51 citations · 494 across the 33 of their papers we have counts for
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Chemo-dynamical Analysis of a CNO-Enhanced Ultra Metal-poor Star (): Insights into Early Enrichment by Faint Population III Supernova
Guilherme Limberg, Vinicius M. Placco, Alexander P. Ji +10
We report an independent identification of the ultra metal-poor (UMP) star () DR3 $\texttt{source_id}$ 4795913112968206720 (GDR3_479591) in the miss…
Carbon Abundances in Metal-Poor Stars Reveal Distinct Galaxy and Star Formation Pathways in the Early Universe
Alexander Yelland, Anna Frebel, Xiaowei Ou +2
Carbon-enhanced metal-poor (CEMP; with and ) stars preserve information about early chemical enrichment, low-mass star formation, and th…
Galactic Archaeology with the Subaru `Ōnohi`ula Prime Focus Spectrograph Strategic Program
Masashi Chiba, Rosemary F. G. Wyse, Evan N. Kirby +48
The recently commissioned Subaru `Ōnohi`ula Prime Focus Spectrograph (PFS) will obtain spectra from nearly 2,400 fibers that cover 1.24 square degrees. The 360 night Subaru Strateg…
Discovery of an Star in XP Spectra
Guilherme Limberg, Vinicius M. Placco, Alexander P. Ji +5
We report on the discovery of GDR3_526285 ( DR3 Source ID 5262850721755411072), a star with and one of the lowest metal ($\text{atomic number} >…
Early r-process Enrichment and Hierarchical Assembly Across the Sagittarius Dwarf Galaxy
Xiaowei Ou, Alexander Yelland, Anirudh Chiti +3
Dwarf galaxies like Sagittarius (Sgr) provide a unique window into the early stages of galactic chemical evolution, particularly through their metal-poor stars. By studying the che…
Cosmological insights into the early accretion of r-process-enhanced stars II. Dynamical identification of lost members of Reticulum II
P. Berczik, M. Ishchenko, O. Sobodar +1
Aims. We identify the possible dynamical connection between individual r-process-enhanced stars and the ultra-faint dwarf galaxy Reticulum II based on the current phase-space infor…
The oldest stars with low neutron-capture element abundances and origins in ancient dwarf galaxies
Hillary Diane Andales, Ananda Santos Figueiredo, Casey Gordon Fienberg +2
We present a detailed chemical abundance and kinematic analysis of six extremely metal-poor ( [Fe/H] 2.9) halo stars with very low neutron-capture abundances ([Sr…
Signatures of tidal disruption of the Hercules ultra-faint dwarf galaxy
Xiaowei Ou, Anirudh Chiti, Nora Shipp +6
The Hercules ultra-faint dwarf galaxy (UFD) has long been hypothesized to be tidally disrupting, yet no conclusive evidence has been found for tidal disruption owing partly to diff…
A Strontium-rich Ultra Metal-poor Star in the Atari Disk Component
Mohammad K. Mardini, Anna Frebel, Anirudh Chiti
We report on the discovery of the first ultra metal-poor (UMP) star 2MASS~J205001946613298 (J20506613; \mbox{[Fe/H] = }) selected from the Gaia BP/RP spectral catalog…
Unraveling the Origins and Development of the Galactic Disk through Metal-Poor Stars
Maria Rah, Manolya Yatman, Ali Taani +2
The Milky Way is a spiral galaxy comprising three main components: the Bulge, the Disk, and the Halo. Of particular interest is the Galactic disk, which holds a significant portion…
Enrichment by Extragalactic First Stars in the Large Magellanic Cloud
Anirudh Chiti, Mohammad Mardini, Guilherme Limberg +8
The Large Magellanic Cloud (LMC) is the Milky Way's most massive satellite galaxy, which only recently (~2 billion years ago) fell into our Galaxy. Since stellar atmospheres preser…
Candidate Members of the VMP/EMP Disk System of the Galaxy from the SkyMapper and SAGES Surveys
Jihye Hong, Timothy C. Beers, Young Sun Lee +15
Photometric stellar surveys now cover a large fraction of the sky, probe to fainter magnitudes than large-scale spectroscopic surveys, and are relatively free from the target-selec…
Metal-poor stars observed with the Magellan Telescope. IV. Neutron-capture element signatures in 27 main-sequence stars
Mohammad K. Mardini, Anna Frebel, Leyatt Betre +3
Based on high-resolution spectra obtained with Magellan/MIKE, we present a chemo-dynamical analysis for 27 near main-sequence turnoff metal-poor stars, including 20 stars analyzed…
The chemical abundance pattern of the extremely metal-poor thin disk star 2MASS J1808-5104 and its origins
Mohammad K. Mardini, Anna Frebel, Rana Ezzeddine +6
We present a high-resolution (), high signal-to-noise () Magellan/MIKE spectrum of the bright extremely metal-poor star 2MASS~J18085104. We find [Fe/H] = $…
Possibilities and Limitations of Kinematically Identifying Stars from Accreted Ultra-Faint Dwarf Galaxies
Kaley Brauer, Hillary Diane Andales, Alexander P. Ji +4
The Milky Way has accreted many ultra-faint dwarf galaxies (UFDs), and stars from these galaxies can be found throughout our Galaxy today. Studying these stars provides insight int…
The Atari Disk, a Metal-Poor Stellar Population in the Disk System of the Milky Way
Mohammad K. Mardini, Anna Frebel, Anirudh Chiti +3
We have developed a chemo-dynamical approach to assign 36,010 metal-poor SkyMapper stars to various Galactic stellar populations. Using two independent techniques (velocity and act…
Detailed chemical abundances of stars in the outskirts of the Tucana II ultra-faint dwarf galaxy
Anirudh Chiti, Anna Frebel, Alexander P. Ji +6
We present chemical abundances and velocities of five stars between 0.3 kpc to 1.1 kpc from the center of the Tucana II ultra-faint dwarf galaxy (UFD) from high-resolution Magellan…
Stellar Metallicities from SkyMapper Photometry II: Precise photometric metallicities of 280,000 giant stars with [Fe/H] in the Milky Way
Anirudh Chiti, Anna Frebel, Mohammad K. Mardini +3
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliabl…
The Metal-Poor Metallicity Distribution of the Ancient Milky Way
Anirudh Chiti, Mohammad K. Mardini, Anna Frebel +1
We present a low metallicity map of the Milky Way consisting of 111,000 giants with [Fe/H] 0.75, based on public photometry from the second data r…
Metal-poor Stars Observed with the Automated Planet Finder Telescope. III. CEMP-no Stars are the Descendant of Population III Stars
Nour Aldein Almusleh, Ali Taani, Sergen Özdemir +4
In this study, we report a probabilistic insight into the stellar mass and supernovae (SNe) explosion energy of the possible progenitors of five CEMP-no stars. This was done by a d…
Cosmological Insights into the Early Accretion of \textit{r}-Process-Enhanced stars. I. A Comprehensive Chemo-dynamical Analysis of LAMOST J1109+0754
Mohammad K. Mardini, Vinicius M. Placco, Yohai Meiron +10
This study presents a comprehensive chemo-dynamical analysis of LAMOST J1109+0754, a bright (V = 12.8), extremely metal-poor (\abund{Fe}{H} = ) star, with a strong \textit{r…
Metal-poor Stars Observed with the Automated Planet Finder Telescope. II. Chemodynamical Analysis of Six Low-Metallicity Stars in the Halo System of the Milky Way
Mohammad K. Mardini, Vinicius M. Placco, Ali Taani +2
In this work, we study the chemical compositions and kinematic properties of six metal-poor stars with [Fe/H] in the Galactic halo. From high-resolution (R ~110,000)…
Metal-poor stars observed with the automated planet finder telescope. I. Discovery of five carbon-enhanced metal-poor stars from LAMOST
Mohammad K. Mardini, Haining Li, Vinicius M. Placco +6
We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of [Fe/H] . These stars were selected from the LAMOST DR3 low-res…