael; Schiavi, Carlo; Schier, Sheena; Schildgen, Lara Katharina; Schillaci, Zachary Michael; Schioppa, Enrico Junior; Schioppa, Marco; Schleicher, Katharina; Schlenker, Stefan; Schmidt-Sommerfeld, Korbinian Ralf; Schmieden, Kristof; Schmitt, Christian; Schmitt, Stefan; Schmitz, Simon; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schopf, Elisabeth; Schott, Matthias; Schouwenberg, Jeroen; Schovancova, Jaroslava; Schramm, Steven; Schulte, Alexandra; Schultz-Coulon, Hans-Christian; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Sciandra, Andrea; Sciolla, Gabriella; Scornajenghi, Matteo; Scuri, Fabrizio; Scutti, Federico; Scyboz, Ludovic Michel; Searcy, Jacob; Sebastiani, Cristiano David; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seiss, Todd; Seixas, Jose; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen Jacob; Semprini-Cesari, Nicola; Sen, Sourav; Senkin, Sergey; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Sessa, Marco; Severini, Horst; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shahinian, Jeffrey David; Shaikh, Nabila Wahab; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Sharma, Abhishek; Sharma, Abhishek; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shen, Yu-Ting; Sherafati, Nima; Sherman, Alexander David; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shipsey, Ian Peter Joseph; Shirabe, Shohei; Shiyakova, Mariya; Shlomi, Jonathan; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyed Ruhollah; Shope, David Richard; Shrestha, Suyog; Shulga, Evgeny; Sicho, Petr; Sickles, Anne Marie; Sidebo, Per Edvin; Sideras Haddad, Elias; Sidiropoulou, Ourania; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, Jose Manuel; Silva, Manuel Jr; Silva Oliveira, Marcos Vinicius; Silverstein, Samuel; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simon, Manuel; Simoniello, Rosa; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Siral, Ismet; Sivoklokov, Serguei; Sjoelin, Joergen; Skinner, Malcolm Bruce; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Slovak, Radim; Smakhtin, Vladimir; Smart, Ben; Smiesko, Juraj; Smirnov, Nikita; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Joshua Wyatt; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snyder, Ian Michael; Snyder, Scott; Sobie, Randall; Soffa, Aaron Michael; Soffer, Abner; Sogaard, Andreas; Su, Daxian; Sokhrannyi, Grygorii; Solans, Carlos; Solar, Michael; Soldatov, Evgeny; Soldevila- Serrano, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Son, Hyungsuk; Song, Weimin; Sopczak, Andre; Sopkova, Filomena; Sosa Corral, David Eduardo; Sotiropoulou, Calliope Louisa; Sottocornola, Simone; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin Charles; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spano, Francesco; Sperlich, Dennis; Spettel, Fabian; Spieker, Thomas Malte; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spiteri, Dwayne Patrick; Spousta, Martin; Stabile, Alberto; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanislaus, Beojan; Stanitzki, Marcel Michael; Stapf, Birgit Sylvia; Stapnes, Steinar; Starchenko, Evgeny; Stark, Giordon Holtsberg; Stark, Jan; Stark, Simon Holm; Staroba, Pavel; Starovoitov, Pavel; Staerz, Steffen; Staszewski, Rafal; Stegler, Martin; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Thomas James; Stewart, Graeme; Stockton, Mark; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara Kristina; Strauss, Michael; Strizenec, Pavol; Stroehmer, Raimund; Strom, David; Stroynowski, Ryszard; Struebig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Stupak, John; Styles, Nicholas Adam; Su, Dong; Su, Jun; Suchek, Stanislav; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultan, Dms; Sultanov, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Suruliz, Kerim; Suster, Carl; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian J; Swift, Stewart Patrick; Sydorenko, Alexander; Sykora, Ivan; Sykora, Tomas; Ta, Duc Bao; Tackmann, Kerstin; Kinghorn-taenzer, Joseph Peter; Taffard, Anyes; Tafirout, Reda; Tahirovic, Elvedin; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takasugi, Eric Hayato; Takeda, Kosuke; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tanaka, Junichi; Tanaka, Masahiro; Tanaka, Reisaburo; Tanioka, Ryo; Tannenwald, Benjamin Bordy; Tapia Araya, Sebastian; Tapprogge, Stefan; Tarek Abouelfadl Mohamed, Ahmed; Tarem, Shlomit; Tarna, Grigore; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Aaron; Taylor, Alan James; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Tee, Amy Selvi; Teixeira-Dias, Pedro; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Thais, Savannah Jennifer; Theveneaux-Pelzer, Timothee; Thiele, Fabian; Thomas, Juergen; Thompson, Stan; Thompson, Paul; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Tian, Yun; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorova-Nova, Sharka; Todt, Stefanie; Tojo, Junji; Tokar, Stanislav; Tokushuku, Katsuo; Tolley, Emma; Tomiwa, Kehinde Gbenga; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Baojia; Tornambe, Peter; Torrence, Eric; Torres, Heberth; Torro Pastor, Emma; Tosciri, Cecilia; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Treado, Colleen Jennifer; Trefzger, Thomas; Tresoldi, Fabio; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocme, Benjamin; Trofymov, Artur; Troncon, Clara; Trovatelli, Monica; Trovato, Fabrizio; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tsai, Fang-ying; Tseng, Jeffrey; Tsiareshka, Pavel; Tsirintanis, Nikolaos; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tu, Yanjun; Tudorache, Alexandra; Tudorache, Valentina; Tulbure, Traian Tiberiu; Tuna, Alexander Naip; Turchikhin, Semen; Turgeman, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tzovara, Eftychia; Ucchielli, Giulia; Ueda, Ikuo; Ughetto, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Uno, Kenta; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usui, Junya; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vadla, Knut Oddvar Hoie; Vaidya, Amal; Valderanis, Chrysostomos; Valdes Santurio, Eduardo; Valente, Marco; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Vallance, Robert Adam; Vallier, Alexis Roger Louis; Valls Ferrer, Juan Antonio; Van Daalen, Tal Roelof; Van Den Wollenberg, Wouter; van der Graaf, Harry; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vari, Riccardo; Varnes, Erich; Varni, Carlo; Varol, Tulin; Varouchas, Dimitris; Varvell, Kevin; Vasquez Arenas, Gerardo Alexis; Vasquez, Jared Gregory; Vazeille, Francois; Vazquez Furelos, David; Vazquez Schroeder, Tamara; Veatch, Jason; Vecchio, Valentina; Veloce, Laurelle Maria; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Vergel Infante, Carlos Miguel; Verkerke, Wouter; Vermeulen, Ambrosius Thomas; Vermeulen, Jos; Vetterli, Michel; Viaux Maira, Nicolas; Vicente Barreto Pinto, Mateus; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigani, Luigi; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vishwakarma, Akanksha; Vittori, Camilla; Vivarelli, Iacopo; Vlachos, Sotirios; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Von Buddenbrock, Stefan Erich; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Sfiligoj, Tina; Vuillermet, Raphael; Vukotic, Ilija; Zenis, Tibor; Zivkovic, Lidija; Wagner, Peter; Wagner, Wolfgang; Wagner-kuhr, Jeannine; Wahlberg, Hernan; Wahrmund, Sebastian; Wakamiya, Kotaro; Walbrecht, Verena Maria; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wallangen, Veronica; Wang, Ann Miao; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jin; Wang, Jike; Wang, Peilong; Wang, Qing; Wang, Renjie; Wang, Rongkun; Wang, Rui; Wang, Song-Ming; Wang, Wei; Wang, Wenxiao; Wang, Weitao; Wang, Yufeng; Wang, Zirui; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Aaron Foley; Webb, Samuel; Weber, Christian; Weber, Michele; Weber, Stephen Albert; Weber, Sebastian Mario; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weirich, Marcel; Weiser, Christian; Wells, Pippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Michael David; Werner, Per; Wessels, Martin; Weston, Thomas Daniel; Whalen, Kathleen; Whallon, Nikola Lazar; Wharton, Andrew Mark; White, Aaron; White, Andrew; White, Martin; White, Ryan; Whiteson, Daniel; Whitmore, Ben William; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wildauer, Andreas; Wilk, Fabian; Wilkens, Henric George; Wilkins, Lewis Joseph; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wingerter-Seez, Isabelle; Winkels, Emma; Winklmeier, Frank; Winston, Oliver James; Winter, Benedict Tobias; Wittgen, Matthias; Wobisch, Markus; Wolf, Anton; Wolf, Tim Michael Heinz; Wolff, Robert; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Vincent Wai Sum; Woods, Natasha Lee; Worm, Steven; Wosiek, Barbara; Wozniak, Krzysztof; Wraight, Kenneth; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xi, Zhaoxu; Xia, Ligang; Xu, Da; Xu, Hanlin; Xu, Lailin; Xu, Tairan; Xu, Wenhao; Yabsley, Bruce; Yacoob, Sahal; Yajima, Kazuki; Yallup, David Paul; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamanaka, Takashi; Yamane, Fumiya; Yamatani, Masahiro; Yamazaki, Tomohiro; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Siqi; Yang, Yi-lin; Yang, Zongchang; Yao, Weiming; Yap, Yee Chinn; Yasu, Yoshiji; Yatsenko, Elena; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yigitbasi, Efe; Yildirim, Eda; Yorita, Kohei; Yoshihara, Keisuke; Young, Christopher John; Young, Charles; Yu, Jaehoon; Yu, Jie; Yue, Xiaoguang; Yuen, Stephanie Pui Yan; Zabinski, Bartlomiej; Zacharis, George; Zaffaroni, Ettore; Zaidan, Remi; Zaitsev, Alexander; Zakharchuk, Nataliia; Zalieckas, Justas; Zambito, Stefano; Zanzi, Daniele; Zaripovas, Donatas Ramilas; Zeissner, Sonja Verena; Zeitnitz, Christian; Zemaityte, Gabija; Zeng, Jian Cong; Zeng, Qi; Zenin, Oleg; Zerwas, Dirk; Zgubic, Miha; Zhang, Dongliang; Zhang, Dengfeng; Zhang, Fangzhou; Zhang, Guangyi; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Liqing; Zhang, Matt; Zhang, Peng; Zhang, Ruiqi; Zhang, Rui; Zhang, Xueyao; Zhang, Yu; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhou, Bing; Zhou, Chen; Zhou, Li; Zhou, Maosen; Zhou, Mingliang; Zhou, Ning; Zhou, You; Zhu, Cheng Guang; Zhu, Heling; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zhulanov, Vladimir; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Zobernig, Georg; Zoccoli, Antonio; Zoch, Knut; Zorbas, Theodoros Georgio; Zou, Rui; zur Nedden, Martin; Zwalinski, Lukasz

2018-01-01

This paper presents a measurement of jet fragmentation functions in 0.49 nb$^{-1}$ of Pb+Pb collisions and 25 pb$^{-1}$ of $pp$ collisions at $\\sqrt{s_{NN}} = 5.02$ TeV collected in 2015 with the ATLAS detector at the LHC. These measurements provide insight into the jet quenching process in the quark--gluon plasma created in the aftermath of ultra-relativistic collisions between two nuclei. The modifications to the jet fragmentation functions are quantified by dividing the measurements in Pb+Pb collisions by baseline measurements in $pp$ collisions. This ratio is studied as a function of the transverse momentum of the jet, the jet rapidity, and the centrality of the collision. In both collision systems, the jet fragmentation functions are measured for jets with transverse momentum between 126 GeV and 398 GeV and with an absolute value of jet rapidity less than 2.1. An enhancement of particles carrying a small fraction of the jet momentum is observed, which increases with centrality and with increasing jet...

Jet studies in heavy ion collisions with the ATLAS detector

CERN Document Server

Slovak, Radim; The ATLAS collaboration

2016-01-01

In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. Jets are produced at the early stages of this collision and are known to become attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. ATLAS has provided a quantification of this jet suppression by the jet Raa measurement in run 1 of LHC. A factor of two suppression was seen in central heavy ion collisions with respect to pp collisions. The Raa exhibited only a week, if any, rapidity dependence, and a slow rise with increasing jet momentum. This talk summarizes the run 1 results on the inclusive jet production and the new results on dijet measurements.

Investigating the anatomy of magnetosheath jets - MMS observations

Science.gov (United States)

Karlsson, Tomas; Plaschke, Ferdinand; Hietala, Heli; Archer, Martin; Blanco-Cano, Xóchitl; Kajdič, Primož; Lindqvist, Per-Arne; Marklund, Göran; Gershman, Daniel J.

2018-04-01

We use Magnetosphere Multiscale (MMS) mission data to investigate a small number of magnetosheath jets, which are localized and transient increases in dynamic pressure, typically due to a combined increase in plasma velocity and density. For two approximately hour-long intervals in November, 2015 we found six jets, which are of two distinct types. (a) Two of the jets are associated with the magnetic field discontinuities at the boundary between the quasi-parallel and quasi-perpendicular magnetosheath. Straddling the boundary, the leading part of these jets contains an ion population similar to the quasi-parallel magnetosheath, while the trailing part contains ion populations similar to the quasi-perpendicular magnetosheath. Both populations are, however, cooler than the surrounding ion populations. These two jets also have clear increases in plasma density and magnetic field strength, correlated with a velocity increase. (b) Three of the jets are found embedded within the quasi-parallel magnetosheath. They contain ion populations similar to the surrounding quasi-parallel magnetosheath, but with a lower temperature. Out of these three jets, two have a simple structure. For these two jets, the increases in density and magnetic field strength are correlated with the dynamic pressure increases. The other jet has a more complicated structure, and no clear correlations between density, magnetic field strength and dynamic pressure. This jet has likely interacted with the magnetosphere, and contains ions similar to the jets inside the quasi-parallel magnetosheath, but shows signs of adiabatic heating. All jets are associated with emissions of whistler, lower hybrid, and broadband electrostatic waves, as well as approximately 10 s period electromagnetic waves with a compressional component. The latter have a Poynting flux of up to 40 µW m-2 and may be energetically important for the evolution of the jets, depending on the wave excitation mechanism. Only one of the jets is

Analysis of JET LCHD/ICRH synergy experiments in terms of relativistic current drive theory

Energy Technology Data Exchange (ETDEWEB)

Start, D F.H.; Baranov, Y; Brusati, M; Ekedahl, A; Froissard, P; Gormezano, C; Jacquinot, J; Paquin, L; Rimini, F G [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Cox, M; Gardner, C; O` Brien, M R [UKAEA Culham Lab., Abingdon (United Kingdom); Di Vita, A [Ansaldo SpA, Genoa (Italy)

1994-07-01

The present analysis shows that the observed efficiency of current drive with synergy between LHCD and ICRH is in good agreement with the relativistic theory of Karney and Fisch for Landau damped waves. The predicted power absorption from the fast wave by the electron tail is within 30% of the measured value. In the presence of significant fast electron diffusion within a slowing down time it would be possible to produce central current drive using multiple ICRF resonances even when the LHCD deposition is at half radius, as in an ITER type device. (authors). 4 refs., 6 figs.

Analysis of JET LCHD/ICRH synergy experiments in terms of relativistic current drive theory

International Nuclear Information System (INIS)

Start, D.F.H.; Baranov, Y.; Brusati, M.; Ekedahl, A.; Froissard, P.; Gormezano, C.; Jacquinot, J.; Paquin, L.; Rimini, F.G.; Di Vita, A.

1994-01-01

The present analysis shows that the observed efficiency of current drive with synergy between LHCD and ICRH is in good agreement with the relativistic theory of Karney and Fisch for Landau damped waves. The predicted power absorption from the fast wave by the electron tail is within 30% of the measured value. In the presence of significant fast electron diffusion within a slowing down time it would be possible to produce central current drive using multiple ICRF resonances even when the LHCD deposition is at half radius, as in an ITER type device. (authors). 4 refs., 6 figs

Jet suppression and the flavor dependence of partonic energy loss with ATLAS

Energy Technology Data Exchange (ETDEWEB)

Kosek, Tomas

2016-12-15

In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. One manifestation of the energy loss of jets propagating through the medium is a lower yield of jets and hadrons emerging from this medium than expected in the absence of medium effects. Therefore modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. In this publication, the latest ATLAS results on single hadron suppression along with the complementary measurements of single jet suppression are presented. Rapidity dependence, which is sensitive to the relative energy loss between quark and gluon jets, is discussed. Finally, a new measurement of jet fragmentation functions is presented.

A wide and collimated radio jet in 3C84 on the scale of a few hundred gravitational radii

Science.gov (United States)

Giovannini, G.; Savolainen, T.; Orienti, M.; Nakamura, M.; Nagai, H.; Kino, M.; Giroletti, M.; Hada, K.; Bruni, G.; Kovalev, Y. Y.; Anderson, J. M.; D'Ammando, F.; Hodgson, J.; Honma, M.; Krichbaum, T. P.; Lee, S.-S.; Lico, R.; Lisakov, M. M.; Lobanov, A. P.; Petrov, L.; Sohn, B. W.; Sokolovsky, K. V.; Voitsik, P. A.; Zensus, J. A.; Tingay, S.

2018-04-01

Understanding the formation of relativistic jets in active galactic nuclei remains an elusive problem1. This is partly because observational tests of jet formation models suffer from the limited angular resolution of ground-based very-long-baseline interferometry that has thus far been able to probe the structure of the jet acceleration and collimation region in only two sources2,3. Here, we report observations of 3C84 (NGC 1275)—the central galaxy of the Perseus cluster—made with an interferometric array including the orbiting radio telescope of the RadioAstron4 mission. The data transversely resolve the edge-brightened jet in 3C84 only 30 μas from the core, which is ten times closer to the central engine than was possible in previous ground-based observations5 and allows us to measure the jet collimation profile from 102 to 104 gravitational radii (rg) from the black hole. The previously found5, almost cylindrical jet profile on scales larger than a few thousand rg is seen to continue at least down to a few hundred rg from the black hole, and we find a broad jet with a transverse radius of ≳250 rg at only 350 rg from the core. This implies that either the bright outer jet layer goes through a very rapid lateral expansion on scales ≲102 rg or it is launched from the accretion disk.

3D relativistic MHD numerical simulations of X-shaped radio sources

Science.gov (United States)

Rossi, P.; Bodo, G.; Capetti, A.; Massaglia, S.

2017-10-01

Context. A significant fraction of extended radio sources presents a peculiar X-shaped radio morphology: in addition to the classical double lobed structure, radio emission is also observed along a second axis of symmetry in the form of diffuse wings or tails. In a previous investigation we showed the existence of a connection between the radio morphology and the properties of the host galaxies. Motivated by this connection we performed two-dimensional numerical simulations showing that X-shaped radio sources may naturally form as a jet propagates along the major axis a highly elliptical density distribution, because of the fast expansion of the cocoon along the minor axis of the distribution. Aims: We intend to extend our analysis by performing three-dimensional numerical simulations and investigating the role of different parameters in determining the formation of the X-shaped morphology. Methods: The problem is addressed by numerical means, carrying out three-dimensional relativistic magnetohydrodynamic simulations of bidirectional jets propagating in a triaxial density distribution. Results: We show that only jets with power ≲ 1044 erg s-1 can give origin to an X-shaped morphology and that a misalignment of 30° between the jet axis and the major axis of the density distribution is still favourable to the formation of this kind of morphology. In addition we compute synthetic radio emission maps and polarization maps. Conclusions: In our scenario for the formation of X-shaped radio sources only low power FRII can give origin to such kind of morphology. Our synthetic emission maps show that the different observed morphologies of X-shaped sources can be the result of similar structures viewed under different perspectives.

HOMOLOGOUS HELICAL JETS: OBSERVATIONS BY IRIS, SDO, AND HINODE AND MAGNETIC MODELING WITH DATA-DRIVEN SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Cheung, Mark C. M.; Pontieu, B. De; Tarbell, T. D.; Fu, Y.; Martínez-Sykora, J.; Boerner, P.; Wülser, J. P.; Lemen, J.; Title, A. M.; Hurlburt, N. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street Bldg. 252, Palo Alto, CA 94304 (United States); Tian, H.; Testa, P.; Reeves, K. K.; Golub, L.; McKillop, S.; Saar, S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kleint, L. [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstr. 6, 5210 Windisch (Switzerland); Kankelborg, C.; Jaeggli, S. [Department of Physics, Montana State University, Bozeman, P.O. Box 173840, Bozeman, MT 59717 (United States); Carlsson, M., E-mail: cheung@lmsal.com [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway); and others

2015-03-10

We report on observations of recurrent jets by instruments on board the Interface Region Imaging Spectrograph, Solar Dynamics Observatory (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21, recurrent coronal jets were observed to emanate from NOAA Active Region 11793. Far-ultraviolet spectra probing plasma at transition region temperatures show evidence of oppositely directed flows with components reaching Doppler velocities of ±100 km s{sup −1}. Raster Doppler maps using a Si iv transition region line show all four jets to have helical motion of the same sense. Simultaneous observations of the region by SDO and Hinode show that the jets emanate from a source region comprising a pore embedded in the interior of a supergranule. The parasitic pore has opposite polarity flux compared to the surrounding network field. This leads to a spine-fan magnetic topology in the coronal field that is amenable to jet formation. Time-dependent data-driven simulations are used to investigate the underlying drivers for the jets. These numerical experiments show that the emergence of current-carrying magnetic field in the vicinity of the pore supplies the magnetic twist needed for recurrent helical jet formation.

Towards relativistic quantum geometry

Energy Technology Data Exchange (ETDEWEB)

Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)

2015-12-17

We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.

Beam-beam observations in the Relativistic Heavy Ion Collider

Energy Technology Data Exchange (ETDEWEB)

Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

2015-06-24

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

Magnetohydrodynamic Kelvin-Helmholtz instabilities in astrophysics. 1. Relativistic flows-plane boundary layer in vortex sheet approximation

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Trussoni, E; Zaninetti, L [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica)

1980-11-01

In this paper some unsolved problems of the linear MHD Kelvin-Helmholtz instability are re-examined, starting from the analysis of relativistic (and non-relativistic) flows in the approximation of a plane vortex sheet, for the contact layer between the fluids in relative motion. Results are discussed for a range of physical parameters in specific connection with application to models of jets in extragalactic radio sources. Other physical aspects of the instability will be considered in forthcoming papers.

Searching for Jet Emission in LMXBs: A Polarimetric View

Directory of Open Access Journals (Sweden)

Maria Cristina Baglio

2017-10-01

Full Text Available We present results taken from a study aiming at detecting the emission from relativistic particles jets in neutron star-low mass X-ray binaries using optical polarimetric observations. First, we focus on a polarimetric study performed on the persistent LMXB 4U 0614+091. Once corrected for interstellar effects, we measured an intrinsic linear polarization in the r-band of ~3% at a 3σ confidence level. This is in-line with the observation of an infrared excess in the spectral energy distribution (SED of the source, reported in a previous work, which the authors linked to the optically thin synchrotron emission of a jet. We then present a study performed on the transitional millisecond pulsar PSR J1023+0038 during quiescence. We measured a linear polarization of 1.09 ± 0.27% and 0.90 ± 0.17% in the V and R bands, respectively. The phase-resolved polarimetric curve of the source in the R-band reveals a hint of a sinusoidal modulation at the source orbital period. The NIR -optical SED of the system did not suggest the presence of a jet. We conclude that the optical linear polarization observed for PSR J1023+0038 is possibly due to Thomson scattering with electrons in the disc, as also suggested by the hint of the modulation of the R-band linear polarization at the system orbital period.

Studies of Jet Quenching in PbPb collisions at CMS

CERN Document Server

Nguyen, Matthew

2012-01-01

Jets are an important tool to probe the hot, dense medium produced in ultra-relativistic heavy-ion collisions. At the collision energies available at the Large Hadron Collider (LHC), there is copious production of hard processes, such that high p_T jets may be differentiated from the heavy-ion underlying event. The multipurpose Compact Muon Solenoid (CMS) detector is well designed to measure hard scattering processes with its high quality calorimeters and high precision silicon tracker. Jet quenching has been studied in CMS in PbPb collisions at sqrt(s_NN)= 2.76 TeV. As a function of centrality, dijet events with a high p_T leading jet were found to have an increasing momentum imbalance that was significantly larger than predicted by simulations. The angular distribution of jet fragmentation products has been explored by associating charged tracks with the jets measured in the calorimeters. By projecting the momenta of charged tracks onto the leading jet axis it is shown that the apparent momentum imbalance o...

Segmentation and fragmentation of melt jets due to generation of large-scale structures. Observation in low subcooling conditions

International Nuclear Information System (INIS)

Sugiyama, Ken-ichiro; Yamada, Tsuyoshi

1999-01-01

In order to clarify a mechanism of melt-jet breakup and fragmentation entirely different from the mechanism of stripping, a series of experiments were carried out by using molten tin jets of 100 grams with initial temperatures from 250degC to 900degC. Molten tin jets with a small kinematic viscosity and a large thermal diffusivity were used to observe breakup and fragmentation of melt jets enhanced thermally and hydrodynamically. We observed jet columns with second-stage large-scale structures generated by the coalescence of large-scale structures recognized in the field of fluid mechanics. At a greater depth, the segmentation of jet columns between second-stage large-scale structures and the fragmentation of the segmented jet columns were observed. It is reasonable to consider that the segmentation and the fragmentation of jet columns are caused by the boiling of water hydrodynamically entrained within second-stage large-scale structures. (author)

The energy distribution of electrons in radio jets

Science.gov (United States)

Tsouros, Alexandros; Kylafis, Nikolaos D.

2017-07-01

Context. Black-hole and neutron-star X-ray binaries exhibit compact radio jets, when they are in the so called quiescent, hard, or hard intermediate states. The radio spectrum in these states is flat to slightly inverted, I.e., the spectral index of the observed flux density is in the range 0 ≲ α ≲ 0.5. It is widely accepted that the energy distribution of the electrons, in the rest frame of the jet, is a power law with index in the range 3 ≲ p ≲ 5. Aims: Contrary to what our thinking was decades ago, now we know that the jets originate in the hot, inner flow around black holes and neutron stars. So it is worth investigating the radio spectrum that is emitted by a thermal jet as a function of direction. Methods: As an example, we consider a parabolic jet and, with the assumption of flux freezing, we compute the emitted spectrum in all directions, from radio to near infrared, using either a thermal distribution of electrons or a power-law one. Results: We have found that parabolic jets with a thermal distribution of electrons give also flat to slightly inverted spectra. In particular, for directions along the jet (θ = 0), both distributions of electron energies give α = 0 ± 0.01. The index α increases as the viewing angle θ increases and for directions perpendicular to the jet (θ = π/ 2), the thermal distribution gives α = 0.40 ± 0.05, while the power-law distribution gives α = 0.20 ± 0.05. The break frequency νb, which marks the transition from partially optically thick to optically thin synchrotron emission, is comparable for the power-law and the thermal distributions. Conclusions: Contrary to common belief, it is not necessary to invoke a power-law energy distribution of the electrons in a jet to explain its flat to slightly inverted radio spectrum. A relativistic Maxwellian produces similar radio spectra. Thus, the jet may be the widely invoked "corona" around black holes in X-ray binaries.

A Reconnection Switch to Trigger gamma-Ray Burst Jet Dissipation

Energy Technology Data Exchange (ETDEWEB)

McKinney, Jonathan C.; Uzdensky, Dmitri A.

2012-03-14

Prompt gamma-ray burst (GRB) emission requires some mechanism to dissipate an ultrarelativistic jet. Internal shocks or some form of electromagnetic dissipation are candidate mechanisms. Any mechanism needs to answer basic questions, such as what is the origin of variability, what radius does dissipation occur at, and how does efficient prompt emission occur. These mechanisms also need to be consistent with how ultrarelativistic jets form and stay baryon pure despite turbulence and electromagnetic reconnection near the compact object and despite stellar entrainment within the collapsar model. We use the latest magnetohydrodynamical models of ultrarelativistic jets to explore some of these questions in the context of electromagnetic dissipation due to the slow collisional and fast collisionless reconnection mechanisms, as often associated with Sweet-Parker and Petschek reconnection, respectively. For a highly magnetized ultrarelativistic jet and typical collapsar parameters, we find that significant electromagnetic dissipation may be avoided until it proceeds catastrophically near the jet photosphere at large radii (r {approx} 10{sup 13}-10{sup 14}cm), by which the jet obtains a high Lorentz factor ({gamma} {approx} 100-1000), has a luminosity of L{sub j} {approx} 10{sup 50}-10{sup 51} erg s{sup -1}, has observer variability timescales of order 1s (ranging from 0.001-10s), achieves {gamma}{theta}{sub j} {approx} 10-20 (for opening half-angle {theta}{sub j}) and so is able to produce jet breaks, and has comparable energy available for both prompt and afterglow emission. A range of model parameters are investigated and simplified scaling laws are derived. This reconnection switch mechanism allows for highly efficient conversion of electromagnetic energy into prompt emission and associates the observed prompt GRB pulse temporal structure with dissipation timescales of some number of reconnecting current sheets embedded in the jet. We hope this work helps motivate the

The Shock Dynamics of Heterogeneous YSO Jets: 3D Simulations Meet Multi-epoch Observations

Energy Technology Data Exchange (ETDEWEB)

Hansen, E. C.; Frank, A. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Lebedev, S. V. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom)

2017-03-10

High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of these bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a “frothy” emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in H α and [S ii]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig–Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.

Uncovering Nature’s 100 TeV Particle Accelerators in the Large-Scale Jets of Quasars

Science.gov (United States)

Georganopoulos, Markos; Meyer, Eileen; Sparks, William B.; Perlman, Eric S.; Van Der Marel, Roeland P.; Anderson, Jay; Sohn, S. Tony; Biretta, John A.; Norman, Colin Arthur; Chiaberge, Marco

2016-04-01

Since the first jet X-ray detections sixteen years ago the adopted paradigm for the X-ray emission has been the IC/CMB model that requires highly relativistic (Lorentz factors of 10-20), extremely powerful (sometimes super-Eddington) kpc scale jets. R I will discuss recently obtained strong evidence, from two different avenues, IR to optical polarimetry for PKS 1136-135 and gamma-ray observations for 3C 273 and PKS 0637-752, ruling out the EC/CMB model. Our work constrains the jet Lorentz factors to less than ~few, and leaves as the only reasonable alternative synchrotron emission from ~100 TeV jet electrons, accelerated hundreds of kpc away from the central engine. This refutes over a decade of work on the jet X-ray emission mechanism and overall energetics and, if confirmed in more sources, it will constitute a paradigm shift in our understanding of powerful large scale jets and their role in the universe. Two important findings emerging from our work will also discussed be: (i) the solid angle-integrated luminosity of the large scale jet is comparable to that of the jet core, contrary to the current belief that the core is the dominant jet radiative outlet and (ii) the large scale jets are the main source of TeV photon in the universe, something potentially important, as TeV photons have been suggested to heat up the intergalactic medium and reduce the number of dwarf galaxies formed.

Contraint's theory and relativistic dynamics

International Nuclear Information System (INIS)

Longhi, G.; Lusanna, L.

1987-01-01

The purpose of this Workshop was to examine the current situation of relativistic dynamics. In particular, Dirac-Bergmann's theory of constraints, which lies at the heart of gauge theories, general relativity, relativistic mechanics and string theories, was chosen as the unifying theoretical framework best suited to investigate such a field. The papers discussed were on general relativity; relativistic mechanics; particle physics and mathematical physics. Also discussed were the problems of classical and quantum level, namely the identification of the classical observables of constrained systems, the equivalence of the nonequivalence of the various ways to quantize such systems; the problem of the anomalies; the best geometrical approach to the theory of constraints; the possibility of unifying all the treatments of relativistic mechanics. This book compiles the papers presented at proceedings of relativistic dynamics and constraints theory

VERY LARGE ARRAY OBSERVATIONS OF DG TAU'S RADIO JET: A HIGHLY COLLIMATED THERMAL OUTFLOW

Energy Technology Data Exchange (ETDEWEB)

Lynch, C.; Mutel, R. L.; Gayley, K. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52240 (United States); Guedel, M. [Department of Astrophysics, University of Vienna, A-1180 Vienna (Austria); Ray, T. [Astronomy and Astrophysics Section, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Skinner, S. L. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Schneider, P. C. [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany)

2013-03-20

The active young protostar DG Tau has an extended jet that has been well studied at radio, optical, and X-ray wavelengths. We report sensitive new Very Large Array (VLA) full-polarization observations of the core and jet between 5 GHz and 8 GHz. Our high angular resolution observation at 8 GHz clearly shows an unpolarized inner jet with a size of 42 AU (0.''35) extending along a position angle similar to the optical-X ray outer jet. Using our nearly coeval 2012 VLA observations, we find a spectral index {alpha} = +0.46 {+-} 0.05, which combined with the lack of polarization is consistent with bremsstrahlung (free-free) emission, with no evidence for a non-thermal coronal component. By identifying the end of the radio jet as the optical depth unity surface, and calculating the resulting emission measure, we find that our radio results are in agreement with previous optical line studies of electron density and consequent mass-loss rate. We also detect a weak radio knot at 5 GHz located 7'' from the base of the jet, coincident with the inner radio knot detected by Rodriguez et al. in 2009 but at lower surface brightness. We interpret this as due to expansion of post-shock ionized gas in the three years between observations.

MMS Observations of Protons and Heavy Ions Acceleration at Plasma Jet Fronts

Science.gov (United States)

Catapano, F.; Retino, A.; Zimbardo, G.; Cozzani, G.; Breuillard, H.; Le Contel, O.; Alexandrova, A.; Mirioni, L.; Cohen, I. J.; Turner, D. L.; Perri, S.; Greco, A.; Mauk, B.; Torbert, R. B.; Russell, C. T.; Khotyaintsev, Y. V.; Lindqvist, P. A.; Ergun, R.; Giles, B. L.; Fuselier, S. A.; Moore, T. E.; Burch, J.

2017-12-01

Plasma jet fronts in the Earth's magnetotail are kinetic-scale boundaries separating hot fast plasma jets, generally attributed to reconnection outflows, from colder ambient plasma. Jet fronts are typically associated with a sharp increase of the vertical component of the magnetic field Bz, an increase of the plasma temperature and a drop of plasma density. Spacecraft observations and numerical simulations indicate that jet fronts are sites of major ion acceleration. The exact acceleration mechanisms as well as the dependence of such mechanisms on ion composition are not fully understood, yet. Recent high-resolution measurements of ion distribution functions in the magnetotail allow for the first time to study the acceleration mechanisms in detail. Here, we show several examples of jet fronts and discuss ion acceleration therein. We show fronts that propagate in the mid-tail magnetotail both as isolated laminar boundaries and as multiple boundaries embedded in strong magnetic fluctuations and turbulence. We also show fronts in the near-Earth jet braking region, where they interact with the dipolar magnetic field and are significantly decelerated/diverted. Finally, we study the acceleration of different ion species (H+, He++, O+) at different types of fronts and we discuss possible different acceleration mechanisms and how they depend on the ion species.

Rarefaction acceleration of ultrarelativistic magnetized jets in gamma-ray burst sources

Science.gov (United States)

Komissarov, Serguei S.; Vlahakis, Nektarios; Königl, Arieh

2010-09-01

When a magnetically dominated superfast-magnetosonic long/soft gamma-ray burst (GRB) jet leaves the progenitor star, the external pressure support will drop and the jet may enter the regime of ballistic expansion, during which additional magnetic acceleration becomes ineffective. However, recent numerical simulations by Tchekhovskoy et al. have suggested that the transition to this regime is accompanied by a spurt of acceleration. We confirm this finding numerically and attribute the acceleration to a sideways expansion of the jet, associated with a strong magnetosonic rarefaction wave that is driven into the jet when it loses pressure support, which induces a conversion of magnetic energy into kinetic energy of bulk motion. This mechanism, which we dub rarefaction acceleration, can only operate in a relativistic outflow because in this case the total energy can still be dominated by the magnetic component even in the superfast-magnetosonic regime. We analyse this process using the equations of relativistic magnetohydrodynamics and demonstrate that it is more efficient at converting internal energy into kinetic energy when the flow is magnetized than in a purely hydrodynamic outflow, as was found numerically by Mizuno et al. We show that, just as in the case of the magnetic acceleration of a collimating jet that is confined by an external pressure distribution - the collimation-acceleration mechanism - the rarefaction-acceleration process in a magnetized jet is a consequence of the fact that the separation between neighbouring magnetic flux surfaces increases faster than their cylindrical radius. However, whereas in the case of effective collimation-acceleration the product of the jet opening angle and its Lorentz factor does not exceed ~1, the addition of the rarefaction-acceleration mechanism makes it possible for this product to become >>1, in agreement with the inference from late-time panchromatic breaks in the afterglow light curves of long/soft GRBs.

Apparent unambiguousness of relativistic time dilation

International Nuclear Information System (INIS)

Strel'tsov, V.N.

1992-01-01

It is indicated on the definite analogy between the dependence of visible sizes of relativistic objects and period of the wave, emitted by the moving source from the observation conditions ('retradition factor'). It is noted that the definition of time for moving extended objects, led to relativistic dilation, corresponds to the definition of the relativistic (radar) length led to the 'elongation formula'. 10 refs

Fermi Non-detections of Four X-Ray Jet Sources and Implications for the IC/CMB Mechanism

Science.gov (United States)

Breiding, Peter; Meyer, Eileen T.; Georganopoulos, Markos; Keenan, M. E.; DeNigris, N. S.; Hewitt, Jennifer

2017-11-01

Since its launch in 1999, the Chandra X-ray observatory has discovered several dozen X-ray jets associated with powerful quasars. In many cases, the X-ray spectrum is hard and appears to come from a second spectral component. The most popular explanation for the kpc-scale X-ray emission in these cases has been inverse-Compton (IC) scattering of Cosmic Microwave Background (CMB) photons by relativistic electrons in the jet (the IC/CMB model). Requiring the IC/CMB emission to reproduce the observed X-ray flux density inevitably predicts a high level of gamma-ray emission, which should be detectable with the Fermi Large Area Telescope (LAT). In previous work, we found that gamma-ray upper limits from the large-scale jets of 3C 273 and PKS 0637-752 violate the predictions of the IC/CMB model. Here, we present Fermi/LAT flux density upper limits for the X-ray jets of four additional sources: PKS 1136-135, PKS 1229-021, PKS 1354+195, and PKS 2209+080. We show that these limits violate the IC/CMB predictions at a very high significance level. We also present new Hubble Space Telescope observations of the quasar PKS 2209+080 showing a newly detected optical jet, and Atacama Large Millimeter/submillimeter Array band 3 and 6 observations of all four sources, which provide key constraints on the spectral shape that enable us to rule out the IC/CMB model.

Exploring Jets from a Supermassive Black Hole

Science.gov (United States)

Kohler, Susanna

2018-06-01

What are the feeding and burping habits of the supermassive black holes peppering the universe? In a new study, observations of one such monster reveal more about the behavior of its powerful jets.Beams from BehemothsAcross the universe, supermassive black holes of millions to billions of solar masses lie at the centers of galaxies, gobbling up surrounding material. But not all of the gas and dust that spirals in toward a black hole is ultimately swallowed! A large fraction of it can instead be flung out into space again, in the form of enormous, powerful jets that extend for thousands or even millions of light-years in opposite directions.M87, shown in this Hubble image, is a classic example of a nearby (55 million light-years distant) supermassive black hole with a visible, collimated jet. Its counter-jet isnt seen because relativistic effects make the receding jet appear less bright. [The Hubble Heritage Team (STScI/AURA) and NASA/ESA]What causes these outflows to be tightly beamed collimated in the form of jets, rather than sprayed out in all directions? Does the pressure of the ambient medium the surrounding gas and dust that the jet is injected into play an important role? In what regions do these jets accelerate and decelerate? There are many open questions that scientists hope to understand by studying some of the active black holes with jets that live closest to us.Eyes on a Nearby GiantIn a new study led by Satomi Nakahara (The Graduate University for Advanced Studies in Japan), a team of scientists has used multifrequency Very Long Baseline Array (VLBA) and Very Long Array (VLA) images to explore jets emitted from a galaxy just 100 million light-years away: NGC 4261.This galaxys (relatively) close distance as well as the fact that were viewing it largely from the side, so we can clearly see both of its polar jets allows us to observe in detail the structure and intensity of its jets as a function of their distance from the black hole. Nakahara and

RELATIVISTIC PLASMA AS THE DOMINANT SOURCE OF THE OPTICAL CONTINUUM EMISSION IN THE BROAD-LINE RADIO GALAXY 3C 120

International Nuclear Information System (INIS)

Leon-Tavares, J.; Lobanov, A. P.; Arshakian, T. G.; Chavushyan, V. H.; Doroshenko, V. T.; Sergeev, S. G.; Efimov, Y. S.; Nazarov, S. V.

2010-01-01

We report a relation between radio emission in the inner jet of the Seyfert galaxy 3C 120 and optical continuum emission in this galaxy. Combining the optical variability data with multi-epoch high-resolution very long baseline interferometry observations reveals that an optical flare rises when a superluminal component emerges into the jet, and its maxima is related to the passage of such component through the location of a stationary feature at a distance of ∼1.3 pc from the jet origin. This indicates that a significant fraction of the optical continuum produced in 3C 120 is non-thermal, and it can ionize material in a sub-relativistic wind or outflow. We discuss implications of this finding for the ionization and structure of the broad emission line region, as well as for the use of broad emission lines for determining black hole masses in radio-loud active galactic nucleus.

Investigating the anatomy of magnetosheath jets – MMS observations

Directory of Open Access Journals (Sweden)

T. Karlsson

2018-04-01

Full Text Available We use Magnetosphere Multiscale (MMS mission data to investigate a small number of magnetosheath jets, which are localized and transient increases in dynamic pressure, typically due to a combined increase in plasma velocity and density. For two approximately hour-long intervals in November, 2015 we found six jets, which are of two distinct types. (a Two of the jets are associated with the magnetic field discontinuities at the boundary between the quasi-parallel and quasi-perpendicular magnetosheath. Straddling the boundary, the leading part of these jets contains an ion population similar to the quasi-parallel magnetosheath, while the trailing part contains ion populations similar to the quasi-perpendicular magnetosheath. Both populations are, however, cooler than the surrounding ion populations. These two jets also have clear increases in plasma density and magnetic field strength, correlated with a velocity increase. (b Three of the jets are found embedded within the quasi-parallel magnetosheath. They contain ion populations similar to the surrounding quasi-parallel magnetosheath, but with a lower temperature. Out of these three jets, two have a simple structure. For these two jets, the increases in density and magnetic field strength are correlated with the dynamic pressure increases. The other jet has a more complicated structure, and no clear correlations between density, magnetic field strength and dynamic pressure. This jet has likely interacted with the magnetosphere, and contains ions similar to the jets inside the quasi-parallel magnetosheath, but shows signs of adiabatic heating. All jets are associated with emissions of whistler, lower hybrid, and broadband electrostatic waves, as well as approximately 10 s period electromagnetic waves with a compressional component. The latter have a Poynting flux of up to 40 µW m−2 and may be energetically important for the evolution of the jets, depending on the wave excitation

Heavy quark production form jet conversions in a quark-gluon plasma

Energy Technology Data Exchange (ETDEWEB)

Liu , W.; Fries, R.

2008-05-22

Recently, it has been demonstrated that the chemical composition of jets in heavy ion collisions is significantly altered compared to the jets in the vacuum. This signal can be used to probe the medium formed in nuclear collisions. In this study we investigate the possibility that fast light quarks and gluons can convert to heavy quarks when passing through a quark-gluon plasma. We study the rate of light to heavy jet conversions in a consistent Fokker-Planck framework and investigate their impact on the production of high-p{sub T} charm and bottom quarks at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

STAR-JET INTERACTIONS AND GAMMA-RAY OUTBURSTS FROM 3C454.3

Energy Technology Data Exchange (ETDEWEB)

Khangulyan, D. V. [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Barkov, M. V. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Bosch-Ramon, V. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E-08028 Barcelona (Spain); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Dorodnitsyn, A. V. [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

2013-09-10

We propose a model to explain the ultra-bright GeV gamma-ray flares observed from the blazar 3C454.3. The model is based on the concept of a relativistic jet interacting with compact gas condensations produced when a star (a red giant) crosses the jet close to the central black hole. The study includes an analytical treatment of the evolution of the envelope lost by the star within the jet, and calculations of the related high-energy radiation. The model readily explains the day-long that varies on timescales of hours, GeV gamma-ray flare from 3C454.3, observed during 2010 November on top of a plateau lasting weeks. In the proposed scenario, the plateau state is caused by a strong wind generated by the heating of the stellar atmosphere due to nonthermal particles accelerated at the jet-star interaction region. The flare itself could be produced by a few clouds of matter lost by the red giant after the initial impact of the jet. In the framework of the proposed scenario, the observations constrain the key model parameters of the source, including the mass of the central black hole: M{sub BH} {approx_equal} 10{sup 9} M{sub Sun }, the total jet power: L{sub j} {approx_equal} 10{sup 48} erg s{sup -1}, and the Doppler factor of the gamma-ray emitting clouds: {delta} {approx_equal} 20. Whereas we do not specify the particle acceleration mechanisms, the potential gamma-ray production processes are discussed and compared in the context of the proposed model. We argue that synchrotron radiation of protons has certain advantages compared to other radiation channels of directlyaccelerated electrons. An injected proton distribution {proportional_to}E {sup -1} or harder below the relevant energies would be favored to alleviate the tight energetic constraints and to avoid the violation of the observational low-energy constraints.

Relativistic Outflows from ADAFs

Science.gov (United States)

Becker, Peter; Subramanian, Prasad; Kazanas, Demosthenes

2001-04-01

Advection-dominated accretion flows (ADAFs) have a positive Bernoulli parameter, and are therefore gravitationally bound. The Newtonian ADAF model has been generalized recently to obtain the ADIOS model that includes outflows of energy and angular momentum, thereby allowing accretion to proceed self-consistently. However, the utilization of a Newtonian gravitational potential limits the ability of this model to describe the inner region of the disk, where any relativistic outflows are likely to originate. In this paper we modify the ADIOS scenario to incorporate a seudo - Newtonian potential, which approximates the effects of general relativity. The analysis yields a unique, self - similar solution for the structure of the coupled disk/wind system. Interesting features of the new solution include the relativistic character of the outflow in the vicinity of the radius of marginal stability, which represents the inner edge of the quasi-Keplerian disk in our model. Our self - similar model may therefore help to explain the origin of relativistic jets in active galaxies. At large distances the radial dependence of the accretion rate approachs the unique form dot M ∝ r^1/2, with an associated density variation given by ρ ∝ r-1. This density variation agrees with that implied by the dependence of the X-ray hard time lags on the Fourier frequency for a number of accreting galactic black hole candidates. While intriguing, the results of our self-similar model need to be confirmed in the future by incorporating a detailed physical description of the energization mechanism that drives the outflow, which is likely to be powered by the shear of the underlying accretion disk.

Modified Newtonian Dynamics (MOND: Observational Phenomenology and Relativistic Extensions

Directory of Open Access Journals (Sweden)

Stacy S. McGaugh

2012-09-01

Full Text Available A wealth of astronomical data indicate the presence of mass discrepancies in the Universe. The motions observed in a variety of classes of extragalactic systems exceed what can be explained by the mass visible in stars and gas. Either (i there is a vast amount of unseen mass in some novel form - dark matter - or (ii the data indicate a breakdown of our understanding of dynamics on the relevant scales, or (iii both. Here, we first review a few outstanding challenges for the dark matter interpretation of mass discrepancies in galaxies, purely based on observations and independently of any alternative theoretical framework. We then show that many of these puzzling observations are predicted by one single relation - Milgrom's law - involving an acceleration constant a_0 (or a characteristic surface density Σ_† = a_0∕G on the order of the square-root of the cosmological constant in natural units. This relation can at present most easily be interpreted as the effect of a single universal force law resulting from a modification of Newtonian dynamics (MOND on galactic scales. We exhaustively review the current observational successes and problems of this alternative paradigm at all astrophysical scales, and summarize the various theoretical attempts (TeVeS, GEA, BIMOND, and others made to effectively embed this modification of Newtonian dynamics within a relativistic theory of gravity.

Video, LMA and ULF observations of a negative gigantic jet in North Texas

Science.gov (United States)

Bruning, E. C.; Cummer, S.; Palivec, K.; Lyons, W. A.; Chmielewski, V.; MacGorman, D. R.

2017-12-01

On 8 September 2016 at 0125:38 UTC video of a negative gigantic jet was captured from Hawley, TX. VHF Lightning Mapping Arrays in West Texas and Oklahoma also observed the parent flash (duration of about 1 s) and, for the first time, mapped dozens of points along ascending negative leaders, lasting about 50 ms, which extended well above cloud top to about 35 km MSL altitude. A few well-located VHF sources were also detected near 50 km. Together, the video and VHF observations provide additional confirmation of the altitude at which the leader-to-streamer transition takes place in gigantic jet discharges. ULF magnetic field data from the Duke iCMC network show a current excursion associated with the onset of the upward movement of negative charge and leaders in the VHF. As the gigantic jet reached its full height, current spiked to 80 kA, followed by several hundred milliseconds of continuing current of 10-20 kA. Total charge moment change was about 6000 C km. The storm complex produced predominantly negative large charge moment change events, which is characteristic of storms that produce negative gigantic jets.

Relativistic inverse Compton scattering of photons from the early universe.

Science.gov (United States)

Malu, Siddharth; Datta, Abhirup; Colafrancesco, Sergio; Marchegiani, Paolo; Subrahmanyan, Ravi; Narasimha, D; Wieringa, Mark H

2017-12-05

Electrons at relativistic speeds, diffusing in magnetic fields, cause copious emission at radio frequencies in both clusters of galaxies and radio galaxies through non-thermal radiation emission called synchrotron. However, the total power radiated through this mechanism is ill constrained, as the lower limit of the electron energy distribution, or low-energy cutoffs, for radio emission in galaxy clusters and radio galaxies, have not yet been determined. This lower limit, parametrized by the lower limit of the electron momentum - p min - is critical for estimating the total energetics of non-thermal electrons produced by cluster mergers or injected by radio galaxy jets, which impacts the formation of large-scale structure in the universe, as well as the evolution of local structures inside galaxy clusters. The total pressure due to the relativistic, non-thermal population of electrons can be measured using the Sunyaev-Zel'dovich Effect, and is critically dependent on p min , making the measurement of this non-thermal pressure a promising technique to estimate the electron low-energy cutoff. We present here the first unambiguous detection of this Sunyaev-Zel'dovich Effect for a non-thermal population of electrons in a radio galaxy jet/lobe, located at a significant distance away from the center of the Bullet cluster of galaxies.

Evaluating results from the Relativistic Heavy Ion Collider with perturbative QCD and hydrodynamics

Energy Technology Data Exchange (ETDEWEB)

Fries, R.J.; Nonaka, C.

2011-07-01

We review the basic concepts of perturbative quantum chromodynamics (QCD) and relativistic hydrodynamics, and their applications to hadron production in high energy nuclear collisions. We discuss results from the Relativistic Heavy Ion Collider (RHIC) in light of these theoretical approaches. Perturbative QCD and hydrodynamics together explain a large amount of experimental data gathered during the first decade of RHIC running, although some questions remain open. We focus primarily on practical aspects of the calculations, covering basic topics like perturbation theory, initial state nuclear effects, jet quenching models, ideal hydrodynamics, dissipative corrections, freeze-out and initial conditions. We conclude by comparing key results from RHIC to calculations.

PHOTOSPHERIC EMISSION FROM STRATIFIED JETS

International Nuclear Information System (INIS)

Ito, Hirotaka; Nagataki, Shigehiro; Ono, Masaomi; Lee, Shiu-Hang; Mao, Jirong; Yamada, Shoichi; Pe'er, Asaf; Mizuta, Akira; Harikae, Seiji

2013-01-01

We explore photospheric emissions from stratified two-component jets, wherein a highly relativistic spine outflow is surrounded by a wider and less relativistic sheath outflow. Thermal photons are injected in regions of high optical depth and propagated until the photons escape at the photosphere. Because of the presence of shear in velocity (Lorentz factor) at the boundary of the spine and sheath region, a fraction of the injected photons are accelerated using a Fermi-like acceleration mechanism such that a high-energy power-law tail is formed in the resultant spectrum. We show, in particular, that if a velocity shear with a considerable variance in the bulk Lorentz factor is present, the high-energy part of observed gamma-ray bursts (GRBs) photon spectrum can be explained by this photon acceleration mechanism. We also show that the accelerated photons might also account for the origin of the extra-hard power-law component above the bump of the thermal-like peak seen in some peculiar bursts (e.g., GRB 090510, 090902B, 090926A). We demonstrate that time-integrated spectra can also reproduce the low-energy spectrum of GRBs consistently using a multi-temperature effect when time evolution of the outflow is considered. Last, we show that the empirical E p -L p relation can be explained by differences in the outflow properties of individual sources

Quark and gluon jet properties in symmetric three-jet events

Science.gov (United States)

Buskulic, D.; Casper, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Chmeissani, M.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Palla, F.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Farilla, A.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Jacobsen, R.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palazzi, P.; Pater, J. R.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Tanaka, R.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Colling, D. J.; Dornan, P. J.; Moutoussi, A.; Nash, J.; San Martin, G.; Sedgbeer, J. K.; Stacey, A. M.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Nicod, D.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Johnson, D. L.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Maley, P.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Beddall, A.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Rankin, C.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Feigl, E.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Ragusa, F.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Turk, J. D.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.; Aleph Collaboration

1996-02-01

Quark and gluon jets with the same energy, 24 GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on a track impact parameter method. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity, Evidence is presented which shows that the corresponding differences between gluon and b jets are significantly smaller. In a statistically limited comparison the multiplicity in c jets was found to be comparable with that observed for the jets of mixed quark flavour.

EVIDENCE OF THE DYNAMICS OF RELATIVISTIC JET LAUNCHING IN QUASARS

Energy Technology Data Exchange (ETDEWEB)

Punsly, Brian, E-mail: brian.punsly1@verizon.net [1415 Granvia Altamira, Palos Verdes Estates CA, USA 90274 and ICRANet, Piazza della Repubblica 10 Pescara I-65100 (Italy)

2015-06-10

Hubble Space Telescope (HST) spectra of the EUV, the optically thick emission from the innermost accretion flow onto the central supermassive black hole, indicate that radio loud quasars (RLQs) tend to be EUV weak compared to the radio-quiet quasars; yet the remainder of the optically thick thermal continuum is indistinguishable. The deficit of EUV emission in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. This article is an examination of the evidence for a distribution of magnetic flux tubes in the innermost accretion flow that results in magnetically arrested accretion (MAA) and creates the EUV deficit. These same flux tubes and possibly the interior magnetic flux that they encircle are the sources of the jet power as well. In the MAA scenario, islands of large-scale vertical magnetic flux perforate the innermost accretion flow of RLQs. The first prediction of the theory that is supported by the HST data is that the strength of the (large-scale poloidal magnetic fields) jets in the MAA region is regulated by the ram pressure of the accretion flow in the quasar environment. The second prediction that is supported by the HST data is that the rotating magnetic islands remove energy from the accretion flow as a Poynting flux dominated jet in proportion to the square of the fraction of the EUV emitting gas that is displaced by these islands.

An introduction to relativistic hydrodynamics

Energy Technology Data Exchange (ETDEWEB)

Font, Jose A [Departamento de AstronomIa y AstrofIsica, Universidad de Valencia, Dr. Moliner 50, 46100 Burjassot (Valencia) (Spain)

2007-11-15

We review formulations of the equations of (inviscid) general relativistic hydrodynamics and (ideal) magnetohydrodynamics, along with methods for their numerical solution. Both systems can be cast as first-order, hyperbolic systems of conservation laws, following the explicit choice of an Eulerian observer and suitable fluid and magnetic field variables. During the last fifteen years, the so-called (upwind) high-resolution shock-capturing schemes based on Riemann solvers have been successfully extended from classical to relativistic fluid dynamics, both special and general. Nowadays, general relativistic hydrodynamical simulations in relativistic astrophysics are routinely performed, particularly within the test-fluid approximation but also for dynamical spacetimes. While such advances also hold true in the case of the MHD equations, the astrophysical applications investigated so far are still limited, yet the field is bound to witness major developments in the near future. The article also presents a brief overview of numerical techniques, providing state-of-the-art examples of their applicability to general relativistic fluids and magneto-fluids in characteristic scenarios of relativistic astrophysics.

THE DISK-WIND-JET CONNECTION IN THE BLACK HOLE H 1743-322

Energy Technology Data Exchange (ETDEWEB)

Miller, J. M.; King, A. L. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Raymond, J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Fabian, A. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 OHA (United Kingdom); Reynolds, C. S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Kallman, T. R. [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Cackett, E. M. [Department of Physics and Astronomy, Wayne State University, 666 West Hancock Street, Detroit, MI 48201 (United States); Van der Klis, M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098-XH, Amsterdam (Netherlands); Steeghs, D. T. H., E-mail: jonmm@umich.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

2012-11-01

X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ks Chandra/HETGS observation of the black hole candidate H 1743-322 in the low/hard state. The spectrum shows no evidence of a disk wind, with tight limits, and within the range of ionizing flux levels that were measured in prior Chandra observations wherein a wind was clearly detected. In H 1743-322, at least, disk winds are actually diminished in the low/hard state, and disk winds and jets are likely state dependent and anti-correlated. These results suggest that although the launching radii of winds and jets may differ by orders of magnitude, they may both be tied to a fundamental property of the inner accretion flow, such as the mass accretion rate and/or the magnetic field topology of the disk. We discuss these results in the context of disk winds and jets in other stellar-mass black holes, and possible launching mechanisms for black hole outflows.

General relativistic model for the gravitational field of active galactic nuclei surrounded by a disk

NARCIS (Netherlands)

Vogt, D.; Letelier, P.S.

2005-01-01

An exact but simple general relativistic model for the gravitational field of active galactic nuclei is constructed, based on the superposition in Weyl coordinates of a black hole, a Chazy-Curzon disk and two rods, which represent matter jets. The influence of the rods on the matter properties of

Study of quantum spin correlations of relativistic electron pairs - Testing nonlocality of relativistic quantum mechanics

International Nuclear Information System (INIS)

Bodek, K.; Rozpędzik, D.; Zejma, J.; Caban, P.; Rembieliński, J.; Włodarczyk, M.; Ciborowski, J.; Enders, J.; Köhler, A.; Kozela, A.

2013-01-01

The Polish-German project QUEST aims at studying relativistic quantum spin correlations of the Einstein-Rosen-Podolsky-Bohm type, through measurement of the correlation function and the corresponding probabilities for relativistic electron pairs. The results will be compared to theoretical predictions obtained by us within the framework of relativistic quantum mechanics, based on assumptions regarding the form of the relativistic spin operator. Agreement or divergence will be interpreted in the context of non-uniqueness of the relativistic spin operator in quantum mechanics as well as dependence of the correlation function on the choice of observables representing the spin. Pairs of correlated electrons will originate from the Mo/ller scattering of polarized 15 MeV electrons provided by the superconducting Darmstadt electron linear accelerator S-DALINAC, TU Darmstadt, incident on a Be target. Spin projections will be determined using the Mott polarimetry technique. Measurements (starting 2013) are planned for longitudinal and transverse beam polarizations and different orientations of the beam polarization vector w.r.t. the Mo/ller scattering plane. This is the first project to study relativistic spin correlations for particles with mass

NUCLEAR RADIO JET FROM A LOW-LUMINOSITY ACTIVE GALACTIC NUCLEUS IN NGC 4258

Energy Technology Data Exchange (ETDEWEB)

Doi, Akihiro [The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210 (Japan); Kohno, Kotaro [Institute of Astronomy, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Nakanishi, Kouichiro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kameno, Seiji [Department of Physics, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Inoue, Makoto [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Hada, Kazuhiro [INAF, Istituto di Radioastronomia, via Gobetti 101, Bologna I-40129 (Italy); Sorai, Kazuo [Department of Physics, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Sapporo 060-0810 (Japan)

2013-03-01

The nearby low-luminosity active galactic nucleus (LLAGN) NGC 4258 has a weak radio continuum component at the galactic center. We investigate its radio spectral properties on the basis of our new observations using the Nobeyama Millimeter Array at 100 GHz and archival data from the Very Large Array at 1.7-43 GHz and the James Clerk Maxwell telescope at 347 GHz. The NGC 4258 nuclear component exhibits (1) an intra-month variable and complicated spectral feature at 5-22 GHz and (2) a slightly inverted spectrum at 5-100 GHz ({alpha} {approx} 0.3; F {sub {nu}}{proportional_to}{nu}{sup {alpha}}) in time-averaged flux densities, which are also apparent in the closest LLAGN M81. These similarities between NGC 4258 and M81 in radio spectral natures in addition to previously known core shift in their AU-scale jet structures produce evidence that the same mechanism drives their nuclei. We interpret the observed spectral property as the superposition of emission spectra originating at different locations with frequency-dependent opacity along the nuclear jet. Quantitative differences between NGC 4258 and M81 in terms of jet/counter jet ratio, radio loudness, and degree of core shift can be consistently understood by fairly relativistic speeds ({Gamma} {approx}> 3) of jets and their quite different inclinations. The picture established from the two closest LLAGNs is useful for understanding the physical origin of unresolved and flat/inverted spectrum radio cores that are prevalently found in LLAGNs, including Sgr A*, with starved supermassive black holes in the present-day universe.

Observation and studies of jet quenching in PbPb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV

CERN Document Server

Chatrchyan, Serguei; Sirunyan, Albert M.; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Haensel, Stephan; Hartl, Christian; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kasieczka, Gregor; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Teischinger, Florian; Wagner, Philipp; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Benucci, Leonardo; De Wolf, Eddi A.; Janssen, Xavier; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Beauceron, Stephanie; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Devroede, Olivier; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Joris; Maes, Michael; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Adler, Volker; Costantini, Silvia; Grunewald, Martin; Klein, Benjamin; Marinov, Andrey; Mccartin, Joseph; Ryckbosch, Dirk; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Caudron, Julien; Ceard, Ludivine; Cortina Gil, Eduardo; Delaere, Christophe; Favart, Denis; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Ovyn, Severine; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; De Jesus Damiao, Dilson; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Carvalho, Wagner; Melo Da Costa, Eliza; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Sznajder, Andre; Torres Da Silva De Araujo, Felipe; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Da Cunha Marinho, Franciole; Mercadante, Pedro G.; Novaes, Sergio F.; Padula, Sandra; Darmenov, Nikolay; Dimitrov, Lubomir; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vankov, Ivan; Dyulendarova, Milena; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Marinova, Evelina; Mateev, Matey; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Zhang, Linlin; Zhu, Bo; Zou, Wei; Cabrera, Andrés; Gomez Moreno, Bernardo; Ocampo Rios, Alberto Andres; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Lelas, Karlo; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A.; Finger, Miroslav; Finger Jr., Michael; Assran, Yasser; Khalil, Shaaban; Mahmoud, Mohammed; Hektor, Andi; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Azzolini, Virginia; Eerola, Paula; Czellar, Sandor; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J.; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Gentit, François-Xavier; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Marionneau, Matthieu; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Verrecchia, Patrice; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dobrzynski, Ludwik; Elgammal, Sherif; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Ochando, Christophe; Paganini, Pascal; Roxlo, Thomas; Sabes, David; Salerno, Roberto; Sirois, Yves; Thiebaux, Christophe; Wyslouch, Bolek; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Greder, Sebastien; Juillot, Pierre; Karim, Mehdi; Le Bihan, Anne-Catherine; Mikami, Yoshinari; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Baty, Clement; Beaupere, Nicolas; Bedjidian, Marc; Bondu, Olivier; Boudoul, Gaelle; Boumediene, Djamel; Brun, Hugues; Chanon, Nicolas; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Falkiewicz, Anna; Fay, Jean; Gascon, Susan; Ille, Bernard; Kurca, Tibor; Le Grand, Thomas; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Xiao, Hong; Megrelidze, Luka; Lomidze, David; Anagnostou, Georgios; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Mohr, Niklas; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Weber, Martin; Wittmer, Bruno; Ata, Metin; Bender, Walter; Erdmann, Martin; Frangenheim, Jens; Hebbeker, Thomas; Hinzmann, Andreas; Hoepfner, Kerstin; Hof, Carsten; Klimkovich, Tatsiana; Klingebiel, Dennis; Kreuzer, Peter; Lanske, Dankfried; Magass, Carsten; Masetti, Gianni; Merschmeyer, Markus; Meyer, Arnd; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Tonutti, Manfred; Bontenackels, Michael; Davids, Martina; Duda, Markus; Flügge, Günter; Geenen, Heiko; Giffels, Manuel; Haj Ahmad, Wael; Heydhausen, Dirk; Kress, Thomas; Kuessel, Yvonne; Linn, Alexander; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Thomas, Maarten; Tornier, Daiske; Zoeller, Marc Henning; Aldaya Martin, Maria; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Borras, Kerstin; Cakir, Altan; Campbell, Alan; Castro, Elena; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Flossdorf, Alexander; Flucke, Gero; Geiser, Achim; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katkov, Igor; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Mankel, Rainer; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Olzem, Jan; Pitzl, Daniel; Raspereza, Alexei; Raval, Amita; Rosin, Michele; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Tomaszewska, Justyna; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Gebbert, Ulla; Kaschube, Kolja; Kaussen, Gordon; Lange, Jörn; Mura, Benedikt; Naumann-Emme, Sebastian; Nowak, Friederike; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schröder, Matthias; Schum, Torben; Schwandt, Joern; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Barth, Christian; Bauer, Julia; Buege, Volker; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Feindt, Michael; Gruschke, Jasmin; Hackstein, Christoph; Hartmann, Frank; Heindl, Stefan Michael; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Kuhr, Thomas; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Peiffer, Thomas; Piparo, Danilo; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Renz, Manuel; Saout, Christophe; Scheurer, Armin; Schieferdecker, Philipp; Schilling, Frank-Peter; Schmanau, Mike; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Wagner-Kuhr, Jeannine; Weiler, Thomas; Zeise, Manuel; Zhukov, Valery; Ziebarth, Eva Barbara; Daskalakis, Georgios; Geralis, Theodoros; Karafasoulis, Konstantinos; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Petrakou, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Triantis, Frixos A.; Aranyi, Attila; Bencze, Gyorgy; Boldizsar, Laszlo; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Kapusi, Anita; Krajczar, Krisztian; Sikler, Ferenc; Veres, Gabor Istvan; Vesztergombi, Gyorgy; Beni, Noemi; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Veszpremi, Viktor; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Jindal, Monika; Kaur, Manjit; Kohli, Jatinder Mohan; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Anil; Singh, Jas Bir; Singh, Supreet Pal; Ahuja, Sudha; Bhattacharya, Satyaki; Choudhary, Brajesh C.; Gupta, Pooja; Jain, Sandhya; Jain, Shilpi; Kumar, Ashok; Ranjan, Kirti; Shivpuri, Ram Krishen; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Devdatta; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Saha, Anirban; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Mondal, Naba Kumar; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Dimitrov, Anton; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Manna, Norman; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pierro, Giuseppe Antonio; Pompili, Alexis; Pugliese, Gabriella; Romano, Francesco; Roselli, Giuseppe; Selvaggi, Giovanna; Silvestris, Lucia; Trentadue, Raffaello; Tupputi, Salvatore; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Giunta, Marina; Marcellini, Stefano; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Ghezzi, Alessio; Malberti, Martina; Malvezzi, Sandra; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Tancini, Valentina; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; Cimmino, Anna; De Cosa, Annapaola; De Gruttola, Michele; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Merola, Mario; Noli, Pasquale; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; De Mattia, Marco; Dorigo, Tommaso; Dosselli, Umberto; Fanzago, Federica; Gasparini, Fabrizio; Gasparini, Ugo; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Mazzucato, Mirco; Meneguzzo, Anna Teresa; Nespolo, Massimo; Perrozzi, Luca; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Berzano, Umberto; Ratti, Sergio P.; Riccardi, Cristina; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Caponeri, Benedetta; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Santocchia, Attilio; Taroni, Silvia; Valdata, Marisa; Volpe, Roberta; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Palmonari, Francesco; Segneri, Gabriele; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Di Marco, Emanuele; Diemoz, Marcella; Franci, Daniele; Grassi, Marco; Longo, Egidio; Nourbakhsh, Shervin; Organtini, Giovanni; Palma, Alessandro; Pandolfi, Francesco; Paramatti, Riccardo; Rahatlou, Shahram; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Castello, Roberto; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Marone, Matteo; Maselli, Silvia; Migliore, Ernesto; Mila, Giorgia; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Trocino, Daniele; Vilela Pereira, Antonio; Belforte, Stefano; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Montanino, Damiana; Penzo, Aldo; Heo, Seong Gu; Nam, Soon-Kwon; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kong, Dae Jung; Park, Hyangkyu; Ro, Sang-Ryul; Son, Dohhee; Son, Dong-Chul; Kim, Jaeho; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Ji Hyun; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Rhee, Han-Bum; Seo, Eunsung; Shin, Seungsu; Sim, Kwang Souk; Choi, Minkyoo; Kang, Seokon; Kim, Hyunyong; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Martisiute, Dalia; Petrov, Pavel; Sabonis, Tomas; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Lopez-Fernandez, Ricardo; Sánchez-Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A.; Krofcheck, David; Butler, Philip H.; Doesburg, Robert; Silverwood, Hamish; Ahmad, Muhammad; Ahmed, Ijaz; Asghar, Muhammad Irfan; Hoorani, Hafeez R.; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Nayak, Aruna; Seixas, Joao; Varela, Joao; Afanasiev, Serguei; Belotelov, Ivan; Bunin, Pavel; Golutvin, Igor; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Toropin, Alexander; Troitsky, Sergey; Epshteyn, Vladimir; Gavrilov, Vladimir; Kaftanov, Vitali; Kossov, Mikhail; Krokhotin, Andrey; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Proskuryakov, Alexander; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Vardanyan, Irina; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Rusakov, Sergey V.; Vinogradov, Alexey; Azhgirey, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Slabospitsky, Sergey; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cepeda, Maria; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M.; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Vizan Garcia, Jesus Manuel; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chamizo Llatas, Maria; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bell, Alan James; Benedetti, Daniele; Bernet, Colin; Bialas, Wojciech; Bloch, Philippe; Bocci, Andrea; Bolognesi, Sara; Bona, Marcella; Breuker, Horst; Brona, Grzegorz; Bunkowski, Karol; Camporesi, Tiziano; Cerminara, Gianluca; Coarasa Perez, Jose Antonio; Curé, Benoît; D'Enterria, David; De Roeck, Albert; Di Guida, Salvatore; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Gaddi, Andrea; Gennai, Simone; Georgiou, Georgios; Gerwig, Hubert; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Glege, Frank; Gomez-Reino Garrido, Robert; Gouzevitch, Maxime; Govoni, Pietro; Gowdy, Stephen; Guiducci, Luigi; Hansen, Magnus; Harvey, John; Hegeman, Jeroen; Hegner, Benedikt; Hoffmann, Hans Falk; Honma, Alan; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Lecoq, Paul; Lourenco, Carlos; Macpherson, Alick; Maki, Tuula; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Nesvold, Erik; Nguyen, Matthew; Orimoto, Toyoko; Orsini, Luciano; Perez, Emmanuelle; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Polese, Giovanni; Racz, Attila; Rodrigues Antunes, Joao; Rolandi, Gigi; Rommerskirchen, Tanja; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sharma, Archana; Siegrist, Patrice; Simon, Michal; Sphicas, Paraskevas; Spiropulu, Maria; Stöckli, Fabian; Stoye, Markus; Tropea, Paola; Tsirou, Andromachi; Vichoudis, Paschalis; Voutilainen, Mikko; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Starodumov, Andrei; Bortignon, Pierluigi; Caminada, Lea; Chen, Zhiling; Cittolin, Sergio; Dissertori, Günther; Dittmar, Michael; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hervé, Alain; Hintz, Wieland; Lecomte, Pierre; Lustermann, Werner; Marchica, Carmelo; Martinez Ruiz del Arbol, Pablo; Meridiani, Paolo; Milenovic, Predrag; Moortgat, Filip; Nef, Pascal; Nessi-Tedaldi, Francesca; Pape, Luc; Pauss, Felicitas; Punz, Thomas; Rizzi, Andrea; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Sawley, Marie-Christine; Stieger, Benjamin; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Matthias; Wehrli, Lukas; Weng, Joanna; Aguiló, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Regenfus, Christian; Robmann, Peter; Schmidt, Alexander; Snoek, Hella; Chang, Yuan-Hann; Chen, E Augustine; Chen, Kuan-Hsin; Chen, Wan-Ting; Dutta, Suchandra; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Ming-Hsiung; Liu, Zong-Kai; Lu, Yun-Ju; Mekterovic, Darko; Wu, Jing-Han; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wang, Minzu; Adiguzel, Aytul; Demir, Zahide; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karaman, Turker; Kayis Topaksu, Aysel; Nart, Alisah; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Uzun, Dilber; Vergili, Latife Nukhet; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yildirim, Eda; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Demir, Durmus; Gülmez, Erhan; Halu, Arda; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Levchuk, Leonid; Bell, Peter; Bostock, Francis; Brooke, James John; Cheng, Teh Lee; Clement, Emyr; Cussans, David; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Hansen, Maria; Hartley, Dominic; Heath, Greg P.; Heath, Helen F.; Huckvale, Benedickt; Jackson, James; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M.; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J.; Ward, Simon; Basso, Lorenzo; Bell, Ken W.; Belyaev, Alexander; Brew, Christopher; Brown, Robert M.; Camanzi, Barbara; Cockerill, David J.A.; Coughlan, John A.; Harder, Kristian; Harper, Sam; Kennedy, Bruce W.; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R.; Womersley, William John; Worm, Steven; Bainbridge, Robert; Ball, Gordon; Ballin, Jamie; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Davies, Gavin; Della Negra, Michel; Fulcher, Jonathan; Futyan, David; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Karapostoli, Georgia; MacEvoy, Barry C.; Magnan, Anne-Marie; Marrouche, Jad; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rompotis, Nikolaos; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Whyntie, Tom; Barrett, Matthew; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R.; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Teodorescu, Liliana; Hatakeyama, Kenichi; Bose, Tulika; Carrera Jarrin, Edgar; Fantasia, Cory; Heister, Arno; St. John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Avetisyan, Aram; Bhattacharya, Saptaparna; Chou, John Paul; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Landsberg, Greg; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Speer, Thomas; Tsang, Ka Vang; Breedon, Richard; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Friis, Evan; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Liu, Haidong; Maruyama, Sho; Miceli, Tia; Nikolic, Milan; Pellett, Dave; Robles, Jorge; Salur, Sevil; Schwarz, Thomas; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Veelken, Christian; Andreev, Valeri; Arisaka, Katsushi; Cline, David; Cousins, Robert; Deisher, Amanda; Duris, Joseph; Erhan, Samim; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Jarvis, Chad; Plager, Charles; Rakness, Gregory; Schlein, Peter; Tucker, Jordan; Valuev, Vyacheslav; Babb, John; Chandra, Avdhesh; Clare, Robert; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Jeng, Geng-Yuan; Kao, Shih-Chuan; Liu, Feng; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Nguyen, Harold; Shen, Benjamin C.; Stringer, Robert; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G.; Cerati, Giuseppe Benedetto; Dusinberre, Elizabeth; Evans, David; Golf, Frank; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Mangano, Boris; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pi, Haifeng; Pieri, Marco; Ranieri, Riccardo; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tu, Yanjun; Vartak, Adish; Wasserbaech, Steven; Würthwein, Frank; Yagil, Avraham; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Koay, Sue Ann; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Mccoll, Nickolas; Pavlunin, Viktor; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; Vlimant, Jean-Roch; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Gataullin, Marat; Ma, Yousi; Mott, Alexander; Newman, Harvey B.; Rogan, Christopher; Timciuc, Vladlen; Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Jun, Soon Yung; Liu, Yueh-Feng; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Dinardo, Mauro Emanuele; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T.; Gaz, Alessandro; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Zang, Shi-Lei; Agostino, Lorenzo; Alexander, James; Cassel, David; Chatterjee, Avishek; Das, Souvik; Eggert, Nicholas; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Puigh, Darren; Ryd, Anders; Shi, Xin; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Biselli, Angela; Cirino, Guy; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Atac, Muzaffer; Bakken, Jon Alan; Banerjee, Sunanda; Bauerdick, Lothar A.T.; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C.; Bloch, Ingo; Borcherding, Frederick; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Cooper, William; Eartly, David P.; Elvira, Victor Daniel; Esen, Selda; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Green, Dan; Gunthoti, Kranti; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M.; Hirschauer, James; Hooberman, Benjamin; Jensen, Hans; Johnson, Marvin; Joshi, Umesh; Khatiwada, Rakshya; Klima, Boaz; Kousouris, Konstantinos; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Limon, Peter; Lincoln, Don; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Mason, David; McBride, Patricia; Miao, Ting; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Pordes, Ruth; Prokofyev, Oleg; Saoulidou, Niki; Sexton-Kennedy, Elizabeth; Sharma, Seema; Spalding, William J.; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D.; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Goldberg, Sean; Kim, Bockjoo; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Matchev, Konstantin; Mitselmakher, Guenakh; Muniz, Lana; Pakhotin, Yuriy; Prescott, Craig; Remington, Ronald; Schmitt, Michael Houston; Scurlock, Bobby; Sellers, Paul; Skhirtladze, Nikoloz; Wang, Dayong; Yelton, John; Zakaria, Mohammed; Ceron, Cristobal; Gaultney, Vanessa; Kramer, Laird; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bandurin, Dmitry; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F.; Prosper, Harrison; Quertenmont, Loic; Sekmen, Sezen; Veeraraghavan, Venkatesh; Baarmand, Marc M.; Dorney, Brian; Guragain, Samir; Hohlmann, Marcus; Kalakhety, Himali; Ralich, Robert; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Kunde, Gerd J.; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silvestre, Catherine; Smoron, Agata; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Duru, Firdevs; Lae, Chung Khim; McCliment, Edward; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bonato, Alessio; Eskew, Christopher; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Tran, Nhan Viet; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Wood, Jeffrey Scott; Zhukova, Victoria; Barfuss, Anne-fleur; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Wan, Zongru; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Eno, Sarah Catherine; Ferencek, Dinko; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G.; Kirn, Malina; Lu, Ying; Mignerey, Alice; Rossato, Kenneth; Rumerio, Paolo; Santanastasio, Francesco; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C.; Twedt, Elizabeth; Alver, Burak; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Everaerts, Pieter; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Harris, Philip; Kim, Yongsun; Klute, Markus; Lee, Yen-Jie; Li, Wei; Loizides, Constantinos; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Sumorok, Konstanty; Sung, Kevin; Wenger, Edward Allen; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cole, Perrie; Cooper, Seth; Cushman, Priscilla; Dahmes, Bryan; De Benedetti, Abraham; Dudero, Phillip Russell; Franzoni, Giovanni; Haupt, Jason; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Rekovic, Vladimir; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Cremaldi, Lucien Marcus; Godang, Romulus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Summers, Don; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R.; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kelly, Tony; Kravchenko, Ilya; Lazo-Flores, Jose; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R.; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Boeriu, Oana; Chasco, Matthew; Reucroft, Steve; Swain, John; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Kolberg, Ted; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Wayne, Mitchell; Ziegler, Jill; Bylsma, Ben; Durkin, Lloyd Stanley; Gu, Jianhui; Hill, Christopher; Killewald, Phillip; Kotov, Khristian; Rodenburg, Marissa; Williams, Grayson; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hunt, Adam; Jones, John; Laird, Edward; Lopes Pegna, David; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E.; Bolla, Gino; Borrello, Laura; Bortoletto, Daniela; Everett, Adam; Garfinkel, Arthur F.; Gutay, Laszlo; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T.; Leonardo, Nuno; Liu, Chang; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Jindal, Pratima; Parashar, Neeti; Boulahouache, Chaouki; Cuplov, Vesna; Ecklund, Karl Matthew; Geurts, Frank J.M.; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Flacher, Henning; Garcia-Bellido, Aran; Goldenzweig, Pablo; Gotra, Yury; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Orbaker, Douglas; Petrillo, Gianluca; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Yan, Ming; Atramentov, Oleksiy; Barker, Anthony; Duggan, Daniel; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hits, Dmitry; Lath, Amitabh; Panwalkar, Shruti; Patel, Rishi; Richards, Alan; Rose, Keith; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Asaadi, Jonathan; Eusebi, Ricardo; Gilmore, Jason; Gurrola, Alfredo; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Nguyen, Chi Nhan; Osipenkov, Ilya; Pivarski, James; Safonov, Alexei; Sengupta, Sinjini; Tatarinov, Aysen; Toback, David; Weinberger, Michael; Akchurin, Nural; Damgov, Jordan; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Roh, Youn; Sill, Alan; Volobouev, Igor; Wigmans, Richard; Yazgan, Efe; Appelt, Eric; Brownson, Eric; Engh, Daniel; Florez, Carlos; Gabella, William; Issah, Michael; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Buehler, Marc; Conetti, Sergio; Cox, Bradley; Francis, Brian; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Lamichhane, Pramod; Mattson, Mark; Milstène, Caroline; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Bellinger, James Nugent; Carlsmith, Duncan; Dasu, Sridhara; Efron, Jonathan; Flood, Kevin; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Loveless, Richard; Mohapatra, Ajit; Reeder, Don; Ross, Ian; Savin, Alexander; Smith, Wesley H.; Swanson, Joshua; Weinberg, Marc

2011-01-01

Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relativ...

Relativistic beaming and quasar statistics

International Nuclear Information System (INIS)

Orr, M.J.L.; Browne, I.W.A.

1982-01-01

The statistical predictions of a unified scheme for the radio emission from quasars are explored. This scheme attributes the observed differences between flat- and steep-spectrum quasars to projection and the effects of relativistic beaming of the emission from the nuclear components. We use a simple quasar model consisting of a compact relativistically beamed core with spectral index zero and unbeamed lobes, spectral index - 1, to predict the proportion of flat-spectrum sources in flux-limited samples selected at different frequencies. In our model this fraction depends on the core Lorentz factor, γ and we find that a value of approximately 5 gives satisfactory agreement with observation. In a similar way the model is used to construct the expected number/flux density counts for flat-spectrum quasars from the observed steep-spectrum counts. Again, good agreement with the observations is obtained if the average core Lorentz factor is about 5. Independent estimates of γ from observations of superluminal motion in quasars are of the same order of magnitude. We conclude that the statistical properties of quasars are entirely consistent with the predictions of simple relativistic-beam models. (author)

Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration

International Nuclear Information System (INIS)

Molnar, Denes

2015-01-01

This report summarizes research activities at Purdue University done as part of the DOE JET Topical Collaboration. These mainly involve calculation of covariant radiative energy loss in the (Djordjevic-)Gyulassy-Levai-Vitev ((D)GLV) framework for relativistic A+A reactions at RHIC and LHC energies using realistic bulk medium evolution with both transverse and longitudinal expansion. The single PDF file provided also includes a report from the entire JET Collaboration.

Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration

Energy Technology Data Exchange (ETDEWEB)

Molnar, Denes [Purdue Univ., West Lafayette, IN (United States). Dept. of Physics and Astronomy

2015-09-01

This report summarizes research activities at Purdue University done as part of the DOE JET Topical Collaboration. These mainly involve calculation of covariant radiative energy loss in the (Djordjevic-)Gyulassy-Levai-Vitev ((D)GLV) framework for relativistic A+A reactions at RHIC and LHC energies using realistic bulk medium evolution with both transverse and longitudinal expansion. The single PDF file provided also includes a report from the entire JET Collaboration.

Sensitivity of relativistic impulse approximation proton-nucleus elastic scattering calculations on relativistic mean-field parameterizations

International Nuclear Information System (INIS)

Hojsik, M.; Gmuca, S.

1998-01-01

Relativistic microscopic calculations are presented for proton elastic scattering from 40 Ca at 500 MeV. The underlying target densities are calculated within the framework of the relativistic mean-field theory with several parameter sets commonly in use. The self consistency of the scalar and vector densities (and thus to relativistic mean-field parameters) is investigated. Recently, the relativistic impulse approximation (RIA) has been widely and repeatedly used for the calculations of proton-nucleus scattering at intermediate energies. These calculations have exhibited significant improvements over the nonrelativistic approaches. The relativistic impulse approximation calculations. in particular, provide a dramatically better description of the spin observables, namely the analyzing power, A y , and the spin-rotation function, Q, at least for energies higher than 400 MeV. In the relativistic impulse approximation, the Dirac optical potential is obtained by folding of the local Lorentz-invariant amplitudes with the corresponding nuclear densities. For the spin zero targets the scalar and vector terms give the dominant contributions. Thus the scalar and vector nuclear densities (both, proton and neutron ones) play the dominant role in the relativistic impulse approximation. While the proton vector densities can be obtained by unfolding from the empirically known charge densities, all other densities used rely to a great extent on theoretical models. The various recipes are used to construct the neutron vector densities and the scalar densities for both, neutrons and protons. In this paper we will study the sensitivity of the relativistic impulse approximation results on the various sets of relativistic mean-field parameters currently in use

THE DISK-WIND-JET CONNECTION IN THE BLACK HOLE H 1743–322

International Nuclear Information System (INIS)

Miller, J. M.; King, A. L.; Raymond, J.; Fabian, A. C.; Reynolds, C. S.; Kallman, T. R.; Cackett, E. M.; Van der Klis, M.; Steeghs, D. T. H.

2012-01-01

X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ks Chandra/HETGS observation of the black hole candidate H 1743–322 in the low/hard state. The spectrum shows no evidence of a disk wind, with tight limits, and within the range of ionizing flux levels that were measured in prior Chandra observations wherein a wind was clearly detected. In H 1743–322, at least, disk winds are actually diminished in the low/hard state, and disk winds and jets are likely state dependent and anti-correlated. These results suggest that although the launching radii of winds and jets may differ by orders of magnitude, they may both be tied to a fundamental property of the inner accretion flow, such as the mass accretion rate and/or the magnetic field topology of the disk. We discuss these results in the context of disk winds and jets in other stellar-mass black holes, and possible launching mechanisms for black hole outflows.

Jet substructure using semi-inclusive jet functions in SCET

International Nuclear Information System (INIS)

Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

2016-01-01

We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function G_i"h(z=ω_J/ω,z_h=ω_h/ω_J,ω_J,R,μ), which depends on the jet radius R and the large light-cone momenta of the parton ‘i’ initiating the jet (ω), the jet (ω_J), and the hadron h (ω_h). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function G_i"h(z,z_h,ω_J,R,μ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL_R) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL_R results for the hadron distribution inside the jet. We present numerical results for pp→(jet h)X in the new framework, and find excellent agreement with existing LHC experimental data.

UNDERCOVER EUV SOLAR JETS OBSERVED BY THE INTERFACE REGION IMAGING SPECTROGRAPH

Energy Technology Data Exchange (ETDEWEB)

Chen, N.-H. [Korea Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Innes, D. E. [Max-Planck-Institut für Sonnensystemforschung, D-37077 Göttingen (Germany)

2016-12-10

It is well-known that extreme ultraviolet (EUV) emission emitted at the solar surface is absorbed by overlying cool plasma. Especially in active regions, dark lanes in EUV images suggest that much of the surface activity is obscured. Simultaneous observations from the Interface Region Imaging Spectrograph, consisting of UV spectra and slit-jaw images (SJI), give vital information with sub-arcsecond spatial resolution on the dynamics of jets not seen in EUV images. We studied a series of small jets from recently formed bipole pairs beside the trailing spot of active region 11991, which occurred on 2014 March 5 from 15:02:21 UT to 17:04:07 UT. Collimated outflows with bright roots were present in SJI 1400 Å (transition region) and 2796 Å (upper chromosphere) that were mostly not seen in Atmospheric Imaging Assembly (AIA) 304 Å (transition region) and AIA 171 Å (lower corona) images. The Si iv spectra show a strong blue wing enhancement, but no red wing, in the line profiles of the ejecta for all recurrent jets, indicating outward flows without twists. We see two types of Mg ii line profiles produced by the jets spires: reversed and non-reversed. Mg ii lines remain optically thick, but turn optically thin in the highly Doppler shifted wings. The energy flux contained in each recurrent jet is estimated using a velocity differential emission measure technique that measures the emitting power of the plasma as a function of the line-of-sight velocity. We found that all the recurrent jets release similar energy (10{sup 8} erg cm{sup −2} s{sup −1}) toward the corona and the downward component is less than 3%.

Bulk Comptonization of the Cosmic Microwave Background by Extragalactic Jets as a Probe of their Matter Content

Science.gov (United States)

Georganopoulos, Markos; Kazanas, Demosthenes; Perlman, Eric; Stecker, Floyd W.

2004-01-01

We propose a method for estimating the composition, i.e. the relative amounts of leptons and protons, of extragalactic jets which exhibit Chandra - detected knots in their kpc scale jets. The method relies on measuring, or setting upper limits on, the component of the Cosmic Microwave Background (CMB) radiation that is bulk-Comptonized by the cold electrons in the relativistically flowing jet. These measurements, along with modeling of the broadband knot emission that constrain the bulk Lorentz factor GAMMA of the jets, can yield estimates of the jet power carried by protons and leptons. We provide an explicit calculation of the spectrum of the bulk-Comptonized (BC) CMB component and apply these results to PKS 0637 - 752 and 3C 273, two superluminal quasars with Chandra - detected large scale jets. What makes these sources particularly suited for such a procedure is the absence of significant non-thermal jet emission in the 'bridge', the region between the core and the first bright jet knot, which guarantees that most of the electrons are cold there, leaving the BC scattered CMB radiation as the only significant source of photons in this region. At lambda = 3.6 - 8.0 microns, the most likely band to observe the BC scattered CMB emission, the Spitzer angular resolution (approximately 1" - 3") is considerably smaller than the the 'bridges' of these jets (approximately 10"), making it possible to both measure and resolve this emission.

Observation of four-jet structure in e+e--annihilation at √s = 33 GeV

International Nuclear Information System (INIS)

Bartel, W.; Cords, D.; Dittmann, P.; Eichler, R.; Felst, R.; Haidt, D.; Krehbiel, H.; Meier, K.; Naroska, B.; O'Neill, L.H.

1982-03-01

Topological distributions of hadrons from the reaction e + e - → hadrons are studied at center of mass energies of about 33 GeV. The experimental distributions in the parameters acoplanarity and tripodity, both sensitive to events with a four-jet structure, show significant deviations from the expectations for two- and three-jet events. They can be described well by the inclusion of four-jet events. The relative magnitude of the observed effect indicates second order QCD as its probable origin. (orig.)

The Study on the Physical Properties of Blazar Jets

Science.gov (United States)

Kang, S. J.

2017-09-01

Active galactic nuclei (AGNs) belong to a special class of active galaxies, and have violent active phenomena and intense physical processes in the nuclei. Blazar is a subclass of AGNs, and has a relativistic jet with a small jet viewing angle. Therefore, the boosting effect is very important, and almost all the observed radiation is dominated by the jet. The relativistic jet physics is not very clear yet, such as the jet formation, collimation, and matter content etc. The multi-waveband radiation of blazar is dominated by jet, which provides an ideal laboratory for studying the jet physics. The first chapter of this thesis introduces the recent progress of AGNs and blazars. We further introduce the jet model that commonly used in blazars in the second chapter. In the third chapter, we fit simultaneously (or quasi-simultaneously) the multi-waveband spectral energy distributions (SEDs) for a sample of low-synchrotron-peaked (LSP) blazars with the jet model and χ2 procedure, which takes into account different soft photon fields (broad line region or a molecular torus). We find that the SED fitting with an external soft photon from IR torus is systematically better than that from the broad line region (BLR) based on a χ2 test, which suggests that the γ-ray emitting region most possibly stays outside the BLR. The minimum electron Lorentz factor, γmin, is constrained from the modeling of these LSP blazars with good soft X-ray data, and in a range from 5 to 160 (with a median value of 55), which plays a key role in jet power estimation. Assuming one-to-one ratio of proton and electron, we find that the jet power for LSP blazars is systematically higher than that of Fanaroff-Riley type II (FR II) radio galaxies. A possible reason for this is that there are some positrons in the jets of these blazars. If this is the case, the jet power will be reduced. Therefore, we propose a mixed composition of e±-p in the jets of these LSP blazars. If we assume that the jet power

Reflection jets and collimation of radio sources

International Nuclear Information System (INIS)

Pacholczyk, A.G.

1983-01-01

The author proposes a description of only a certain class of jets in extended radio sources by discussing hydrodynamics of jets formed by discrete portions of material ejected from the parent galaxy through a channel and reflected back into it as a result of an encounter with the material accumulated at the end of the channel. The picture presented here combines some older ideas with recent ones. The older ideas consist of modeling of extended radio sources in terms of multiple ejection of plasmons through a channel ploughed by the first few plasmons in the ambient medium with a resupply of energy in plasmons through the conversion of bulk kinetic energy into relativistic electron energy through instability driven turbulence. The recent ideas concern the formation of retro-jets as the result of interaction of a plasmon with the dense relic material at the end of a channel and the collimation of plasmon material in channels. (Auth.)

Kinetic instabilities in relativistic plasmas: the Harris instability revisited

International Nuclear Information System (INIS)

Tautz, R.C.

2008-01-01

Plasma instabilities that generate aperiodic fluctuations are of outstanding importance in the astrophysical context. Two prominent examples are the electromagnetic Weibel instability and the electrostatic Harris instability, which operate in initially non-magnetized and magnetized plasmas, respectively. In this talk, the original formulation of the Harris instability will be reviewed and generalizations will be presented such as the inclusion of (1) relativistic effects, (2) ion effects, and (3) mode coupling. It will be shown that, with these modifications, a powerful method has been developed for the determination of both the existence and the growth rate of low-frequency instabilities. Applications can be found in astrophysical jets, where the rest frame can be used and so no parallel motion is present. At the end of the talk, how the particle composition of gamma-ray burst jets can be predicted using the Harris technique. (author)

High performance imaging of relativistic soft X-ray harmonics by sub-micron resolution LiF film detectors

Energy Technology Data Exchange (ETDEWEB)

Pikuz, Tatiana; Faenov, Anatoly [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Pirozhkov, Alexander; Esirkepov, Timur; Koga, James; Nakamura, Tatsufumi; Bulanov, Sergei; Fukuda, Yuji; Hayashi, Yukio; Kotaki, Hideyuki; Kando, Masaki [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Astapov, Artem; Pikuz, Sergey Jr. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Klushin, Georgy [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Nagorskiy, Nikolai; Magnitskiy, Sergei [International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Kato, Yoshiaki [The Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka (Japan)

2012-12-15

The spectrum variation and the coherent properties of the high-order harmonics (HOH) generated by an oscillating electron spikes formed at the joint of the boundaries of a cavity and a bow wave, which are created by a relativistically self-focusing laser in underdense gas jet plasma, are investigated. This new mechanism for HOH generation efficiently produces emission from ultraviolet up to the XUV ''water window'' spectral range. To characterize such source in the wide spectral range a diffraction imaging technique is applied. High spatial resolution EUV and soft X-ray LiF film detector have been used for precise measurements of diffraction patterns. The measurements under observation angle of 8 to the axis of laser beam propagation have been performed. The diffraction patterns were observed on the detector clearly, when the square mesh was placed at the distance of 500 mm from the output of plasma and at the distance of 27.2 mm in front of the detector. It is shown that observed experimental patterns are well consistent with modeled ones for theoretical HOH spectrum, provided by particle-in-cell simulations of a relativistic-irradiance laser pulse interaction with underdense plasma (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... We present a numerical model developed to calculate observed fluxes of relativistic jets in active galactic nuclei. The observed flux of each turbulent eddy is dependent upon its variable Doppler boosting factor, computed as a function of the relativistic sum of the individual eddy and bulk jet velocities, and ...

Low-frequency variation of a zonally localized jet stream: Observation and theory

International Nuclear Information System (INIS)

Cai, M.

1994-01-01

The climatological mean circulation in the extratropics of the Northern Hemisphere is characterized by two zonally localized jet streams over the east coasts of the two major continents. The zonal inhomogeneity of the climatological mean circulation is believed to be a primary factor determining the geographical locations of the maximum activity centers of the atmospheric transients, such as storm tracks over the east coasts of the two major continents and frequent blocking episodes occurring over the central regions of the two oceans. The impact of the transients on the zonally localized jet streams is studied mostly in the linear dynamics framework in terms of so-called open-quotes feedbackclose quotes diagnosis. This study investigates nonlinear instability of a zonally localized jet stream. The emphasis is on the nonlinear adjustment of a zonally localized jet stream associated with the development of the transients via local instability. The adjustment of a zonally localized jet stream would naturally consists of two parts: One is the time-invariant part and the other is the transient part (temporal variation of the adjustment). In conjunction with the observation, the time-mean adjustment is part of the climatological mean flow and hence is open-quotes invisible.close quotes The transient part of the adjustment is evidenced by the changes of the jet streams in terms of both location and intensity. In this study, we tend to relate the transient part of the adjustment of the jet stream to the maximum activity centers of low-frequency variability. The underlying mechanisms that are responsible for the temporal variation of the adjustment will be investigated. The time-mean adjustment will be also studied to better understand the temporal variation of the adjustment

Jet substructure using semi-inclusive jet functions in SCET

Energy Technology Data Exchange (ETDEWEB)

Kang, Zhong-Bo [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095 (United States); Ringer, Felix; Vitev, Ivan [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States)

2016-11-25

We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function G{sub i}{sup h}(z=ω{sub J}/ω,z{sub h}=ω{sub h}/ω{sub J},ω{sub J},R,μ), which depends on the jet radius R and the large light-cone momenta of the parton ‘i’ initiating the jet (ω), the jet (ω{sub J}), and the hadron h (ω{sub h}). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function G{sub i}{sup h}(z,z{sub h},ω{sub J},R,μ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL{sub R}) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL{sub R} results for the hadron distribution inside the jet. We present numerical results for pp→(jet h)X in the new framework, and find excellent agreement with existing LHC experimental data.

Observational study on the fine structure and dynamics of a solar jet. II. Energy release process revealed by spectral analysis

Science.gov (United States)

Sakaue, Takahito; Tei, Akiko; Asai, Ayumi; Ueno, Satoru; Ichimoto, Kiyoshi; Shibata, Kazunari

2018-01-01

We report on a solar jet phenomenon associated with the C5.4 class flare on 2014 November 11. The data of the jet was provided by the Solar Dynamics Observatory, the X-Ray Telescope (XRT) aboard Hinode, and the Interface Region Imaging Spectrograph and Domeless Solar Telescope (DST) at Hida Observatory, Kyoto University. These plentiful data enabled us to present this series of papers to discuss all the processes of the observed phenomena, including energy storage, event trigger, and energy release. In this paper, we focus on the energy release process of the observed jet, and mainly describe our spectral analysis on the Hα data of DST to investigate the internal structure of the Hα jet and its temporal evolution. This analysis reveals that in the physical quantity distributions of the Hα jet, such as line-of-sight velocity and optical thickness, there is a significant gradient in the direction crossing the jet. We interpret this internal structure as the consequence of the migration of the energy release site, based on the idea of ubiquitous reconnection. Moreover, by measuring the horizontal flow of the fine structures in the jet, we succeeded in deriving the three-dimensional velocity field and the line-of-sight acceleration field of the Hα jet. The analysis result indicates that part of the ejecta in the Hα jet experienced additional acceleration after it had been ejected from the lower atmosphere. This secondary acceleration was found to occur in the vicinity of the intersection between the trajectories of the Hα jet and the X-ray jet observed by Hinode/XRT. We propose that a fundamental cause of this phenomenon is magnetic reconnection involving the plasmoid in the observed jet.

Cross sections and transverse single-spin asymmetries in forward jet production from proton collisions at s=500 GeV

Directory of Open Access Journals (Sweden)

L.C. Bland

2015-11-01

Full Text Available Measurements of the production of forward jets from transversely polarized proton collisions at s=500 GeV conducted at the Relativistic Heavy Ion Collider (RHIC are reported. Our measured jet cross section is consistent with hard scattering expectations. Our measured analyzing power for forward jet production is small and positive, and provides constraints on the Sivers functions that are related to partonic orbital angular momentum through theoretical models.

Relativistic viscoelastic fluid mechanics

International Nuclear Information System (INIS)

Fukuma, Masafumi; Sakatani, Yuho

2011-01-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

Relativistic viscoelastic fluid mechanics.

Science.gov (United States)

Fukuma, Masafumi; Sakatani, Yuho

2011-08-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

AN HST PROPER-MOTION STUDY OF THE LARGE-SCALE JET OF 3C273

Energy Technology Data Exchange (ETDEWEB)

Meyer, Eileen T.; Georganopoulos, Markos [University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Sparks, William B. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Anderson, Jay; Marel, Roeland van der; Biretta, John; Chiaberge, Marco; Norman, Colin [Space Telescope Science Institute, Baltimore, MD 21210 (United States); Tony Sohn, Sangmo [Johns Hopkins University, Baltimore, MD 21210 (United States); Perlman, Eric, E-mail: meyer@stsci.edu [Florida Institute of Technology, Melbourne, FL 32901 (United States)

2016-02-20

The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of −0.2 ± 0.5c over the whole jet. Assuming the knots are packets of moving plasma, an upper limit of 1c implies a bulk Lorentz factor Γ < 2.9. This suggests that the jet has either decelerated significantly by the time it reaches the kiloparsec scale, or that the knots in the jet are standing shock features. The second scenario is incompatible with the inverse Compton off the Cosmic Microwave Background (IC/CMB) model for the X-ray emission of these knots, which requires the knots to be in motion, but IC/CMB is also disfavored in the first scenario due to energetic considerations, in agreement with the recent finding of Meyer and Georganopoulos which ruled out the IC/CMB model for the X-ray emission of 3C 273 via gamma-ray upper limits.

Perpendicular relativistic shocks in magnetized pair plasma

Science.gov (United States)

Plotnikov, Illya; Grassi, Anna; Grech, Mickael

2018-04-01

Perpendicular relativistic (γ0 = 10) shocks in magnetized pair plasmas are investigated using two dimensional Particle-in-Cell simulations. A systematic survey, from unmagnetized to strongly magnetized shocks, is presented accurately capturing the transition from Weibel-mediated to magnetic-reflection-shaped shocks. This transition is found to occur for upstream flow magnetizations 10-3 10-2, it leaves place to a purely electromagnetic precursor following from the strong emission of electromagnetic waves at the shock front. Particle acceleration is found to be efficient in weakly magnetized perpendicular shocks in agreement with previous works, and is fully suppressed for σ > 10-2. Diffusive Shock Acceleration is observed only in weakly magnetized shocks, while a dominant contribution of Shock Drift Acceleration is evidenced at intermediate magnetizations. The spatial diffusion coefficients are extracted from the simulations allowing for a deeper insight into the self-consistent particle kinematics and scale with the square of the particle energy in weakly magnetized shocks. These results have implications for particle acceleration in the internal shocks of AGN jets and in the termination shocks of Pulsar Wind Nebulae.

Particle acceleration and injection problem in relativistic and nonrelativistic shocks

International Nuclear Information System (INIS)

Hoshino, M.

2008-01-01

Acceleration of charged particles at the collisionless shock is believed to be responsible for production of cosmic rays in a variety of astrophysical objects such as supernova, AGN jet, and GRB etc., and the diffusive shock acceleration model is widely accepted as a key process for generating cosmic rays with non-thermal, power-law energy spectrum. Yet it is not well understood how the collisionless shock can produce such high energy particles. Among several unresolved issues, two major problems are the so-called '' injection '' problem of the supra-thermal particles and the generation of plasma waves and turbulence in and around the shock front. With recent advance of computer simulations, however, it is now possible to discuss those issues together with dynamical evolution of the kinetic shock structure. A wealth of modern astrophysical observations also inspires the dynamical shock structure and acceleration processes along with the theoretical and computational studies on shock. In this presentation, we focus on the plasma wave generation and the associated particle energization that directly links to the injection problem by taking into account the kinetic plasma processes of both non-relativistic and relativistic shocks by using a particle-in-cell simulation. We will also discuss some new particle acceleration mechanisms such as stochastic surfing acceleration and wakefield acceleration by the action of nonlinear electrostatic fields. (author)

Observations of supra-arcade fans: instabilities at the head of reconnection jets

International Nuclear Information System (INIS)

Innes, D. E.; Guo, L.-J.; Schmit, D.; Bhattacharjee, A.; Huang, Y.-M.

2014-01-01

Supra-arcade fans are bright, irregular regions of emission that develop during eruptive flares above flare arcades. The underlying flare arcades are thought to be a consequence of magnetic reconnection along a current sheet in the corona. At the same time, theory predicts plasma jets from the reconnection sites which are extremely difficult to observe directly because of their low densities. It has been suggested that the dark supra-arcade downflows (SADs) seen falling through supra-arcade fans may be low-density jet plasma. The head of a low-density jet directed toward higher-density plasma would be Rayleigh-Taylor unstable, and lead to the development of rapidly growing low- and high-density fingers along the interface. Using Solar Dynamics Observatory/Atmospheric Imaging Assembly 131 Å images, we show details of SADs seen from three different orientations with respect to the flare arcade and current sheet, and highlight features that have been previously unexplained, such as the splitting of SADs at their heads, but are a natural consequence of instabilities above the arcade. Comparison with three-dimensional magnetohydrodynamic simulations suggests that SADs are the result of secondary instabilities of the Rayleigh-Taylor type in the exhaust of reconnection jets.

Observations of Supra-arcade Fans: Instabilities at the Head of Reconnection Jets

Science.gov (United States)

Innes, D. E.; Guo, L.-J.; Bhattacharjee, A.; Huang, Y.-M.; Schmit, D.

2014-11-01

Supra-arcade fans are bright, irregular regions of emission that develop during eruptive flares above flare arcades. The underlying flare arcades are thought to be a consequence of magnetic reconnection along a current sheet in the corona. At the same time, theory predicts plasma jets from the reconnection sites which are extremely difficult to observe directly because of their low densities. It has been suggested that the dark supra-arcade downflows (SADs) seen falling through supra-arcade fans may be low-density jet plasma. The head of a low-density jet directed toward higher-density plasma would be Rayleigh-Taylor unstable, and lead to the development of rapidly growing low- and high-density fingers along the interface. Using Solar Dynamics Observatory/Atmospheric Imaging Assembly 131 Å images, we show details of SADs seen from three different orientations with respect to the flare arcade and current sheet, and highlight features that have been previously unexplained, such as the splitting of SADs at their heads, but are a natural consequence of instabilities above the arcade. Comparison with three-dimensional magnetohydrodynamic simulations suggests that SADs are the result of secondary instabilities of the Rayleigh-Taylor type in the exhaust of reconnection jets.

Relativistic astrophysics

CERN Document Server

Price, R H

1993-01-01

Work reported in the workshop on relativistic astrophysics spanned a wide varicy of topics. Two specific areas seemed of particular interest. Much attention was focussed on gravitational wave sources, especially on the waveforms they produce, and progress was reported in theoretical and observational aspects of accretion disks.

Plasma jets and FTE Dayside Generation for Northward IMF on 8 June 2007: THEMIS Observations

Science.gov (United States)

Eriksson, S.; Cully, C. M.; Ergun, R. E.; Gosling, J. T.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.; Glassmeier, K.; Roux, A.; Auster, H.; Le Contel, O.

2007-12-01

Five-spacecraft THEMIS (TH) observations are presented for a 15.5 MLT equatorial magnetopause crossing on 8 June 2007 when the upstream IMF was predominantly northward with a negative IMF By component at Wind. During the 0650-0855 UT period on this day TH-B was the most tailward probe while TH-A was the most sunward probe. TH-E was closest to TH-A with a maximum separation of only 0.71 RE. The maximum TH-A to TH-B GSM separation was 1.85 RE. TH-B showed a clean magnetopause crossing into the magnetosphere as the magnetopause expanded over the probes while TH-A spent this 2-hour period within a boundary layer inside the magnetopause with frequent transitions between a magnetosheath-like and a magnetosphere-like plasma as previously seen by Cluster at high-latitudes for southward IMF [Wild et al., 2003]. TH-E observed similar activity for a shorter period of time. Many of the sheath-like transitions showed evidence of plasma jets at TH-A with enhanced speed in the tailward and/or duskward direction suggesting a subsolar component merging region. Some jets were related to frequent bipolar FTE signatures in the normal BN component with enhanced total pressure observed at their centers. The more common ±BN sequence suggests that TH-A observed tailward propagating FTEs on the sheath side of the magnetopause. We compare TH-E ExB velocities with the enhanced jet velocities observed by TH-A and discuss whether the jets observed within this boundary layer were caused by subsolar magnetopause reconnection. We also compare these low-latitude northward IMF observations with prior Cluster FTE observations at high-latitude for southward IMF.

An Orientation-Based Unification of Young Jetted AGN: The Case of 3C 286

Energy Technology Data Exchange (ETDEWEB)

Berton, Marco [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Brera Astronomical Observatory (INAF), Merate (Italy); Foschini, Luigi; Caccianiga, Alessandro [Brera Astronomical Observatory (INAF), Merate (Italy); Ciroi, Stefano [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Congiu, Enrico [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Brera Astronomical Observatory (INAF), Merate (Italy); Cracco, Valentina; Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero, E-mail: marco.berton@unipd.it [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy)

2017-07-25

In recent years, the old paradigm according to which only high-mass black holes can launch powerful relativistic jets in active galactic nuclei (AGN) has begun to crumble. The discovery of γ-rays coming from narrow-line Seyfert 1 galaxies (NLS1s), usually considered young and growing AGN harboring a central black hole with mass typically lower than 10{sup 8} M{sub ⊙}, indicated that also these low-mass AGN can produce powerful relativistic jets. The search for parent population of γ-ray emitting NLS1s revealed their connection with compact steep-spectrum sources (CSS). In this proceeding we present a review of the current knowledge of these sources, we present the new important case of 3C 286, classified here for the fist time as NLS1, and we finally provide a tentative orientation based unification of NLS1s and CSS sources.

An Orientation-Based Unification of Young Jetted AGN: The Case of 3C 286

International Nuclear Information System (INIS)

Berton, Marco; Foschini, Luigi; Caccianiga, Alessandro; Ciroi, Stefano; Congiu, Enrico; Cracco, Valentina; Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero

2017-01-01

In recent years, the old paradigm according to which only high-mass black holes can launch powerful relativistic jets in active galactic nuclei (AGN) has begun to crumble. The discovery of γ-rays coming from narrow-line Seyfert 1 galaxies (NLS1s), usually considered young and growing AGN harboring a central black hole with mass typically lower than 10 8 M ⊙ , indicated that also these low-mass AGN can produce powerful relativistic jets. The search for parent population of γ-ray emitting NLS1s revealed their connection with compact steep-spectrum sources (CSS). In this proceeding we present a review of the current knowledge of these sources, we present the new important case of 3C 286, classified here for the fist time as NLS1, and we finally provide a tentative orientation based unification of NLS1s and CSS sources.

Powerful jets from accreting black holes: evidence from the optical and infrared

NARCIS (Netherlands)

Russell, D.M.; Fender, R.P.; Wachter, A.D.; Propst, R.J.

2010-01-01

A common consequence of accretion onto black holes is the formation of powerful, relativistic jets that escape the system. In the case of supermassive black holes at the centres of galaxies this has been known for decades, but for stellar-mass black holes residing within galaxies like our own, it

Relativistic Calculations for Be-like Iron

International Nuclear Information System (INIS)

Yang Jianhui; Zhang Jianping; Li Ping; Li Huili

2008-01-01

Relativistic configuration interaction calculations for the states of 1s 2 2s 2 , 1s 2 2s3l (l = s,p,d) and 1s 2 2p3l (l = s,p,d) configurations of iron are carried out using relativistic configuration interaction (RCI) and multi-configuration Dirac-Fock (MCDF) method in the active interaction approach. In the present calculation, a large-scale configuration expansion was used in describing the target states. These results are extensively compared with other available calculative and experimental and observed values, the corresponding present results are in good agreement with experimental and observed values, and some differences are found with other available calculative values. Because more relativistic effects are considered than before, the present results should be more accurate and reliable

Relativistic and non-relativistic studies of nuclear matter

NARCIS (Netherlands)

Banerjee, MK; Tjon, JA

2002-01-01

We point out that the differences between the results of the non-relativistic lowest order Brueckner theory (LOBT) and the relativistic Dirac-Brueckner analysis predominantly arise from two sources. Besides effects from a nucleon mass modification M* in nuclear medium we have in a relativistic

NEUTRON-STAR MERGER EJECTA AS OBSTACLES TO NEUTRINO-POWERED JETS OF GAMMA-RAY BURSTS

Energy Technology Data Exchange (ETDEWEB)

Just, O.; Janka, H.-T.; Schwarz, N. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Obergaulinger, M. [Departament d´Astronomia i Astrofísica, Universitat de València, Edifici d´Investigació Jeroni Muñoz, C/ Dr. Moliner, 50, E-46100 Burjassot (València) (Spain); Bauswein, A., E-mail: ojust@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2016-01-10

We present the first special relativistic, axisymmetric hydrodynamic simulations of black hole-torus systems (approximating general relativistic gravity) as remnants of binary-neutron star (NS–NS) and neutron star–black hole (NS–BH) mergers, in which the viscously driven evolution of the accretion torus is followed with self-consistent energy-dependent neutrino transport and the interaction with the cloud of dynamical ejecta expelled during the NS–NS merging is taken into account. The modeled torus masses, BH masses and spins, and the ejecta masses, velocities, and spatial distributions are adopted from relativistic merger simulations. We find that energy deposition by neutrino annihilation can accelerate outflows with initially high Lorentz factors along polar low-density funnels, but only in mergers with extremely low baryon pollution in the polar regions. NS–BH mergers, where polar mass ejection during the merging phase is absent, provide sufficiently baryon-poor environments to enable neutrino-powered, ultrarelativistic jets with terminal Lorentz factors above 100 and considerable dynamical collimation, favoring short gamma-ray bursts (sGRBs), although their typical energies and durations might be too small to explain the majority of events. In the case of NS–NS mergers, however, neutrino emission of the accreting and viscously spreading torus is too short and too weak to yield enough energy for the outflows to break out from the surrounding ejecta shell as highly relativistic jets. We conclude that neutrino annihilation alone cannot power sGRBs from NS–NS mergers.

NEUTRON-STAR MERGER EJECTA AS OBSTACLES TO NEUTRINO-POWERED JETS OF GAMMA-RAY BURSTS

International Nuclear Information System (INIS)

Just, O.; Janka, H.-T.; Schwarz, N.; Obergaulinger, M.; Bauswein, A.

2016-01-01

We present the first special relativistic, axisymmetric hydrodynamic simulations of black hole-torus systems (approximating general relativistic gravity) as remnants of binary-neutron star (NS–NS) and neutron star–black hole (NS–BH) mergers, in which the viscously driven evolution of the accretion torus is followed with self-consistent energy-dependent neutrino transport and the interaction with the cloud of dynamical ejecta expelled during the NS–NS merging is taken into account. The modeled torus masses, BH masses and spins, and the ejecta masses, velocities, and spatial distributions are adopted from relativistic merger simulations. We find that energy deposition by neutrino annihilation can accelerate outflows with initially high Lorentz factors along polar low-density funnels, but only in mergers with extremely low baryon pollution in the polar regions. NS–BH mergers, where polar mass ejection during the merging phase is absent, provide sufficiently baryon-poor environments to enable neutrino-powered, ultrarelativistic jets with terminal Lorentz factors above 100 and considerable dynamical collimation, favoring short gamma-ray bursts (sGRBs), although their typical energies and durations might be too small to explain the majority of events. In the case of NS–NS mergers, however, neutrino emission of the accreting and viscously spreading torus is too short and too weak to yield enough energy for the outflows to break out from the surrounding ejecta shell as highly relativistic jets. We conclude that neutrino annihilation alone cannot power sGRBs from NS–NS mergers

Jet angularity measurements for single inclusive jet production

Science.gov (United States)

Kang, Zhong-Bo; Lee, Kyle; Ringer, Felix

2018-04-01

We study jet angularity measurements for single-inclusive jet production at the LHC. Jet angularities depend on a continuous parameter a allowing for a smooth interpolation between different traditional jet shape observables. We establish a factorization theorem within Soft Collinear Effective Theory (SCET) where we consistently take into account in- and out-of-jet radiation by making use of semi-inclusive jet functions. For comparison, we elaborate on the differences to jet angularities measured on an exclusive jet sample. All the necessary ingredients for the resummation at next-to-leading logarithmic (NLL) accuracy are presented within the effective field theory framework. We expect semiinclusive jet angularity measurements to be feasible at the LHC and we present theoretical predictions for the relevant kinematic range. In addition, we investigate the potential impact of jet angularities for quark-gluon discrimination.

Nonlinear dynamics of the relativistic standard map

International Nuclear Information System (INIS)

Nomura, Y.; Ichikawa, Y.H.; Horton, W.

1991-04-01

Heating and acceleration of charged particles by RF fields have been extensively investigated by the standard map. The question arises as to how the relativistic effects change the nonlinear dynamical behavior described by the classical standard map. The relativistic standard map is a two parameter (K, Β = ω/kc) family of dynamical systems reducing to the standard map when Β → 0. For Β ≠ 0 the relativistic mass increase suppresses the onset of stochasticity. It shown that the speed of light limits the rate of advance of the phase in the relativistic standard map and introduces KAM surfaces persisting in the high momentum region. An intricate structure of mixing in the higher order periodic orbits and chaotic orbits is analyzed using the symmetry properties of the relativistic standard map. The interchange of the stability of the periodic orbits in the relativistic standard map is also observed and is explained by the local linear stability of the orbits. 12 refs., 16 figs

Black hole spin from wobbling and rotation of the M87 jet and a sign of a magnetically arrested disc

Science.gov (United States)

Sob'yanin, Denis Nikolaevich

2018-06-01

New long-term Very Long Baseline Array observations of the well-known jet in the M87 radio galaxy at 43 GHz show that the jet experiences a sideways shift with an approximately 8-10 yr quasi-periodicity. Such jet wobbling can be indicative of a relativistic Lense-Thirring precession resulting from a tilted accretion disc. The wobbling period together with up-to-date kinematic data on jet rotation opens up the possibility for estimating angular momentum of the central supermassive black hole. In the case of a test-particle precession, the specific angular momentum is J/Mc = (2.7 ± 1.5) × 1014 cm, implying moderate dimensionless spin parameters a = 0.5 ± 0.3 and 0.31 ± 0.17 for controversial gas-dynamic and stellar-dynamic black hole masses. However, in the case of a solid-body-like precession, the spin parameter is much smaller for both masses, 0.15 ± 0.05. Rejecting this value on the basis of other independent spin estimations requires the existence of a magnetically arrested disc in M87.

Isolating relativistic effects in large-scale structure

Science.gov (United States)

Bonvin, Camille

2014-12-01

We present a fully relativistic calculation of the observed galaxy number counts in the linear regime. We show that besides the density fluctuations and redshift-space distortions, various relativistic effects contribute to observations at large scales. These effects all have the same physical origin: they result from the fact that our coordinate system, namely the galaxy redshift and the incoming photons’ direction, is distorted by inhomogeneities in our Universe. We then discuss the impact of the relativistic effects on the angular power spectrum and on the two-point correlation function in configuration space. We show that the latter is very well adapted to isolate the relativistic effects since it naturally makes use of the symmetries of the different contributions. In particular, we discuss how the Doppler effect and the gravitational redshift distortions can be isolated by looking for a dipole in the cross-correlation function between a bright and a faint population of galaxies.

Relativistic electron kinetic effects on laser diagnostics in burning plasmas

Science.gov (United States)

Mirnov, V. V.; Den Hartog, D. J.

2018-02-01

Toroidal interferometry/polarimetry (TIP), poloidal polarimetry (PoPola), and Thomson scattering systems (TS) are major optical diagnostics being designed and developed for ITER. Each of them relies upon a sophisticated quantitative understanding of the electron response to laser light propagating through a burning plasma. Review of the theoretical results for two different applications is presented: interferometry/polarimetry (I/P) and polarization of Thomson scattered light, unified by the importance of relativistic (quadratic in vTe/c) electron kinetic effects. For I/P applications, rigorous analytical results are obtained perturbatively by expansion in powers of the small parameter τ = Te/me c2, where Te is electron temperature and me is electron rest mass. Experimental validation of the analytical models has been made by analyzing data of more than 1200 pulses collected from high-Te JET discharges. Based on this validation the relativistic analytical expressions are included in the error analysis and design projects of the ITER TIP and PoPola systems. The polarization properties of incoherent Thomson scattered light are being examined as a method of Te measurement relevant to ITER operational regimes. The theory is based on Stokes vector transformation and Mueller matrices formalism. The general approach is subdivided into frequency-integrated and frequency-resolved cases. For each of them, the exact analytical relativistic solutions are presented in the form of Mueller matrix elements averaged over the relativistic Maxwellian distribution function. New results related to the detailed verification of the frequency-resolved solutions are reported. The precise analytic expressions provide output much more rapidly than relativistic kinetic numerical codes allowing for direct real-time feedback control of ITER device operation.

Inclusive jet production in ultrarelativistic proton-nucleus collisions

CERN Document Server

Perepelitsa, Dennis

High-$p_\\mathrm{T}$ processes in proton- and deuteron-nucleus collisions at TeV energies are the best presently available way to study the partonic structure of the nucleus in a high-density regime. Jet production over a wide range of phase space can significantly constrain the current knowledge of nuclear parton distribution functions (nPDFs), which are substantially less well understood than the corresponding PDFs in protons and which have only recently begun to be treated in a spatially-dependent way. An accurate knowledge of nPDFs is crucial for a definitive control of perturbative processes in a cold nuclear environment, since high-$p_\\mathrm{T}$ probes are used to quantitatively investigate the hot QCD matter created in ultrarelativistic nucleus-nucleus collisions. Furthermore, jets from low Bjorken-$x$ partons can probe the transition from the dilute to saturated nuclear regimes. Jet production is investigated in $d$+Au collisions at $\\sqrt{s} = 200$ GeV with the PHENIX detector at the Relativistic Hea...

First Observation of Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum Space

CERN Document Server

Plettner, Tomas; Colby, Eric R; Cowan, Benjamin; Sears, Chris M S; Siemann, Robert; Smith, Todd I; Spencer, James

2005-01-01

We have observed acceleration of relativistic electrons in vacuum driven by a linearly polarized laser beam incident on a thin gold-coated reflective boundary. The observed energy modulation effect follows all the characteristics expected for linear acceleration caused by a longitudinal electric field. As predicted by the Lawson-Woodward theorem the laser driven modulation only appears in the presence of the boundary. It shows a linear dependence with the strength of the electric field of the laser beam and also it is critically dependent on the laser polarization. Finally, it appears to follow the expected angular dependence of the inverse transition radiation process.

Inclusive jet measurements in Pb+Pb collisions at 5 TeV with the ATLAS detector

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00443411; The ATLAS collaboration

2017-01-01

In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. Jets are produced at the early stages of this collision and are known to be affected by parton energy loss during their propagation through the hot medium. One manifestation of this energy loss is a lower yield of jets propagating the medium than expected in the absence of medium effects. ATLAS has provided a quantification of this jet suppression by the jet $R_{AA}$ measurement in run 1 of the LHC. A factor of two suppression was seen in central heavy ion collisions with respect to pp collisions. The $R_{AA}$ exhibited only a weak, if any, rapidity dependence, and a slow rise with increasing jet momentum. These proceedings summarizes results on the inclusive jet production, new results on dijet measurements and the measurement of the jet fragmentation in Pb+Pb collisions at center of mass energy of 2.76 TeV.

Gamma-jet physics with the electro-magnetic calorimeter in the ALICE experiment at LHC

Science.gov (United States)

Bourdaud, G.

2008-05-01

The Electro-Magnetic Calorimeter (EMCal) will be fully installed for the first LHC heavy ion beam in order to improve the ALICE experiment performances in detection of high transverse momentum particles and in particular in reconstruction of γ-jet events. These events appear to be very interesting to probe the strongly interacting matter created in ultra-relativistic heavy ion collisions and the eventual Quark Gluon Plasma (QGP) state. Indeed, they may give information on the degree of medium opacity which induces the jet-quenching phenomenon: measuring the energy of the γ and comparing it to that of the associated jet may provide a unique way to quantify the jet energy loss in the dense matter. The interest of γ-jet studies in the framework of the quark gluon plasma physics will be discussed. A particular highlight will be stressed on the EMCal calorimeter. The detection of the γ-jet events will be then presented using this new ALICE detector.

Relativistic Quantum Mechanics

International Nuclear Information System (INIS)

Antoine, J-P

2004-01-01

The aim of relativistic quantum mechanics is to describe the finer details of the structure of atoms and molecules, where relativistic effects become nonnegligible. It is a sort of intermediate realm, between the familiar nonrelativistic quantum mechanics and fully relativistic quantum field theory, and thus it lacks the simplicity and elegance of both. Yet it is a necessary tool, mostly for quantum chemists. Pilkuhn's book offers to this audience an up-to-date survey of these methods, which is quite welcome since most previous textbooks are at least ten years old. The point of view of the author is to start immediately in the relativistic domain, following the lead of Maxwell's equations rather than classical mechanics, and thus to treat the nonrelativistic version as an approximation. Thus Chapter 1 takes off from Maxwell's equations (in the noncovariant Coulomb gauge) and gradually derives the basic aspects of Quantum Mechanics in a rather pedestrian way (states and observables, Hilbert space, operators, quantum measurement, scattering,. Chapter 2 starts with the Lorentz transformations, then continues with the Pauli spin equation and the Dirac equation and some of their applications (notably the hydrogen atom). Chapter 3 is entitled 'Quantum fields and particles', but falls short of treating quantum field theory properly: only creation/annihilation operators are considered, for a particle in a box. The emphasis is on two-electron states (the Pauli principle, the Foldy--Wouthuysen elimination of small components of Dirac spinors, Breit projection operators. Chapter 4 is devoted to scattering theory and the description of relativistic bound states. Chapter 5, finally, covers hyperfine interactions and radiative corrections. As we said above, relativistic quantum mechanics is by nature limited in scope and rather inelegant and Pilkuhn's book is no exception. The notation is often heavy (mostly noncovariant) and the mathematical level rather low. The central topic

JET PROPERTIES OF GeV-SELECTED RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES AND POSSIBLE CONNECTION TO THEIR DISK AND CORONA

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiao-Na; Lin, Da-Bin; Liang, En-Wei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Zhang, Jin [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Xue, Zi-Wei; Zhang, Shuang-Nan, E-mail: zhang.jin@hotmail.com [Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China)

2015-01-01

The observed spectral energy distributions of five GeV-selected narrow-line Seyfert 1 (NLS1) galaxies are fitted with a model including the radiation ingredients from the relativistic jet, the accretion disk, and the corona. We compare the properties of these GeV NLS1 galaxies with flat spectrum radio quasars (FSRQs), BL Lacertae objects (BL Lacs), and radio-quiet (RQ) Seyfert galaxies, and explore possible hints for jet-disk/corona connection. Our results show that the radiation physics and the jet properties of the GeV NLS1 galaxies resemble that of FSRQs. The luminosity variations of PMN J0948+0022 and 1H 0323+342 at the GeV band is tightly correlated with the beaming factor (δ), similar to that observed in FSRQ 3C 279. The accretion disk luminosities and the jet powers of the GeV NLS1 galaxies cover both the ranges of FSRQs and BL Lacs. With the detection of bright corona emission in 1H 0323+342, we show that the ratio of the corona luminosity (L {sub corona}) to the accretion disk luminosity (L {sub d}) is marginally within the high end of this ratio distribution for an RQ Seyfert galaxy sample, and the variation of jet luminosity may connect with L {sub corona}. However, it is still unclear whether a system with a high L {sub corona}/L {sub d} ratio prefers to power a jet.

Merger and reconnection of Weibel separated relativistic electron beam

Science.gov (United States)

Shukla, Chandrasekhar; Kumar, Atul; Das, Amita; Patel, Bhavesh G.

2018-02-01

The relativistic electron beam (REB) propagation in a plasma is fraught with beam plasma instabilities. The prominent amongst them is the collisionless Weibel destabilization which spatially separates the forward propagating REB and the return shielding currents. This results in the formation of REB current filaments which are typically of the size of electron skin depth during the linear stage of the instability. It has been observed that in the nonlinear stage, the size of filaments increases as they merge with each other. With the help of 2-D particle-in-cell simulations in the plane perpendicular to the REB propagation, it is shown that these mergers occur in two distinct nonlinear phases. In the first phase, the total magnetic energy increases. Subsequently, however, during the second phase, one observes a reduction in magnetic energy. It is shown that the transition from one nonlinear regime to another occurs when the typical current associated with individual filaments hits the Alfvén threshold. In the second nonlinear regime, therefore, the filaments can no longer permit any increase in current. Magnetic reconnection events then dissipate the excess current (and its associated magnetic energy) that would result from a merger process leading to the generation of energetic electron jets in the perpendicular plane. At later times when there are only few filaments left, the individual reconnection events can be clearly identified. It is observed that in between such events, the magnetic energy remains constant and shows a sudden drop as and when two filaments merge. The electron jets released in these reconnection events are thus responsible for the transverse heating which has been mentioned in some previous studies [Honda et al., Phys. Plasmas 7, 1302 (2000)].

CONFRONTING THE JET MODEL OF Sgr A* WITH THE FARADAY ROTATION MEASURE OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Li, Ya-Ping; Yuan, Feng [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Daniel Wang, Q., E-mail: fyuan@shao.ac.cn, E-mail: wqd@astro.umass.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

2015-01-01

Sgr A* is probably the supermassive black hole being investigated most extensively due to its proximity to Earth. Several theoretical models for its steady state emission have been proposed in the past two decades. Both the radiative-inefficient accretion flow and the jet model have been shown to well explain the observed spectral energy distribution. The Faraday rotation measure (RM) has been unambiguously measured at the submillimeter wavelength, but it has only been tested against the accretion flow model. Here we first calculate the RM based on the jet model and find that the predicted value is two orders of magnitude lower than the measured value. We then include an additional contribution from the accretion flow in front of the jet and show that the measured RM may be reconciled with the model under some tight constraints. The main constraint is that the inclination angle should be greater than ∼73°. However, this requirement is not consistent with an existing observational estimate of the inclination angle.

Observation and explanation of the JET n=0 chirping mode

Energy Technology Data Exchange (ETDEWEB)

Boswell, C.J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)]. E-mail: christopher.boswell@navy.mil; Berk, H.L. [Institute for Fusion Studies, University of Texas at Austin, Austin, TX 78712-1060 (United States); Borba, D.N. [Centro de Fusao Nuclear Associacao Euratom-IST, Instituto Superior Tecnico, 1049001 Lisbon (Portugal); EFDA Close Support Unit, Culham Science Centre, OX14 3DB (United Kingdom); Johnson, T. [Alfven Laboratory, KTH, Euratom-VR Association (Sweden); Pinches, S.D. [Max-Planck Institute for Plasma Physics, EURATOM Association, D-85748 Garching (Germany); Sharapov, S.E. [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2006-10-09

Persistent rapid up and down frequency chirping modes with a toroidal mode number of zero (n=0) have been observed in the JET tokamak when energetic ions, with a mean energy {approx}500keV, were created by high field side ion cyclotron resonance frequency heating. This heating method enables the formation of an energetically inverted ion distribution function that allows ions to spontaneously excite the observed instability, identified as a global geodesic acoustic mode. The interpretation is that phase space structures form and interact with the fluid zonal flow to produce the pronounced frequency chirping.

Nonthermal Particle Acceleration in 3D Relativistic Magnetic Reconnection in Pair Plasma

Energy Technology Data Exchange (ETDEWEB)

Werner, Gregory R.; Uzdensky, Dmitri A., E-mail: Greg.Werner@colorado.edu [Center for Integrated Plasma Studies, Physics Department, University of Colorado, 390 UCB, Boulder, CO 80309 (United States)

2017-07-10

As a fundamental process converting magnetic to plasma energy in high-energy astrophysical plasmas, relativistic magnetic reconnection is a leading explanation for the acceleration of particles to the ultrarelativistic energies that are necessary to power nonthermal emission (especially X-rays and gamma-rays) in pulsar magnetospheres and pulsar wind nebulae, coronae and jets of accreting black holes, and gamma-ray bursts. An important objective of plasma astrophysics is therefore the characterization of nonthermal particle acceleration (NTPA) effected by reconnection. Reconnection-powered NTPA has been demonstrated over a wide range of physical conditions using large 2D kinetic simulations. However, its robustness in realistic 3D reconnection—in particular, whether the 3D relativistic drift-kink instability (RDKI) disrupts NTPA—has not been systematically investigated, although pioneering 3D simulations have observed NTPA in isolated cases. Here, we present the first comprehensive study of NTPA in 3D relativistic reconnection in collisionless electron–positron plasmas, characterizing NTPA as the strength of 3D effects is varied systematically via the length in the third dimension and the strength of the guide magnetic field. We find that, while the RDKI prominently perturbs 3D reconnecting current sheets, it does not suppress particle acceleration, even for zero guide field; fully 3D reconnection robustly and efficiently produces nonthermal power-law particle spectra closely resembling those obtained in 2D. This finding provides strong support for reconnection as the key mechanism powering high-energy flares in various astrophysical systems. We also show that strong guide fields significantly inhibit NTPA, slowing reconnection and limiting the energy available for plasma energization, yielding steeper and shorter power-law spectra.

Quark and gluon jet properties in symmetric three-jet events

CERN Document Server

Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Nicod, D; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Letho, M; Newton, W M; Rankin, C; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

1996-01-01

Quark and gluon jets with the same energy, 24GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on either a track impact parameter method or a high transverse momentum lepton tag. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity. Evidence is also presented which shows that the corresponding differences between gluon and heavy flavour jets are significantly smaller.

“Orphan” γ-Ray Flares and Stationary Sheaths of Blazar Jets

Science.gov (United States)

MacDonald, Nicholas R.; Jorstad, Svetlana G.; Marscher, Alan P.

2017-11-01

Blazars exhibit flares across the entire electromagnetic spectrum. Many γ-ray flares are highly correlated with flares detected at longer wavelengths; however, a small subset appears to occur in isolation, with little or no correlated variability at longer wavelengths. These “orphan” γ-ray flares challenge current models of blazar variability, most of which are unable to reproduce this type of behavior. MacDonald et al. have developed the Ring of Fire model to explain the origin of orphan γ-ray flares from within blazar jets. In this model, electrons contained within a blob of plasma moving relativistically along the spine of the jet inverse-Compton scatter synchrotron photons emanating off of a ring of shocked sheath plasma that enshrouds the jet spine. As the blob propagates through the ring, the scattering of the ring photons by the blob electrons creates an orphan γ-ray flare. This model was successfully applied to modeling a prominent orphan γ-ray flare observed in the blazar PKS 1510-089. To further support the plausibility of this model, MacDonald et al. presented a stacked radio map of PKS 1510-089 containing the polarimetric signature of a sheath of plasma surrounding the spine of the jet. In this paper, we extend our modeling and stacking techniques to a larger sample of blazars: 3C 273, 4C 71.01, 3C 279, 1055+018, CTA 102, and 3C 345, the majority of which have exhibited orphan γ-ray flares. We find that the model can successfully reproduce these flares, while our stacked maps reveal the existence of jet sheaths within these blazars.

Experimental simulation of satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds

Directory of Open Access Journals (Sweden)

M. Füllekrug

2011-01-01

Full Text Available Relativistic electron beams above thunderclouds emit 100 kHz radio waves which illuminate the Earth's atmosphere and near-Earth space. This contribution aims to clarify the physical processes which are relevant for the spatial spreading of the radio wave energy below and above the ionosphere and thereby enables an experimental simulation of satellite observations of 100 kHz radio waves from relativistic electron beams above thunderclouds. The simulation uses the DEMETER satellite which observes 100 kHz radio waves from fifty terrestrial Long Range Aid to Navigation (LORAN transmitters. Their mean luminosity patch in the plasmasphere is a circular area with a radius of 300 km and a power density of 22 μW/Hz as observed at 660 km height above the ground. The luminosity patches exhibit a southward displacement of 450 km with respect to the locations of the LORAN transmitters. The displacement is reduced to 150 km when an upward propagation of the radio waves along the geomagnetic field line is assumed. This residual displacement indicates that the radio waves undergo 150 km sub-ionospheric propagation prior to entering a magnetospheric duct and escaping into near-Earth space. The residual displacement at low (L < 2.14 and high (L > 2.14 geomagnetic latitudes ranges from 100 km to 200 km which suggests that the smaller inclination of the geomagnetic field lines at low latitudes helps to trap the radio waves and to keep them in the magnetospheric duct. Diffuse luminosity areas are observed northward of the magnetic conjugate locations of LORAN transmitters at extremely low geomagnetic latitudes (L < 1.36 in Southeast Asia. This result suggests that the propagation along the geomagnetic field lines results in a spatial spreading of the radio wave energy over distances of 1 Mm. The summative assessment of the electric field intensities measured in space show that nadir observations of terrestrial 100 kHz radio waves, e.g., from

Chiral quark model with relativistic kinematics

International Nuclear Information System (INIS)

Garcilazo, H.; Valcarce, A.

2003-01-01

The nonstrange baryon spectrum is studied within a three-body model that incorporates relativistic kinematics. We found that the combined effect of relativistic kinematics together with the pion exchange between quarks is able to reverse the order of the first positive- and negative-parity nucleon excited states as observed experimentally. Including the chiral partner of the pion (the σ meson) leads to an overall good description of the spectrum

Chiral quark model with relativistic kinematics

OpenAIRE

Garcilazo, H.; Valcarce, A.

2003-01-01

The non-strange baryon spectrum is studied within a three-body model that incorporates relativistic kinematics. We found that the combined effect of relativistic kinematics together with the pion exchange between quarks is able to reverse the order of the first positive- and negative-parity nucleon excited states as observed experimentally. Including the chiral partner of the pion (the $\\sigma$ meson) leads to an overall good description of the spectrum.

Gravitation relativiste

CERN Document Server

Hakim, Rémi

1994-01-01

Il existe à l'heure actuelle un certain nombre de théories relativistes de la gravitation compatibles avec l'expérience et l'observation. Toutefois, la relativité générale d'Einstein fut historiquement la première à fournir des résultats théoriques corrects en accord précis avec les faits.

Relativistic equations

International Nuclear Information System (INIS)

Gross, F.

1986-01-01

Relativistic equations for two and three body scattering are discussed. Particular attention is paid to relativistic three body kinetics because of recent form factor measurements of the Helium 3 - Hydrogen 3 system recently completed at Saclay and Bates and the accompanying speculation that relativistic effects are important for understanding the three nucleon system. 16 refs., 4 figs

Vector boson tagged jets and jet substructure

Directory of Open Access Journals (Sweden)

Vitev Ivan

2018-01-01

Full Text Available In these proceedings, we report on recent results related to vector boson-tagged jet production in heavy ion collisions and the related modification of jet substructure, such as jet shapes and jet momentum sharing distributions. Z0-tagging and γ-tagging of jets provides new opportunities to study parton shower formation and propagation in the quark-gluon plasma and has been argued to provide tight constrains on the energy loss of reconstructed jets. We present theoretical predictions for isolated photon-tagged and electroweak boson-tagged jet production in Pb+Pb collisions at √sNN = 5.02 TeV at the LHC, addressing the modification of their transverse momentum and transverse momentum imbalance distributions. Comparison to recent ATLAS and CMS experimental measurements is performed that can shed light on the medium-induced radiative corrections and energy dissipation due to collisional processes of predominantly quark-initiated jets. The modification of parton splitting functions in the QGP further implies that the substructure of jets in heavy ion collisions may differ significantly from the corresponding substructure in proton-proton collisions. Two such observables and the implication of tagging on their evaluation is also discussed.

The radiative deceleration of ultrarelativistic jets in active galactic nuclei

International Nuclear Information System (INIS)

Melia, F.; Konigl, A.

1989-01-01

A detailed study of the dynamical interaction between a highly relativistic jet and the thermal radiation field from an AGN accretion disk is reported, and the Comptonized spectrum arising from this interaction is self-consistently determined. A simple model that captures the essential radiative and geometrical features of realistic disk configurations is presented, and the disk radiation field is calculated. The results confirm Phinney's (1987) suggestion that the thermal radiation field produced by accretion in an AGN could be very effective in decelerating ultrarelativistic jets that are accreted by electromagnetic or hydromagnetic forces closer to the central black hole. Terminal Lorentz factors are consistent with the values inferred in superluminal radio sources are readily produced in this model for plausible disk and jet parameters without additional acceleration in the interaction zone. A new interpretation of the hard X-ray component detected in BL Lac spectra is proposed. 55 refs

Final Report for Project ``Theory of ultra-relativistic heavy-ion collisions''

Energy Technology Data Exchange (ETDEWEB)

Ulrich W. Heinz

2012-11-09

In the course of this project the Ohio State University group led by the PI, Professor Ulrich Heinz, developed a comprehensive theoretical picture of the dynamical evolution of ultra-relativistic heavy-ion collisions and of the numerous experimental observables that can be used to diagnose the evolving and short-lived hot and dense fireball created in such collisions. Starting from a qualitative understanding of the main features based on earlier research during the last decade of the twentieth century on collisions at lower energies, the group exploited newly developed theoretical tools and the stream of new high-quality data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (which started operations in the summer of the year 2000) to arrive at an increasingly quantitative description of the experimentally observed phenomena. Work done at Ohio State University (OSU) was instrumental in the discovery during the years 2001-2003 that quark-gluon plasma (QGP) created in nuclear collisions at RHIC behaves like an almost perfect liquid with minimal viscosity. The tool of relativistic fluid dynamics for viscous liquids developed at OSU in the years 2005-2007 opened the possibility to quantitatively determine the value of the QGP viscosity empirically from experimental measurements of the collective flow patterns established in the collisions. A first quantitative extraction of the QGP shear viscosity, with controlled theoretical uncertainty estimates, was achieved during the last year of this project in 2010. OSU has paved the way for a transition of the field of relativistic heavy-ion physics from a qualitative discovery stage to a new stage of quantitative precision in the description of quark-gluon plasma properties. To gain confidence in the precision of our theoretical understanding of quark-gluon plasma dynamics, one must test it on a large set of experimentally measured observables. This achievement report demonstrates that we have, at

Observation and studies of jet quenching in PbPb collisions at nucleon-nucleon center-of-mass energy = 2.76 TeV

Energy Technology Data Exchange (ETDEWEB)

Chatrchyan, Serguei [Yerevan Physics Inst. (Armenia); et al.

2011-08-01

Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.

Relativistic three-particle dynamical equations: II. Application to the trinucleon system

International Nuclear Information System (INIS)

Adhikari, S.K.; Tomio, L.

1993-11-01

The contribution of relativistic dynamics on the neutron-deuteron scattering length and triton binding energy is calculated employing five sets tri nucleon potential models and four types of three-dimensional relativistic three-body equations suggested in the preceding paper. The relativistic correction to binding energy may vary a lot and even change sign depending on the relativistic formulation employed. The deviations of these observables from those obtained in nonrelativistic models follow the general universal trend of deviations introduced by off- and on-shell variations of two- and three-nucleon potentials in a nonrelativistic model calculation. Consequently, it will be difficult to separate unambiguously the effect of off-and on-shell variations of two and three-nucleon potentials on low-energy three-nucleon observables from the effect of relativistic dynamics. (author)

Predications and Observations of Global Beta-induced Alfven-acoustic Modes in JET and NSTX

International Nuclear Information System (INIS)

Gorelenkov, N.N.

2008-01-01

In this paper we report on observations and interpretations of a new class of global MHD eigenmode solutions arising in gaps in the low frequency Alfven-acoustic continuum below the geodesic acoustic mode frequency. These modes have been just reported (Gorelenkov et al 2007 Phys. Lett. 370 70-7) where preliminary comparisons indicate qualitative agreement between theory and experiment. Here we show a more quantitative comparison emphasizing recent NSTX experiments on the observations of the global eigenmodes, referred to as beta-induced Alfven-acoustic eigenmodes (BAAEs), which exist near the extrema of the Alfven-acoustic continuum. In accordance to the linear dispersion relations, the frequency of these modes may shift as the safety factor, q, profile relaxes. We show that BAAEs can be responsible for observations in JET plasmas at relatively low beta 20%. In NSTX plasma observed magnetic activity has the same properties as predicted by theory for the mode structure and the frequency. Found numerically in NOVA simulations BAAEs are used to explain the observed properties of relatively low frequency experimental signals seen in NSTX and JET tokamaks

Bayesian Multiscale Analysis of X-Ray Jet Features in High Redshift Quasars

Science.gov (United States)

McKeough, Kathryn; Siemiginowska, A.; Kashyap, V.; Stein, N.

2014-01-01

X-ray emission of powerful quasar jets may be a result of the inverse Compton (IC) process in which the Cosmic Microwave Background (CMB) photons gain energy by interactions with the jet’s relativistic electrons. However, there is no definite evidence that IC/CMB process is responsible for the observed X-ray emission of large scale jets. A step toward understanding the X-ray emission process is to study the Radio and X-ray morphologies of the jet. We implement a sophisticated Bayesian image analysis program, Low-count Image Reconstruction and Analysis (LIRA) (Esch et al. 2004; Conners & van Dyk 2007), to analyze jet features in 11 Chandra images of high redshift quasars (z ~ 2 - 4.8). Out of the 36 regions where knots are visible in the radio jets, nine showed detectable X-ray emission. We measured the ratios of the X-ray and radio luminosities of the detected features and found that they are consistent with the CMB radiation relationship. We derived a range of the bulk lorentz factor (Γ) for detected jet features under the CMB jet emission model. There is no discernible trend of Γ with redshift within the sample. The efficiency of the X-ray emission between the detected jet feature and the corresponding quasar also shows no correlation with redshift. This work is supported in part by the National Science Foundation REU and the Department of Defense ASSURE programs under NSF Grant no.1262851 and by the Smithsonian Institution, and by NASA Contract NAS8-39073 to the Chandra X-ray Center (CXC). This research has made use of data obtained from the Chandra Data Archive and Chandra Source Catalog, and software provided by the CXC in the application packages CIAO, ChIPS, and Sherpa. We thank Teddy Cheung for providing the VLA radio images. Connors, A., & van Dyk, D. A. 2007, Statistical Challenges in Modern Astronomy IV, 371, 101 Esch, D. N., Connors, A., Karovska, M., & van Dyk, D. A. 2004, ApJ, 610, 1213

Hadron matrix elements of quark operators in the relativistic quark model

Energy Technology Data Exchange (ETDEWEB)

Bando, Masako; Toya, Mihoko [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, Hiroshi

1979-07-01

General formulae for evaluating matrix elements of two- and four-quark operators sandwiched by one-hadron states are presented on the basis of the relativistic quark model. Observed hadronic quantities are expressed in terms of those matrix elements of two- and four-quark operators. One observes various type of relativistic expression for the matrix elements which in the non-relativistic case reduce to simple expression of the so-called ''the wave function at the origin /sup +/psi(0)/sup +/''.

Jet-hadron correlations relative to the event plane in Pb--Pb collisions at the LHC in ALICE

CERN Document Server

Mazer, Joel

In relativistic heavy ion collisions at the Large Hadron Collider (LHC), a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP) is produced. Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. Within the framework of perturbative Quantum Chromodynamics (pQCD), jet production is well understood in pp collisions. We can use jets measured in pp interactions as a baseline reference for comparing to heavy ion collision systems to detect and study jet quenching. The jet quenching mechanism can be studied through the angular correlations of trigger jets with charged hadrons and is examined in transverse momentum bins of the trigger jets, transverse momentum bins of the associated hadrons, and studied as a function of collision centrality. A highly robust and precise background subtraction method is used in this analysis to remove the complex, flow domin...

Deformations of free jets

Science.gov (United States)

Paruchuri, Srinivas

This thesis studies three different problems. First we demonstrate that a flowing liquid jet can be controllably split into two separate subfilaments through the applications of a sufficiently strong tangential stress to the surface of the jet. In contrast, normal stresses can never split a liquid jet. We apply these results to observations of uncontrolled splitting of jets in electric fields. The experimental realization of controllable jet splitting would provide an entirely novel route for producing small polymeric fibers. In the second chapter we present an analytical model for the bending of liquid jets and sheets from temperature gradients, as recently observed by Chwalek et al. [Phys. Fluids, 14, L37 (2002)]. The bending arises from a local couple caused by Marangoni forces. The dependence of the bending angle on experimental parameters is presented, in qualitative agreement with reported experiments. The methodology gives a simple framework for understanding the mechanisms for jet and sheet bending. In chapter 4 we address the discrepancy between hydrodynamic theory of liquid jets, and the snap-off of narrow liquid jets observed in molecular dynamics (MD) simulations [23]. This has been previously attributed to the significant role of thermal fluctuations in nanofluidic systems. We argue that hydrodynamic description of such systems should include corrections to the Laplace pressure which result from the failure of the sharp interface assumption when the jet diameter becomes small enough. We show that this effect can in principle give rise to jet shapes similar to those observed in MD simulations, even when thermal fluctuations are completely neglected. Finally we summarize an algorithm developed to simulate droplet impact on a smooth surface.

Liouville equation of relativistic charged fermion

International Nuclear Information System (INIS)

Wang Renchuan; Zhu Dongpei; Huang Zhuoran; Ko Che-ming

1991-01-01

As a form of density martrix, the Wigner function is the distribution in quantum phase space. It is a 2 X 2 matrix function when one uses it to describe the non-relativistic fermion. While describing the relativistic fermion, it is usually represented by 4 x 4 matrix function. In this paper authors obtain a Wigner function for the relativistic fermion in the form of 2 x 2 matrix, and the Liouville equation satisfied by the Wigner function. this equivalent to the Dirac equation of changed fermion in QED. The equation is also equivalent to the Dirac equation in the Walecka model applied to the intermediate energy nuclear collision while the nucleon is coupled to the vector meson only (or taking mean field approximation for the scalar meson). Authors prove that the 2 x 2 Wigner function completely describes the quantum system just the same as the relativistic fermion wave function. All the information about the observables can be obtained with above Wigner function

The gamma-ray emitting region of the jet in Cyg X-3

Science.gov (United States)

Zdziarski, Andrzej A.; Sikora, Marek; Dubus, Guillaume; Yuan, Feng; Cerutti, Benoit; Ogorzałek, Anna

2012-04-01

We study models of the γ-ray emission of Cyg X-3 observed by Fermi. We calculate the average X-ray spectrum during the γ-ray active periods. Then, we calculate spectra from Compton scattering of a photon beam into a given direction by isotropic relativistic electrons with a power-law distribution, both based on the Klein-Nishina cross-section and in the Thomson limit. Applying the results to scattering of stellar blackbody radiation in the inner jet of Cyg X-3, we find that a low-energy break in the electron distribution at a Lorentz factor of ˜300-103 is required by the shape of the observed X-ray/γ-ray spectrum in order to avoid overproducing the observed X-ray flux. The electrons giving rise to the observed γ-rays are efficiently cooled by Compton scattering, and the power-law index of the acceleration process is ≃2.5-3. The bulk Lorentz factor of the jet and the kinetic power before the dissipation region depend on the fraction of the dissipation power supplied to the electrons; if it is ≃1/2, the Lorentz factor is ˜2.5, and the kinetic power is ˜1038 erg s-1, which represents a firm lower limit on the jet power, and is comparable to the bolometric luminosity of Cyg X-3. Most of the power supplied to the electrons is radiated. The broad-band spectrum constrains the synchrotron and self-Compton emission from the γ-ray emitting electrons, which requires the magnetic field to be relatively weak, with the magnetic energy density ≲ a few times 10-3 of that in the electrons. The actual value of the magnetic field strength can be inferred from a future simultaneous measurement of the infrared and γ-ray fluxes.

Measurement of the top-quark mass from the b jet energy spectrum

CERN Document Server

CMS Collaboration

2015-01-01

The top-quark mass is measured using the peak position of the energy distribution of b jets produced from top-quark decays. The analysis is based on a recent theoretical proposal. The measurement is carried out selecting $\\mathrm{t\\overline{t}}$ events with one electron and one muon in the final state in proton-proton collision data at $\\sqrt{s}=8~\\mathrm{TeV}$, corresponding to an integrated luminosity of 19.7$~\\mathrm{fb}^{-1}$. The fitted peak position of the observed energy distribution is calibrated using simulated events and translated to a top-quark mass measurement using relativistic kinematics, with the result $m_{\\mathrm{t}}=172.29\\pm1.17\\,(\\mathrm{stat.})\\pm2.66\\,(\\mathrm{syst.})~\\mathrm{GeV}$.

Point form relativistic quantum mechanics and relativistic SU(6)

Science.gov (United States)

Klink, W. H.

1993-01-01

The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.

Monte Carlo Simulations of Photospheric Emission in Relativistic Outflows

Science.gov (United States)

Bhattacharya, Mukul; Lu, Wenbin; Kumar, Pawan; Santana, Rodolfo

2018-01-01

We study the spectra of photospheric emission from highly relativistic gamma-ray burst outflows using a Monte Carlo code. We consider the Comptonization of photons with a fast-cooled synchrotron spectrum in a relativistic jet with a realistic photon-to-electron number ratio {N}γ /{N}{{e}}={10}5, using mono-energetic protons that interact with thermalized electrons through Coulomb interaction. The photons, electrons, and protons are cooled adiabatically as the jet expands outward. We find that the initial energy distributions of the protons and electrons do not have any appreciable effect on the photon peak energy {E}γ ,{peak} and the power-law spectrum above {E}γ ,{peak}. The Coulomb interaction between the electrons and the protons does not affect the output photon spectrum significantly as the energy of the electrons is elevated only marginally. {E}γ ,{peak} and the spectral indices for the low- and high-energy power-law tails of the photon spectrum remain practically unchanged even with electron-proton coupling. Increasing the initial optical depth {τ }{in} results in a slightly shallower photon spectrum below {E}γ ,{peak} and fewer photons at the high-energy tail, although {f}ν \\propto {ν }-0.5 above {E}γ ,{peak} and up to ∼1 MeV, independent of {τ }{in}. We find that {E}γ ,{peak} determines the peak energy and the shape of the output photon spectrum. Finally, we find that our simulation results are quite sensitive to {N}γ /{N}{{e}}, for {N}{{e}}=3× {10}3. For almost all our simulations, we obtain an output photon spectrum with a power-law tail above {E}γ ,{peak} extending up to ∼1 MeV.

CAFE: A NEW RELATIVISTIC MHD CODE

Energy Technology Data Exchange (ETDEWEB)

Lora-Clavijo, F. D.; Cruz-Osorio, A. [Instituto de Astronomía, Universidad Nacional Autónoma de México, AP 70-264, Distrito Federal 04510, México (Mexico); Guzmán, F. S., E-mail: fdlora@astro.unam.mx, E-mail: aosorio@astro.unam.mx, E-mail: guzman@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio C-3, Cd. Universitaria, 58040 Morelia, Michoacán, México (Mexico)

2015-06-22

We introduce CAFE, a new independent code designed to solve the equations of relativistic ideal magnetohydrodynamics (RMHD) in three dimensions. We present the standard tests for an RMHD code and for the relativistic hydrodynamics regime because we have not reported them before. The tests include the one-dimensional Riemann problems related to blast waves, head-on collisions of streams, and states with transverse velocities, with and without magnetic field, which is aligned or transverse, constant or discontinuous across the initial discontinuity. Among the two-dimensional (2D) and 3D tests without magnetic field, we include the 2D Riemann problem, a one-dimensional shock tube along a diagonal, the high-speed Emery wind tunnel, the Kelvin–Helmholtz (KH) instability, a set of jets, and a 3D spherical blast wave, whereas in the presence of a magnetic field we show the magnetic rotor, the cylindrical explosion, a case of Kelvin–Helmholtz instability, and a 3D magnetic field advection loop. The code uses high-resolution shock-capturing methods, and we present the error analysis for a combination that uses the Harten, Lax, van Leer, and Einfeldt (HLLE) flux formula combined with a linear, piecewise parabolic method and fifth-order weighted essentially nonoscillatory reconstructors. We use the flux-constrained transport and the divergence cleaning methods to control the divergence-free magnetic field constraint.

Relativistic transport theory for cosmic-rays

International Nuclear Information System (INIS)

Webb, G.M.

1985-01-01

Various aspects of the transport of cosmic-rays in a relativistically moving magnetized plasma supporting a spectrum of hydromagnetic waves that scatter the cosmic-rays are presented. A local Lorentz frame moving with the waves or turbulence scattering the cosmic-rays is used to specify the individual particle momentum. The comoving frame is in general a noninertial frame in which the observer's volume element is expanding and shearing, geometric energy change terms appear in the cosmic-ray transport equation which consist of the relativistic generalization of the adiabatic deceleration term and a further term involving the acceleration vector of the scatterers. A relativistic version of the pitch angle evolution equation, including the effects of adiabatic focussing, pitch angle scattering, and energy changes is presented

Relativistic laser channeling in plasmas for fast ignition

Science.gov (United States)

Lei, A. L.; Pukhov, A.; Kodama, R.; Yabuuchi, T.; Adumi, K.; Endo, K.; Freeman, R. R.; Habara, H.; Kitagawa, Y.; Kondo, K.; Kumar, G. R.; Matsuoka, T.; Mima, K.; Nagatomo, H.; Norimatsu, T.; Shorokhov, O.; Snavely, R.; Yang, X. Q.; Zheng, J.; Tanaka, K. A.

2007-12-01

We report an experimental observation suggesting plasma channel formation by focusing a relativistic laser pulse into a long-scale-length preformed plasma. The channel direction coincides with the laser axis. Laser light transmittance measurement indicates laser channeling into the high-density plasma with relativistic self-focusing. A three-dimensional particle-in-cell simulation reproduces the plasma channel and reveals that the collimated hot-electron beam is generated along the laser axis in the laser channeling. These findings hold the promising possibility of fast heating a dense fuel plasma with a relativistic laser pulse.

A unified treatment of the non-relativistic and relativistic hydrogen atom: Pt. 2

International Nuclear Information System (INIS)

Swainson, R.A.; Drake, G.W.F.

1991-01-01

This is the second in a series of three papers in which it is shown how the radial part of non-relativistic and relativistic hydrogenic bound-state calculations involving the Green functions can be presented in a unified manner. In this paper the non-relativistic Green function is examined in detail; new functional forms are presented and a clear mathematical progression is show to link these and most other known forms. A linear transformation of the four radial parts of the relativistic Green function is given which allows for the presentation of this function as a simple generalization of the non-relativistic Green function. Thus, many properties of the non-relativistic Green function are shown to have simple relativistic generalizations. In particular, new recursion relations of the radial parts of both the non-relativistic and relativistic Green functions are presented, along with new expressions for the double Laplace transforms and recursion relations between the radial matrix elements. (author)

Estimation of bipolar jets from accretion discs around Kerr black holes

Science.gov (United States)

Kumar, Rajiv; Chattopadhyay, Indranil

2017-08-01

We analyse flows around a rotating black hole and obtain self-consistent accretion-ejection solutions in full general relativistic prescription. Entire energy-angular momentum parameter space is investigated in the advective regime to obtain shocked and shock-free accretion solutions. Jet equations of motion are solved along the von Zeipel surfaces computed from the post-shock disc, simultaneously with the equations of accretion disc along the equatorial plane. For a given spin parameter, the mass outflow rate increases as the shock moves closer to the black hole, but eventually decreases, maximizing at some intermediate value of shock location. Interestingly, we obtain all types of possible jet solutions, for example, steady shock solution with multiple critical points, bound solution with two critical points and smooth solution with single critical point. Multiple critical points may exist in jet solution for spin parameter as ≥ 0.5. The jet terminal speed generally increases if the accretion shock forms closer to the horizon and is higher for corotating black hole than the counter-rotating and the non-rotating one. Quantitatively speaking, shocks in jet may form for spin parameter as > 0.6 and jet shocks range between 6rg and 130rg above the equatorial plane, while the jet terminal speed vj∞ > 0.35 c if Bernoulli parameter E≥1.01 for as > 0.99.

Uniform relativistic universe models with pressure. Part 2. Observational tests

International Nuclear Information System (INIS)

Krempec, J.; Krygier, B.

1977-01-01

The magnitude-redshift and angular diameter-redshift relations are discussed for the uniform (homogeneous and isotropic) relativistic Universe models with pressure. The inclusion of pressure into the energy-momentum tensor has given larger values of the deceleration parameter q. An increase of the deceleration parameter has led to the brightening of objects as well as to a little larger angular diameters. (author)

Critical Opalescence around the QCD Critical Point and Second-order Relativistic Hydrodynamic Equations Compatible with Boltzmann Equation

International Nuclear Information System (INIS)

Kunihiro, Teiji; Minami, Yuki; Tsumura, Kyosuke

2009-01-01

The dynamical density fluctuations around the QCD critical point (CP) are analyzed using relativistic dissipative fluid dynamics, and we show that the sound mode around the QCD CP is strongly attenuated whereas the thermal fluctuation stands out there. We speculate that if possible suppression or disappearance of a Mach cone, which seems to be created by the partonic jets at RHIC, is observed as the incident energy of the heavy-ion collisions is decreased, it can be a signal of the existence of the QCD CP. We have presented the Israel-Stewart type fluid dynamic equations that are derived rigorously on the basis of the (dynamical) renormalization group method in the second part of the talk, which we omit here because of a lack of space.

Critical Opalescence around the QCD Critical Point and Second-order Relativistic Hydrodynamic Equations Compatible with Boltzmann Equation

Science.gov (United States)

Kunihiro, Teiji; Minami, Yuki; Tsumura, Kyosuke

2009-11-01

The dynamical density fluctuations around the QCD critical point (CP) are analyzed using relativistic dissipative fluid dynamics, and we show that the sound mode around the QCD CP is strongly attenuated whereas the thermal fluctuation stands out there. We speculate that if possible suppression or disappearance of a Mach cone, which seems to be created by the partonic jets at RHIC, is observed as the incident energy of the heavy-ion collisions is decreased, it can be a signal of the existence of the QCD CP. We have presented the Israel-Stewart type fluid dynamic equations that are derived rigorously on the basis of the (dynamical) renormalization group method in the second part of the talk, which we omit here because of a lack of space.

Study of the O-mode in a relativistic degenerate electron plasma

Science.gov (United States)

Azra, Kalsoom; Ali, Muddasir; Hussain, Azhar

2017-03-01

Using the linearized relativistic Vlasov-Maxwell equations, a generalized expression for the plasma conductivity tensor is derived. The dispersion relation for the O-mode in a relativistic degenerate electron plasma is investigated by employing the Fermi-Dirac distribution function. The propagation characteristics of the O-mode (cut offs, resonances, propagation regimes, harmonic structure) are examined by using specific values of the density and the magnetic field that correspond to different relativistic dense environments. Further, it is observed that due to the relativistic effects the cut off and the resonance points are shifted to low frequency values, as a result the propagation regime is reduced. The dispersion relations for the non-relativistic and the ultra-relativistic limits are also presented.

MOJAVE. X. PARSEC-SCALE JET ORIENTATION VARIATIONS AND SUPERLUMINAL MOTION IN ACTIVE GALACTIC NUCLEI

Energy Technology Data Exchange (ETDEWEB)

Lister, M. L.; Richards, J. L. [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Aller, M. F.; Aller, H. D. [Department of Astronomy, University of Michigan, 817 Dennison Building, Ann Arbor, MI 48109 (United States); Homan, D. C. [Department of Physics, Denison University, Granville, OH 43023 (United States); Kellermann, K. I. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Kovalev, Y. Y. [Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Pushkarev, A. B.; Ros, E.; Savolainen, T., E-mail: mlister@purdue.edu [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)

2013-11-01

We describe the parsec-scale kinematics of 200 active galactic nucleus (AGN) jets based on 15 GHz Very Long Baseline Array (VLBA) data obtained between 1994 August 31 and 2011 May 1. We present new VLBA 15 GHz images of these and 59 additional AGNs from the MOJAVE and 2 cm Survey programs. Nearly all of the 60 most heavily observed jets show significant changes in their innermost position angle over a 12-16 yr interval, ranging from 10° to 150° on the sky, corresponding to intrinsic variations of ∼0.°5 to ∼2°. The BL Lac jets show smaller variations than quasars. Roughly half of the heavily observed jets show systematic position angle trends with time, and 20 show indications of oscillatory behavior. The time spans of the data sets are too short compared to the fitted periods (5-12 yr), however, to reliably establish periodicity. The rapid changes and large jumps in position angle seen in many cases suggest that the superluminal AGN jet features occupy only a portion of the entire jet cross section and may be energized portions of thin instability structures within the jet. We have derived vector proper motions for 887 moving features in 200 jets having at least five VLBA epochs. For 557 well-sampled features, there are sufficient data to additionally study possible accelerations. We find that the moving features are generally non-ballistic, with 70% of the well-sampled features showing either significant accelerations or non-radial motions. Inward motions are rare (2% of all features), are slow (<0.1 mas yr{sup –1}), are more prevalent in BL Lac jets, and are typically found within 1 mas of the unresolved core feature. There is a general trend of increasing apparent speed with distance down the jet for both radio galaxies and BL Lac objects. In most jets, the speeds of the features cluster around a characteristic value, yet there is a considerable dispersion in the distribution. Orientation variations within the jet cannot fully account for the

`Zwicky's Nonet': a compact merging ensemble of nine galaxies and 4C 35.06, a peculiar radio galaxy with dancing radio jets

Science.gov (United States)

Biju, K. G.; Bagchi, Joydeep; Ishwara-Chandra, C. H.; Pandey-Pommier, M.; Jacob, Joe; Patil, M. K.; Kumar, P. Sunil; Pandge, Mahadev; Dabhade, Pratik; Gaikwad, Madhuri; Dhurde, Samir; Abraham, Sheelu; Vivek, M.; Mahabal, Ashish A.; Djorgovski, S. G.

2017-10-01

We report the results of our radio, optical and infrared studies of a peculiar radio source 4C 35.06, an extended radio-loud active galactic nucleus (AGN) at the centre of galaxy cluster Abell 407 (z = 0.047). The central region of this cluster hosts a remarkably tight ensemble of nine galaxies, the spectra of which resemble those of passive red ellipticals, embedded within a diffuse stellar halo of ˜1 arcmin size. This system (named 'Zwicky's Nonet') provides unique and compelling evidence for a multiple-nucleus cD galaxy precursor. Multifrequency radio observations of 4C 35.06 with the Giant Meterwave Radio Telescope (GMRT) at 610, 235 and 150 MHz reveal a system of 400-kpc scale helically twisted and kinked radio jets and outer diffuse lobes. The outer extremities of jets contain extremely steep-spectrum (spectral index -1.7 to -2.5) relic/fossil radio plasma with a spectral age of a few ×(107-108) yr. Such ultra-steep spectrum relic radio lobes without definitive hotspots are rare and they provide an opportunity to understand the life cycle of relativistic jets and physics of black hole mergers in dense environments. We interpret our observations of this radio source in the context of growth of its central black hole, triggering of its AGN activity and jet precession, all possibly caused by galaxy mergers in this dense galactic system. A slow conical precession of the jet axis due to gravitational perturbation between interacting black holes is invoked to explain the unusual jet morphology.

Relativistic few body calculations

International Nuclear Information System (INIS)

Gross, F.

1988-01-01

A modern treatment of the nuclear few-body problem must take into account both the quark structure of baryons and mesons, which should be important at short range, and the relativistic exchange of mesons, which describes the long range, peripheral interactions. A way to model both of these aspects is described. The long range, peripheral interactions are calculated using the spectator model, a general approach in which the spectators to nucleon interactions are put on their mass-shell. Recent numerical results for a relativistic OBE model of the NN interaction, obtained by solving a relativistic equation with one-particle on mass-shell, will be presented and discussed. Two meson exchange models, one with only four mesons (π,σ,/rho/,ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with six mesons (π,σ,/rho/,ω,δ,/eta/) but pure γ 5 γ/sup μ/ pion coupling, are shown to give very good quantitative fits to the NN scattering phase shifts below 400 MeV, and also a good description of the /rvec p/ 40 Ca elastic scattering observables. Applications of this model to electromagnetic interactions of the two body system, with emphasis on the determination of relativistic current operators consistent with the dynamics and the exact treatment of current conservation in the presence of phenomenological form factors, will be described. 18 refs., 8 figs

Predictions and observations of global beta-induced Alfven-acoustic modes in JET and NSTX

Energy Technology Data Exchange (ETDEWEB)

Gorelenkov, N N [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Berk, H L [Institute for Fusion Studies, University of Texas, Austin, TX 78712 (United States); Crocker, N A [Institute of Plasma and Fusion Research, University of California, Los Angeles, CA 90095-1354 (United States); Fredrickson, E D [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Kaye, S [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Kubota, S [Institute of Plasma and Fusion Research, University of California, Los Angeles, CA 90095-1354 (United States); Park, H [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Peebles, W [Institute of Plasma and Fusion Research, University of California, Los Angeles, CA 90095-1354 (United States); Sabbagh, S A [Department of Applied Physics, Columbia University, New York, NY 10027-6902 (United States); Sharapov, S E [Euroatom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Stutmat, D [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Tritz, K [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Levinton, F M [Nova Photonics, One Oak Place, Princeton, NJ 08540 (United States); Yuh, H [Nova Photonics, One Oak Place, Princeton, NJ 08540 (United States)

2007-12-15

In this paper we report on observations and interpretations of a new class of global MHD eigenmode solutions arising in gaps in the low frequency Alfven-acoustic continuum below the geodesic acoustic mode frequency. These modes have been just reported (Gorelenkov et al 2007 Phys. Lett. 370 70-7) where preliminary comparisons indicate qualitative agreement between theory and experiment. Here we show a more quantitative comparison emphasizing recent NSTX experiments on the observations of the global eigenmodes, referred to as beta-induced Alfven-acoustic eigenmodes (BAAEs), which exist near the extrema of the Alfven-acoustic continuum. In accordance to the linear dispersion relations, the frequency of these modes may shift as the safety factor, q, profile relaxes. We show that BAAEs can be responsible for observations in JET plasmas at relatively low beta <2% as well as in NSTX plasmas at relatively high beta >20%. In NSTX plasma observed magnetic activity has the same properties as predicted by theory for the mode structure and the frequency. Found numerically in NOVA simulations BAAEs are used to explain the observed properties of relatively low frequency experimental signals seen in NSTX and JET tokamaks.

Relativistic astrophysics

CERN Document Server

Demianski, Marek

2013-01-01

Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity

Measurement of the strong coupling $\\alpha^{s}$ from four-jet observables in $e^{+}e^{-}$ annihilation

CERN Document Server

Abbiendi, G.; Akesson, P.F.; Alexander, G.; Anagnostou, G.; Anderson, K.J.; Asai, S.; Axen, D.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brown, Robert M.; Burckhart, H.J.; Campana, S.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krasznahorkay, A.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Meyer, Niels T.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rossi, A.M.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schorner-Sadenius, T.; Schroder, Matthias; Schumacher, M.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

2006-01-01

Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study the four-jet rate as a function of the Durham algorithm resolution parameter ycut. The four-jet rate is compared to next-to-leading order calculations that include the resummation of large logarithms. The strong coupling measured from the four-jet rate is alphas(Mz0)= 0.1182+-0.0003(stat.)+-0.0015(exp.)+-0.0011(had.)+-0.0012(scale)+-0.0013(mass) in agreement with the world average. Next-to-leading order fits to the D-parameter and thrust minor event-shape observables are also performed for the first time. We find consistent results, but with significantly larger theoretical uncertainties.

Multiple Jets at the LHC with High Energy Jets

DEFF Research Database (Denmark)

Andersen, Jeppe Rosenkrantz; Smillie, Jennifer M.

2011-01-01

We present a flexible Monte Carlo implementation of the perturbative framework of High Energy Jets, describing multi-jet events at hadron colliders. The description includes a resummation which ensures leading logarithmic accuracy for large invariant mass between jets, and is matched to tree......-level accuracy for multiplicities up to 4 jets. The resummation includes all-order hard corrections, which become important for increasing centre-of-mass energy of the hadronic collision. We discuss observables relevant for confronting the perturbative framework with 7 TeV data from the LHC, and the impact...

On the dispersion characteristics of extraordinary mode in a relativistic fully degenerate electron plasma

Science.gov (United States)

Noureen, S.; Abbas, G.; Sarfraz, M.

2018-01-01

The study of relativistic degenerate plasmas is important in many astrophysical and laboratory environments. Using linearized relativistic Vlasov-Maxwell equations, a generalized expression for the plasma conductivity tensor is derived. Employing Fermi-Dirac distribution at zero temperature, the dispersion relation of the extraordinary mode in a relativistic degenerate electron plasma is investigated. The propagation characteristics are examined in different relativistic density ranges. The shifting of cutoff points due to relativistic effects is observed analytically and graphically. Non-relativistic and ultra-relativistic limiting cases are also presented.

Jet substructure in ATLAS

CERN Document Server

Miller, David W

2011-01-01

Measurements are presented of the jet invariant mass and substructure in proton-proton collisions at $\\sqrt{s} = 7$ TeV with the ATLAS detector using an integrated luminosity of 37 pb$^{-1}$. These results exercise the tools for distinguishing the signatures of new boosted massive particles in the hadronic final state. Two "fat" jet algorithms are used, along with the filtering jet grooming technique that was pioneered in ATLAS. New jet substructure observables are compared for the first time to data at the LHC. Finally, a sample of candidate boosted top quark events collected in the 2010 data is analyzed in detail for the jet substructure properties of hadronic "top-jets" in the final state. These measurements demonstrate not only our excellent understanding of QCD in a new energy regime but open the path to using complex jet substructure observables in the search for new physics.

The X-Ray Reflection Spectrum of the Radio-loud Quasar 4C 74.26

DEFF Research Database (Denmark)

Lohfink, Anne M.; Fabian, Andrew C.; Ballantyne, David R.

2017-01-01

The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity of t...... the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies.......The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity...... of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our...

Observations of active galactic nuclei from radio to gamma-rays

International Nuclear Information System (INIS)

Boeck, Moritz

2013-01-01

In this work, Active Galactic Nuclei (AGN) - the brightest persistent objects in the universe - are discussed. According to current knowledge they consist out of several components. The central object of such systems is a supermassive black hole located in the center of a galaxy. Estimated masses of such black holes range from millions to billions of solar masses. The enormous gravitational field of the black hole affects material in its surrounding. Matter, such as gas, dust particles or stellar wind virtually provides the fuel for the AGN. The accretion process is highly efficient and partly explains the extreme luminosities of Active Galactic Nuclei. The thermal emission of the accretion disk is, however, insufficient for explaining the total emission of AGN. Observations show that some of these objects are visible throughout the complete electromagnetic spectrum. The emission in the radio regime as well as, most likely, high-energy emission seem to originate from jets. Unlike material accreted by the black hole, jets are collimated outflows with velocities near the speed of light. AGN are not completely understood. There are numerous open questions remaining, such as the exact accretion geometry, the formation and composition of the relativistic jets, the interaction between different components of these systems, as well as the place of origin and the underlying physical processes of the emission in different energy ranges. In order to address these questions a multiwavelength analysis of AGN has been performed in this work. The different energy regimes and observational techniques allow for insights into different processes and properties of such objects. A study of the connection between the accretion disk and properties of the jet has been done based on the object NGC 1052 using radio and X-ray observations. This object is a galaxy with an active nucleus. In the radio regime a double-sided jet with a projected length of several kpc is visible. In addition

Numerical investigation of kinetic turbulence in relativistic pair plasmas - I. Turbulence statistics

Science.gov (United States)

Zhdankin, Vladimir; Uzdensky, Dmitri A.; Werner, Gregory R.; Begelman, Mitchell C.

2018-02-01

We describe results from particle-in-cell simulations of driven turbulence in collisionless, magnetized, relativistic pair plasma. This physical regime provides a simple setting for investigating the basic properties of kinetic turbulence and is relevant for high-energy astrophysical systems such as pulsar wind nebulae and astrophysical jets. In this paper, we investigate the statistics of turbulent fluctuations in simulations on lattices of up to 10243 cells and containing up to 2 × 1011 particles. Due to the absence of a cooling mechanism in our simulations, turbulent energy dissipation reduces the magnetization parameter to order unity within a few dynamical times, causing turbulent motions to become sub-relativistic. In the developed stage, our results agree with predictions from magnetohydrodynamic turbulence phenomenology at inertial-range scales, including a power-law magnetic energy spectrum with index near -5/3, scale-dependent anisotropy of fluctuations described by critical balance, lognormal distributions for particle density and internal energy density (related by a 4/3 adiabatic index, as predicted for an ultra-relativistic ideal gas), and the presence of intermittency. We also present possible signatures of a kinetic cascade by measuring power-law spectra for the magnetic, electric and density fluctuations at sub-Larmor scales.

Relativistic electron dropout echoes induced by interplanetary shocks

Science.gov (United States)

Schiller, Q.; Kanekal, S. G.; Boyd, A. J.; Baker, D. N.; Blake, J. B.; Spence, H. E.

2017-12-01

Interplanetary shocks that impact Earth's magnetosphere can produce immediate and dramatic responses in the trapped relativistic electron population. One well-studied response is a prompt injection capable of transporting relativistic electrons deep into the magnetosphere and accelerating them to multi-MeV energies. The converse effect, electron dropout echoes, are observations of a sudden dropout of electron fluxes observed after the interplanetary shock arrival. Like the injection echo signatures, dropout echoes can also show clear energy dispersion signals. They are of particular interest because they have only recently been observed and their causal mechanism is not well understood. In the analysis presented here, we show observations of electron drift echo signatures from the Relativistic Electron-Proton Telescope (REPT) and Magnetic Electron and Ion Sensors (MagEIS) onboard NASA's Van Allen Probes mission, which show simultaneous prompt enhancements and dropouts within minutes of the associated with shock impact. We show that the observations associated with both enhancements and dropouts are explained by the inward motion caused by the electric field impulse induced by the interplanetary shock, and either energization to cause the enhancement, or lack of a seed population to cause the dropout.

The First X-shooter Observations of Jets from Young Stars

OpenAIRE

Bacciotti, Francesca; Whelan, Emma T.; Alcala', Juan M.; Nisini, Brunella; Podio, Linda; Randich, Sofia; Stelzer, Beate; Cupani, Guido

2011-01-01

We present the first pilot study of jets from young stars conducted with X-shooter, on ESO/VLT. As it offers simultaneous, high quality spectra in the range 300-2500 nm X-shooter is uniquely important for spectral diagnostics in jet studies. We chose to probe the accretion/ejection mechanisms at low stellar masses examining two targets with well resolved continuous jets lying on the plane of the sky, ESO-HA 574 in Chamaleon I, and Par-Lup3-4 in Lupus III. The mass of the latter is close to th...

LPWA using supersonic gas jet with tailored density profile

Science.gov (United States)

Kononenko, O.; Bohlen, S.; Dale, J.; D'Arcy, R.; Dinter, M.; Erbe, J. H.; Indorf, G.; di Lucchio, L.; Goldberg, L.; Gruse, J. N.; Karstensen, S.; Libov, V.; Ludwig, K.; Martinez de La Ossa, A.; Marutzky, F.; Niroula, A.; Osterhoff, J.; Quast, M.; Schaper, L.; Schwinkendorf, J.-P.; Streeter, M.; Tauscher, G.; Weichert, S.; Palmer, C.; Horbatiuk, Taras

2016-10-01

Laser driven plasma wakefield accelerators have been explored as a potential compact, reproducible source of relativistic electron bunches, utilising an electric field of many GV/m. Control over injection of electrons into the wakefield is of crucial importance in producing stable, mono-energetic electron bunches. Density tailoring of the target, to control the acceleration process, can also be used to improve the quality of the bunch. By using gas jets to provide tailored targets it is possible to provide good access for plasma diagnostics while also producing sharp density gradients for density down-ramp injection. OpenFOAM hydrodynamic simulations were used to investigate the possibility of producing tailored density targets in a supersonic gas jet. Particle-in-cell simulations of the resulting density profiles modelled the effect of the tailored density on the properties of the accelerated electron bunch. Here, we present the simulation results together with preliminary experimental measurements of electron and x-ray properties from LPWA experiments using gas jet targets and a 25 TW, 25 fs Ti:Sa laser system at DESY.

Relativistic quantum logic

International Nuclear Information System (INIS)

Mittelstaedt, P.

1983-01-01

on the basis of the well-known quantum logic and quantum probability a formal language of relativistic quantum physics is developed. This language incorporates quantum logical as well as relativistic restrictions. It is shown that relativity imposes serious restrictions on the validity regions of propositions in space-time. By an additional postulate this relativistic quantum logic can be made consistent. The results of this paper are derived exclusively within the formal quantum language; they are, however, in accordance with well-known facts of relativistic quantum physics in Hilbert space. (author)

Re-hardening of hadron transverse mass spectra in relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Ohnishi, A.; Otuka, N.; Sahu, P.K.; Isse, M.; Nara, Y.

2001-01-01

We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65 + 65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation. (author)

Relativistic quantum mechanics; Mecanique quantique relativiste

Energy Technology Data Exchange (ETDEWEB)

Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)

1998-12-01

These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.

Quark versus Gluon Jet Tagging Using Jet Images with the ATLAS Detector

CERN Document Server

The ATLAS collaboration

2017-01-01

Distinguishing quark-initiated from gluon-initiated jets is useful for many measurements and searches at the LHC. This note presents a jet tagger for distinguishing quark-initiated from gluon-initiated jets, which uses the full radiation pattern inside a jet processed as an image in a deep neural network classifier. The study is conducted using simulated dijet events in $\\sqrt{s}$=13 TeV pp collisions with the ATLAS detector. Across a wide range of quark jet identification efficiencies, the neural network tagger achieves a gluon jet rejection that is comparable to or better than the performance of the jet width and track multiplicity observables conventionally used for quark-versus-gluon jet tagging.

On the possibility of a new relativistic contraction law

International Nuclear Information System (INIS)

Rossler, O.E.; Froehlich, D.; Kleiner, N.; Pfaff, M.; Argyris, J.

2004-01-01

How does a 'standing' light wave that is perpendicular to the direction of motion of a receding observer, look to the observer? Both the relativistic Doppler effect and the relativistic conservation of lateral distances, implicit in the Lorentz transformation, are valid. Nevertheless, the size of all objects in the receding frame can be shown to be changed. To keep the observed light consistent with the observed nodal separation, a scale transformation is required. The factor is the same as governs the frequency change. The proposed result is consistent with a recent size-change result obtained in a gravitational setting

Blue jets and gigantic jets: transient luminous events between thunderstorm tops and the lower ionosphere

International Nuclear Information System (INIS)

Pasko, V P

2008-01-01

An overview of general phenomenology and proposed physical mechanisms of large scale electrical discharges termed 'blue jets' and 'gigantic jets' observed at high altitude in the Earth's atmosphere above thunderstorms is presented. The primary emphasis is placed on summarizing available experimental data on the observed morphological features of upward jet discharges and on the discussion of recently advanced theories describing electrodynamic conditions, which facilitate escape of conventional lightning leaders from thundercloud tops and their upward propagation toward the ionosphere. It is argued that the filamentary plasma structures observed in blue jet and gigantic jet discharges are directly linked to the processes in streamer zones of lightning leaders, scaled by a significant reduction of air pressure at high altitudes.

Relativistic Binaries in Globular Clusters

Directory of Open Access Journals (Sweden)

Matthew J. Benacquista

2013-03-01

Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

Characteristics of polar coronal hole jets

Science.gov (United States)

Chandrashekhar, K.; Bemporad, A.; Banerjee, D.; Gupta, G. R.; Teriaca, L.

2014-01-01

Context. High spatial- and temporal-resolution images of coronal hole regions show a dynamical environment where mass flows and jets are frequently observed. These jets are believed to be important for the coronal heating and the acceleration of the fast solar wind. Aims: We studied the dynamics of two jets seen in a polar coronal hole with a combination of imaging from EIS and XRT onboard Hinode. We observed drift motions related to the evolution and formation of these small-scale jets, which we tried to model as well. Methods: Stack plots were used to find the drift and flow speeds of the jets. A toymodel was developed by assuming that the observed jet is generated by a sequence of single reconnection events where single unresolved blobs of plasma are ejected along open field lines, then expand and fall back along the same path, following a simple ballistic motion. Results: We found observational evidence that supports the idea that polar jets are very likely produced by multiple small-scale reconnections occurring at different times in different locations. These eject plasma blobs that flow up and down with a motion very similar to a simple ballistic motion. The associated drift speed of the first jet is estimated to be ≈27 km s-1. The average outward speed of the first jet is ≈171 km s-1, well below the escape speed, hence if simple ballistic motion is considered, the plasma will not escape the Sun. The second jet was observed in the south polar coronal hole with three XRT filters, namely, C-poly, Al-poly, and Al-mesh filters. Many small-scale (≈3″-5″) fast (≈200-300 km s-1) ejections of plasma were observed on the same day; they propagated outwards. We observed that the stronger jet drifted at all altitudes along the jet with the same drift speed of ≃7 km s-1. We also observed that the bright point associated with the first jet is a part of sigmoid structure. The time of appearance of the sigmoid and that of the ejection of plasma from the bright

Dissipative relativistic hydrodynamics

International Nuclear Information System (INIS)

Imshennik, V.S.; Morozov, Yu.I.

1989-01-01

Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova

Jet-Underlying Event Separation Method for Heavy Ion Collisions at the Relativistic Heavy Ion Collider

OpenAIRE

Hanks, J. A.; Sickles, A. M.; Cole, B. A.; Franz, A.; McCumber, M. P.; Morrison, D. P.; Nagle, J. L.; Pinkenburg, C. H.; Sahlmueller, B.; Steinberg, P.; von Steinkirch, M.; Stone, M.

2012-01-01

Reconstructed jets in heavy ion collisions are a crucial tool for understanding the quark-gluon plasma. The separation of jets from the underlying event is necessary particularly in central heavy ion reactions in order to quantify medium modifications of the parton shower and the response of the surrounding medium itself. There have been many methods proposed and implemented for studying the underlying event substructure in proton-proton and heavy ion collisions. In this paper, we detail a me...

Cosmic anisotropy with reduced relativistic gas

Energy Technology Data Exchange (ETDEWEB)

Castardelli dos Reis, Simpliciano [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Shapiro, Ilya L. [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Tomsk State Pedagogical University, Tomsk (Russian Federation); Tomsk State University, Tomsk (Russian Federation)

2018-02-15

The dynamics of cosmological anisotropies is investigated for Bianchi type I universe filled by a relativistic matter represented by the reduced relativistic gas model (RRG), with equation of state interpolating between radiation and matter. Previously it was shown that the interpolation is observed in the background cosmological solutions for homogeneous and isotropic universe and also for the linear cosmological perturbations. We extend the application of RRG to the Bianchi type I anisotropic model and find that the solutions evolve to the isotropic universe with the pressureless matter contents. (orig.)

Jets, black holes and disks in blazars

Directory of Open Access Journals (Sweden)

Ghisellini Gabriele

2013-12-01

Full Text Available The Fermi and Swift satellites, together with ground based Cherenkov telescopes, has greatly improved our knowledge of blazars, namely Flat Spectrum Radio Quasars and BL Lac objects, since all but the most powerful emit most of their electro–magnetic output at γ–ray energies, while the very powerful blazars emit mostly in the hard X–ray region of the spectrum. Often they show coordinated variability at different frequencies, suggesting that in these cases the same population of electrons is at work, in a single zone of the jet. The location of this region along the jet is a matter of debate. The jet power correlates with the mass accretion rate, with jets existing at all values of disk luminosities, measured in Eddington units, sampled so far. The most powerful blazars show clear evidence of the emission from their disks, and this has revived methods of finding the black hole mass and accretion rate by modelling a disk spectrum to the data. Being so luminous, blazars can be detected also at very high redshift, and therefore are a useful tool to explore the far universe. One interesting line of research concerns how heavy are their black holes at high redshifts. If we associate the presence of a relativistic jets with a fastly spinning black hole, then we naively expect that the accretion efficiency is larger than for non–spinning holes. As a consequence, the black hole mass in jetted systems should grow at a slower rate. In turn, this would imply that, at high redshifts, the heaviest black holes should be in radio–quiet quasars. We instead have evidences of the opposite, challenging our simple ideas of how a black hole grows.

Radiative electron capture studied in relativistic heavy-ion atom collisions

International Nuclear Information System (INIS)

Stoehlker, T.; Kozhuharov, C.; Mokler, P.H.; Warczak, A.; Bosch, F.; Geissel, H.; Moshammer, R.; Scheidenberger, C.; Eichler, J.; Shirai, T.; Stachura, Z.; Rymuza, P.

1994-08-01

The process of Radiative Electron Capture (REC) in relativistic collisions of high-Z ions with low-Z gaseous and solid targets is studied experimentally and theoretically. The observed X-ray spectra are analysed with respect to photon angular distributions as well as to total K-REC cross sections. The experimental results for angle-differential cross sections are well-reproduced by exact relativistic calculations which yield significant deviations from standard sin 2 θ distributions. Total cross sections for K-REC are shown to follow a simple scaling rule obtained from exact relativistic calculations as well as from a non-relativistic dipole approximation. The agreement between these different theoretical approaches must be regarded as fortuitous, but it lends support to the use of the non-relativistic approach for practical purposes. (orig.)

On the time delay between ultra-relativistic particles

Energy Technology Data Exchange (ETDEWEB)

Fleury, Pierre, E-mail: pierre.fleury@uct.ac.za [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa); Department of Physics, University of the Western Cape, Robert Sobukwe Road, Bellville 7535 (South Africa)

2016-09-10

The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through an arbitrary spacetime has been derived recently by Fanizza et al., using a particular coordinate system and self-consistent assumptions. The present article shows that this formula enjoys a simple physical interpretation: the relative velocity between two ultra-relativistic particles is constant. This result reveals an interesting kinematical property of general relativity, namely that the tidal forces experienced by ultra-relativistic particles in the direction of their motion are much smaller than those experienced orthogonally to their motion.

On the time delay between ultra-relativistic particles

International Nuclear Information System (INIS)

Fleury, Pierre

2016-01-01

The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through an arbitrary spacetime has been derived recently by Fanizza et al., using a particular coordinate system and self-consistent assumptions. The present article shows that this formula enjoys a simple physical interpretation: the relative velocity between two ultra-relativistic particles is constant. This result reveals an interesting kinematical property of general relativity, namely that the tidal forces experienced by ultra-relativistic particles in the direction of their motion are much smaller than those experienced orthogonally to their motion.

THE PROPAGATION OF NEUTRINO-DRIVEN JETS IN WOLF-RAYET STARS

Energy Technology Data Exchange (ETDEWEB)

Nagakura, Hiroki, E-mail: hiroki@heap.phys.waseda.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, JapanAND (Japan); Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan)

2013-02-20

We numerically investigate the jet propagation through a rotating collapsing Wolf-Rayet star with detailed central engine physics constructed based on the neutrino-driven collapsar model. The collapsing star determines the evolution of the mass accretion rate, black hole mass, and spin, all of which are important ingredients for determining the jet luminosity. We reveal that neutrino-driven jets in rapidly spinning Wolf-Rayet stars are capable of breaking out from the stellar envelope, while those propagating in slower rotating progenitors fail to break out due to insufficient kinetic power. For progenitor models with successful jet breakouts, the kinetic energy accumulated in the cocoon could be as large as {approx}10{sup 51} erg and might significantly contribute to the luminosity of the afterglow emission or to the kinetic energy of the accompanying supernova if nickel production takes place. We further analyze the post-breakout phase using a simple analytical prescription and conclude that the relativistic jet component could produce events with an isotropic luminosity L {sub p(iso)} {approx} 10{sup 52} erg s{sup -1} and isotropic energy E {sub j(iso)} {approx} 10{sup 54} erg. Our findings support the idea of rapidly rotating Wolf-Rayet stars as plausible progenitors of GRBs, while slowly rotational ones could be responsible for low-luminosity or failed GRBs.

Generation of Attosecond x-ray pulse using Coherent Relativistic Nonlinear Thomson Scattering

Energy Technology Data Exchange (ETDEWEB)

Lee, Ki Tae; Park, Seong Hee; Cha, Yong Ho; Jeong, Young Uk; Lee, Byung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2005-07-01

Relativistic plasma, a new regime in physics, has been opened due to the development in ultra-intense laser technology during the past decade. Not only the fundamental aspect of relativistic plasma are attractive but also its potential application seems to be significant especially in the area of the generation of high energy particles such as electrons, ions, positrons, and {gamma}-rays. The generation of x-ray radiation with a pulse width of sub-femtoseconds presently draws much attention because such a radiation allows one to explore ultra-fast dynamics of electrons and nucleons. Several schemes have been proposed and/or demonstrated to generate an ultra-short x-ray pulse: the relativistic Doppler shift of a backscattered laser pulse by a relativistic electron beam, the harmonic frequency upshift of a laser pulse by relativistic nonlinear motion of electrons, high order harmonic generation in the interaction of intense laser pulse with noble gases and solids The train of a few 100 attosecond pulses has been observed in the case of laser-noble gas interaction. When a low-intensity laser pulse is irradiated on an electron, the electron undergoes a harmonic oscillatory motion and generates a dipole radiation with the same frequency as the incident laser pulse, which is called Thomson scattering. As the laser intensity increases, the oscillatory motion of the electron becomes relativistically nonlinear, which leads to the generation of harmonic radiations, referred to as Relativistic Nonlinear Thomson Scattered (RNTS) radiation. The motion of the electron begins to be relativistic as the following normalized vector potential approaches to unity: a{sub 0}=8.5 x 10{sup -10} {lambda}{iota}{sup 1/2} , (1) where {lambda} is the laser wavelength in {mu}m and I the laser intensity in W/cm{sup 2} The RNTS radiation has been investigated in analytical ways. Recently, indebted to the development of the ultra-intense laser pulse, experiments on RNTS radiation have been carried

Radiatively driven relativistic spherical winds under relativistic radiative transfer

Science.gov (United States)

Fukue, J.

2018-05-01

We numerically investigate radiatively driven relativistic spherical winds from the central luminous object with mass M and luminosity L* under Newtonian gravity, special relativity, and relativistic radiative transfer. We solve both the relativistic radiative transfer equation and the relativistic hydrodynamical equations for spherically symmetric flows under the double-iteration processes, to obtain the intensity and velocity fields simultaneously. We found that the momentum-driven winds with scattering are quickly accelerated near the central object to reach the terminal speed. The results of numerical solutions are roughly fitted by a relation of \\dot{m}=0.7(Γ _*-1)\\tau _* β _* β _out^{-2.6}, where \\dot{m} is the mass-loss rate normalized by the critical one, Γ* the central luminosity normalized by the critical one, τ* the typical optical depth, β* the initial flow speed at the central core of radius R*, and βout the terminal speed normalized by the speed of light. This relation is close to the non-relativistic analytical solution, \\dot{m} = 2(Γ _*-1)\\tau _* β _* β _out^{-2}, which can be re-expressed as β _out^2/2 = (Γ _*-1)GM/c^2 R_*. That is, the present solution with small optical depth is similar to that of the radiatively driven free outflow. Furthermore, we found that the normalized luminosity (Eddington parameter) must be larger than unity for the relativistic spherical wind to blow off with intermediate or small optical depth, i.e. Γ _* ≳ \\sqrt{(1+β _out)^3/(1-β _out)}. We briefly investigate and discuss an isothermal wind.

Looking inside jets: optical polarimetry as a probe of Gamma-Ray Bursts physics

Science.gov (United States)

Kopac, D.; Mundell, C.

2015-07-01

It is broadly accepted that gamma-ray bursts (GRBs) are powered by accretion of matter by black holes, formed during massive stellar collapse, which launch ultra-relativistic, collimated outflows or jets. The nature of the progenitor star, the structure of the jet, and thus the underlying mechanisms that drive the explosion and provide collimation, remain some of the key unanswered questions. To approach these problems, and in particular the role of magnetic fields in GRBs, early time-resolved polarimetry is the key, because it is the only direct probe of the magnetic fields structure. Using novel fast RINGO polarimeter developed for use on the 2-m robotic optical Liverpool Telescope, we have made the first measurements of optical linear polarization of the early optical afterglows of GRBs, finding linear percentage polarization as high as 30% and, for the first time, making time-resolved polarization measurements. I will present the past 8 years of RINGO observations, discuss how the results fit into the GRB theoretical picture, and highlight recent data, in particular high-time resolution multi-colour optical photometry performed during the prompt GRB phase, which also provides some limits on polarization.

Handbook of relativistic quantum chemistry

International Nuclear Information System (INIS)

Liu, Wenjian

2017-01-01

This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.

Universality of hadron jets in soft and hard particle interactions at high energies

International Nuclear Information System (INIS)

Baldin, A.M.; Didenko, L.A.; Grishin, V.G.; Kuznetsov, A.A.

1985-01-01

The hadron jet production in soft π - p- and cumulative π - pC-interactions at a 40 GeV/c momentum is studied. The collective characteristics of jets and the functions of the quark and diquark fragmentation into charged pions and neutral strange particles are analysed. The results obtained are compared with analogous data for e + e - - and ν(anti ν)p- interactions. The hadron jet properties are also studied using relativistic invariant variables - the squared relative 4-velocities b sub(ik).-(Psub(i)/msub(i)-Psub(k)sup(2)/msub(k) (where Psub(i), Psub(k) are 4-momenta of i-th and K-th particles and msub(i), msub(k) are their masses). The results obtained show that the quark (diquark) fragmentation proceed in a similar manner in soft hadron-hadron collisions, cumulative interactions on light nuclei, in e + e - -annihilation and deep inelastic ν(anti ν)p-scattering

Relativistic rotation and the anholonomic object

International Nuclear Information System (INIS)

Corum, J.F.

1977-01-01

The purpose of this communication is to call attention to the conceptual economy provided by the object of anholonomity for the theory of relativity. This geometric object expresses certain consequences of relativity theory and provides a single, simple framework for discussing a variety of phenomena. It particularly clarifies the description of relativistic rotation. The relativistic rotational transformation of the four coordinate differentials of flat space--time generates a set of anholonomic, or inexact differentials, whose duals are an orthogonal set of basis vectors. How should a rotating observer interpret physical events referred to such orthogonal, but anholonomic frames The answer to this question rests upon the origin and physical significance of the object of anholonomity. It is demonstrated that not only is the rotational Lorentz transformation an anholonomic transformation, but that the intrinsic anholonomic effects are essential to interpreting rotational phenomena. In particular, the Sagnac effect may be interpreted as the physical manifestation of temporal anholonomity under rotation. The Thomas precession of a reference axis may be interpreted as a consequence of the spatial anholonomity of the rotating frame. Further, the full four-dimensional covariance of Maxwellian electrodynamics, under a relativistic Lorentz rotation, is possible only with the inclusion of anholonomic effects. The anholonomic approach clarifies the distinction between the physically different operations of source rotation and observer rotation in a flat space--time. It is finally concluded that a consistant theory of relativistic rotation, satisfying the principle of general covariance, inherently requires the presence of the object of anholonomity

Afterglow Observations Shed New Light on the Nature of X-ray Flashes

Energy Technology Data Exchange (ETDEWEB)

Granot, J

2005-02-17

X-ray flashes (XRFs) and X-ray rich gamma-ray bursts (XRGRBs) share many observational characteristics with long duration ({approx}> 2 s) GRBs, but the reason for which the spectral energy distribution of their prompt emission peaks at lower photon energies, E{sub p}, is still a subject of debate. Although many different models have been invoked in order to explain the lower values of E{sub p}, their implications for the afterglow emission were not considered in most cases, mainly because observations of XRF afterglows have become available only recently. Here we examine the predictions of the various XRF models for the afterglow emission, and test them against the observations of XRF 030723 and XRGRB 041006, the events with the best monitored afterglow light curves in their respective class. We show that most existing XRF models are hard to reconcile with the observed afterglow light curves, which are very flat at early times. Such light curves are, however, naturally produced by a roughly uniform jet with relatively sharp edges that is viewed off-axis (i.e. from outside of the jet aperture). This type of model self consistently accommodates both the observed prompt emission and the afterglow light curves of XRGRB 041006 and XRF 030723, implying viewing angles {theta}{sub obs} from the jet axis of ({theta}{sub obs}-{theta}{sub 0}) {approx} 0.15 {theta}{sub 0} and ({theta}{sub obs}-{theta}{sub 0}) {approx} {theta}{sub 0}, respectively, where {theta}{sub 0} {approx} 3{sup o} is the half-opening angle of the jet. This suggests that GRBs, XRGRBs and XRFs are intrinsically similar relativistic jets viewed from different angles. It is then natural to identify GRBs with {gamma}({theta}{sub obs} - {theta}{sub 0}) {approx}< 1, XRGRBs with 1 {approx}< ({theta}{sub obs} - {theta}{sub 0}) {approx}< a few, and XRFs with {gamma}({theta}{sub obs} - {theta}{sub 0}) {approx}> a few, where {gamma} is the Lorentz factor of the outflow near the edge of the jet from which most of the

Relativistic many-body theory of atomic transitions. The relativistic equation-of-motion approach

International Nuclear Information System (INIS)

Huang, K.

1982-01-01

An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated with the use of techniques of quantum-field theory. To reduce the equations of motion to a tractable form which is appropriate for numerical calculations, a graphical method to resolve the complication arising from the antisymmetrization and angular-momentum coupling is employed. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation

Relativistic many-body theory of atomic transitions: the relativistic equation-of-motion approach

International Nuclear Information System (INIS)

Huang, K.N.

1981-01-01

An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated using techniques of quantum field theory. To reduce the equation of motion to a tractable form which is appropriate for numerical calculations, a graphical method is employed to resolve the complication arising from the antisymmetrization and angular momentum coupling. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation

Newly-Developed 3D GRMHD Code and its Application to Jet Formation

Science.gov (United States)

Mizuno, Y.; Nishikawa, K.-I.; Koide, S.; Hardee, P.; Fishman, G. J.

2006-01-01

We have developed a new three-dimensional general relativistic magnetohydrodynamic code by using a conservative, high-resolution shock-capturing scheme. The numerical fluxes are calculated using the HLL approximate Riemann solver scheme. The flux-interpolated constrained transport scheme is used to maintain a divergence-free magnetic field. We have performed various 1-dimensional test problems in both special and general relativity by using several reconstruction methods and found that the new 3D GRMHD code shows substantial improvements over our previous model. The . preliminary results show the jet formations from a geometrically thin accretion disk near a non-rotating and a rotating black hole. We will discuss the jet properties depended on the rotation of a black hole and the magnetic field strength.

Jets and QCD

International Nuclear Information System (INIS)

Ali, A.; Kramer, G.

2010-12-01

The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e + e - collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W ± ,Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

Jets and QCD

Energy Technology Data Exchange (ETDEWEB)

Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, G. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

2010-12-15

The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e{sup +}e{sup -} collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W{sup {+-}},Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

New Jet Substructure Techniques at ATLAS

CERN Document Server

Swiatlowski, M; The ATLAS collaboration

2013-01-01

The Q-jets technique introduces the idea of interpreting jets through multiple sets of possible showering histories. This approach allows jet observables, such as the jet mass, to be evaluated not simply as single values, but rather as distributions. The resulting distributions can be interpreted statistically to form new observables, allowing the separation of boosted, hadronically-decaying particles from light quark and gluon backgrounds. We present a study of Q-jets in boosted, hadronically-decaying $W$ boson and dijet samples, demonstrating the discriminating power of this technique. Different Q-jet parameters and observables are studied, and an optimal configuration based on physics performance and computational efficiency is proposed, leading to a factor of 15 in dijet rejection at a 50\\% efficiency for jets from boosted, hadronically decaying $W$ bosons. The impact of pile-up on the performance of this method is tested up to an average of 40 additional interactions per event and found to be weak. A per...

Experimental observations and modelling of thermal history within a steel plate during water jet impingement

International Nuclear Information System (INIS)

Liu, Z.D.; Fraser, D.; Samarasekera, I.V.; Lockhart, G.T.

2002-01-01

In order to investigate heat transfer of steel plates under a water jet impingement and to further simulate runout table operation in a hot strip mill, a full-scale pilot runout table facility was designed and constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement by one circular water jet from an industrial header. Recorded visual observations at the impinging surface were obtained. The effects of cooling water temperature and impingement velocity on the heat transfer from a steel plate were studied. A two-dimensional finite element method-based transient inverse heat conduction model was developed. With the help of the model, heat fluxes and heat transfer coefficients along the impinging surface under various cooling conditions were calculated. The microstructural evolution of the steel plate was also investigated for the varying cooling conditions. Samples were obtained from each plate, polished, etched and then photographed. (author)

Relativistic spin precession in the double pulsar.

Science.gov (United States)

Breton, Rene P; Kaspi, Victoria M; Kramer, Michael; McLaughlin, Maura A; Lyutikov, Maxim; Ransom, Scott M; Stairs, Ingrid H; Ferdman, Robert D; Camilo, Fernando; Possenti, Andrea

2008-07-04

The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%.

Relativistic duality, and relativistic and radiative corrections for heavy-quark systems

International Nuclear Information System (INIS)

Durand, B.; Durand, L.

1982-01-01

We give a JWKB proof of a relativistic duality relation which relates an appropriate energy average of the physical cross section for e + e - →qq-bar bound states→hadrons to the same energy average of the perturbative cross section for e + e - →qq-bar. We show that the duality relation can be used effectively to estimate relativistic and radiative corrections for bound-quark systems to order α/sub s//sup ts2/. We also present a formula which relates the square of the ''large'' 3 S 1 Salpeter-Bethe-Schwinger wave function for zero space-time separation of the quarks to the square of the nonrelativistic Schroedinger wave function at the origin for an effective potential which reproduces the relativistic spectrum. This formula allows one to use the nonrelativistic wave functions obtained in potential models fitted to the psi and UPSILON spectra to calculate relativistic leptonic widths for qq-bar states via a relativistic version of the van Royen--Weisskopf formula

Handbook of relativistic quantum chemistry

Energy Technology Data Exchange (ETDEWEB)

Liu, Wenjian (ed.) [Peking Univ., Beijing (China). Center for Computational Science and Engineering

2017-03-01

This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.

Causality and relativistic effects in intranuclear cascade calculations

International Nuclear Information System (INIS)

Kodama, T.; Duarte, S.B.; Chung, K.C.; Donangelo, R.J.; Nazareth, R.A.M.S.

1983-01-01

Relativistic effects in high energy nuclear collisions, when non-invariance of simultaneity is taken into account, are studied. It is shown that the time ordering of nucleon-nucleon collisions is quite different for different observers, giving in some cases non-invariant final results for intranuclear cascade (INC) calculations. In particular, an example of such a case is shown, in which the INC simulation, depending on the reference frame, presents a kind of density instability caused by a specific time ordering of collision events. A new INC calculation, using a causality preserving scheme, which minimizes this kind of relativistic effect is proposed. It is verified that the causality preserving INC prescription essentially recovers the relativistic invariance. (Author) [pt

Probing jets from young embedded sources

Science.gov (United States)

Nisini, Brunella

2017-08-01

Jets are intimately related to the process of star formation and disc accretion. Our present knowledge of this key ingredient in protostars mostly relies on observations of optical jets from T Tauri stars, where the original circumstellar envelope has been already cleared out. However, to understand how jets are originally formed and how their properties evolve with time, detailed observations of young accreting protostars, i.e. the class 0/I sources, are mandatory. The study of class0/I jets will be revolutionised by JWST, able to penetrate protostars dusty envelopes with unprecedented sensitivity and resolution. However, complementary information on parameters inferred from lines in different excitation regimes, for at least a representative sample of a few bright sources, is essential for a correct interpretation of the JWST results. Here we propose to observe four prototype bright jets from class0/I sources with the WFC3 in narrow band filters in order to acquire high angular resolution images in the [OI]6300A, [FeII]1.25 and [FeII]1.64um lines. These images will be used to: 1) provide accurate extinction maps of the jets that will be an important archival reference for any future observation on these jets. 2) measure key parameters as the mass flux, the iron abundance and the jet collimation on the hot gas component of the jets. These information will provide an invaluable reference frame for a comparison with similar parameters measured by JWST in a different gas regime. In addition, these observations will allow us to confront the properties of class 0/I jets with those of the more evolved T Tauri stars.

Relativistic non-Hamiltonian mechanics

International Nuclear Information System (INIS)

Tarasov, Vasily E.

2010-01-01

Relativistic particle subjected to a general four-force is considered as a nonholonomic system. The nonholonomic constraint in four-dimensional space-time represents the relativistic invariance by the equation for four-velocity u μ u μ + c 2 = 0, where c is the speed of light in vacuum. In the general case, four-forces are non-potential, and the relativistic particle is a non-Hamiltonian system in four-dimensional pseudo-Euclidean space-time. We consider non-Hamiltonian and dissipative systems in relativistic mechanics. Covariant forms of the principle of stationary action and the Hamilton's principle for relativistic mechanics of non-Hamiltonian systems are discussed. The equivalence of these principles is considered for relativistic particles subjected to potential and non-potential forces. We note that the equations of motion which follow from the Hamilton's principle are not equivalent to the equations which follow from the variational principle of stationary action. The Hamilton's principle and the principle of stationary action are not compatible in the case of systems with nonholonomic constraint and the potential forces. The principle of stationary action for relativistic particle subjected to non-potential forces can be used if the Helmholtz conditions are satisfied. The Hamilton's principle and the principle of stationary action are equivalent only for a special class of relativistic non-Hamiltonian systems.

Jet-hadron correlations relative to the event plane at the LHC with ALICE

Science.gov (United States)

Mazer, Joel; Alice Collaboration

2017-11-01

In ultra relativistic heavy-ion collisions at the Large Hadron Collider (LHC), conditions are met to produce a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP). Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. The outgoing partons scatter and interact with the medium, leading to a manifestation of medium modifications of jets in the final state, known as jet quenching. Within the framework of perturbative QCD, jet production is well understood in pp collisions. We use jets measured in pp interactions as a baseline reference for comparing to heavy-ion collision systems to detect and study jet quenching. The jet quenching mechanism can be studied through the angular correlations of jets with charged hadrons and is examined in transverse momentum (pT) bins of the jets, pT bins of the associated hadrons, and as a function of collision centrality. A robust and precise background subtraction method is used in this analysis to remove the complex, flow dominated, heavy-ion background. The analysis of angular correlations for different orientations of the jet relative to the event plane allows for the study of the path-length dependence of medium modifications to jets. The event plane dependence of azimuthal angular correlations of charged hadrons with respect to the axis of an R = 0.2 reconstructed full (charged + neutral) jet in Pb-Pb collisions at √{sNN} = 2.76 TeV in ALICE is presented. Results are compared for three angular bins of the jet relative to the event plane in mid-peripheral events. The yields relative to the event plane are presented and then quantified through yield ratio calculations. The results show no significant path-length dependence on the medium modifications.

Gamma-hadrons and hadrons-hadrons correlation measurements in p-p collisions at 7 TeV to study jet fragmentation with ALICE at LHC

International Nuclear Information System (INIS)

Mao, Y.

2011-06-01

The ALICE experiment, which uses the ultra-relativistic heavy-ions collisions produced by the LHC at CERN, is dedicated to the study of a new state of nuclear matter, which could be composed of a Quark-Gluon Plasma (QGP). Among the probes sharing information on the medium properties, those relative to the production of high transverse momentum jets are very interesting. The analysis presented in this thesis is focused on photon-jet events, which contain one photon of high transverse momentum and one jet emitted in the opposite direction. The jet comes from the fragmentation of the initial parton, after passing through the medium. The thesis includes a simulation study of the relevant observables for the photon-hadron correlation measurement and an analysis of first data from LHC in proton-proton collisions. Preliminary results on the transverse momentum of incident partons and on the correlation function have been obtained. The layout of the thesis is as follows. In chapter 2 the author reviews the scientific background of heavy ion physics, where the experimental observables exploited so far in different experiments are listed. Jets and 2-particle correlations are described in chapter 3. The experimental apparatus of the ALICE experiment at LHC is introduced in chapter 4. In chapter 5 the approach for a feasibility study with ALICE detectors from Monte-Carlo data is fully validated, then the 2 particle correlations with γ/π 0 triggers measured by ALICE within the data collected in 2010 at the first year LHC run is presented in chapter 6. (author)

First observation of the depolarization of Thomson scattering radiation by a fusion plasma

Science.gov (United States)

Giudicotti, L.; Kempenaars, M.; McCormack, O.; Flanagan, J.; Pasqualotto, R.; contributors, JET

2018-04-01

We report the first experimental observation of the depolarization of the Thomson scattering (TS) radiation, a relativistic effect expected to occur in very high {{T}e} plasmas and never observed so far in a fusion machine. A set of unused optical fibers in the collection optics of the high resolution Thomson scattering system of JET has been used to detect the depolarized TS radiation during a JET campaign with {{T}e}≤slant 8 keV . A linear polarizer with the axis perpendicular to the direction of the incident E-field was placed in front of a fiber optic pair observing a region close to the plasma core, while another fiber pair with no polariser simultaneously observed an adjacent plasma region. The measured intensity ratio was found to be consistent with the theory, taking into account sensitivity coefficients of the two measurement channels determined with post-experiment calibrations and Raman scattering. This depolarization effect is at the basis of polarimetric TS, a different and complementary method for the analysis of TS spectra that can provide significant advantages for {{T}e} measurements in very hot plasmas such as in ITER ≤ft({{T}e}≤slant 40 keV \\right) .

Jets in d (p )-A collisions: Color transparency or energy conservation

Science.gov (United States)

Kordell, Michael; Majumder, Abhijit

2018-05-01

The production of jets, and high momentum hadrons from jets, produced in deuteron-Au (d -Au) collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and proton-Pb (p -Pb) collisions at the CERN Large Hadron Collider (LHC) are studied as a function of centrality, a measure of the impact parameter of the collision. A modified version of the event generator pythia, widely used to simulate p -p collisions, is used in conjunction with a nuclear Monte Carlo event generator which simulates the locations of the nucleons within a large nucleus. We demonstrate how events with a hard jet may be simulated, in such a way that the parton distribution function of the projectile is "frozen" during its interaction with the extended nucleus. Using our approach, we demonstrate that the puzzling enhancement seen in peripheral events at RHIC and the LHC, as well as the suppression seen in central events at the LHC, are possibly due to mis-binning of central and semicentral events, containing a jet, as peripheral events. This occurs due to the suppression of soft particle production away from the jet, caused by the depletion of energy available in a nucleon of the deuteron (in d -Au at RHIC) or in the proton (in p -Pb at LHC), after the production of a hard jet. We conclude that partonic correlations built out of simple energy conservation are responsible for such an effect, though these are sampled at the hard scale of jet production and, as such, represent smaller states.

On the characterization of infinitesimal symmetries of the relativistic phase space

International Nuclear Information System (INIS)

Janyška, Josef; Vitolo, Raffaele

2012-01-01

The phase space of relativistic particle mechanics is defined as the first jet space of motions regarded as time-like one-dimensional submanifolds of spacetime. A Lorentzian metric and an electromagnetic 2-form define naturally a generalized contact structure on the odd-dimensional phase space. In the paper, infinitesimal symmetries of the phase structures are characterized. More precisely, it is proved that all phase infinitesimal symmetries are special Hamiltonian lifts of distinguished conserved quantities on the phase space. It is proved that generators of infinitesimal symmetries constitute a Lie algebra with respect to a special bracket. A momentum map for groups of symmetries of the geometric structures is provided. (paper)

Observation of very large transverse momentum jets at the CERN pp collider

CERN Document Server

Banner, M; Bonaudi, Franco; Borer, K; Borghini, M; Chollet, J C; Clark, A G; Conta, C; Darriulat, Pierre; Di Lella, L; Dines-Hansen, J; Dorsaz, P A; Fayard, L; Fraternali, M; Froidevaux, D; Gaillard, J M; Gildemeister, O; Goggi, V G; Grote, H; Hahn, B; Hänni, H; Hansen, J R; Hansen, P; Himel, T; Hungerbühler, V; Jenni, Peter; Kofoed-Hansen, Otto Møgens; Livan, M; Loucatos, Sotirios S; Madsen, B; Mansoulié, B; Mantovani, G C; Mapelli, L; Merkel, B; Mermikides, Michael E; Møllerud, R; Nilsson, B; Onions, Christopher J; Parrour, G; Pastore, F; Plothow-Besch, H; Repellin, J P; Ringel, J; Rothenberg, A F; Roussarie, A; Sauvage, G; Schacher, J; Siegrist, J L; Stocker, F; Teiger, J; Vercesi, V; Williams, H H; Zaccone, Henri; Zeller, W

1982-01-01

The distribution of total transverse energy Sigma E/sub T/ over the pseudorapidity interval -1( eta (1 and an azimuthal range Delta phi =300 degrees has been measured in the UA2 experiment at the CERN pp collider ( \\sqrt{s}=540 GeV) using a highly segmented total absorption calorimeter. In the events with the very large Sigma E/sub T/ ( Sigma E/sub T/>or approximately=60 GeV) most of the transverse energy is found to be contained in small angular regions as expected for high transverse momentum hadron jets. The authors discuss the properties of a sample of two-jet events with invariant two-jet masses up to 140 GeV/c/sup 2/ and measure the cross section for inclusive jet production in the range of jet transverse momenta between 15 and 60 Ge V/c.

Identifying a new particle with jet substructures

International Nuclear Information System (INIS)

Han, Chengcheng; Kim, Doojin; Kim, Minho; Postech, Pohang

2017-01-01

Here, we investigate a potential of determining properties of a new heavy resonance of mass O(1)TeV which decays to collimated jets via heavy Standard Model intermediary states, exploiting jet substructure techniques. Employing the Z gauge boson as a concrete example for the intermediary state, we utilize a "merged jet" defined by a large jet size to capture the two quarks from its decay. The use of the merged jet bene ts the identification of a Z-induced jet as a single, reconstructed object without any combinatorial ambiguity. We also find that jet substructure procedures may enhance features in some kinematic observables formed with subjet four-momenta extracted from a merged jet. This observation motivates us to feed subjet momenta into the matrix elements associated with plausible hypotheses on the nature of the heavy resonance, which are further processed to construct a matrix element method (MEM)-based observable. For both moderately and highly boosted Z bosons, we demonstrate that the MEM in combination with jet substructure techniques can be a very powerful tool for identifying its physical properties. Finally, we discuss effects from choosing different jet sizes for merged jets and jet-grooming parameters upon the MEM analyses.