274 citations · 321 across the 16 of their papers we have counts for
13 papers · 1 filter
Solar twins in Gaia DR3 GSP-Spec II. Age distribution and its implications for the Sun's migration
Takuji Tsujimoto, Daisuke Taniguchi, Alejandra Recio-Blanco +2
Solar twins are among the most powerful tracers of Galactic disk evolution owing to their unique property of sharing nearly solar metallicities ([Fe/H] ~ 0) while spanning a wide r…
On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid
G. Bono, V. F. Braga, M. Fabrizio +54
We introduce a new photometric catalog of RR Lyrae variables (RRLs, 300,000) mainly based on data available in public datasets. We also present the largest and most homogeneo…
The VISCACHA survey XIV. Chemical evolution history of the SMC: The Southern Bridge Clusters
Sasi Saroon, B. Dias, T. Tsujimotto +18
The chemical evolution history of the Small Magellanic Cloud (SMC) is complex and is best understood through a comprehensive analysis of star clusters across its various regions. T…
An Ultra-Faint, Chemically Primitive Galaxy Forming in the Reionization Era
Kimihiko Nakajima, Masami Ouchi, Yuichi Harikane +9
The formation of the first stars and galaxies marked the onset of chemical enrichment, yet direct observations of such primordial systems remain elusive. Here we present James Webb…
Discovery of WINERED-HVS1: A metal-rich hyper-velocity star candidate ejected from the Galactic center
Kohei Hattori, Daisuke Taniguchi, Takuji Tsujimoto +4
We report the discovery of a metal-rich red giant star, WINERED-HVS1, which is a candidate for a hyper-velocity star (HVS). Its past trajectory suggests that this star may have bee…
MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
Daisuke Taniguchi, Noriyuki Matsunaga, Naoto Kobayashi +11
[Abbreviated] Context. Given their high luminosities (L>~10^4Lsun), red supergiants (RSGs) are good tracers of the chemical abundances of the young stellar population in the Milky…
Solar System Migration Points to a Renewed Concept: Galactic Habitable Orbits
Junichi Baba, Takuji Tsujimoto, Takayuki R. Saitoh
Astrophysical evidence suggests that the Sun was born near 5 kpc from the Galactic center, within the corotation radius of the Galactic bar, around 6-7 kpc. This presents challenge…
Chemical enrichment by collapsars as the origin of the unusually high [Ba/Fe] in a massive star cluster of the dwarf galaxy NGC 1569
Brayden Leicester, Kenji Bekki, Takuji Tsujimoto
The super star cluster NGC1569-B has recently been observed to have an extremely high [Ba/Fe]. We consider that the observed high [Ba/Fe] ( 1.3) is due to the chemical enrich…
Phosphorus enrichment by ONe novae in the Galaxy
Kenji Bekki, Takuji Tsujimoto
Recent observations have shown that [P/Fe] in the Galactic stars decreases with increasing [Fe/H] for [Fe/H] > -1 whereas it is almost subsolar for [Fe/H]< -2. These [P/Fe] trends…
Joint r-Process Enrichment by Supernovae with a Metallicity Threshold and Neutron Star Mergers
Takuji Tsujimoto
The enrichment history of -process elements has been imprinted on the stellar abundances that change in accordance with increasing metallicity in galaxies. Close examination of…
Exploring the Sun's birth radius and the distribution of planet building blocks in the Milky Way galaxy: A multi-zone Galactic chemical evolution approach
Junichi Baba, Takayuki R. Saitoh, Takuji Tsujimoto
We explore the influence of the Milky Way galaxy's chemical evolution on the formation, structure, and habitability of the Solar system. Using a multi-zone Galactic Chemical Evolut…
Implications of a non-universal IMF from C, N, and O abundances in very metal-poor Galactic stars and damped Lyman-alpha absorbers
T. Tsujimoto, K. Bekki
Recently revealed C, N, and O abundances in the most metal-poor damped Lyman-alpha (DLA) absorbers are compared with those of extremely metal-poor stars in the Galactic halo, as we…
Turn-off of Deuterium Astration in the Recent Star Formation of the Galaxy Disk
T. Tsujimoto
Chemical features of the local stellar disk have firmly established that long-term, continuous star formation has been accompanied by a steady rate of accretion of low-metallicity…