T. Hashimoto
YOU?
Author Swipe
View article: JWST MIRI color classification of mid-infrared selected galaxies
JWST MIRI color classification of mid-infrared selected galaxies Open
Context. We investigated the James Webb Space Telescope photometric color classification of mid-infrared (MIR) selected galaxies at high redshifts, toward cosmic noon. Aims. The aim of the present work is to obtain a z -dependent mid-infra…
View article: Extremely UV-bright starbursts at the end of cosmic reionization
Extremely UV-bright starbursts at the end of cosmic reionization Open
We present a study of 27 very UV-bright (-22.010, suggesting a shared evolutionary pathway.[Abridged]
View article: No Metallicity Preference in Fast Radio Burst Host Galaxies
No Metallicity Preference in Fast Radio Burst Host Galaxies Open
Fast radio bursts (FRBs) are millisecond-duration extragalactic radio transients of unknown origin, and studying their host galaxies could offer clues to constrain progenitor models. Among various host properties, gas-phase metallicity is …
View article: Do they repeat? Monitoring 36 non-repeating FRBs with FAST
Do they repeat? Monitoring 36 non-repeating FRBs with FAST Open
The origin of fast radio bursts (FRBs), highly energetic millisecond-duration radio pulses originating from beyond our Galaxy, remains unknown. Observationally, FRBs are classified as non-repeating or repeating; however, this classificatio…
View article: Do they repeat? Monitoring 36 non-repeating FRBs with FAST
Do they repeat? Monitoring 36 non-repeating FRBs with FAST Open
The origin of fast radio bursts (FRBs), highly energetic, millisecond-duration radio pulses originating from beyond our galaxy, remains unknown. Observationally, FRBs are classified as non-repeating or repeating, however, this classificati…
View article: Inferring Obscured Cosmic Black Hole Accretion History from AGN Found by JWST/MIRI CEERS Survey
Inferring Obscured Cosmic Black Hole Accretion History from AGN Found by JWST/MIRI CEERS Survey Open
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-infrared (MIR) SED fitting. We compute black hole accretion rates …
View article: Decoding the cosmological baryonic fluctuations using localized fast radio bursts
Decoding the cosmological baryonic fluctuations using localized fast radio bursts Open
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). They quantify the electron column density along each lin…
View article: Decoding the cosmological baryonic fluctuations using localized fast radio bursts
Decoding the cosmological baryonic fluctuations using localized fast radio bursts Open
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). They quantify the electron column density along each lin…
View article: Machine Learning–based Photometric Redshifts for Galaxies in the North Ecliptic Pole Wide Field: Catalogs of Spectroscopic and Photometric Redshifts
Machine Learning–based Photometric Redshifts for Galaxies in the North Ecliptic Pole Wide Field: Catalogs of Spectroscopic and Photometric Redshifts Open
We perform an MMT/Hectospec redshift survey of the North Ecliptic Pole Wide (NEPW) field covering 5.4 deg 2 and use it to estimate the photometric redshifts for the sources without spectroscopic redshifts. By combining 2572 newly measured …
View article: Composite periodogram analysis for low-event-count fast radio burst repeaters
Composite periodogram analysis for low-event-count fast radio burst repeaters Open
Context. Fast radio bursts (FRBs) are a class of transients characterised by their millisecond-scale duration and relatively high dispersion measures. Some FRBs have been observed to repeat. For such repeating FRBs, measuring the period is…
View article: Retracing the Cold Plasma Dispersion Law in Pulsar B0329+54: New Insights into Frequency-dependent Dispersion Measures
Retracing the Cold Plasma Dispersion Law in Pulsar B0329+54: New Insights into Frequency-dependent Dispersion Measures Open
Multiple studies have investigated potential frequency-dependent dispersion measures (DMs) in PSR B0329+54, with sensitivities at levels of 10 −3 pc cm −3 or higher, using frequencies below 1 GHz. Utilizing the extensive bandwidth of the u…
View article: Machine learning based Photometric Redshifts for Galaxies in the North Ecliptic Pole Wide field: catalogs of spectroscopic and photometric redshifts
Machine learning based Photometric Redshifts for Galaxies in the North Ecliptic Pole Wide field: catalogs of spectroscopic and photometric redshifts Open
We perform an MMT/Hectospec redshift survey of the North Ecliptic Pole Wide (NEPW) field covering 5.4 square degrees, and use it to estimate the photometric redshifts for the sources without spectroscopic redshifts. By combining 2572 newly…
View article: Retracing the Cold Plasma Dispersion Law in Pulsar B0329+54: New Insights into Frequency-Dependent Dispersion Measures
Retracing the Cold Plasma Dispersion Law in Pulsar B0329+54: New Insights into Frequency-Dependent Dispersion Measures Open
Multiple studies have investigated potential frequency-dependent dispersion measures (DM) in PSR B0329+54, with sensitivities at levels of $10^{-3} \, \text{pc} \, \text{cm}^{-3}$ or higher, using frequencies below 1 GHz. Utilizing the ext…
View article: A search for Planet Nine with IRAS and AKARI data
A search for Planet Nine with IRAS and AKARI data Open
The outer solar system is theoretically predicted to harbour an undiscovered planet, often referred to as Planet Nine. Simulations suggest that its gravitational influence could explain the unusual clustering of minor bodies in the Kuiper …
View article: Brown dwarf number density in the JWST COSMOS-Web field
Brown dwarf number density in the JWST COSMOS-Web field Open
Brown dwarfs are failed stars with very low mass (13–75 Jupiter mass) and an effective temperature lower than 2 500 K. Their mass range is between Jupiter and red dwarfs. Thus, they play a key role in understanding the gap in the mass func…
Photometrically selected protocluster candidates at $z\sim 9-10$ in the JWST COSMOS-Web field Open
View article: A far-infrared search for planet nine using AKARI all-sky survey
A far-infrared search for planet nine using AKARI all-sky survey Open
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 system, Planet Nine. However, due to its extreme distance, inte…
View article: Inferring obscured cosmic black hole accretion history from AGN found by JWST/MIRI CEERS survey
Inferring obscured cosmic black hole accretion history from AGN found by JWST/MIRI CEERS survey Open
This study presents the black hole accretion history of obscured active galactic nuclei (AGNs) identified from the JWST CEERS survey by Chien et al. (2024) using mid-infrared (MIR) SED fitting. We compute black hole accretion rates (BHARs)…
View article: No detection of radio continuum from low-redshift passive spiral galaxies
No detection of radio continuum from low-redshift passive spiral galaxies Open
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. It is unclear if all passive galaxy populations host radi…
View article: Constraining the Hubble constant with scattering in host galaxies of fast radio bursts
Constraining the Hubble constant with scattering in host galaxies of fast radio bursts Open
Aims. Measuring the Hubble constant (H 0 ) is one of the most important missions in astronomy. Nevertheless, recent studies exhibit differences between the employed methods. Methods. Fast radio bursts (FRBs) are coherent radio transients w…
View article: Constraining the Hubble constant with scattering in host galaxies of fast radio bursts
Constraining the Hubble constant with scattering in host galaxies of fast radio bursts Open
Measuring the Hubble constant (H$_0$) is one of the most important missions in astronomy. Nevertheless, recent studies exhibit differences between the employed methods. Fast radio bursts (FRBs) are coherent radio transients with large disp…
View article: Revisiting the Mysterious Origin of FRB 20121102A with Machine-learning Classification
Revisiting the Mysterious Origin of FRB 20121102A with Machine-learning Classification Open
Fast radio bursts (FRBs) are millisecond-duration radio waves from the Universe. Even though more than 50 physical models have been proposed, the origin and physical mechanism of FRB emissions are still unknown. The classification of FRBs …
View article: ALMA reveals spatially-resolved properties of molecular gas in the host galaxy of FRB 20191001A at z = 0.2340
ALMA reveals spatially-resolved properties of molecular gas in the host galaxy of FRB 20191001A at z = 0.2340 Open
We report the detection of the CO(2-1) emission line with a spatial resolution of 0.9 arcsec ($3.5 \mathrm{kpc}$) from the host galaxy of the fast radio burst (FRB), FRB 20191001A at $z=0.2340$, using the Atacama Large Millimeter/submillim…
View article: ALMA Reveals Spatially Resolved Properties of Molecular Gas in the Host Galaxy of FRB 20191001A at z = 0.2340
ALMA Reveals Spatially Resolved Properties of Molecular Gas in the Host Galaxy of FRB 20191001A at z = 0.2340 Open
We report the detection of the CO(2–1) emission line with a spatial resolution of 0.″9 (3.5 kpc) from the host galaxy of the fast radio burst (FRB), FRB 20191001A at z = 0.2340, using the Atacama Large Millimeter/submillimeter Array. This …
View article: Finding dusty AGNs from the <i>JWST</i> CEERS survey with mid-infrared photometry
Finding dusty AGNs from the <i>JWST</i> CEERS survey with mid-infrared photometry Open
The nature of the interaction between active galactic nuclei (AGNs) and their host galaxies remains an unsolved question. Therefore, conducting an AGN census is valuable for AGN research. Nevertheless, a significant fraction of AGNs are ob…
View article: Finding dusty AGNs from the JWST CEERS survey with mid-infrared photometry
Finding dusty AGNs from the JWST CEERS survey with mid-infrared photometry Open
The nature of the interaction between active galactic nuclei (AGNs) and their host galaxies remains an unsolved question. Therefore, conducting an AGN census is valuable to AGN research. Nevertheless, a significant fraction of AGNs are obs…
View article: Exploring the faintest end of mid-infrared luminosity functions up to <i>z</i> ≃ 5 with the <i>JWST</i> CEERS survey
Exploring the faintest end of mid-infrared luminosity functions up to <i>z</i> ≃ 5 with the <i>JWST</i> CEERS survey Open
Mid-infrared (MIR) light from galaxies is sensitive to dust-obscured star formation activities because it traces the characteristic emission of dust heated by young, massive stars. By constructing the MIR luminosity functions (LFs), we are…
View article: Exploring the faintest end of mid-infrared luminosity functions up to $z\simeq 5$ with the JWST CEERS survey
Exploring the faintest end of mid-infrared luminosity functions up to $z\simeq 5$ with the JWST CEERS survey Open
Mid-infrared (MIR) light from galaxies is sensitive to dust-obscured star-formation activities because it traces the characteristic emission of dust heated by young, massive stars. By constructing the MIR luminosity functions (LFs), we are…
View article: Polycyclic aromatic hydrocarbon (PAH) luminous galaxies in JWST CEERS data
Polycyclic aromatic hydrocarbon (PAH) luminous galaxies in JWST CEERS data Open
It has been an unanswered question how many dusty galaxies have been undetected from the state-of-the-art observational surveys. JWST enables us to detect faint IR galaxies that have prominent polycyclic aromatic hydrocarbon (PAH) features…
View article: Pre-experiment of 70 MeV H <sup>-</sup> cyclotron for producing ISOL RI beam.
Pre-experiment of 70 MeV H <sup>-</sup> cyclotron for producing ISOL RI beam. Open
The Rare Isotope Science Project (RISP) is currently constructing equipment and facilities for the Rare Isotope Accelerator complex for ON-line experiments (RAON). The first experiment being conducted involves the acceleration of a proton …