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A one-shot valve made using MEMS (micro-electro-mechanical systems) technologies has been designed, fabricated and characterized. The operation of the device is temperature and pressure dependent. It consists in a channel obstructed by a membrane coated with a low melting point alloy. The valve is normally closed and opens if the ambient temperature is higher than the melting temperature of the alloy and if the pressure difference across the channel is such as to fracture the membrane. The working principle of the device has been demonstrated and several characteristics have been measured. [ABSTRACT FROM AUTHOR]

The Hitachi and Takahagi 32 m radio telescopes (former satellite communication antennas) were so upgraded as to work at 6, 8, and 22GHz. We developed the receiver systems, IF systems, back-end systems (including samplers and recorders), and reference systems. We measured the performance of the antennas. The system temperature including the atmosphere toward the zenith, T*sys, is measured to be ~30-40 K for 6 GHz and ~25-35 K for 8GHz. T*sys for 22GHz is measured to be ~40-100 K in winter and ~150-500 K in summer seasons, respectively. The aperture efficiency is 55%-75% for Hitachi at 6GHz and 8GHz, and 55%-65% for Takahagi at 8GHz. The beam sizes at 6 GHz and 8 GHz are ~4'.6 and ~3'.8, respectively. The side-lobe level is less than 3%-4% at 6 and 8GHz. Pointing accuracy was measured to be better than ~0'.3 for Hitachi and ~0'.6 for Takahagi. We succeeded in VLBI observations in 2010 August, indicating good performance of the antenna. We started single-dish monitoring observations of 6.7GHz methanol maser sources in 2012 December, and found several new sources showing short-term periodic variation of the flux density. [ABSTRACT FROM AUTHOR]

We have measured an annual parallax of the Mira variable R Ursae Majoris (RUMa) with the VLBI Exploration for Radio Astronomy (VERA). From the monitoring VLBI observations over a span of about two years, we detected H2O maser spots in the LSR velocity range from 37 to 42 km s-1. We derived an annual parallax of 1.97 ± 0.05 mas, and this gives a corresponding distance of 508±13 pc. The VLBI maps revealed 72 maser spots distributed in an ~110 au area around the expected stellar position. Circumstellar kinematics of the maser spots were also revealed by subtracting a systemic motion in the Hipparcos catalog from proper motions of each maser spot derived from our VLBI observations. Infrared photometry was also conducted to measure a K-band apparent magnitude, and we obtained a mean magnitude of mK = 1.19 ± 0.02 mag. Using the trigonometric distance, mK is converted to a K-band absolute magnitude of MK =-7.34 ± 0.06 mag. This result gives a much more accurate absolute magnitude for RUMa than previously provided. We solved a zero-point of the MK-log P relation for the Galactic Mira variables and obtained a relation of MK = -3.52 log P + (1.09 ± 0.14). Other long-period variables, including red supergiants, whose distances were determined with astrometric VLBI, were also compiled to explore the different sequences of the MK-log P relation. [ABSTRACT FROM AUTHOR]

We detected internal proper motions of the methanol maser features at 6.7GHz in a high-mass star-forming region G006.79-00.25 with the East-Asian VLBI Network. The spatial distribution of the maser features shows an elliptical morphology. The internal proper motions of 17 methanol maser features relative to the barycenter of the features were measured. The amplitude of the internal motions ranged from 1.30 to 10.25 km s-1. Most of the internal proper motions of the maser features seem to point counterclockwise along the elliptical morphology of the maser features. We applied the disk model, which includes both rotating and expanding components, to the observed positions, l.o.s. velocities, and proper motions. The derived rotation, expansion, and systemic velocities are +3-2+2, +6-2+2, and +21-2+2 km s-1, respectively, at the radius of 1260 au on the disk with a position angle of the semi-major axis of -140° and an inclination of 60°. The derived rotating motion suggests that the methanol maser emissions showing the elliptical spatial morphology possibly trace the rotating disk. The derived expanding motion might be caused by the magnetic-centrifugal wind on the disk, which was estimated on the basis of the typical magnetic field strength at emitting zones of a methanol maser. [ABSTRACT FROM AUTHOR]

We conducted astrometric very long baseline interferometry (VLBI) observations ofwatervapor maser emission in the massive star-forming region IRAS 21379+5106 in order to measure the annual parallax and proper motion, using VLBI Exploration of Radio Astrometry (VERA). The annual parallax measured 0.262 ± 0.031 mas, corresponding to a distance of 3.82+0.51-0.41 kpc. The proper motion was (μα cosδ, μδ) = (-2.74 ± 0.08, -2.87 ± 0.18) mas yr-1. By using this result, the Galactic rotational velocity was estimated to be Vθ = 218 ± 19kms-1 at the galactocentric distance R = 9.22 ± 0.43 kpc, when we adopted the Galactic constants R0 = 8.05 ± 0.45 kpc and V0 = 238 ± 14km s-1. With the newly determined distance, the bolometric luminosity of the central young stellar object was reestimated to be (2.15 ± 0.54) × 103 L⊙, which corresponds to the spectral type of B2-B3. The maser features were found to be distributed along a straight line extending from the southwest to the northeast. In addition, a vector map of the internal motions, constructed from the residual proper motions, implies that the maser features trace a bipolar flow, and that it cannot be explained by simple ballistic motions. [ABSTRACT FROM AUTHOR]

The capacity to model magnetohydrodynamical (MHD) flows in dynamical, strongly curved spacetimes significantly extends the reach of numerical relativity in addressing many problems at the forefront of theoretical astrophysics. We have developed and tested an evolution code for the coupled Einstein-Maxwell-MHD equations which combines a BSSN solver with a high resolution shock capturing scheme. As one application, we evolve magnetized, differentially rotating neutron stars under the influence of a small seed magnetic field. Of particular significance is the behaviour found for hypermassive neutron stars (HMNSs), which have rest masses greater than the mass limit allowed by uniform rotation for a given equation of state. The remnant of a binary neutron star merger is likely to be a HMNS. We find that magnetic braking and the magnetorotational instability lead to the collapse of HMNSs and the formation of rotating black holes surrounded by massive, hot accretion tori and collimated magnetic field lines. Such tori radiate strongly in neutrinos, and the resulting neutrino-antineutrino annihilation (possibly in concert with energy extraction by MHD effects) could provide enough energy to power short-hard gamma-ray bursts. To explore the range of outcomes, we also evolve differentially rotating neutron stars with lower masses and angular momenta than the HMNS models. Instead of collapsing, the non-hypermassive models form nearly uniformly rotating central objects which, in cases with significant angular momentum, are surrounded by massive tori. [ABSTRACT FROM AUTHOR]

We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst sGRB 160821B. The spectroscopic redshift of the host is z = 0.162, making it one of the lowest redshift short-duration gamma-ray bursts (sGRBs) identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as well as Hubble Space Telescope, XMM-Newton, and Swift, shows evidence for a late-time excess of optical and near-infrared emission in addition to a complex afterglow. The afterglow light curve at X-ray frequencies reveals a narrow jet, deg, that is refreshed at >1 day post-burst by a slower outflow with significantly more energy than the initial outflow that produced the main GRB. Observations of the 5 GHz radio afterglow shows a reverse shock into a mildly magnetized shell. The optical and near-infrared excess is fainter than AT2017gfo associated with GW170817, and is well explained by a kilonova with dynamic ejecta mass Mdyn = (1.0 ± 0.6) × 10−3M⊙ and a secular (post-merger) ejecta mass with Mpm = (1.0 ± 0.6) × 10−2M⊙, consistent with a binary neutron star merger resulting in a short-lived massive neutron star. This optical and near-infrared data set provides the best-sampled kilonova light curve without a gravitational wave trigger to date. [ABSTRACT FROM AUTHOR]

We report on the analysis of the 10–1000 TeV large-scale sidereal anisotropy of Galactic cosmic rays (GCRs) with the data collected by the Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve the energy estimate and extend the decl. range down to −30°. We find that the anisotropy maps above 100 TeV are distinct from that at a multi-TeV band. The so-called tail-in and loss-cone features identified at low energies get less significant, and a new component appears at ∼100 TeV. The spatial distribution of the GCR intensity with an excess (7.2σ pre-trial, 5.2σ post-trial) and a deficit (−5.8σ pre-trial) are observed in the 300 TeV anisotropy map, in close agreement with IceCube’s results at 400 TeV. Combining the Tibet results in the northern sky with IceCube’s results in the southern sky, we establish a full-sky picture of the anisotropy in hundreds of TeV band. We further find that the amplitude of the first order anisotropy increases sharply above ∼100 TeV, indicating a new component of the anisotropy. All these results may shed new light on understanding the origin and propagation of GCRs. [ABSTRACT FROM AUTHOR]

A new air-shower core-detector array (YAC: Yangbajing air-shower Core-detector array) has been developed to measure the primary cosmic-ray composition at the ‘knee’ energies in Tibet, China, focusing mainly on the light components. The prototype experiment (YAC-I) consisting of 16 detectors has been constructed and operated at Yangbajing (4300 m a.s.l.) in Tibet since May 2009. YAC-I is installed in the Tibet-III AS array and operates together. In this paper, we performed a Monte Carlo simulation to check the sensitivity of the YAC-I+Tibet-III array to the cosmic-ray light component of cosmic rays around the knee energies, taking account of the observation conditions of the actual YAC-I+Tibet-III array. The selection of light component from others was made by use of an artificial neural network. The simulation shows that the light-component spectrum estimated by our methods can well reproduce the input ones within 10% error, and there will be about 30% systematic errors mostly induced by the primary and interaction models used. It is found that the full-scale YAC and the Tibet-III array is powerful to study the cosmic-ray composition, in particular, to obtain the energy spectra of protons and helium nuclei around the knee energies. [ABSTRACT FROM AUTHOR]

Objectives. Following lesions in somatosensory pathways, deafferentation pain often occurs. Patients report that the pain is qualitatively complex, and its treatment can be difficult. Mirror visual feedback (MVF) treatment can improve deafferentation pain. We sought to classify the qualities of the pain in order to examine whether the potential analgesic effect of MVF depends on these qualities. Methods. Twenty-two patients with phantom limb pain, or pain related to spinal cord or nerve injury, performed a single MVF procedure. Before and after the MVF procedure, we evaluated phantom limb awareness, movement representation of the phantom or affected/paralysed limb, pain intensity on an 11-point numerical rating scale (0–10) and the qualities of the pain [skin surface-mediated (superficial pain) vs deep tissue-mediated (deep pain)] using lists of pain descriptors for each of the two categories. Results. Fifteen of the patients perceived the willed visuomotor imagery of the phantom or affected/paralysed limb after the MVF procedure. In most of the patients, a reduction in pain intensity and a decrease in the reporting of deep-pain descriptors were linked to the emergence of willed visuomotor imagery. Conclusions. In this pilot study, we roughly classified the pain descriptor items into two types for evaluating the qualities of deafferentation pain. We found that visually induced motor imagery by MVF was more effective for reducing deep pain than superficial pain. This suggests that the analgesic effect of MVF treatment does depend on the qualities of the pain. Further research will be required to confirm that this effect is a specific consequence of MVF. [ABSTRACT FROM AUTHOR]