40 citations · 50 across the 20 of their papers we have counts for
22 papers
COSMOS-3D: Spectro-photometric Confirmation of Shabgard, a Cool, Metal-poor Brown Dwarf in the COSMOS Field
Bahareh S. Salmasi, Priyanka Jalan, Tomotsugu Goto +19
Brown dwarfs are unique laboratories for studying cool atmospheres, the low-mass end of star formation, and the transition between stars and giant planets. Identifying and characte…
SHELLQs. Black Hole Mass and Eddington Ratio Distributions of Intermediate-Luminosity Quasars at 6<z<7
Masafusa Onoue, John D. Silverman, Yoshiki Matsuoka +31
We present near-infrared spectroscopy of 21 quasars at 6.07 < z < 6.90 obtained with JWST/NIRSpec and Subaru/MOIRCS. These targets have absolute ultraviolet magnitudes of -25 < M_1…
Statistical inference of fast radio burst environments using galaxy number density
Vignesh V. V. Rao, Tetsuya Hashimoto, Tomotsugu Goto +9
Fast radio bursts (FRBs) are bright, millisecond-duration radio transients of unknown origin. They are categorized as repeaters and non-repeaters, possibly indicating distinct prog…
Tracing Obscured AGN Contribution and Number Fraction Across 0 < z < 6 with JWST
Angel Rodriguez Barbosa, Tomotsugu Goto, Daryl Joe D. Santos +8
Active galactic nuclei (AGN) are key drivers of galaxy evolution, yet many remain undetected in ultraviolet and optical surveys due to heavy dust obscuration. In these systems, abs…
A search for Fast Radio Bursts from globular clusters in M49 with FAST
Simon C. -C. Ho, Chris Flynn, Matthew Bailes +7
The origins of fast radio bursts (FRBs) remain uncertain, although magnetars are a leading progenitor candidate. Because magnetars are thought to form primarily through core-collap…
Constraints on the Physical Association between ICECAT1 Neutrinos and Fast Radio Bursts Using the Second CHIME/FRB Catalogue
Hiroto Masaoka, Tetsuya Hashimoto, Shotaro Yamasaski +8
We present a search for neutrino counterparts to fast radio bursts (FRBs) using temporal and spatial cross-matching between the Second CHIME/FRB catalogue and the IceCube high-ener…
Single-Pulse Correlations in PSR B0329+54: Implications for Radio Emission Zones
Shyam S. Sharma, Tetsuya Hashimoto, Tomotsugu Goto +3
Individual radio pulses from a pulsar are directly linked to the underlying emission processes and the associated magnetic field geometry within its magnetosphere. Thus, single-pul…
Unveiling Hidden Clustering: An Unsupervised Machine Learning Study of Repeating FRB 20220912A
An-Chieh Hsu, Tetsuya Hashimoto, Tomotsugu Goto +2
Fast Radio Bursts (FRBs) are millisecond-duration radio transients of extragalactic origin. Classifying repeating FRBs is essential for understanding their emission mechanisms, but…
Mid-IR luminosity functions: inferred dusty cosmic star-formation and black hole accretion histories from the JWST SMILES
Chih-Teng Ling, Tomotsugu Goto, Seong Jin Kim +5
Mid-infrared (mid-IR) observations are crucial for understanding galaxy evolution, tracing star formation, and active galactic nuclei (AGN) activity via dust emission. This work pr…
JWST MIRI color classification of mid-infrared selected galaxies: MIRI color classification toward cosmic noon
Ece Kilerci, Tomotsugu Goto, Matthew A. Malkan +7
We investigated the James Webb Space Telescope photometric color classification of mid-infrared (MIR) selected galaxies at high redshifts, toward cosmic noon. The aim of the presen…
Irregularity in Active Fast Radio Burst Repeaters and Magnetar Periodic Radio Pulses: Time, Energy, and Frequency Analyses
Ellen C. C. Lin, Shotaro Yamasaki, Tomotsugu Goto +1
Fast Radio Bursts (FRBs) are millisecond-duration radio pulses with largely unknown origins, with a subset exhibiting repeating behavior. Magnetars highly magnetized neutron stars…
Machine learning classification of baseband data of CHIME FRBs
Mohanraj Madheshwaran, Tetsuya Hashimoto, Tomotsugu Goto +5
Fast Radio Bursts (FRBs) are bright millisecond radio pulses. Their origin is still unknown in the field of astronomy. A notable distinction among FRBs is that some sources repeat,…
Photometrically Selected Protocluster Candidates at z~9-10 in the JWST COSMOS-Web field
Cossas K. -W. Wu, Chih-Teng Ling, Tomotsugu Goto +8
High-redshift protoclusters are crucial for understanding the formation of galaxy clusters and the evolution of galaxies in dense environments. The James Webb Space Telescope (JWST…
No Metallicity Preference in Fast Radio Burst Host Galaxies
Shotaro Yamasaki, Tetsuya Hashimoto, Haruka Kusakabe +1
Fast radio bursts (FRBs) are millisecond-duration extragalactic radio transients of unknown origin, and studying their host galaxies could offer clues to constrain progenitor model…
A Far-Infrared Search for Planet Nine Using AKARI All-Sky Survey
Amos Y. -A. Chen, Tomotsugu Goto, Issei Yamamura +7
An unusual orbital element clustering of Kuiper belt objects (KBOs) has been observed. The most promising dynamic solution is the presence of a giant planet in the outer Solar syst…
Inferring Obscured Cosmic Black Hole Accretion History from AGN Found by JWST/MIRI CEERS Survey
Cheng-An Hsieh, Tomotsugu Goto, Chih-Teng Ling +4
This study presents the black hole accretion history (BHAH) of obscured active galactic nuclei (AGNs) identified from the JWST CEERS survey by Chien et al. (2024) using mid-infrare…
Do they repeat? Monitoring 36 non-repeating FRBs with FAST
Yuri Uno, Tetsuya Hashimoto, Tomotsugu Goto +12
The origin of fast radio bursts (FRBs), highly energetic, millisecond-duration radio pulses originating from beyond our galaxy, remains unknown. Observationally, FRBs are classifie…
Decoding the cosmological baryonic fluctuations using localized fast radio bursts
Tzu-Yin Hsu, Tetsuya Hashimoto, Tsung-Ching Yang +7
Aims: The enigma of the missing baryons poses a prominent and unresolved problem in astronomy. Dispersion measures (DM) serve as a distinctive observable of fast radio bursts (FRBs…
A Search for Planet Nine with IRAS and AKARI Data
Terry Long Phan, Tomotsugu Goto, Issei Yamamura +6
The outer solar system is theoretically predicted to harbour an undiscovered planet, often referred to as P9. Simulations suggest that its gravitational influence could explain the…
No detection of radio continuum from low-redshift passive spiral galaxies
Hei Yung Chan, Michael J. I. Brown
Radio-emitting active galactic nuclei (AGNs) are common in elliptical galaxies and AGN feedback is one of the possible mechanisms for regulating star formation in massive galaxies.…
Brown dwarf number density in the JWST COSMOS-Web field
Amos Y. -A. Chen, Tomotsugu Goto, Cossas K. -W. Wu +9
Brown dwarfs are failed stars with very low mass (13 to 75 ), and an effective temperature lower than 2500 K. Thus, they play a key role in understanding the gap in the mass f…
VLT/X-shooter spectroscopy of the afterglow of the Swift GRB 130606A: Chemical abundances and reionisation at
O. E. Hartoog, D. Malesani, J. P. U. Fynbo +28
The reionisation of the Universe is thought to have ended around z~6, as inferred from spectroscopy of distant bright background sources, such as quasars (QSO) and gamma-ray burst…