bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Early Stages of Galaxy Formation Using Very Metal-poor Stars from the Hamburg/ESO Survey
Authors: Carollo Daniela , Christlieb Norbert , Tissera Patricia B. , Sillero Emanuel 
Published: April 2023

Abstract
We explore the chemodynamical properties of a sample of very metal-poor (VMP) stars selected from the Hamburg/ESO survey, matched with Gaia EDR3, in the phase space identified by the three integrals of motion (L

z
, E, I
3). Disk and halo orbits are separated by using the criteria defined in Carollo & Chiba. We found 26 stars with [Fe/H] ≤ −2.5 possessing disk kinematics, of which 13 are extremely metal-poor. At these metallicities, the number of stars with disk kinematics is three times its retrograde counterpart. In the same range of metallicity we also identified 37 halo stars most tightly bound to the gravitational potential of the progenitor halo. The origins of these stars are investigated by comparing the observational results with simulated galaxies from the Aquarius Project and the IllustrisTNG simulations. We found two mechanisms of formation of VMP stars with disk kinematics: accretion from early satellites (which is dominant), and in situ formation. These stars are very old, with ages >12.5 Gyr (z > 5), and they are α-enriched. Accretion and in situ formation are also found for the retrograde counterparts, with accretion also being the dominant mode. Contributing accreted satellites have stellar masses in the range 106–109
M
☉ and are very gas-rich. The most bound halo stars are the oldest detected, with a median age of ∼13.3 Gyr (z ∼ 11), and are α-enriched. Our finding clearly shows that very old, VMP stars store important information on the first stages of assembly of our Galaxy and its halo.
Disentangling Stellar and Airglow Emission Lines from Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) Spectra
Authors: Cruz Aguirre Fernando , Youngblood Allison , France Kevin , Bourrier Vincent 
Published: April 2023

Abstract
H i Lyα (1215.67 Å) and the O i triplet (1302.17, 1304.86, and 1306.03 Å) are bright far-ultraviolet (FUV) emission lines that trace the stellar chromosphere. Observations of stellar Lyα and O i using the Hubble Space Telescope's (HST) most sensitive FUV spectrograph, the Cosmic Origins Spectrograph (COS), are contaminated with geocoronal emission, or airglow. This study demonstrates that airglow emission profiles as observed by COS are sufficiently stable to create airglow templates that can be reliably subtracted from the data, recovering the underlying stellar flux. We developed a graphical user interface to implement the airglow subtraction on a sample of 171 main-sequence F-, G-, K-, and M-type dwarfs from the COS data archive. Correlations between recovered stellar emission and measures of stellar activity were investigated. Several power-law relationships are presented for predicting the stellar Lyα and O i emission. The apparent brightness of the stellar emission relative to the airglow is a critical factor in the success or failure of an airglow subtraction. We developed a predictor for the success of an airglow subtraction using the signal-to-noise ratio of the nearby chromospheric emission line Si iii (1206.51 Å). The minimum attenuated Lyα flux that was successfully recovered is 1.39 × 10−14 erg cm−2 s−1, and we recommend this as a minimum flux for COS Lyα recoveries.
A New Wide-field Infrared Survey Explorer Calibration of Stellar Mass
Authors: Jarrett T. H. , Cluver M. E. , Taylor Edward N. , Bellstedt Sabine , Robotham A. S. G. , Yao H. F. M. 
Published: April 2023

Abstract
We derive new empirical scaling relations between Wide-field Infrared Survey Explorer (WISE) mid-IR (MIR) galaxy photometry and well-determined stellar masses from spectral energy distribution modeling of a suite of optical–infrared photometry provided by the Data Release 4 (DR4) Catalog of the GAMA-KiDS-VIKING survey of the southern G23 field. The MIR source extraction and characterization are drawn from the WISE Extended Source Catalogue and the archival ALLWISE catalog, combining both resolved and compact galaxies in the G23 sample to a redshift of 0.15. Three scaling relations are derived: W1 3.4 μm luminosity versus stellar mass, and WISE W1–W2, W1–W3 colors versus mass-to-light ratio (M/L, sensitive to a variety of galaxy types from passive to star-forming). For each galaxy in the sample, we then derive the combined stellar mass from these scaling relations, producing M
⋆ estimates with better than ∼25%–30% accuracy for galaxies with >109
M
⊙ and <40%–50% for lower-luminosity dwarf galaxies. We also provide simple prescriptions for rest-frame corrections and estimating stellar masses using only the W1 flux and the W1–W2 color, making stellar masses more accessible to users of the WISE data. Given a redshift or distance, these new scaling relations will enable stellar mass estimates for any galaxy in the sky detected by WISE with high fidelity across a range of M/L ratios.
The Role of Electrons and Helium Atoms in Global Modeling of the Heliosphere
Authors: Fraternale F. , Pogorelov N. V. , Bera R. K. 
Published: April 2023

Abstract
We present a new three-dimensional, MHD-plasma/kinetic-neutrals model of the solar wind (SW) interaction with the local interstellar medium (LISM), which self-consistently includes neutral hydrogen and helium atoms. This new model also treats electrons as a separate fluid and includes the effect of Coulomb collisions. While the properties of electrons in the distant SW and in the LISM are mostly unknown due to the lack of in situ observations, a common assumption for any global, single-ion model is to assume that electrons have the temperature of the ion mixture, which includes pickup ions. In the new model, electrons in the SW are colder, which results in a better agreement with New Horizons observations in the supersonic SW. In the LISM, however, ions and electrons are almost in thermal equilibrium. As for the plasma mixture, the major differences between the models are in the inner heliosheath, where the new model predicts a charge-exchange-driven cooling and a decrease of the heliosheath thickness. The filtration of interstellar neutral atoms at the heliospheric interface is discussed. The new model predicts an increase in the H density by ∼2% at 1 au. However, the fraction of pristine H atoms decreases by ∼12%, while the density of atoms born in the outer and inner heliosheath increases by 5% and ∼35%, respectively. While at 1 au the density of He atoms remains unchanged, the contribution from the “warm breeze” increases by ∼3%.
Time-dependent Photoionization Modeling of Warm Absorbers in Active Galactic Nuclei
Authors: Sadaula Dev R , Bautista Manuel A , García Javier A , Kallman Timothy R 
Published: April 2023

Abstract
Warm absorber spectra contain bound-bound and bound-free absorption features seen in the X-ray and UV spectra from many active galactic nuclei. The widths and centroid energies of these features indicate they occur in outflowing gas, and the outflow can affect the gas within the host galaxy. Thus, the warm absorber mass and energy budgets are of great interest. Estimates for these properties depend on models that connect the observed strengths of the absorption features with the density, composition, and ionization state of the absorbing gas. Such models assume that the ionization and heating of the gas come primarily from the strong continuum near the central black hole. They also assume that the various heating, cooling, ionization, and recombination processes are in a time-steady balance. This assumption may not be valid, owing to the intrinsic time variability of the illuminating continuum or other factors that change the cloud environment. This paper presents models for warm absorbers that follow the time dependence of the ionization, temperature, and radiation field in warm absorber gas clouds in response to a changing continuum illumination. We show that the effects of time variability are important over a range of parameter values, that time-dependent models differ from equilibrium models in meaningful ways, and that these effects should be included in models that derive properties of warm absorber outflows.
The Halo Mass–Temperature Relation for Clusters, Groups, and Galaxies
Authors: Babyk Iurii V. , McNamara Brian R. 
Published: April 2023

Abstract
The halo mass–temperature (M–T) relation for a sample of 216 galaxy clusters, groups, and individual galaxies observed by the Chandra X-ray Observatory is presented. Using accurate spectral measurements of their hot atmospheres, we derive the M–T relation for systems with temperatures ranging between 0.4 and 15.0 keV. We measure the total masses of the clusters, groups, and galaxies at radius R
2500, finding that the M
2500 ∝ T

α
relation follows a power law with α = 1.65 ± 0.06. Our relation agrees with recent lensing studies of the M–T relation at R
200 and is consistent with self-similar theoretical predictions and recent simulations. This agreement indicates that the M–T relation is weakly affected by nongravitational heating processes. Using lensing masses within R
200 we find M
200–T follows a power law with a slope of 1.61 ± 0.19, consistent with the M
2500–T relation. No evidence for a break or slope change is found in either relation. Potential biases associated with sample selection, evolution, and the assumption of hydrostatic equilibrium that may affect the scaling are examined. No significant impacts attributable to these biases are found. Non-cool-core clusters and early spirals produce higher scatter in the M–T relation than cool-core clusters and elliptical galaxies.
Progrès et harmonie : La Grande Période de Jean Delormel
Authors: Ritz Olivier 
Published: April 2023

Dans La Grande Période, publiée en 1790, 1796 et 1805, Jean Delormel défend l’idée que l’inclinaison de l’axe de rotation de la Terre diminue lentement et que par conséquent l’humanité avance très lentement vers un nouvel âge d’or. Sa théorie présente trois paradoxes : d’une part, le temps est à la fois progressif et cyclique ; d’autre part, le progrès est à la fois très lent et très rapide ; enfin, le progrès est fait d’événements heureux et malheureux et, par conséquent, la Révolution française peut être l’un ou l’autre, selon le contexte de publication. Delormel défend l’utilité sociale d’une théorie de l’harmonie qui doit susciter l’espoir et qui peut avoir des applications concrètes. Bien qu’elle soit fondée sur l’astronomie et qu’elle s’appuie sur des éléments de la tradition biblique, sa science est une science pratique qui procède par deux opérations principales : simplifier et concilier. Le théoricien de l’harmonie se présente ainsi comme celui qui dépasse les querelles et qui fournit les moyens de les éteindre. Écrivant pour la concorde et pour le progrès, il peut offrir ses services aux institutions nouvelles, ce qu’il fait auprès du Comité d’instruction publique, puis du Premier Consul. Si La Grande Période est l’ouvrage singulier d’un auteur qui n’a joué aucun rôle majeur dans l’histoire des sciences, elle témoigne de la permanence de la demande sociale à laquelle Delormel s’est efforcé de répondre. Le désir d’unité qu’il exprime et auquel il entend contribuer est l’une des principales lignes de force politique et littéraire de la période révolutionnaire.
PENGARUH PROFITABILITAS DAN LEVERAGE TERHADAP PAJAK PENGHASILAN BADAN TERUTANG PADA PERUSAHAAN PERTAMBANGAN YANG TERDAFTAR DI BURSA EFEK INDONESIA (BEI) PERIODE 2019-2021
Authors: Mariana Citra , Mulyati Yati , Andari Diah , Purnamasari Dyah 
Published: April 2023

Tujuan penelitian ini adalah untuk mengetahui pengaruh profitabilitas dan leverage terhadap terhadap PPh Badan terutang. Objek penelitian ini adalah profitabilitas, leverage dan PPh Badan Terutang pada perusahaan sektor pertambangan yang terdaftar di Bursa Efek Indonesia periode 2019-2020. Populasi dalam penelitian ini sebanyak 189 laporan keuangan dari 63 perusahaan selama 3 tahun. Pemilihan sampel dilakukan dengan teknik purposive sampling. Sampel diperoleh sebanyak 18 perusahaan dengan total 54 sampel laporan keuangan yang dianalisis. Metode penelitian yang dilakukan adalah metode eksplanatori. deskriptif dan verifikatif . Metode analisis data menggunakan analisis regresi data panel menggunakan eviews 9. Hasil penelitian menyatakan bahwa profitabilitas berpengaruh terhadap PPh Badan terutang, sedangkan leverage tidak berpengaruh terhadap PPh Badan terutang.
PENINGKATAN HASIL BELAJAR SISWA PADA MATA PELAJARAN EKONOMI DENGAN MEDIA YOUTUBE DI KELAS XI IPS SMA NEGERI 1 SIDAMANIK T.A 2022/2023
Authors: Damanik Rafael , Sibagariang Susy Alestriani , Margareta Elisabeth 
Published: April 2023

Masalah dalam penelitian ini adalah rendahnya hasil belajar IPS siswa dalam proses pembelajaran. Penelitian ini bertujuan ini untuk mengetahui peningkatan hasil belajar siswa pada mata pelajaran ekonomi dengan media youtube di kelas XI IPS SMA Negeri 1 Sidamanik T.A 2022/213. Jenis penelitian ini adalah kuantitatif subjek pada penelitian ini adalah kelas XI IPS 1 yang berjumlah 30 siswa, XI IPS 2 yang berjumlah 30 siswa, XI IPS 3 yang berjumah 30 siswa dan XI IPS 4 yang berjumlah 30 siswa. Teknik pengumpulan data dalam penelitian ini adalah observasi, dokumentasi dan tes. Dari hasil analisis data diperoleh hasil belajar siswa pada kelas XI IPS-1 mengalami peningkatan sebesar 39,4 dari nilai rata-rata 47,60 menjadi 87, pada kelas XI IPS-2 mengalami peningkatan sebesar 44,4 dari nilai rata –rata 43,23 menjadi 87,67, pada kelas XI IPS-3 mengalami peningkatan 42,47 dari nilai rata-rata 42,93 menjadi 85,40 dan pada kelas XI IPS-4 mengalami peningkatan 45,66 dari nilai rata-rata 40,67 menjadi 86,33. Dapat disimpulkan bahwa dengan menerapkan pembelajaran dengan media youtube dapat meningkatkan hasil belajar siswa di kelas XI IPS SMA Negeri 1 Sidamanik T.A 2022/2023.
PENGARUH METODE PEMBELAJARAN KOOPERATIF TIPE JIGSAW TERHADAP HASIL BELAJAR SISWA MATA PELAJARAN IPS KELAS VIII SMP NEGERI
Authors: Girsang Novia Anzelia , Sibagariang Susy A , Simamora Benjamin Albert 
Published: April 2023

Penelitian ini bertujuan mengetahui pengaruh model pembelajaran kooperatif tipe jigsaw terhadap hasil belajar siswa kelas VIII SMP Negeri 2 Tanah Jawa T.A. 2022/2023. Metode penelitian yang digunakan adalah metode one group eksperimen design yang dilaksanakan di SMP Negeri 2 Tanah Jawa. Dari hasil analisis data diperoleh hasil belajar siswa pada kelas eksperimen VIII-3 mengalami peningkatan nilai rata-rata dari 39,69 menjadi 58,44. Jumlah hasil siswa yang ada siswa. Pada kelas VIII-4 mengalami penurunan dari nilai 43,39 menjadi 62,45. Jumlah yang tuntas ada 5 siswa. Pada kelas VIII-5 mengalami kenaikan 44,53 menjadi 67,03. Jumlah siswa yang tuntas ada 7 siswa. Dapat disimpulkan bahwa dengan menerapkan model pembelajaran Jisaw dapat meningkatkan hasil belajar IPS di kelas VIII SMP Negerei 2 Tanah Jawa.
EVALUSI KINERJA SUPPLIER PRODUCTION PART DENGAN METODE ANALYTICAL HIERARCHY PROCESS (AHP) DI PT METINDO ERASAKTI
Authors: Pitaloka Adelia Amanda , Barry Husnil , Sofa Nidia 
Published: April 2023

Evaluasi kinerja pemasok adalah salah satu kegiatan dalam manajemen rantai pasokan yang mempengaruhi ketepatan dalam pemilihan pemasok. PT Metindo Erasakti merupakan perusahaan dibidang manufaktur otomotif yang memproduksi part kendaraan roda dua dan roda empat. Saat melakukan evaluasi kinerja supplier, adapun permasalahan yang ditemukan diantaranya keterlambatan pengiriman part, ditemukannya part yang tidak sesuai dengan standar quality perusahaan, dan supplier tidak disiplin dalam mengikuti safety rule yang diterapkan oleh perusahaan. Penilaian kinerja pemasok penting bagi perusahaan untuk mengelola dan meningkatkan kinerja pemasok. Penelitian ini menggunakan metode Analytical Hierarchy Process (AHP) untuk mengidentifikasi kriteria utama dan memilih pemasok potensial. Kriteria untuk mengevaluasi kinerja pemasok adalah cost, quality, delivery, dan safety. Division head, Department head, dan senior supervisor adalah respondendalam penelitian ini yang memiliki wewenang untuk mengambil keputusan pemilihan supplier. Penentuan sampel penelitian menggunakan teknik purposive sampling. Maka, sampel dari penelitian ini berjumlah tiga pemasok stamping dan tiga pemasok painting. Hasil dari pembobotan kriteria diketahui prioritas kriteria adalah kriteria safety dengan skor 0,377 (38%) untuk stamping dan skor 0,388 (39%) untuk painting. Hasil penelitian ini menunjukkan supplier potensial untuk memasok part adalah supplier C (PT DRC) dengan skor 0,34668 untuk stamping, dan supplier A (PT PMU) dengan skor 0,36226 untuk pemasok painting.
Discolored Components from the Black-streaked Heartwood Extracts of Teak
Authors: Lukmandaru Ganis , Ashitani Tatsuya , Takahashi Koetsu 
Published: April 2023

With regard to black-streaked discoloration of teak wood, the ethyl acetate extract from successive extraction was examined. By column chromatography, tectol and and two unknown compounds i.e. C-1 (molecular weight of 240) and C-2 (molecular weight of 210) were isolated. Discoloration tests, i.e. air oxidation, acidic (acetic acid), and alkaline (potassiun hydrogen carbonate) treatments were conducted to the isolated and other standard quinoine compounds (tectoquinone, lapachol, 2-tert-buthyl- anthraqunone, 2-hydroxy-methyl-anthraqunone). The results showed that tectol changes its color by the considerable decreasing in brightness whereas C-1 showed huge decrease in yellowness by air oxydation. Tectol did not change its color in pH value of 2.9 to 8.3 but C-1, C-2, and lapachol did change. Tectoquinone was hardly change color under alkaline or acidic treatment. The difference in quinone coloration might be due the structural features of a hydroxyl group and a double bond conjugated
Chemical precursors of new particle formation in coastal New Zealand
Authors: Peltola Maija , Rose Clémence , Trueblood Jonathan V. , Gray Sally , Harvey Mike , Sellegri Karine 
Published: April 2023

Abstract. To reduce uncertainties in climate predictions, we need to better understand aerosol formation in different environments. An important part of this is studying which chemical species are responsible for particle formation. While many advances have been made in this field, measurements are especially lacking from marine environments. Here, we measured the chemical composition of ambient anions over 7 months at Baring Head station, located in coastal New Zealand. This adds to our previous work which reported the aerosol size distribution measurements and investigated new particle formation and environmental conditions favouring new particle formation at the station. By combining the information on ion chemical composition with our previous work, we were able to study the chemical precursors of new particle formation. Our results showed that while over land new particle formation is likely driven by sulfuric acid and organic species, in clean marine air iodine oxoacids and sulfur species are likely important drivers of particle formation processes. These data were also used to characterise the diurnal and seasonal cycles of the most important anion groups and their geographical source regions. Bisulfate anions displayed a clear daytime maximum where as iodine oxoacids had morning and evening maximums. Highly oxygenated organic molecules, on the other hand, were most abundant during the night when the air was land-influenced. This data set is highly valuable and our results provide important information on the chemical species driving new particle formation at a remote Southern Hemisphere coastal site.
Observations of anomalous propagation over waters near Sweden
Authors: Norin Lars 
Published: April 2023

Abstract. Radio waves propagating in the atmosphere are affected by the prevailing atmospheric state. The state of the atmosphere can cause radio waves to refract more or less towards the ground. When the refractive index of the atmosphere differs from standard atmospheric conditions, the propagation is considered to be anomalous. Radars which are affected by anomalous propagation can observe ground clutter far beyond the radar horizon. In this work, 4.5 years' worth of data from five operational Swedish C-band dual-polarization weather radars are presented. Analyses of the data reveal a strong seasonal cycle and a weaker diurnal cycle in ground clutter from coastal regions across nearby waters. A comparison was drawn between the impacts of anomalous propagation on ground clutter measured with horizontal polarization and vertical polarization, respectively; however, no clear difference was found.
In-Vitro Cytotoxic and Proliferative Activity of Three Plant Extract on Human Peripheral Blood Mononuclear Cells (PBMCs)
Authors: Hamid Kabir Magaji , Muhammad Adamu Ibrahim , Balogun Abdulbasit Opeyemi , Nkom Dorcas Murna , Usman Abubakar Babangida , Aliyu Mansur 
Published: April 2023

Plant products provide a vast source of therapeutics, but not without toxicity. This study evaluated the in vitro cytotoxic and proliferative activity of selected plant extracts on human peripheral blood mononuclear cells (PBMCs). The PBMCs from healthy donors were exposed to varying concentrations (25 µg/ml, 50 µg/ml, 100 µg/ml and 200 µg/ml) of aqueous extracts of young leaves of Mangifera indica (MI) and stem barks of Commiphora kerstingii (CK), and Lannea acida and Acacia sieberiana formulation (LAASF). Trypan blue assay was used to determine the viability of human PBMCs after isolation. Cytotoxicity and proliferation of PBMCs were determined using WST-8 assay. The total viable cell count of the isolated PBMCs in this study was 8000 x 104 cells/ml while viability was 96.15%. The extract of LAASF showed the lowest percentage cytotoxicity (2.63%) at 25 µg/ml concentration, followed by CK (2.70%), then MI (7.71%). There was significant decrease in PBMCs mean absorbance scores across the different concentrations of MI (p=0.008), CK (p<0.0001) and LAASF (p=0.01). There was statistically significant proliferation of PBMCs for MI (p=0.003) and CK (p=0.005) compared to control. However, no significant difference was observed in LAASF on proliferation. Mean absorbance scores significantly decreased with an increase in the concentration of the extracts. The extracts have potential cytotoxicity on the PBMCs at higher concentrations. The extract of MI and CK exhibited higher cytotoxic and proliferative activity on the PBMCs than LAASF. An in-depth study to identify specific immune cells proliferated by the extracts will improve the credence of this study’s findings.

Keywords: Herbal medicine, cytotoxicity, cell proliferation, humans, mononuclear leukocytes