The Blazar TXS 0506+056 Associated with a High-energy Neutrino: Insights into Extragalactic Jets and Cosmic-Ray Acceleration

A neutrino with energy of ∼290 TeV, IceCube-170922A, was detected in coincidence with the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, with chance coincidence being rejected at ∼ 3σ level. We monitored the object in the very-high-energy (VHE) band with the MAGIC telescopes for ∼41 hours from 1.3 to 40.4 days after the neutrino detection. Day-timescale variability is clearly resolved. We interpret the quasi-simultaneous neutrino and broadband electromagnetic observations with a novel one-zone lepto-hadronic model, based on interactions of electrons and protons co-accelerated in the jet with external photons originating from a slow-moving plasma sheath surrounding the faster jet spine. We can reproduce the multiwavelength spectra of TXS 0506+056 with neutrino rate and energy compatible with IceCube-170922A, and with plausible values for the jet power of ∼ 10^45 − 4×10^46 erg s^{; ; ; −1}; ; ; . The steep spectrum observed by MAGIC is concordant with internal γγ absorption above ∼100 GeV entailed by photohadronic production of a ∼290 TeV neutrino, corroborating a genuine connection between the multi-messenger signals. In contrast to previous predictions of predominantly hadronic emission from neutrino sources, the gamma-rays can be mostly ascribed to inverse Compton up-scattering of external photons by accelerated electrons. The X-ray and VHE bands provide crucial constraints on the emission from both accelerated electrons and protons. We infer that the maximum energy of protons in the jet co-moving frame can be in the range ∼ 10^14 to 10^18 eV

Synthesis of hematite and iron oxyhydroxide nanocrystals by precipitation of Fe3+ ions inside oleic acid micelles

alpha-Fe2O3 nanospheres with diameters of 20-40 nm and FeOOH nanorods with diameters of 150-200 nm and lengths of 0.5-1.0 mu m were synthesized via hydrolysis of Fe(NO3)(3) and FeCl3 solutions, respectively, in the presence of urea and oleic acid, under reflux at temperature similar to 90 degrees C for 8 h. The molar ratio of Fe3+ ions and urea were changed until pure phases have been obtained. The key parameter of the synthesis which provides pure hematite and beta-FeOOH phases was the pH. The samples were characterized by X-ray powder diffraction, transmission electron microscopy and Mossbauer spectroscopy. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Multifocal Abrikossoff's granular cell tumor of the oesophagus: Case report

INTRODUCTION Granular cell tumors, relatively uncommon soft tissue tumors, have been a matter of debate among pathologists regarding histogenesis for a long time. Less common locations are in the aerodigestive tract including the oesophagus. CASE OUTLINE We have recently treated a rare case, a 37-year old male, who was admitted due to dysphagia and a painful swallow with occasional pharyngo-nasal regurgitation followed with a mild loss of weight. Standard clinical examination including X-ray chest, ECG and laboratory tests did not show pathological findings. Barium contrast oesophagography demonstrated multiple ovoid defects in the wall of the oesophagus. CT scan of the chest confirmed luminal narrowing owing to the tumor of the upper oesophagus. Upper endoscopy showed unusual multifocal nodular lesions alongside the oesophageal axis covered by smooth mucosa. A primary biopsy specimen taken from the largest nodules confirmed an unusual pathological finding of the granular cell tumor. Subtotal, transpleural oesophagectomy was performed and reconstruction was derived by long colon segment interposition through the posterior mediastinum. The postoperative course was uneventful. The operative specimen consisted of four ovoid tumors alongside the oesophagus (the greatest diameter 0.5-1.8, average 1.25). All verified tumors histologicaly consisted of a spindle-shaped or polygonal cells containing small and large eosinophilic granules and central nuclei. Most tumor cells showed strongly positive immunohistochemical staining for S-100 protein. These tumor cells were partially positive for p-53 and Ki-67. No lymph node metastases were detected histologically. CONCLUSION Multifocal granular cell tumor of the oesophagus is an unusual finding with low incidence, and rarely caused symptoms. Pathological features and multiplicity of such tumors emphasized malignant predisposition requiring surgical resection of the oesophagus