A5104753098- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Astrophysics and Star Formation Studies
- Nuclear physics research studies
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Seismic Waves and Analysis
- Nuclear Physics and Applications
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Geophysics and Sensor Technology
- Neutrino Physics Research
- Astronomy and Astrophysical Research
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Gas Dynamics and Kinetic Theory
- Atmospheric Ozone and Climate
- Astronomical and nuclear sciences
- Scientific Research and Discoveries
Ulsan National Institute of Science and Technology
2015-2024
The University of Tokyo
2020-2023
Pusan National University
2018
Texas A&M University
2018
Daegu University
2018
Ewha Womans University
2016
Sungkyunkwan University
2016
University of Georgia
2009-2012
Korea Astronomy and Space Science Institute
2012
Stony Brook University
2006
Abstract KAGRA is a newly built gravitational-wave telescope, laser interferometer comprising arms with length of 3 km, located in Kamioka, Gifu, Japan. was constructed under the ground and it operated using cryogenic mirrors that help reducing seismic thermal noise. Both technologies are expected to provide directions for future telescopes. In 2019, finished all installations designed configuration, which we call baseline KAGRA. For this occasion, present an overview from various viewpoints...
KAGRA is a newly built gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this series of articles, we present an overview the baseline KAGRA, for which finished installing designed configuration 2019. This article describes method calibration (CAL) used reconstructing signals from detector outputs, as well characterization (DET). We also review physical environmental monitors (PEM) system and geophysics (GIF). Both are...
KAGRA is a gravitational-wave (GW) detector constructed in Japan with two unique key features: It was underground, and the test-mass mirrors are cooled to cryogenic temperatures. These features not included other kilometer-scale detectors but will be adopted future such as Einstein Telescope. performed its first joint observation run GEO600 2020. In this observation, sensitivity of GWs inferior that LIGO Virgo. However, further upgrades ongoing reach for detecting next run, which scheduled...
Highly ionized species, such as C iv, N v, and O vi, are commonly observed in diffuse gas various places the universe, our Galaxy's disk halo, high velocity clouds (HVCs), external galaxies, intergalactic medium. These ions often used to trace hot whose temperature is a few times 105 K. One possible mechanism for producing turbulent mixing of cool (such that or intermediate cloud) with hotter (a 106 K) locations where these gases slide past each other. By using hydrodynamic simulations...
Stars emit MeV neutrinos during their evolution via nuclear syntheses and thermal processes, detecting them could provide insights into stellar structure beyond what is accessible through electromagnetic wave observations. So far, have been observed from the Sun SN 1987A. It has suggested that pre-supernova stars in oxygen silicon burning stages would enough to be detectable on Earth, provided they are local universe. In this study, we investigate prospect of red supergiants (RSGs)...
Abstract Stars emit megaelectronvolt neutrinos during their evolution via nuclear syntheses and thermal processes, detecting them could provide insights into stellar structure beyond what is accessible through electromagnetic wave observations. So far, have been observed from the Sun SN 1987A. It has suggested that pre-supernova stars in oxygen- silicon-burning stages would enough to be detectable on Earth, provided they are local Universe. In this study, we investigate prospect of red...
We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in Galactic halo. A suite models was created using FLASH hydrodynamics code, sampling various cloud sizes, densities, and velocities. In all cases, cloud-halo interaction ablates material from clouds. The ablated falls behind clouds, where it mixes with ambient to produce intermediate-temperature gas, some which radiatively cools less than 10,000 K. Using a non-equilibrium ionization...
Abstract KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan. In April 2020, an astrophysics observation was performed KAGRA detector in combination with GEO 600 detector; this operation called O3GK. The optical configuration O3GK based on a power-recycled Fabry–Pérot–Michelson interferometer; all mirrors were set room temperature. duty factor of approximately 53%, and displacement sensitivity 1 × 10−18 ${\rm m}/\sqrt{\rm {Hz}}$ 250 Hz....
We compare the predictions of three physical models for origin hot halo gas with observed X-ray emission, derived from 26 high-latitude XMM-Newton observations soft background between l = 120° and 240°. These were chosen a much larger set as they are expected to be least contaminated by solar wind charge exchange emission. characterize emission in band single-temperature plasma model. find that temperature is fairly constant across sky (∼(1.8–2.4) × 106 K), whereas measure varies an order...
We investigate nuclear matter equations of state in neutron star with kaon condensation. It is generally known that the existence kaons makes equation soft so maximum mass not likely to be greater than 2.0 $M_{\odot}$, constrained by current observations. With existing Skyrme force model parameters, we calculate and check possibility condensation core stars. The results show even condensation, satisfies both allowed ranges radius.
We consider the so called hyperon puzzle of neutron star (NS). employ Skyrme force models for description in-medium nucleon-nucleon, nucleon-Lambda ($N\Lambda$), and Lambda-Lambda ($\Lambda\Lambda$) interactions. A phenomenological finite-range $\Lambda\Lambda$ interaction is considered as well. Equation state (EoS) NS matter obtained in framework density functional theory, Tolman-Oppenheimer-Volkoff equations are solved to obtain mass-radius relations NSs. It has been generally known that...
In the Galactic halo, metal-bearing halo material mixes into high velocity clouds (HVCs) as they hydrodynamically interact. This interaction begins long before completely dissipate and slow to of material. order make quantitative estimates mixing efficiency resulting metal enrichment HVCs, we made detailed 2 3 dimensional simulations cloud-ISM interactions. Our track hydrodynamics time dependent ionization levels. They assume that cloud originally has a warm temperature extremely low...
We investigate the constraints on mass and radius of neutron stars by considering tidal deformability in merge star binaries. employ models based Skyrme force density-functional theory select that are consistent with empirical data finite nuclei, measured properties nuclear matter around saturation density, observation maximum stars. From selected models, we calculate Love number ${k}_{2}$, dimensionless $\mathrm{\ensuremath{\Lambda}}$, mass-weighted $\stackrel{\ifmmode \tilde{}\else...
In the Galactic fountain scenario, supernovae and/or stellar winds propel material into halo. As cools, it condenses clouds. By using FLASH three-dimensional magnetohydrodynamic simulations, we model and study dynamical evolution of these gas clouds after they form begin to fall toward plane. our assume that at a height z=5 kpc above midplane, then from rest. We investigate how cloud's evolution, dynamics, interaction with interstellar medium (ISM) are affected by initial mass cloud. find...
The possibilities for production of yet unknown neutron-rich isotopes $^{261--265}\mathrm{Md}$ are explored in the multinucleon transfer reactions with stable beams bombarding on Cf and Es targets. a given isotope Md is optimized by appropriate choices projectile-target combinations energies. cross sections $0n$ $1n$ evaporation channels compared. prospects use radioactive new discussed.
Modern ground-based gravitational wave (GW) detectors require a complex interferometer configuration with multiple coupled optical cavities.Since achieving the resonances of arm cavities is most challenging among lock acquisition processes, scheme called length stabilization (ALS) had been employed for cavities.We designed new type ALS, which compatible interferometers having long arms like next generation GW detectors.The features ALS are that control simpler than those previous ones and it...
We investigate possible production of neutron-rich isotopes nobelium. calculate the cross sections $^{261--266}\mathrm{No}$ in multinucleon transfer reactions same projectiles ($^{36}\mathrm{S},\phantom{\rule{0.28em}{0ex}}^{40}\mathrm{Ar},\phantom{\rule{0.28em}{0ex}}^{48}\mathrm{Ca}$, and $^{50}\mathrm{Ti}$) targets ($^{254}\mathrm{Es}$ $^{248--251}\mathrm{Cf}$) that were used previous study for Md. find No are about an order magnitude smaller than those Md isotopes. By combining results...
We present predictions of the Si iv ions in turbulent mixing layers (TMLs) between hot and cool gas high-velocity clouds (HVCs) that travel through a halo, complementing C iv, N v, O vi Kwak & Shelton, et al., Henley al. find are most abundant regions where gases first begin to mix or mixed has cooled significantly. The predicted column densities high velocity ratios found on individual sightlines our HVC simulations good agreement with observations gas. Low is also seen simulations, as...
The long-term Swift monitoring of ESO 243-49 HLX-1 provides an opportunity to investigate the detailed timing and spectral behaviour this hyper-luminous X-ray source. has detected 7 outbursts since 2009 mid-August. Using different dynamical algorithms, we confirm increasing trend for time intervals between outbursts, which is manifest in delays latest outbursts. spectra quiescence can be described with a single power-law model while thermal component dominates emission during outburst. There...
We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements from Milky Way's hot halo. These are 110 sight lines, spanning full range Galactic longitudes. find that a magnetohydrodynamical simulation supernova-driven interstellar medium, which features flow gas disk to halo, reproduces temperature but significantly underpredicts 0.5-2.0 keV surface brightness halo (by two orders magnitude, if we compare median predicted and observed values). This is...
Context. X-ray bursts (XRBs) are energetic explosive events that have been observed in low-mass binaries (LMXBs). Some Type-I XRBs exhibit photospheric radius expansion (PRE) and these PRE used to simultaneously estimate the mass of a neutron star LMXB. Aims. The estimation depends on several model parameters, most which still uncertain. Here, we focus effects chemical composition photosphere, determines opacity during phase, touchdown radius, can be larger than radius. We investigate how...
In order to determine if the material ablated from high-velocity clouds (HVCs) is a significant source of low-velocity high ions (C iv, N v, and O vi) such as those found in Galactic halo, we simulate hydrodynamics gas time-dependent ionization evolution its carbon, nitrogen, oxygen ions. Our suite simulations examines ablation warm various sizes, densities, velocities they pass through hot halo. The mixes with environmental gas, producing an intermediate-temperature mixture that rich slows...
With the goal of understanding why X-rays have been reported near some high velocity clouds, we perform detailed 3 dimensional hydrodynamic and magnetohydrodynamic simulations clouds interacting with environmental gas like that in Galaxy's thick disk/halo or Magellanic Stream. We examine 2 scenarios. In first, travel fast enough to shock-heat warm gas. this scenario, X-ray productivity depends strongly on speed cloud radiative cooling rate. order temperatures > = 10^6 K, speeds 300 km/s are...