117 citations · 387 across the 17 of their papers we have counts for
17 papers
Axion-photon multimessenger astronomy with giant flares
Javier De Miguel, Chiko Otani
We treat prospects for multimessenger astronomy with giant flares (GFs), a rare transient event featured by magnetars that can be as luminous as a hundred of the brightest supernov…
Superdense beaming of axion dark matter in the vicinity of the light cylinder of pulsars
Javier De Miguel, Chiko Otani
In this article we treat the non-adiabatic photon-to-axion resonant conversion of curvature radiation, synchrotron emission and inverse Compton scattering dominating the spectral d…
Characterization of two-level system noise for microwave kinetic inductance detector comprising niobium film on silicon substrate
Yoshinori Sueno, Shunsuke Honda, Hiroki Kutsuma +5
A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector. It comprises a resonator circuit constructed with a superconducting film on a dielectric…
Hot carrier dynamics and electron-optical phonon coupling in photoexcited graphene via time-resolved ultrabroadband terahertz spectroscopy
Sho Ikeda, Chiko Otani, Masatsugu Yamashita
Electron-electron (e-e) interaction is known as a source of logarithmic renormalizations for Dirac fermions in quantum field theory. The renormalization of electron--optical phonon…
Intrinsic and extrinsic effects on intraband optical conductivity of hot carriers in photoexcited graphene
Masatsugu Yamashita, Chiko Otani
We present a numerical study on the intraband optical conductivity of hot carriers at quasi-equilibria in photoexcited graphene based on the semiclassical Boltzmann transport equat…
A method to measure superconducting transition temperature of microwave kinetic inductance detector by changing power of readout microwaves
Hiroki Kutsuma, Yoshinori Sueno, Makoto Hattori +5
A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector, and its principle is based on a superconducting resonator circuit. The superconducting tr…
Closed-form formulae of hyperbolic metamaterial made by stacked hole-array layers working at terahertz or microwave radiation
Piyawath Tapsanit, Masatsugu Yamashita, Chiko Otani +2
A metamaterial made by stacked hole-array layers known as a fishnet metamaterial behaves as a hyperbolic metamaterial at wavelength much longer than hole-array period. However, the…
Quasi-analytical solutions of hybrid platform and the optimization of highly sensitive thin-film sensors for terahertz radiation
Piyawath Tapsanit, Masatsugu Yamashita, Teruya Ishihara +1
We present quasi-analytical solutions (QANS) of hybrid platform (HP) comprising metallic grating (MG) and stacked-dielectric layers for terahertz (THz) radiation. The QANS are vali…
A Possible Emission Feature in an X-ray Afterglow of GRB970828 as a Radiative Recombination Edge
A. Yoshida, M. Namiki, D. Yonetoku +6
A gamma-ray burst of 28 August 1997 was localized by the All-Sky Monitor on the Rossi XTE satellite and its coordinates were promptly disseminated. An ASCA followup started 1.17 da…
RE J2248-511 - Not all variable, ultrasoft, X-ray AGN have narrow Balmer lines
A. A. Breeveld, E. M. Puchnarewicz, C. Otani
We present ASCA data on RE J2248-511, extending existing optical and soft X-ray coverage to 10 keV, and monitoring the soft component. These data show that, despite a very strong u…
ASCA Observations of the Seyfert 2 Galaxy NGC 7582: An Obscured and Scattered View of the Hidden Nucleus
S. -J. Xue, C. Otani, T. Mihara +2
ASCA observations of the Seyfert 2 galaxy NGC 7582 revealed it was highly variable on the timescale of s in the hard X-ray (2-10 keV) band, while the soft X-ray (…
BeppoSAX observation of NGC 7674: a new reflection-dominated Seyfert 2 galaxy
G. Malaguti, G. G. C. Palumbo, M. Cappi +6
The Seyfert 2 galaxy NGC 7674 has been observed within the BeppoSAX Core Programme with the onboard narrow field instruments between 0.1 and 100 keV. The broad-band spectrum shows…
Multiwavelength Monitoring of the BL Lacertae Object PKS 2155-304 in May 1994. III. Probing the Inner Jet through Multiwavelength Correlations
C. Megan Urry, A. Treves, L. Maraschi +16
In May 1994 the BL Lac object PKS 2155-304 was observed continuously for ~10 d with IUE and EUVE and for 2 d with ASCA, as well as with ROSAT and with ground- based radio, IR, and…
The ASCA X-ray spectrum of the powerful radio galaxy 3C109
S. W. Allen, A. C. Fabian, E. Idesawa +3
We report the results from an ASCA X-ray observation of the powerful Broad Line Radio Galaxy, 3C109. The ASCA spectra confirm our earlier ROSAT detection of intrinsic X-ray absorpt…
Spectral Variability and iron line emission in the ASCA Observations of the Seyfert 1 Galaxy NGC4051
Matteo Guainazzi, Tatehiro Mihara, Chiko Otani +1
We present the results of an extensive analysis of the ``ASCA'' AO2 observation of the Seyfert 1 galaxy NGC4051. The target exhibits broadband [0.5--10 keV] variability by a factor…
ASCA Observations of the Composite Warm Absorber in NGC 3516
G. A. Kriss, J. H. Krolik, C. Otani +11
We obtained X-ray spectra of the Seyfert 1 galaxy NGC~3516 in March 1995 using ASCA. Simultaneous far-UV observations were obtained with HUT on the Astro-2 shuttle mission. The ASC…
Warm absorber, reflection and Fe K line in the X-ray spectrum of IC 4329A
M. Cappi, T. Mihara, M. Matsuoka +3
Results from the X-ray spectral analysis of the ASCA PV phase observation of the Seyfert 1 galaxy IC 4329A are presented. We find that the 0.4 - 10 keV spectrum of IC 4329A is best…