The IceCube report of a excess of 13 5 neutrino events in the direction of the blazar TXS 0506+056 in 2014-2015 and the 2017 detection of a high-energy neutrino event, IceCube-170922A, during a ...gamma-ray flare from the same blazar, have revived the interest in scenarios for neutrino production in blazars. We perform comprehensive analyses on the long-term electromagnetic emission of TXS 0506+056 using optical, X-ray, and gamma-ray data from the All-Sky Automated Survey for Supernovae, the Neil Gehrels Swift Observatory, Monitor of All-sky X-ray Image, and the Fermi Large Area Telescope. We also perform numerical modeling of the spectral energy distributions (SEDs) in four epochs prior to 2017 with contemporaneous gamma-ray and lower-energy (optical and/or X-ray) data. We find that the multi-epoch SEDs are consistent with a hybrid leptonic scenario, where the gamma-rays are produced in the blazar zone via external inverse Compton scattering of accelerated electrons, and high-energy neutrinos are produced via the photomeson production process of co-accelerated protons. The multi-epoch SEDs can be satisfactorily explained with the same jet parameters and variable external photon density and electron luminosity. Using the maximal neutrino flux derived for each epoch, we put an upper limit of ∼0.4-2 on the muon neutrino number in 10 years of IceCube observations. Our results are consistent with the IceCube-170922A detection, which can be explained as an upper fluctuation from the average neutrino rate expected from the source, but in strong tension with the 2014-2015 neutrino flare.
The Astrophysical Multimessenger Observatory Network (AMON) has been built with the purpose of enabling near real-time coincidence searches using data from leading multimessenger observatories and ...astronomical facilities. Its mission is to evoke discovery of multimessenger astrophysical sources, exploit these sources for purposes of astrophysics and fundamental physics, and explore multimessenger datasets for evidence of multimessenger source population AMON aims to promote the advancement of multimessenger astrophysics by allowing its participants to study the most energetic phenomena in the universe and to help answer some of the outstanding enigmas in astrophysics, fundamental physics, and cosmology. The main strength of AMON is its ability to combine and analyze sub-threshold data from different facilities. Such data cannot generally be used stand-alone to identify astrophysical sources. The analyses algorithms used by AMON can identify statistically significant coincidence candidates of multimessenger events, leading to the distribution of AMON alerts used by partner observatories for real-time follow-up that may identify and, potentially, confirm the reality of the multimessenger association. We present the science motivation, partner observatories, implementation and summary of the current status of the AMON project.
We present the results of a study that simulates trajectories of ultra-high energy cosmic rays from Centaurus A to Earth, for particle rigidities from E/Z=2EV to 100EV, i.e., covering the possibility ...of primary particles as heavy as Fe nuclei with energies exceeding 50EeV. The Galactic magnetic field is modeled using the recent work of Jansson and Farrar (JF12) which fitted its parameters to match extragalactic Faraday rotation measures and WMAP7 synchrotron emission maps. We include the random component of the GMF using the JF12 3D model for Brand(r→) and explore the impact of different random realizations, coherence length and other features on cosmic ray deflections. Gross aspects of the arrival direction distribution such as mean deflection and the RMS dispersion depend mainly on rigidity and differ relatively little from one realization to another. However different realizations exhibit non-trivial substructure whose specific features vary considerably from one realization to another, especially for lower rigidities. At the lowest rigidity of 2EV, the distribution is broad enough that it might be compatible with a scenario in which Cen A is the principle source of all UHECRs. No attempt is made here to formulate a robust test of this possibility, although some challenges to such a scenario are noted.
Abstract
Electromagnetic observations of gravitational-wave and high-energy neutrino events are crucial in understanding the physics of their astrophysical sources. X-ray counterparts are especially ...useful in studying the physics of the jet, the energy of the outflow, and the particle acceleration mechanisms in the system. Ultraviolet and optical observations can help us constrain the mass and velocity of the outflow and provide hints on the viewing angle. We present the Neil Gehrels Swift Observatory prompt searches for X-ray and UV/optical counterparts to the joint gravitational-wave and high-energy neutrino coincident events that happened during the third observing run of LIGO/Virgo. Swift observed the overlap between gravitational-wave and neutrino error regions for three of the considerable (
p
-value < 1%) joint gravitational-wave and high-energy neutrino coincident alerts, which were generated by the IceCube Neutrino Observatory in real time after triggering by the LIGO/Virgo gravitational-wave public alerts. The searches did not associate any X-ray or UV/optical counterparts with any of the joint gravitational-wave and high-energy neutrino coincident events; however, the follow-up of these alerts significantly improved the tiling techniques covering regions between the gravitational-wave sky maps and the neutrino’s error regions, making the real-time system ready for future potential discoveries. We discuss the details of each follow-up procedure, the results of each search, and the plans for future searches.
Abstract Objective To identify the spectrum of mutations in connexin 26 gene and frequency of two deletions in connexin 30 gene in central Iran. Methods After extraction of DNA from 300 blood ...samples, connexin 26 gene coding region was amplified using specific primers. PCR products were used for bidirectional sequencing. Multiplex PCR was used for detection of del( GJB6 -D13S1830) and del( GJB6 -D13S1854) in the GJB6 gene. Results Eighteen different mutations including two novel variants in GJB2 gene were detected. The GJB2 mutations were observed in 23.3% of all the subjects. In addition, none of the deaf patients carried the del( GJB6 -D13S1830) and del( GJB6 -D13S1854) in the GJB6 gene. The 35delG mutation was the most common mutation, accounting for 32.65% of the mutant alleles. Conclusion The present study indicates that mutations in the GJB2 gene particularly 35delG are important causes for ARNSHL. 60% of the patients were heterozygous carriers. Thus, further investigation is needed to detect the genetic cause of hearing loss in patients with mono allelic mutations in the coding region of GJB2.
ABSTRACT
High-energy neutrinos are a promising tool for identifying astrophysical sources of high and ultra-high energy cosmic rays (UHECRs). Prospects of detecting neutrinos at high energies (≳TeV) ...from blazars have been boosted after the recent association of IceCube-170922A and TXS 0506+056. We investigate the high-energy neutrino, IceCube-190331A, a high-energy starting event (HESE) with a high likelihood of being astrophysical in origin. We initiated a Swift/XRT and UVOT tiling mosaic of the neutrino localization and followed up with ATCA radio observations, compiling a multiwavelength spectral energy distribution (SED) for the most likely source of origin. NuSTAR observations of the neutrino location and a nearby X-ray source were also performed. We find two promising counterpart in the 90 per cent confidence localization region and identify the brightest as the most likely counterpart. However, no Fermi/LAT γ-ray source and no prompt Swift/BAT source is consistent with the neutrino event. At this point, it is unclear whether any of the counterparts produced IceCube-190331A. We note that the Helix Nebula is also consistent with the position of the neutrino event and we calculate that associated particle acceleration processes cannot produce the required energies to generate a high-energy HESE neutrino.
Background: lumbar disc degeneration is a multifactorial degenerative disease which is affected by genetic inheritance and environmental factors. Type XI collagen is important for organization of the ...extracellular matrix and cartilage collagen construction. Rs1676486 is a SNP that causes the conversion of C-T, resulting in a change in the expression of the collagen 11 alpha chain. The T allele reduces the alpha 1 chain transcription of collagen 11 and ultimately leads to an imbalance in gene expression. Methods: This study aims to determine the genetic variant of alpha1 type11 collagen is associated with the progress of intervertebral disc degeneration. All patients were selected from the AL-Zahra Hospital of medical university of Isfahan, Iran, between April 2016 and September 2017. SNP rs1676486 of alpha1 type11 collagen was genotyped in 100 patients and 100 healthy controls. The inclusion criteria for patients were: individuals who had typical clinical and imaging symptoms and signs of intervertebral disc degeneration. Exclusion criteria were: patients with trauma, metabolic and neuromuscular diseases, and congenital disorder of the spine. The Genomic DNA was extracted from peripheral blood samples by a Whole Blood Genomic DNA Extraction Kit. The chi-square test and fisher’s exact test were evaluated to determine differences of genotype and allele distributions between intervertebral disc degeneration patients and healthy controls. To compare the relationship between genotypes and clinical features the Mann-Whitney U test was used. Results: The mean age was 39.54±9.52 years for the patients and 28.14±5.32 years for the controls, respectively. The mean BMI were 26.3±3.18 kg/m2 and 27.3±3.52 kg/m2 for the patients and the controls, respectively. In addition, the results showed that the prevalence of surgical disc in patients with L4-L5 levels was 52.1% and L5-S1, with 31.1%. This study showed, rs1676486 in alpha1 type11 collagen gene was associated with modified intervertebral disc degeneration at age ≤50 years and this gene increases intervertebral disc degeneration risk at age >50 years. SNP rs1676486 had the significant association with the intervertebral disc degeneration (P=0.019), and patients were found to have higher frequency of AA than the controls. Conclusion: This observation shows that type XI collagen is related to age and genetic factor in intervertebral disc degeneration disease.
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