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๐Ÿ” mikel lujan ๐Ÿ“‚ Physics
Showing 201 results for "mikel lujan" in Physics
Physics Preprint PDF DOI

The chemical DNA of the Magellanic Clouds V. R-process dominates neutron capture elements production in the oldest SMC stars

Lorenzo Santarelli, Marco Palla, Alessio Mucciarelli, Lorenzo Monaco, Deimer Antonio Alvarez Garay, Donatella Romano, Carmela Lardo ยท 2025

We present the chemical abundances of Fe, alpha- and neutron-capture elements in 12 metal-poor Small Magellanic Cloud (SMC) giant stars, observed with the high-resolution spectrographs UVES/VLT and MIโ€ฆ

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Physics Preprint PDF DOI

Detailed Chemical Abundance Analysis of the Brightest Stars in the Turranburra and Willka Yaku Stellar Streams

Kaitlin B. Webber, Terese T. Hansen, Jennifer L. Marshall, Alexander P. Ji, Ting S. Li, Gary S. Da Costa, Lara R. Cullinane, Denis Erkal, Sergey E. Koposov, Kyler Kuehn, Geraint F. Lewis, Dougal Mackey, Sarah L. Martell, Andrew B. Pace, Nora Shipp, Jeffrey D. Simpson, Zhen Wan, Daniel B. Zucker, Victor A. Alvarado, Joss Bland-Hawthorn, Guilherme Limberg, Gustavo E. Medina, Sam A. Usman ยท 2025

We present a detailed chemical abundance analysis of the three brightest known stars from each of the Turranburra and Willka Yaku stellar streams using high-resolution Magellan/MIKE spectra. Abundanceโ€ฆ

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Physics Preprint PDF DOI

Egent: An Autonomous Agent for Equivalent Width Measurement

Yuan-Sen Ting, Serat Mahmud Saad, Fan Liu, Yuting Shen ยท 2025

We present Egent, an autonomous agent that combines classical multi-Voigt profile fitting with large language model (LLM) visual inspection and iterative refinement. The fitting engine is built from sโ€ฆ

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Physics Preprint PDF DOI

A search for black holes with metal-poor stellar companions: I. Survey sample selection and single epoch radial velocity follow-up

Casey Y. Lam, Joshua D. Simon, Kareem El-Badry, Howard Isaacson, Daniel D. Kelson, Jessica Lu ยท 2025

Stellar-mass black holes (BHs) above $30 M_\odot$ are predicted to form from low-metallicity progenitors, but direct detections of such systems in the Milky Way remain scarce. Motivated by the recent โ€ฆ

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Physics Preprint PDF DOI

The chemical DNA of the Magellanic Clouds III. The first, extragalactic Mg-K anticorrelation: the LMC globular cluster NGC 1786

Deimer Antonio Alvarez Garay, Alessio Mucciarelli, Lorenzo Monaco ยท 2025

In this work we derived [K/Fe] and [Mg/Fe] abundance ratios for six stars of the old globular cluster NGC 1786 in the Large Magellanic Cloud. We employed high-resolution spectra acquired with the MIKEโ€ฆ

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Physics Preprint PDF DOI

Probing the \ion{He}{2} re-Ionization ERa via Absorbing \ion{C}{4} Historical Yield (HIERACHY) IV: A complex redshifted absorption system intrinsic to quasar

Huiyang Mao, Jiang-Tao Li, Xiaodi Yu, Zhijie Qu, Weizhe Liu, Li Ji ยท 2025

High-resolution spectra provide a powerful tool in studying the associated absorption lines (AALs) in quasars. We present a case study of the quasar J014741-030247 at $z \sim$ 4.75, which hosts compleโ€ฆ

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Physics Preprint PDF DOI

Shocks and complex chemodynamics in the metal-poor starburst galaxy CGCG 007-025 revealed through high-resolution echelle spectroscopy

Macarena G. del Valle-Espinosa, Vital Fernandez, Ruben Sanchez-Janssen, Ricardo Amorin, Karla Z. Arrellano-Cordova, Konstantina Boutsia ยท 2025

We use Magellan/MIKE echelle spectroscopy to conduct an in-depth chemodynamical analysis of the most luminous star-forming region within the metal-poor starburst dwarf galaxy CGCG 007-025. Leveraging โ€ฆ

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Physics Preprint PDF DOI

A Spectroscopic Hunt for Post-Red Supergiants in the Large Magellanic Cloud II: Turbulent Line Broadening in the Spectra of LMC Yellow Supergiants

Trevor Z. Dorn-Wallenstein, Kaitlyn M. Chen, Samantha C. Wu, Jared A. Goldberg, Anna J. G. O'Grady, Ayanna T. Mann, Poderosa I. Don-Wallanchez ยท 2025

Massive stars in the Hertzsprung gap are a mixed population of objects in short-lived evolutionary phases: yellow supergiants (YSGs) evolving towards the red supergiant (RSG) phase, partially-strippedโ€ฆ

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Physics Preprint PDF DOI

Not-so-heavy metal(s): Chemical Abundances in the Ultra-faint Dwarf Galaxies Eridanus IV and Centaurus I

Mairead E Heiger, Alexander P Ji, Ting S Li, Joshua D Simon, Guilherme Limberg, Julio A Carballo-Bello, William Cerny, Astha Chaturvedi, Anirudh Chiti, Yumi Choi, Denija Crnojevic, Clara E Martinez-Vazquez, Gustavo E Medina, Burcin Mutlu-Pakdil, Mahdieh Navabi, Noelia E D Noel, Andrew B Pace, Vinicius M Placco, Alexander H Riley, Joanna D Sakowska, Guy S Stringfellow ยท 2025

We present detailed chemical abundances of the brightest star in each of the ultra-faint dwarf galaxies Eridanus IV and Centaurus I using high-resolution Magellan/MIKE spectroscopy. The brightest starโ€ฆ

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Physics Preprint PDF DOI

Effective Field Theory Constraints on Primordial Black Holes from the High-Redshift Lyman-$\alpha$ Forest

Mikhail M. Ivanov, Sokratis Trifinopoulos ยท 2025

We present updated constraints on the abundance of primordial black holes (PBHs) dark matter from the high-redshift Lyman-$\alpha$ forest data from MIKE/HIRES experiments. Our analysis leverages an efโ€ฆ

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Physics Preprint PDF DOI

Spectroscopic Analysis of Pictor II: a very low metallicity ultra-faint dwarf galaxy bound to the Large Magellanic Cloud

A. B. Pace (University of Virginia), T. S. Li, A. P. Ji, J. D. Simon, W. Cerny, A. M. Senkevich, A. Drlica-Wagner, K. Bechtol, C. Y. Tan, A. Chiti, D. Erkal, C. E. Martinez-Vazquez, P. S. Ferguson, R. G. Kron, K R. Atzberger, A. Chaturvedi, J. A. Frieman, N. Kallivayalil, G. Limberg, G. E. Medina, V. M. Placco, A. H. Riley, D. J. Sand, G. S. Stringfellow, R. P. van der Marel, J. A. Carballo-Bello, Y. Choi, D. Crnojevic, P. Massana, B. Mutlu-Pakdil, M. Navabi, N. E. D. Noel, J. D. Sakowska ยท 2025

We present Magellan/IMACS and Magellan/MIKE spectroscopy of the ultra-faint dwarf (UFD) galaxy Pictor~II (Pic~II) that is located only 12 kpc from the Large Magellanic Cloud (LMC). From the IMACS specโ€ฆ

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Physics Preprint PDF DOI

Power-law Emission-line Wings and Radiation-Driven Superwinds in Local Lyman Continuum Emitters

Lena Komarova, Sally Oey, Rui Marques-Chaves, Ricardo Amorin, Alaina Henry, Daniel Schaerer, Alberto Saldana-Lopez, Alexandra Le Reste, Claudia Scarlata, Matthew J. Hayes, Omkar Bait, Sanchayeeta Borthakur, Cody Carr, John Chisholm, Harry C. Ferguson, Vital Gutierrez Fernandez, Brian Fleming, Sophia R. Flury, Mauro Giavalisco, Andrea Grazian, Timothy Heckman, Anne E. Jaskot, Zhiyuan Ji, Goran Ostlin, Laura Pentericci, Swara Ravindranath, Trinh Thuan, Jose M. Vilchez, Gabor Worseck, Xinfeng Xu ยท 2025

We investigate broad emission-line wings, reaching $\leq 800\rm~km~s^{-1}$, observed in 26 galaxies with Lyman continuum (LyC) observations, primarily from the Low-redshift Lyman Continuum Survey (LzLโ€ฆ

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Physics Preprint PDF DOI

Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster

Sam A. Usman, Alexander P. Ji, Jandrie Rodriguez, Jeffrey D. Simpson, Sarah L. Martell, Ting S. Li, Ana Bonaca, Shivani P. Shah, Madeleine McKenzie ยท 2025

We present the first high-resolution abundance study of ESO 280-SC06, one of the least luminous and most metal-poor gravitationally bound Milky Way globular clusters. Using Magellan/MIKE spectroscopy โ€ฆ

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Physics Preprint PDF DOI

The Impact of Triangular-Toothed Gears on the Functionality of the Antikythera Mechanism

Esteban Guillermo Szigety y Gustavo Francisco Arenas ยท 2025

The Antikythera Mechanism is based on a complex system of interconnected gears. Recent analyses have highlighted the influence of triangular tooth profiles and manufacturing inaccuracies on its perforโ€ฆ

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Physics Preprint PDF DOI

The Cosmic One-Eyed Smile: Revealing the Hidden Face of Mike Wazowski

Chun Huang ยท 2025

We present a novel and somewhat whimsical approach to pulsar hotspot modeling by drawing inspiration from the iconic one-eyed monster, Mike Wazowski, from \emph{Monsters, Inc.}. Utilizing X-ray high-qโ€ฆ

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Physics Preprint PDF DOI

Probing the He II reionization ERa via Absorbing C IV Historical Yield (HIERACHY) III: The C IV absorber catalog and initial results on cosmic abundance evolution at $z\approx 3-5$

Xiaodi Yu, Zhijie Qu, Zheng Cai, Jiangtao Li, Huiyang Mao, Xin Wang ยท 2025

As part of the HIERACHY program, we collect the high-SN and high-spectral resolution optical spectra of 25 quasars at $z\approx4-5$ to constrain the C IV evolution at $z\approx 3-5$. In this paper, weโ€ฆ

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Physics Preprint PDF DOI

The R-Process Alliance: Hunting for gold in the near-UV spectrum of 2MASS J05383296-5904280

Terese T. Hansen, Ian U. Roederer, Shivani P. Shah, Rana Ezzeddine, Timothy C. Beers, Anna Frebel, Erika M. Holmbeck, Vinicius M. Placco, Charli M. Sakari, Alexander P. Ji, Jennifer L. Marshall, Mohammad K.Mardini, Anirudh Chit ยท 2025

Context. Over the past few years, the $R$-Process Alliance (RPA) has successfully carried out a search for stars that are highly enhanced in elements produced via the rapid neutron-capture ($r$-) procโ€ฆ

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Physics Preprint PDF DOI

A New Look at Disk Winds and External Photoevaporation in the $\sigma$-Orionis Cluster

K. Mauco, C. F. Manara, A. Bayo, J. Hernandez, J. Campbell-White, N. Calvet, G. Ballabio, M. L. Aru, J. M. Alcala, M. Ansdell, C. Briceno, S. Facchini, T. J. Haworth, M. McClure, J. P. Williams ยท 2024

Disk winds play a crucial role in the evolution of protoplanetary disks. Typical conditions for star and planet formation are in regions with intermediate or strong UV radiation fields produced by masโ€ฆ

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Planets Around Solar Twins/Analogs (PASTA) I.: High precision stellar chemical abundance for 17 planet-hosting stars and the condensation temperature trend

Qinghui Sun, Sharon Xuesong Wang, Tianjun Gan, Chenyang Ji, Zitao Lin, Yuan-Sen Ting, Johanna Teske, Haining Li, Fan Liu, Xinyan Hua, Jiaxin Tang, Jie Yu, Jiayue Zhang, Mariona Badenas-Agusti, Andrew Vanderburg, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Jon M. Jenkins, Richard P. Schwarz, Tristan Guillot, Thiam-Guan Tan, Dennis M. Conti, Kevin I. Collins, Gregor Srdoc, Chris Stockdale, Olga Suarez, Roberto Zambelli, Don Radford, Khalid Barkaoui, Phil Evans, Allyson Bieryla ยท 2024

The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets. Here we present high-resolution, high signal-to-noise sโ€ฆ

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Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield (HIERACHY) II: Project Design, Current Status, and Examples of Initial Data Products

Jiang-Tao Li, Xiaodi Yu, Huiyang Mao, Hanxiao Chen, Tiancheng Yang, Zhijie Qu, Fuyan Bian, Joel N. Bregman, Zheng Cai, Xiaohui Fan, Taotao Fang, Li Ji, Zhiyuan Ji, Sean D. Johnson, Guoliang Li, Weizhe Liu, Ying-Yi Song, Feige Wang, Tao Wang, Xin Wang, Christina Williams, Mingxuan Xu, Jinyi Yang, Yang Yang, Xianzhong Zheng ยท 2024

The He II reionization epoch is expected to take place at $z\sim3-5$. In this stage, the helium and metals in the inter-galactic medium (IGM) are further ionized with additional contributions from harโ€ฆ

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