4 papers
Evidence for Multiple Orbiting Hotspots in the 340 GHz Variability of Sgr A*
Kazuki Yanagisawa, Tomoharu Oka, Tatsuya Kotani +3
We analyzed 11 epochs of archival Atacama Large Millimeter/submillimeter Array (ALMA) data to investigate flux density variability of Sgr A* at 340 GHz. In one epoch, the light cur…
Detection of a Molecular Cloud toward the Heartbeating Gamma-ray Source near the Microquasar SS 433
Tomoharu Oka, Ryo Ariyama, Tatsuya Kotani
We report the detection of a molecular cloud, CO+40.05-2.40, positionally coincident with the "heartbeating" GeV source Fermi J1913+0515 at the northern boundary of the SS 433/W50…
A Face-on Accretion Disk Geometry Revealed by Millimeter-wave Periodicity in Sgr A
Kazuki Yanagisawa, Tomoharu Oka, Ryo Ariyama +3
We analyzed 77 epochs of Atacama Large Millimeter/submillimeter Array (ALMA) archival data to investigate flux variability in Sagittarius A (Sgr A), the supermassive black…
A New Precise Measurement of the Cosmic Microwave Background Radiation Temperature at Toward PKS1830-211
Tatsuya Kotani, Tomoharu Oka, Rei Enokiya +3
In this study, we analyzed millimeter-wave data toward the quasar PKS1830-211 observed with the Atacama Large Millimeter/submillimeter Array to obtain absorption spectra of HCN …