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Low [O/Fe] Ratio in a Luminous Galaxy at the Early Cosmic Epoch (z > 10): Signature of Short Delay Time or Bright Hypernovae/Pair-Instability Supernovae?

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arXiv 2024年

作者： Nakane, Minami Ouchi, Masami Nakajima, Kimihiko Harikane, Yuichi Tominaga, Nozomu Takahashi, Koh Kashino, Daichi Yanagisawa, Hiroto Watanabe, Kuria Nomoto, Ken'ichi Isobe, Yuki Nishigaki, Moka Ishigaki, Miho N. Ono, Yoshiaki Takeda, Yui Institute for Cosmic Ray Research The University of Tokyo 5-1-5 Kashiwanoha Kashiwa Chiba 277-8582 Japan Department of Physics Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo113-0033 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Osawa 2-21-1 Mitaka Tokyo181-8588 Japan University of Tokyo Kashiwa Chiba277-8583 Japan Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Physics Faculty of Science and Engineering Konan University 8-9-1 Okamoto Kobe Hyogo658-8501 Japan Waseda Research Institute for Science and Engineering Faculty of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku Tokyo169-8555 Japan

We present an [O/Fe] ratio of a luminous galaxy GN-z11 at z = 10.60 derived with the deep public JWST/NIRSpec data. We fit the medium-resolution grating (G140M, G235M, and G395M) data with the model spectra consisting of BPASS-stellar and Cloudy-nebular spectra in the rest-frame UV wavelength ranges with Fe absorption lines, carefully masking out the other emission and absorption lines in the same manner as previous studies conducted for lower redshift (z ∼ 2 − 6) galaxies with oxygen abundance measurements. We obtain an Fe-rich abundance ratio [O/Fe] = −0.37+0.−04322, which is confirmed with the independent deep prism data as well as by the classic 1978 index method. This [O/Fe] measurement is lower than measured for star-forming galaxies at z ∼ 2−3. Because z = 10.60 is an early epoch after the Big Bang (∼ 430 Myr) and first star formation (likely ∼ 200 Myr), it is difficult to produce Fe by Type Ia supernovae (SNeIa) requiring sufficient delay time for white-dwarf formation and gas accretion. The Fe-rich abundance ratio in GN-z11 suggests that the delay time is short, or that the major Fe enrichment is not accomplished by SNeIa but bright hypernovae (BrHNe) and/or pair-instability supernovae (PISNe), where the yield models of BrHNe and PISNe explain Fe, Ne, and O abundance ratios of GN-z11. The [O/Fe] measurement is not too low to rule out the connection between GN-z11 and globular clusters (GCs) previously suggested by the nitrogen abundance, but rather supports the connection with a GC population at high [N/O] if a metal dilution process exists. © 2024, CC BY.

关键词： White dwarfs

Synthesized Tetrakis (2-Oxy Benzylidene ) -Hyroanthracen-2-Yloxy Zinc and Cobalt (Ii) Phthalocyanines: Structural, Dft and Sem Eds Study

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SSRN

SSRN 2024年

作者： Sener, Sevil Cavdan, Seda Erdem Acar-Selcuki, Nursel Kaya, Dogan Ekicibil, Ahmet Department of Chemical Technology Program Aliaga Vocational School Ege University Izmir Turkey Department of Chemistry Faculty of Science Ege University Bornova IzmirTR-35100 Turkey Department of Physics Faculty of Art and Sciences Cukurova University Adana Turkey Department of Advance Materials and Nanotechnology Graduate School of Sciences Cukurova University Adana Turkey Department of Bioengeeniring Faculty of Engeeniring Ege University Izmir Turkey

The Synthesis reaction, define structure, spectroscopic, and binding properties of newly Zn(II) and Co(II) phthalocyanine (Pc) complexes, denoted as Co-Pc (4) and Zn-Pc (5), respectively, containing two (2-oxybenzylidene) anthracene-dione groups, are described. Following the synthesis 3-[(6-hydroxy-9,10-dihydroanthracen-2-yloxy)phthalonitrile] 3, Zinc Phthalocyanine (Zn-Pc) 4 and Cobalt Phthalocyanine (Co-Pc) 5 were subsequently prepared via chemical reaction with zinc and cobalt salts in dimethylformamide (DMF) under heat and vacuum conditions. SEM image analysis confirmed homogen formation for both Zn-Pc and Co-Pc compounds with the average size of 470 μm and 69 μm, respectively. Compounds 3, 4, and were characterized through percent quantity analysis of elements, Ultraviole-Visible is spectroscopy, Fourier Transform-Infrared Spectroscopy, 1H-Nucleer Magnetic Resonans Spectroscopy, and Q-TOF MS. Besides, Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) calculations were performed to inquire into the structural and electronic effects of compounds 4 and 5. To date, many phthalocyanine compounds have been synthesized. In this research the synthesis of Compound 4 with corrosion inhibitors properties is very important in this respect. © 2024, The Authors. All rights reserved.

关键词： Density functional theory

Nonlocal phase-change metaoptics for reconfigurable nonvolatile image processing

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arXiv 2024年

作者： Yang, Guoce Wang, Mengyun Lee, June Sang Farmakidis, Nikolaos Shields, Joe de Galarreta, Carlota Ruiz Kendall, Stuart Bertolotti, Jacopo Moskalenko, Andriy Huang, Kairan Alù, Andrea Wright, C. David Bhaskaran, Harish Department of Materials University of Oxford Parks Road OX1 3PH United Kingdom Department of Engineering University of Exeter ExeterEX4 QF United Kingdom Photonics Initiative Advanced Science Research Center City University of New York New York United States Physics Program Graduate Center City University of New York New York United States

The next generation of smart imaging and vision systems will require compact and tunable optical computing hardware to perform high-speed and low-power image processing. These requirements are driving the development of computing metasurfaces to realize efficient front-end analog optical pre-processors, especially for edge-detection capability. Yet, there is still a lack of reconfigurable or programmable schemes, which may drastically enhance the impact of these devices at the system level. Here, we propose and experimentally demonstrate a reconfigurable flat optical image processor using low-loss phase-change nonlocal metasurfaces. The metasurface is configured to realize different transfer functions in spatial frequency space, when transitioning the phase-change material between its amorphous and crystalline phases. This enables edge detection and bright-field imaging modes on the same device. The metasurface is compatible with a large numerical aperture of ~0.5, making it suitable for high resolution coherent optical imaging microscopy. The concept of phase-change reconfigurable nonlocal metasurfaces may enable emerging applications of artificial intelligence-assisted imaging and vision devices with switchable multitasking. © 2024, CC BY.

关键词： Image enhancement

A Comparative Study of Machine Learning Classifiers for Enhancing Knee Osteoarthritis Diagnosis

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Information (Switzerland) 2024年第4期15卷 183页

作者： Raza, Aquib Phan, Thien-Luan Li, Hung-Chung Hieu, Nguyen Van Nghia, Tran Trung Ching, Congo Tak Shing Graduate Institute of Biomedical Engineering National Chung Hsing University Taichung402 Taiwan Department of Physics and Electronic Engineering University of Science Vietnam National University of Ho Chi Minh City Ho Chi Minh City70000 Viet Nam Undergraduate Program of Intellectual Creativity Engineering National Chung Hsing University Taichung402 Taiwan VNU-HCM Ho Chi Minh City72409 Viet Nam Department of Electrical Engineering National Chi Nan University Puli Township545 Taiwan International Doctoral Program in Agriculture National Chung Hsing University Taichung402 Taiwan

Knee osteoarthritis (KOA) is a leading cause of disability, particularly affecting older adults due to the deterioration of articular cartilage within the knee joint. This condition is characterized by pain, stiffness, and impaired movement, posing a significant challenge in medical diagnostics and treatment planning, especially due to the current inability for early and accurate detection or monitoring of disease progression. This research introduces a multifaceted approach employing feature extraction and machine learning (ML) to improve the accuracy of diagnosing and classifying KOA stages from radiographic images. Utilizing a dataset of 3154 knee X-ray images, this study implemented feature extraction methods such as Histogram of Oriented Gradients (HOG) with Linear Discriminant Analysis (LDA) and Min–Max scaling to prepare the data for classification. The study evaluates six ML classifiers—K Nearest Neighbors classifier, Support Vector Machine (SVM), Gaussian Naive Bayes, Decision Tree, Random Forest, and XGBoost—optimized via GridSearchCV for hyperparameter tuning within a 10-fold Stratified K-Fold cross-validation framework. An ensemble model has also been made for the already high-accuracy models to explore the possibility of enhancing the accuracy and reducing the risk of overfitting. The XGBoost classifier and the ensemble model emerged as the most efficient for multiclass classification, with an accuracy of 98.90%, distinguishing between healthy and unhealthy knees. These results underscore the potential of integrating advanced ML methodologies for the nuanced and accurate diagnosis and classification of KOA, offering new avenues for clinical application and future research in medical imaging diagnostics. © 2024 by the authors.

关键词： Extraction

Stokesian Dynamics with odd viscosity

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arXiv 2022年

作者： Yuan, Hang de la Cruz, Monica Olvera Applied Physics Graduate Program Northwestern University EvanstonIL60208 United States Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Department of Chemistry Northwestern University EvanstonIL60208 United States Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States

Stokesian Dynamics is a well-established computational method for simulating dynamics of many particles suspended in a conventional passive fluid medium. Active fluids composed of self-propelling particles with broken time reversal symmetry permit the emergence of a so-called odd viscosity. In this work, we extended the conventional Stokesian Dynamics formalism to incorporate the additional hydrodynamic effects due to odd viscosity, which enables simulating collective behaviors of many particles suspended in an active fluid medium with both even viscosity and odd viscosity. © 2022, CC BY.

关键词： Viscosity

Application of Open-Path Fourier Transform Infrared (OP-FTIR) spectroscopy to air-sea greenhouse gas exchange

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Application of Open-Path Fourier Transform Infrared (OP-FTIR...

Applied Industrial Spectroscopy, AIS 2021 - Part of Optical Sensors and Sensing Congress 2021

作者： Wiacek, Aldona Hellmich, Martin Flesch, Thomas Department of Environmental Science Saint Mary's University HalifaxNS Canada Department of Astronomy and Physics Saint Mary's University HalifaxNS Canada Applied Science Graduate Program Saint Mary's University HalifaxNS Canada Department of Earth and Atmospheric Sciences University of Alberta EdmontonABT6G 2E3 Canada

An OP-FTIR system was deployed over the ocean surface to collect absorption spectra at two heights, alternating quickly in time. Gas concentrations were derived and used to calculate air-sea gas fluxes by the flux-gra... 详细信息

ISBN: (纸本)9781557528209

关键词： Fourier transform infrared spectroscopy

Variational tensor network operator

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Physical Review Research 2022年第4期4卷 043153-043153页

作者： Yu-Hsueh Chen Ke Hsu Wei-Lin Tu Hyun-Yong Lee Ying-Jer Kao Center for Theoretical Physics and Department of Physics National Taiwan University Taipei 10607 Taiwan Division of Display and Semiconductor Physics Korea University Sejong 30019 Korea Department of Applied Physics Graduate School Korea University Sejong 30019 Korea Interdisciplinary Program in E·ICT-Culture-Sports Convergence Korea University Sejong 30019 Korea Center for Quantum Science and Technology National Taiwan University Taipei 10607 Taiwan National Center for High-Performance Computing Hsinchu City 30076 Taiwan

We propose a simple and generic construction of the variational tensor network operators to study the quantum spin systems by the synergy of ideas from the imaginary-time evolution and the variational optimization of trial wave functions. By applying these operators to simple initial states, accurate variational ground-state wave functions with extremely few parameters can be obtained. Furthermore, the framework can be applied to spontaneously study symmetry-breaking, symmetry-protected topological, and intrinsic topologically ordered phases, and we show that symmetries of the local tensors associated with these phases can emerge directly after the optimization without any gauge fixing. This provides a universal way to identify quantum phase transitions without prior knowledge of the system.

关键词： Magnetism Topological order Quantum many-body systems Tensor network methods

Topological thermal Hall effect of magnons in magnetic skyrmion lattice

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Physical Review Research 2022年第4期4卷 043085-043085页

作者： Masatoshi Akazawa Hyun-Yong Lee Hikaru Takeda Yuri Fujima Yusuke Tokunaga Taka-hisa Arima Jung Hoon Han Minoru Yamashita The Institute for Solid State Physics The University of Tokyo Kashiwa 277-8581 Japan Department of Applied Physics Graduate School Korea University Sejong 30019 South Korea Division of Display and Semiconductor Physics Korea University Sejong 30019 South Korea Interdisciplinary Program in E·ICT-Culture-Sports Convergence Korea University Sejong 30019 South Korea Department of Advanced Materials Science University of Tokyo Kashiwa 277-8561 Japan Department of Physics Sungkyunkwan University Suwon 16419 South Korea

Topological transport of fermions is governed by the Chern numbers of the energy bands lying below the Fermi energy. For bosons, e.g., phonons and magnons in a crystal, topological transport is dominated by the Chern number of the lowest energy band when the bandgap is comparable with the thermal energy. Here, we demonstrate the presence of topological transport by bosonic magnons in a lattice of magnetic skyrmions—topological defects formed by a vortexlike texture of spins. We find a distinct thermal Hall signal in the magnetic skyrmion phase of an insulating polar magnet GaV4Se8, identified as the topological thermal Hall effect of magnons governed by the Chern number of the lowest energy band of the magnons in a triangular lattice of magnetic skyrmions. Our findings lay a foundation for studying topological phenomena of other bosonic excitations via thermal Hall probe.

关键词： Magnons Skyrmions Thermal Hall effect

A-STEP: The AstroPix Sounding Rocket Technology Demonstration Payload

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arXiv 2024年

作者： Violette, Daniel P. Steinhebel, Amanda Roy, Abhradeep Boggs, Ryan Caputo, Regina Durachka, David Fukazawa, Yasushi Hashizume, Masaki Hesh, Scott Jadhav, Manoj Kierans, Carolyn Kumar, Kavic Kushima, Shin Leys, Richard Metcalfe, Jessica Metzler, Zachary Nakano, Norito Peric, Ivan Perkins, Jeremy Seo, Lindsey Taylor Shin, K.-W. Striebig, Nicolas Suda, Yusuke Tajima, Hiroyasu NASA Goddard Space Flight Center GreenbeltMD United States United States Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima Japan NASA Wallops Flight Facility Wallops IslandVA United States Argonne National Laboratory LemontIL United States Department of Physics University of Maryland College ParkMD United States Institute for Space–Earth Environmental Research Nagoya University Aichi Japan ASIC and Detector Laboratory Karlsruhe Institute of Technology Karlsruhe Germany Institute for Particle Physics University of California Santa CruzCA United States

A next-generation medium-energy (100 keV to 100 MeV) gamma-ray observatory will greatly enhance the identification and characterization of multimessenger sources in the coming decade. Coupling gamma-ray spectroscopy, imaging, and polarization to neutrino and gravitational wave detections will develop our understanding of various astrophysical phenomena including compact object mergers, supernovae remnants, active galactic nuclei and gamma-ray bursts. An observatory operating in the MeV energy regime requires technologies that are capable of measuring Compton scattered photons and photons interacting via pair production. AstroPix is a monolithic high voltage CMOS active pixel sensor which enables future gamma-ray telescopes in this energy range. AstroPix’s design is iterating towards low-power (∼1.5 mW/cm2), high spatial (500 µm pixel pitch) and spectral (2 building block of future large area AstroPix instruments, such as ComPair-2 and AMEGO-X. This payload will be the first demonstration of AstroPix detectors operated in a space environment and will demonstrate the technology’s readiness for future astrophysical and nuclear physics applications. In this work, we overview the design and state of development of the A-STEP payload. Copyright © 2024, The Authors. All rights reserved.

关键词： Photons