902 citations · 3.1k across the 73 of their papers we have counts for
73 papers
Production of High Energy Neutrinos in the Coronae of Ultraluminous X-ray Sources
Norita Kawanaka, Shigeo S. Kimura
We investigate the possibility of high-energy neutrino production in coronae associated with ultraluminous X-ray sources (ULXs) as super-Eddington accreting black holes. Adopting t…
Diffusive or Ballistic? Distributions and Spectra of PeV Cosmic Rays around Microquasars
Yutaka Fujita, Rohta Takahashi, Norita Kawanaka
In the standard Galactic cosmic-ray (CR) paradigm, protons are accelerated up to ~1 PeV by Galactic sources. While supernova remnants (SNRs) have been traditionally considered as t…
Re-examination of the CO absorption line in the M87 nucleus
Norita Kawanaka, Hiroshi Nagai, Yutaka Fujita
We analyzed the archival ALMA data of the nuclear region of M87 and evaluate the molecular gas content from the CO(2--1) absorption line. We found an enigmatic variability in the a…
Precision spectral measurements of Chromium and Titanium from 10 to 250 GeV and sub-Iron to Iron ratio with the Calorimetric Electron Telescope on the ISS
O. Adriani, Y. Akaike, K. Asano +77
The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray (CR) iron and sub-iron events over a…
Hadronic origin of the very high-energy gamma-ray emission from the low-luminosity AGN in NGC 4278
Asahi Shoji, Yutaka Fujita, Norita Kawanaka +2
The Large High Altitude Air Shower Observatory has detected very high-energy (VHE) gamma rays from NGC 4278, which is known to host a low-luminosity active galactic nucleus (AGN).…
Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) XXII. Chandra observations of narrow-line quasar candidates at z>6
K. Iwasawa, R. Gilli, F. Vito +13
We report on Chandra X-ray observations of four narrow-line quasar candidates at z~6, selected from the SHELLQs project, based on the Subaru Hyper Suprime-Cam survey. These objects…
ALMA observations of the gamma-ray binary system PSR B1259-63/LS 2883 during the 2024 periastron passage
Yutaka Fujita, Akiko Kawachi, Atsuo T. Okazaki +3
We present observations of the gamma-ray binary PSR B1259-63/LS 2883 with the Atacama Large Millimeter/submillimeter Array (ALMA) at Bands 3 (97 GHz), 6 (233 GHz), and 7 (343 GHz).…
Beyond Diffusion: A Causality-Preserving Model for Cosmic Ray Propagation
Norita Kawanaka, Rohta Takahashi
We propose a brand-new formalism for the propagation of relativistic cosmic ray (CR) particles. The propagation of CRs has often been described using the diffusion approximation, w…
A Relativistic Formula for the Multiple Scattering of Photons
Rohta Takahashi, Masayuki Umemura, Ken Ohsuga +6
We have discovered analytical expressions for the probability density function (PDF) of photons that are multiply scattered in relativistic flows, under the assumption of isotropic…
Influence of Black Hole Kick Velocity on Microlensing Distributions
Naoki Koshimoto, Norita Kawanaka, Daichi Tsuna
The natal kick velocity distribution for black holes (BHs) is unknown regardless of its importance for understanding the BH formation process. Gravitational microlensing is a uniqu…
Direct Measurement of the Spectral Structure of Cosmic-Ray Electrons+Positrons in the TeV Region with CALET on the International Space Station
O. Adriani, Y. Akaike, K. Asano +77
Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric…
Broadband non-thermal emission of odd radio circles induced by explosive galactic outflow remnants and their evolution
Yutaka Fujita, Norita Kawanaka, Susumu Inoue
Odd radio circles (ORCs) are mysterious rings of faint, diffuse emission recently discovered in radio surveys, some of which may be associated with galaxies in relatively dense env…
The relationships between AGN power and molecular gas mass within 500 pc of the center of elliptical galaxies
Yutaka Fujita, Takuma Izumi, Hiroshi Nagai +2
The physical quantity that directly controls the feedback of active galactic nuclei (AGNs) in elliptical galaxies remains to be determined. The discovery of molecular gas around th…
JASMINE: Near-Infrared Astrometry and Time Series Photometry Science
Daisuke Kawata, Hajime Kawahara, Naoteru Gouda +86
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 Aero…
Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station
O. Adriani, Y. Akaike, K. Asano +77
We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the CALorimetric Electron Telescope onboard the International Space Stati…
Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station
O. Adriani, Y. Akaike, K. Asano +77
We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observati…
Effects of Heat Conduction on Blocking off the Super-Eddington Growth of Black Holes at High Redshift
Norita Kawanaka, Kazunori Kohri
We investigate the effect of conductive heating of the gas surrounding a geometrically thick accretion disk on the growth of a black hole at high redshift. If a black hole is accre…
Model of a `Warm Corona' as the Origin of the Soft X-ray Excess of Active Galactic Nuclei
Norita Kawanaka, Shin Mineshige
The soft X-ray excess in the spectra of active galactic nuclei is characterized by similar electron temperatures of 0.1 -- 0.3 keV and similar photon indices around 2.2 -- 3, if fi…
Spatial and Binary Parameter Distributions of Black Hole Binaries in the Milky Way Detectable with Gaia
Minori Shikauchi, Daichi Tsuna, Ataru Tanikawa +1
Soon after the Gaia data release (DR) 3 in June 2022, some candidates (and one confirmed) of detached black hole (BH) - luminous companion (LC) binaries have been reported. Existin…
Cosmic-ray Boron Flux Measured from 8.4 GeV to 3.8 TeV with the Calorimetric Electron Telescope on the International Space Station
O. Adriani, Y. Akaike, K. Asano +77
We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux \textcolor{black}{in an energy interval from 8.4 GeV to 3.…
Observation of Spectral Structures in the Flux of Cosmic-Ray Protons from 50 GeV to 60 TeV with the Calorimetric Electron Telescope on the International Space Station
O. Adriani, Y. Akaike, K. Asano +77
A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observat…
Search for a Black Hole Binary in Gaia DR3 Astrometric Binary Stars with Spectroscopic Data
Ataru Tanikawa, Kohei Hattori, Norita Kawanaka +3
We report the discovery of a candidate binary system consisting of a black hole (BH) and a red giant branch star from the Gaia DR3. This binary system is discovered from 64108 bina…
CALET Search for electromagnetic counterparts of gravitational waves during the LIGO/Virgo O3 run
O. Adriani, Y. Akaike, K. Asano +78
The CALorimetric Electron Telescope (CALET) on the International Space Station (ISS) consists of a high-energy cosmic ray CALorimeter (CAL) and a lower-energy CALET Gamma ray Burst…
Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station
O. Adriani, Y. Akaike, K. Asano +78
The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other trans-iron elements, therefore it provides a favorable opportunity for a…