196 citations · 307 across the 10 of their papers we have counts for
10 papers
Origin of an Orbiting Star Around the Galactic Supermassive Black Hole
Shogo Nishiyama, Tomohiro Kara, Brian Thorsbro +6
The tremendous tidal force that is linked to the supermassive black hole (SMBH) at the center of our galaxy is expected to strongly subdue star formation in its vicinity. Stars wit…
Follow-up survey for the binary black hole merger GW200224_222234 using Subaru/HSC and GTC/OSIRIS
Takayuki Ohgami, Josefa Becerra Gonzalez, Nozomu Tominaga +19
The LIGO/Virgo detected a gravitational wave (GW) event, named GW200224_222234 (a.k.a. S200224ca) and classified as a binary-black-hole coalescence, on February 24, 2020. Given its…
J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO's and Virgo's third observing run
Mahito Sasada, Yousuke Utsumi, Ryosuke Itoh +68
The Laser Interferometer Gravitational-wave Observatory Scientific Collaboration and Virgo Collaboration (LVC) sent out 56 gravitational-wave (GW) notices during the third observin…
Gravitational Wave Physics and Astronomy in the nascent era
Makoto Arimoto, Hideki Asada, Michael L. Cherry +50
The detections of gravitational waves (GW) by LIGO/Virgo collaborations provide various possibilities to physics and astronomy. We are quite sure that GW observations will develop…
Optical follow-up observation for GW event S190510g using Subaru/Hyper Suprime-Cam
Takayuki Ohgami, Nozomu Tominaga, Yousuke Utsumi +13
A gravitational wave event, S190510g, which was classified as a binary-neutron-star coalescence at the time of preliminary alert, was detected by LIGO/Virgo collaboration on May 10…
Constraints on the dark mass distribution surrounding Sgr A*: simple analysis for the redshift of photons from orbiting stars
Yohsuke Takamori, Shogo Nishiyama, Takayuki Ohgami +3
Sagittarius A* (Sgr A*) is the central supermassive black hole with the mass in the Milky Way and stars are orbiting around it. In May 2018, one of th…
A Significant Feature in the General Relativistic Time Evolution of the Redshift of Photons Coming from a Star Orbiting Sgr A*
Hiromi Saida, Shogo Nishiyama, Takayuki Ohgami +16
The star S0-2, orbiting the Galactic central massive black hole candidate Sgr A*, passed its pericenter in May 2018. This event is the first chance to detect the general relativist…
Can we identify massless braneworld black holes by observations?
M. Kuniyasu, K. Nanri, N. Sakai +3
For an extension of the previous work on gravitational lensing by massless braneworld black holes, we investigate their microlensing phenomena and shadows and discuss how to distin…
Wormhole Shadows in Rotating Dust
Takayuki Ohgami, Nobuyuki Sakai
As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in rotating dust…
Wormhole Shadows
Takayuki Ohgami, Nobuyuki Sakai
We propose a new method of detecting Ellis wormholes by use of the images of wormholes surrounded by optically thin dust. First, we derive steady solutions of dust and more general…