Search

The fraction of the contribution from yet-unresolved gamma-ray sources in the Galactic diffuse gamma rays observed by the Tibet air shower array is an important key to interpreting recent multi-messenger observations. This paper shows a surprising fact: no Tibet diffuse events above 398TeV come from the gamma-ray sources newly detected above 100 TeV by LHAASO. Based on this observational fact, the contribution of sources unresolved by LHAASO to the Tibet diffuse events is estimated to be less than 31% above 398TeV with a 99% confidence level. Our result shows that unresolved sources make only a sub-dominant contribution to the Tibet diffuse events above 398 TeV and a large fraction of the events are truly a diffusive nature., Comment: Calculations in Eq-(2) should have used the probability p that a Tibet diffuse gamma-ray event is of unresolved-source origin, but the parameter p in Eq-(2) is the probability that a gamma-ray event above 398 TeV from a source marginally detected by LHAASO is detected by the Tibet. This mistake leads to a wrong estimate of the limit on the source fraction to the Tibet diffuse gamma-ray events

A phase-resolved analysis on the X-ray spectrum of Ultra-Luminous X-ray Pulsar (ULXP) NGC 300 ULX-1 is performed with data taken with XMM-Newton and NuSTAR on 2016 December 16th. In addition to the classical phase-restricting analysis, a method developed in active galactic nuclei studies is newly employed for ULXP. It has revealed that the pulsation cycle of the source can be divided into two intervals in terms of X-ray variability. This suggests the rotating flow consists of at least two representative emission regions. Furthermore, the new method successfully decomposed the spectrum into an independent pair in each interval. One is an unchanging-component spectrum that can be reproduced by a standard disk model with a $720^{+220}_{-120}$ km inner radius and a $0.25\pm0.03$ keV peak temperature. The other is the spectrum of the component that coincides with the pulsation. This was explained with a Comptonization of a $0.22^{+0.2}_{-0.1}$ keV blackbody and exhibited a harder photon index in the brighter phase interval of two. The results are consistent with a picture that the pulsating emission originates from a funnel-like flow formed within the magnetosphere, and the inner flow exhibiting a harder continuum is observed exclusively when the opening cone points to the observer., Comment: 27 pages, 15 figures, accepted for publication in ApJ

Soft robotics, with their inherent flexibility and infinite degrees of freedom (DoF), offer promising advancements in human-machine interfaces. Particularly, pneumatic artificial muscles (PAMs) and pneumatic bending actuators have been fundamental in driving this evolution, capitalizing on their mimetic nature to natural muscle movements. However, with the versatility of these actuators comes the intricate challenge of hysteresis - a nonlinear phenomenon that hampers precise positioning, especially pronounced in pneumatic actuators due to gas compressibility. In this study, we introduce a novel 2-DoF adaptive control for precise bending tracking using a pneumatic continuum actuator. Notably, our control method integrates adaptability into both the feedback and the feedforward element, enhancing trajectory tracking in the presence of profound nonlinear effects. Comparative analysis with existing approaches underscores the superior tracking accuracy of our proposed strategy. This work discusses a new way of simple yet effective control designs for soft actuators with hysteresis properties., Comment: Submitted to IEEE Conference on Robotics and Automation (ICRA 2024), Under Review

We propose an approach to estimate the end-to-end GSNR accurately in a short time when a data center interconnect (DCI) network operator receives a service request from users, not by measuring the GSNR at the operational route and wavelength for the End-End optical path but by simply applying a QoT probe channel link by link, at a convenient wavelength/modulation-format for measurement. Assuming connections between coherent transceivers of various frequency ranges, modulators, and modulation formats, we propose a new device software architecture in which the DCI network operator optimizes the transmission mode between user transceivers with high accuracy using only standard parameters such as Bit Error Rate. In this paper, we first experimentally built three different routes of 32 km/72 km/122 km in the C-band to confirm the accuracy of this approach. For the operational end-to-end GSNR measurements, the accuracy estimated from the sum of the measurements for each link was 0.6 dB, and the wavelength-dependent error was about 0.2 dB. Then, using field fibers deployed in the NSF COSMOS testbed (deployed in an urban area), a Linux-based transmission device software architecture, and coherent transceivers with different optical frequency ranges, modulators, and modulation formats, the fast WDM provisioning of an optical path was completed within 6 minutes (with a Q-factor error of about 0.7 dB)., Comment: 10 pages, 11 figures, 3 tables

In this study, we conducted experiments on CaC6 for elucidating the Na-catalyzed formation mechanism and achieving rapid mass synthesis of graphite intercalation compounds (GICs). Rapidly synthesized CaC6 was characterized by analysis of its crystal structure and physical properties. We found that the formation of the reaction intermediate Na-GIC (NaCx, x = 64) requires a larger amount of Na than is intercalated between the graphite interlayers. The requirement for excess Na may provide insights into the mechanism of Na-catalyzed GIC formation. A Na-to-C molar mixing ratio of 1.5-2.0:6 was suitable for the efficient formation of CaC6 under heat treatment at 250{\deg}C for 2 h, and the catalytic Na remaining in the sample was demonstrably reduced to a Na:Ca ratio of approximately 3:97. The upper critical field Hc2 was enhanced approximately three times compared to those of previous reports. Based on X-ray diffraction and experimental parameter analysis, we concluded that the enhancement of Hc2 was attributed to the disordered stacking sequence in CaC6, possibly because of the rapid and low-temperature formation. Physical properties derived from specific heat measurements were comparable to those of high-quality CaC6, which is slowly synthesized using the molten Li-Ca alloy method. This study provides new avenues for future research and exploration in the rapid mass synthesis of GICs as practical materials, for applications such as battery electrodes and superconducting wires., Comment: 17 pages, 6 figures, 1 table

The Event Horizon Telescope (EHT) observed in 2017 the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz ($\lambda$=1.3 mm). The fundamental physics tests that even a single pulsar orbiting Sgr A* would enable motivate searching for pulsars in EHT datasets. The high observing frequency means that pulsars - which typically exhibit steep emission spectra - are expected to be very faint. However, it also negates pulse scattering, an effect that could hinder pulsar detections in the Galactic Center. Additionally, magnetars or a secondary inverse Compton emission could be stronger at millimeter wavelengths than at lower frequencies. We present a search for pulsars close to Sgr A* using the data from the three most-sensitive stations in the EHT 2017 campaign: the Atacama Large Millimeter/submillimeter Array, the Large Millimeter Telescope and the IRAM 30 m Telescope. We apply three detection methods based on Fourier-domain analysis, the Fast-Folding-Algorithm and single pulse search targeting both pulsars and burst-like transient emission; using the simultaneity of the observations to confirm potential candidates. No new pulsars or significant bursts were found. Being the first pulsar search ever carried out at such high radio frequencies, we detail our analysis methods and give a detailed estimation of the sensitivity of the search. We conclude that the EHT 2017 observations are only sensitive to a small fraction ($\lesssim$2.2%) of the pulsars that may exist close to Sgr A*, motivating further searches for fainter pulsars in the region., Comment: 33 pages, 7 figures, 6 Tables. Accepted for publication in ApJ

Gamma rays from HESS J1849$-$000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches $4.0\, \sigma$ and $4.4\, \sigma$ levels above 25 TeV and 100 TeV, respectively, in units of Gaussian standard deviation $\sigma$. The energy spectrum measured between $40\, {\rm TeV} < E < 320\, {\rm TeV}$ for the first time is described with a simple power-law function of ${\rm d}N/{\rm d}E = (2.86 \pm 1.44) \times 10^{-16}(E/40\, {\rm TeV})^{-2.24 \pm 0.41}\, {\rm TeV}^{-1}\, {\rm cm}^{-2}\, {\rm s}^{-1}$. The gamma-ray energy spectrum from the sub-TeV ($E < 1\, {\rm TeV}$) to sub-PeV ($100\, {\rm TeV} < E < 1\, {\rm PeV}$) ranges including the results of previous studies can be modeled with the leptonic scenario, inverse Compton scattering by high-energy electrons accelerated by the PWN of PSR J1849$-$0001. On the other hand, the gamma-ray energy spectrum can also be modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray emitting region. The cutoff energy of cosmic-ray protons $E_{\rm p\, cut}$, cut is estimated at ${\rm log}_{10}(E_{\rm p,\, cut}/{\rm TeV}) = 3.73^{+2.98}_{-0.66}$, suggesting that protons are accelerated up to the PeV energy range. Our study thus proposes that HESS J1849$-$000 should be further investigated as a new candidate for a Galactic PeV cosmic-ray accelerator, PeVatron., Comment: 10 pages, 2 figures, Accepted for publication from the Astrophysical Journal

HESS J1843$-$033 is a very-high-energy gamma-ray source whose origin remains unidentified. This work presents, for the first time, the energy spectrum of gamma rays beyond $100\, {\rm TeV}$ from the HESS J1843$-$033 region using the data recorded by the Tibet air shower array and its underground muon detector array. A gamma-ray source with an extension of $0.34^{\circ} \pm 0.12^{\circ}$ is successfully detected above $25\, {\rm TeV}$ at $(\alpha,\, \delta) = (281.09^{\circ}\pm 0.10^{\circ},\, -3.76^{\circ}\pm 0.09^{\circ})$ near HESS J1843$-$033 with a statistical significance of $6.2\, \sigma$, and the source is named TASG J1844$-$038. The position of TASG J1844$-$038 is consistent with those of HESS J1843$-$033, eHWC J1842$-$035, and LHAASO J1843$-$0338. The measured gamma-ray energy spectrum in $25\, {\rm TeV} < E < 130\, {\rm TeV}$ is described with ${\rm d}N/{\rm d}E = (9.70\pm 1.89)\times 10^{-16} (E/40\, {\rm TeV})^{-3.26\pm 0.30}\, {\rm TeV}^{-1} {\rm cm}^{-2} {\rm s}^{-1}$, and the spectral fit to the combined spectra of HESS J1843$-$033, LHAASO J1843$-$0338, and TASG J1844$-$038 implies the existence of a cutoff at $49.5\pm 9.0\, {\rm TeV}$. Associations of TASG J1844-038 with SNR G28.6$-$0.1 and PSR J1844-0346 are also discussed in detail for the first time., Comment: 11 pages, 4 figures, 1 table

Soft robotics is a swiftly evolving field. Pneumatic actuators are suitable for driving soft robots because of their superior performance. However, their control is challenging due to the hysteresis characteristics. In response to this challenge, we propose an adaptive control method to compensate for the hysteresis of soft actuators. Employing a novel dual pneumatic artificial muscle (PAM) bending actuator, the innovative control approach abates hysteresis effects by dynamically modulating gains within a traditional PID controller corresponding to the predicted variation of the reference trajectory. Through experimental evaluation, we found that the proposed control method outperforms its conventional counterparts regarding tracking accuracy and response speed. Our work reveals a new direction for advancing model-free control in soft actuators., Comment: This paper has been published in the IEEE Robotics and Automation Letters ,DOI 10.1109/LRA.2023.3334098, copyright has been transfferd to the IEEE. Final version is available at IEEE Xplore

This paper proposes joint attention estimation in a single image. Different from related work in which only the gaze-related attributes of people are independently employed, (I) their locations and actions are also employed as contextual cues for weighting their attributes, and (ii) interactions among all of these attributes are explicitly modeled in our method. For the interaction modeling, we propose a novel Transformer-based attention network to encode joint attention as low-dimensional features. We introduce a specialized MLP head with positional embedding to the Transformer so that it predicts pixelwise confidence of joint attention for generating the confidence heatmap. This pixelwise prediction improves the heatmap accuracy by avoiding the ill-posed problem in which the high-dimensional heatmap is predicted from the low-dimensional features. The estimated joint attention is further improved by being integrated with general image-based attention estimation. Our method outperforms SOTA methods quantitatively in comparative experiments. Code: https://anonymous.4open.science/r/anonymized_codes-ECA4., Comment: Accepted to ICCV2023

We report synthesis, characterization, and physical properties of layered bismuth-sulfide compounds La2O2Bi3-xPb1+xS6. We synthesized a new La2O2Bi3PbS6 compound, whose crystal structure is similar to those of the La2O2Bi3AgS6 superconductor or La2O2Bi2Pb2S6 (insulator) with a four-layer-type conducting layer. The crystal structure of La2O2Bi3PbS6 is characterized in a tetragonal P4/nmm space group, and the lattice parameters are a = 4.084(1) {\AA} and c = 19.71(2) {\AA}. The obtained La2O2Bi3PbS6 sample exhibits narrow gap semiconductor (metallic-like) transport behavior with an anomaly near the 160 K. A metallic-like to insulator transition has been observed through Pb substitution, with increasing x in La2O2Bi3-xPb1+xS6. Furthermore, we applied external pressure for x = 0 and observed pressure-induced superconductivity. The onset of superconductivity appeared at 0.93 GPa, and the highest transition temperature was 3.1 K at 2.21 GPa., Comment: 10 pages, 8 figures, accepted in Superconductor Science and Technology

$\mathcal{H}\Phi$ [$aitch$-$phi$] is an open-source software package of numerically exact and stochastic calculations for a wide range of quantum many-body systems. In this paper, we present the newly added functions and the implemented methods in vers. 2 and 3. In ver. 2, we implement spectrum calculations by the shifted Krylov method, and low-energy excited state calculations by the locally optimal blocking preconditioned conjugate gradient (LOBPCG) method. In ver. 3, we implement the full diagonalization method using ScaLAPACK and GPGPU computing via MAGMA. We also implement a real-time evolution method and the canonical thermal pure quantum (cTPQ) state method for finite-temperature calculations. The Wannier90 format for specifying the Hamiltonians is also implemented. Using the Wannier90 format, it is possible to perform the calculations for the $ab$ $initio$ low-energy effective Hamiltonians of solids obtained by the open-source software RESPACK. We also update Standard mode $\unicode{x2014}$simplified input format in $\mathcal{H}\Phi$$\unicode{x2014}$ to use these functions and methods. We explain the basics of the implemented methods and how to use them., Comment: 21 pages, 10 figures, 2 tables

To demonstrate the magnetic energy dissipation via relativistic shocks, we carry out spherically symmetrical one-dimensional special relativistic magneto-hydrodynamic simulations of highly magnetised outflows with an adaptive mesh refinement method. We first investigate the detail of the dynamical energy dissipation via interaction between a single ejecta and an external medium. The energy dissipation timescales, which affect the early behaviour of the afterglow emission in gamma-ray bursts, are estimated for a wide range of magnetisation. In addition, we demonstrate the internal shock dissipation in multiple interactions between magnetically dominated relativistic ejecta and kinetically dominated non-relativistic winds. Our numerical results show that almost 10% of the magnetic energy in the ejecta can be converted into the thermal energy of the relativistic and low-magnetised outflows via shocks in the rarefaction waves or the winds. Such hot and less magnetised outflows are relevant for observed non-thermal emissions in blazars or gamma-ray bursts., Comment: 12 pages, 14 figures, Animations are available from here https://www.youtube.com/playlist?list=PLgnUM4yGp9oLxqXlcKcc8ftJne9kTpHEs

Diagrammatic summation is a common bottleneck in modern applications of projected entangled-pair states, especially in computing low-energy excitations of a two-dimensional quantum many-body system. To solve this problem, here we extend the generating function approach for tensor network diagrammatic summation, a scheme previously proposed in the context of matrix product states. Taking the form of a one-particle excitation, we show that the excited state can be computed efficiently in the generating function formalism, which can further be used in evaluating the dynamical structure factor of the system. Our benchmark results for the spin-$1/2$ transverse-field Ising model and Heisenberg model on the square lattice provide a desirable accuracy, showing good agreement with known results. We then study the spin-$1/2$ $J_1$-$J_2$ model on the same lattice and investigate the dynamical properties of the putative gapless spin liquid phase. We conclude with a discussion on generalizations to multi-particle excitations., Comment: 13 pages, 6 figures

Isotope $^{121,123}$Sb nuclei with large electric quadrupole moments are applied to investigate the dynamics of orbital degrees of freedom in Sb-substituted iron(Fe)-based compounds. In the parent compound LaFe(As$_{0.6}$Sb$_{0.4}$)O, the nuclear spin relaxation rate $^{121,123}(T_{1}^{-1})$ at $^{121,123}$Sb sites was enhanced at structural transition temperature ($T_{s}\sim$ 135 K), which is higher than N\'eel temperature ($T_{\rm N}\sim$125 K). The isotope ratio $^{123}(T_{1}^{-1})/^{121}(T_{1}^{-1})$ indicates that the electric quadrupole relaxation due to the dynamical electric field gradient at Sb site increases significantly toward $T_{s}$. It is attributed to the critically enhanced nematic fluctuations of stripe-type arrangement of Fe-$3d_{xz}$ (or $3d_{yz}$) orbitals. In the lightly electron-doped superconducting (SC) compound LaFe(As$_{0.7}$Sb$_{0.3}$)(O$_{0.9}$F$_{0.1}$), the nematic fluctuations are largely suppressed in comparison with the case of the parent compound, however, it remains a small enhancement below 80 K down to the $T_c$($\sim$ 20 K). The results indicate that the fluctuations from both the spin and orbital degrees of freedom on the $3d_{xz}$(or $3d_{yz}$) orbitals can be seen in lightly electron-doped SC state of LaFeAsO-based compounds. We emphasize that isotope $^{121,123}$Sb quadrupole moments are sensitive local probe to identify the dynamics of orbital degrees of freedom in Fe-pnictides, which provides with a new opportunity to discuss the microscopic correlation between the superconductivity and both nematic and spin fluctuations simultaneously even in the polycrystalline samples., Comment: 7 pages, 4 figures and 1 supplemental file

Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is the Galactic archaeology with Galactic Center Survey, which aims to reveal the Milky Way's central core structure and formation history from Gaia-level (~25 $\mu$as) astrometry in the Near-Infrared (NIR) Hw-band (1.0-1.6 $\mu$m). The other is the Exoplanet Survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information of the stars in the Galactic center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars and microlensing studies, including discovery of (intermediate mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions., Comment: 50 pages, 22 figures, accepted for publication in PASJ