A Review of Recent Solar Type III Imaging Spectroscopy

Solar type III radio bursts are the most common impulsive radio signatures from the Sun, stimulated by electron beams traveling through the solar corona and solar wind. Type III burst analysis provides us with a powerful remote sensing diagnostic tool for both the electron beams and the plasma they travel through. Advanced radio telescopes like the LOw Frequency ARray (LOFAR), the Murchison Widefield Array (MWA) and the Karl G. Jansky Very Large Array (VLA) are now giving us type III imaging spectroscopy with orders of magnitude better resolution than before. In this review, the recent observational progress provided by the new observations is discussed for type III bursts at GHz and MHz frequencies, including how this enhanced resolution has facilitated study of type III burst fine structure. The new results require more detailed theoretical understanding of how type III bursts are produced. Consequently, recent numerical work is discussed which improves our understanding of how electron beams, Langmuir waves and radio waves evolve through the turbulent solar system plasma. Looking toward the future, some theoretical challenges are discussed that we need to overcome on our quest to understand type III bursts and the electron beams that drive them

Biliary complications after liver transplantation: With special reference to the biliary cast syndrome and techniques of secondary duct repair

In 93 consecutive cases of orthotopic liver transplantation, there were 24 examples of biliary obstruction and eight of bile fistula formation. Six of the obstructed livers developed biliary cast formation so extensive that the smaller intrahepatic ducts became plugged to an extent that they could no longer have been treated by surgical means. In each of the six cases, the most important causative factor was neglected obstruction of the large bile ducts with the intrahepatic lesions apparently being late and secondary. Stone and/or cast formation also occurred in other obstructed livers in the presence of bile fistulas, but these deposits were limited to the large ducts where they could have been or were removed. Although homograft bile undoubtedly has increased lithogenicity at certain postoperative times, the data from the present study have shown that biliary sludge formation essentially is always associated with defective bile duct reconstruction, and the observations have underscored the urgency with which reoperation must be considered. Techniques of secondary intervention have been described, with emphasis on conversion of cholecystojejunostomy to choledochojejunostomy. This operation has permitted salvage of homografts in eight of nine trials and the survival of seven patients. © 1977

Liver Transplantation for Budd-Chiari Syndrome

Orthotopic liver transplantation was accomplished in a 22-year-old woman dying of the Budd-Chiari syndrome. She is well and has normal liver function 16 months postoperatively. In view of the good early result, it will be appropriate to consider liver replacement for this disease in further well-selected cases. © 1976, American Medical Association. All rights reserved

Localized Acceleration of Energetic Particles by a Weak Shock in the Solar Corona

Globally-propagating shocks in the solar corona have long been studied to quantify their involvement in the acceleration of energetic particles. However, this work has tended to focus on large events associated with strong solar flares and fast coronal mass ejections (CMEs), where the waves are sufficiently fast to easily accelerate particles to high energies. Here we present observations of particle acceleration associated with a global wave event which occurred on 1 October 2011. Using differential emission measure analysis, the global shock wave was found to be incredibly weak, with an Alfv\'en Mach number of ~1.008-1.013. Despite this, spatially-resolved type III radio emission was observed by the Nan\c{c}ay RadioHeliograph at distinct locations near the shock front, suggesting localised acceleration of energetic electrons. Further investigation using a magnetic field extrapolation identified a fan structure beneath a magnetic null located above the source active region, with the erupting CME contained within this topological feature. We propose that a reconfiguration of the coronal magnetic field driven by the erupting CME enabled the weak shock to accelerate particles along field lines initially contained within the fan and subsequently opened into the heliosphere, producing the observed type III emission. These results suggest that even weak global shocks in the solar corona can accelerate energetic particles via reconfiguration of the surrounding magnetic field

A study of the Relationship Between the Microwave and Meter-Wavelength Emissions from the Solar Flare on June 3, 2021

We present the preliminary results of the flare analysis. The event took place on 3rd June 2021, at 01:36 UT. It was observed in microwaves by Siberian Radioheliograph (SRH) within the 3-6 GHz, Broadband Microwave Spectropolarimeter (BBMS) and in meter radio range by e-Callisto spectrograph network. We found several of the type III bursts and the type-J burst in the meter radio range. At the same time, only the one burst was detected in the averaged time profiles of microwaves emission. This one corresponds to the strongest type III radio burst. Using the images by SRH, we defined the two sources and analysis of the time profiles of them separately. This approach allowed us finding the microwave bursts associated with the radio bursts, which were not distinguished in averaged time profiles. The delays between microwave and meter radio emission obtained from observations were compared with the results of preliminary analysis of dynamic spectra in radio meter range

The high-energy Sun - probing the origins of particle acceleration on our nearest star

As a frequent and energetic particle accelerator, our Sun provides us with an excellent astrophysical laboratory for understanding the fundamental process of particle acceleration. The exploitation of radiative diagnostics from electrons has shown that acceleration operates on sub-second time scales in a complex magnetic environment, where direct electric fields, wave turbulence, and shock waves all must contribute, although precise details are severely lacking. Ions were assumed to be accelerated in a similar manner to electrons, but γ-ray imaging confirmed that emission sources are spatially separated from X-ray sources, suggesting distinctly different acceleration mechanisms. Current X-ray and γ-ray spectroscopy provides only a basic understanding of accelerated particle spectra and the total energy budgets are therefore poorly constrained. Additionally, the recent detection of relativistic ion signatures lasting many hours, without an electron counterpart, is an enigma. We propose a single platform to directly measure the physical conditions present in the energy release sites and the environment in which the particles propagate and deposit their energy. To address this fundamental issue, we set out a suite of dedicated instruments that will probe both electrons and ions simultaneously to observe; high (seconds) temporal resolution photon spectra (4 keV – 150 MeV) with simultaneous imaging (1 keV – 30 MeV), polarization measurements (5–1000 keV) and high spatial and temporal resolution imaging spectroscopy in the UV/EUV/SXR (soft X-ray) regimes. These instruments will observe the broad range of radiative signatures produced in the solar atmosphere by accelerated particles

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s=7 TeV

This is the pre-print version of the Published Article which can be accessed from the link below.Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at √s=7  TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch/dη||η|<0.5=5.78±0.01(stat)±0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from √s=0.9 to 7 TeV is [66.1±1.0(stat)±4.2(syst)]%. The mean transverse momentum is measured to be 0.545±0.005(stat)±0.015(syst)  GeV/c. The results are compared with similar measurements at lower energies

Search for supersymmetry in events with b jets and missing transverse momentum at the LHC

A search for supersymmetry is presented using a sample of events with b jets and missing transverse momentum. The search uses a data sample of proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 35 pb(-1), collected with the CMS detector. A total of 0.33(-0.33)(+0.43) (stat.) +/- 0.13 (syst.) events is predicted, using control samples in the data, to arise from standard model processes, and one event is observed in the data. Upper limits are set at the 95% confidence level on the cross sections of benchmark supersymmetric models

Indications of suppression of excited Υ states in Pb-Pb collisions at √sNN = 2.76TeV

This is the pre-print version of the Published Article which can be accessed from the link below.A comparison of the relative yields of Υ resonances in the μ+μ- decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4  GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)]Pb-Pb/[Υ(2S+3S)/Υ(1S)]pp, is found to be 0.31-0.15+0.19(stat)±0.03(syst). The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%