Abstract The A eos project introduces a series of high-resolution cosmological simulations that model star-by-star chemical enrichment and galaxy formation in the early Universe, achieving 1 pc resolution. These capture complexities evolution within first ~300 Myr by modeling individual stars their feedback processes. By incorporating yields from stars, generates galaxies with diverse stellar abundances, linking them to hierarchical nucleosynthetic events. underscore importance abundance...

Abstract We have developed a chemodynamical approach to assign 36,010 metal-poor SkyMapper stars various Galactic stellar populations. Using two independent techniques (velocity and action space behavior), Gaia EDR3 astrometry, photometric metallicities, we selected with the characteristics of “metal-weak” thick-disk population by minimizing contamination canonical thick disk or other structures. This sample comprises 7127 stars, spans metallicity range −3.50 < [Fe/H] −0.8, has systematic...

Abstract We investigate how stellar feedback from the first stars (Population III) distributes metals through interstellar and intergalactic medium using star-by-star cosmological hydrodynamics simulation, A eos . find that energy injected supernovae (SNe) of is enough to expel a majority gas beyond virial radius halos with mass M dm ≲ 10 7 ⊙ , regardless number SNe. This prevents self-enrichment results in nonmonotonic increase metallicity at early times. Most minihalos ( ≳ 5 ) do not...

It is unclear if neutron star mergers can explain the observed r-process abundances of metal-poor stars. Collapsars, defined here as rotating massive stars whose collapse results in a rapidly accreting disk around black hole that launch jets, are promising alternative. We find we produce self-consistent model which population collapsars with stochastic europium yields synthesizes all material ([Fe/H] < -2.5) Our reproduces scatter and evolution [Eu/Fe] abundances. dominant site for stars,...

Abstract We present high-resolution Magellan/MIKE spectra of 22 bright (9 &lt; V 13.5) metal-poor stars (−3.18 [Fe/H] −1.37) in three different stellar streams, the Helmi debris stream, trail and ω Centauri progenitor stream. augment our sample with results for 10 by Roederer et al. a total 32 stars. Detailed chemical abundances light elements as well heavy neutron-capture have been determined All streams contain carbon-enhanced For 13 stars, element lines were detectable, they all show...

The Milky Way has accreted many ultra-faint dwarf galaxies (UFDs), and stars from these can be found throughout our Galaxy today. Studying provides insight into galaxy formation early chemical enrichment, but identifying them is difficult. Clustering stellar dynamics in 4D phase space ($E$, $L_z$, $J_r$, $J_z$) one method of structure which currently being utilized the search for UFDs. We produce 32 simulated halos using particle tagging with \textit{Caterpillar} simulation suite thoroughly...

The highly r-process enhanced (r-II) metal-poor halo stars we observe today could play a key role in understanding early ultra-faint dwarf galaxies, the smallest building blocks of Milky Way. If significant fraction r-II originated galaxies that merged to help form Way, observations us study these now-destroyed systems and probe formation history our Galaxy. To conduct initial investigation into this possible connection, use high-resolution cosmological simulations Milky-Way-mass from...

We present the first high-resolution chemical abundances of seven stars in recently discovered high-energy stream Typhon. Typhon have apocenters >100 kpc, making this detailed picture Milky Way's very distant stellar halo. Though sample size is limited, we find that Typhon's are more like a dwarf galaxy than globular cluster, showing metallicity dispersion and no presence multiple populations. display enhanced $\alpha$-element increasing r-process with metallicity. The high-$\alpha$ suggest...

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 preserve their natal cloud's composition, LMC's recent infall makes its ancient, metal-deficient ("low-metallicity") stars unique windows early star formation and nucleosynthesis in a formerly distant region of high-redshift universe. Previously, identifying such LMC was challenging. But new techniques have opened this...

The AEOS project introduces a series of high-resolution cosmological simulations that model star-by-star chemical enrichment and galaxy formation in the early Universe, achieving 1 pc resolution. These capture complexities evolution within first ~300 Myr by modeling individual stars their feedback processes. By incorporating yields from stars, generates galaxies with diverse stellar abundances, linking them to hierarchical nucleosynthetic events. underscore importance abundance patterns...

We investigate how stellar feedback from the first stars (Population III) distributes metals through interstellar and intergalactic medium using star-by-star cosmological hydrodynamics simulation, Aeos. find that energy injected supernovae of is enough to expel a majority gas beyond virial radius halos with mass $M_* \lesssim 10^7$ M$_\odot$, regardless number supernovae. This prevents self-enrichment results in non-monotonic increase metallicity at early times. Most minihalos ($M \gtrsim...

We present phase-resolved optical spectra of the low-mass X-ray binary system V801 Ara. The spectra, obtained in 2014 with Inamori Magellan Areal Camera and Spectrograph on Magellan/Baade telescope at Las Campanas Observatory, cover full orbit 3.8 h. They contain strong emission features allowing us to map H α, β, He ii λ4686, Bowen blend λ4640. radial velocity curves shows significantly stronger modulation orbital period than α as expected for former originating secondary latter consistent...

A small group of postdocs, graduate students, and undergraduates inadvertently formed a longitudinal study contrasting expected productivity levels with actual levels. Over the last nine months, our self-reported 559 tasks, dates, completion times -- actual. Here, I show which types tasks we are worst at completing in originally planned amount time (spoiler: coding writing tasks), whether more senior researchers have accurate expectations not much), improve only little).

Abstract The Milky Way’s stellar halo preserves a fossil record of smaller dwarf galaxies that merged with the Way throughout its formation history. Currently, though, we lack reliable ways to identify which stars originated in or even were definitively accreted. Selecting specific chemical signatures may provide way forward. We investigate this theoretically and observationally for r-process nucleosynthesis signatures. Theoretically, combine high-resolution cosmological simulations an...

The Milky Way has accreted many ultra-faint dwarf galaxies (UFDs), and stars from these can be found throughout our Galaxy today. Studying provides insight into galaxy formation early chemical enrichment, but identifying them is difficult. Clustering stellar dynamics in 4D phase space ($E$, $L_z$, $J_r$, $J_z$) one method of structure which currently being utilized the search for UFDs. We produce 32 simulated halos using particle tagging with \textit{Caterpillar} simulation suite thoroughly...

We present the first high-resolution chemical abundances of seven stars in recently discovered high-energy stream Typhon. Typhon have apocenters &gt;100 kpc, making this detailed picture Milky Way's very distant stellar halo. Though sample size is limited, we find that Typhon's are more like a dwarf galaxy than globular cluster, showing metallicity dispersion and no presence multiple populations. display enhanced $α$-element increasing r-process with metallicity. The high-$α$ suggest short...