bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discovery, Timing, and Multiwavelength Observations of the Black Widow Millisecond Pulsar PSR J1555–2908
Authors: Ray Paul S. , Nieder Lars , Clark Colin J. , Ransom Scott M. , Cromartie H. Thankful , Frail Dale A. , Mooley Kunal P. , Intema Huib , Jagannathan Preshanth , Demorest Paul , Stovall Kevin , Halpern Jules P. , Deneva Julia , Guillot Sebastien , Kerr Matthew , Swihart Samuel J. , Bruel Philippe , Stappers Ben W. , Lyne Andrew , Mickaliger Mitch , Camilo Fernando , Ferrara Elizabeth C. , Wolff Michael T. , Michelson P. F. 
Published: March 2022

Abstract
We report the discovery of PSR J1555−2908, a 1.79 ms radio and gamma-ray pulsar in a 5.6 hr binary system with a minimum companion mass of 0.052 M
⊙. This fast and energetic (

E

̇

=
3
×

10

35

erg s−1) millisecond pulsar was first detected as a gamma-ray point source in Fermi Large Area Telescope (LAT) sky survey observations. Guided by a steep-spectrum radio point source in the Fermi error region, we performed a search at 820 MHz with the Green Bank Telescope that first discovered the pulsations. The initial radio pulse timing observations provided enough information to seed a search for gamma-ray pulsations in the LAT data, from which we derive a timing solution valid for the full Fermi mission. In addition to the discovery and timing of radio and gamma-ray pulsations, we searched for X-ray pulsations using NICER but no significant pulsations were detected. We also obtained time-series r-band photometry that indicates strong heating of the companion star by the pulsar wind. Material blown off the heated companion eclipses the 820 MHz radio pulse during inferior conjunction of the companion for ≈10% of the orbit, which is twice the angle subtended by its Roche lobe in an edge-on system.
Asymmetric Star Formation Triggered by Gas Inflow in a Barred Lenticular Galaxy PGC 34107
Authors: Lu Shiying , Gu Qiusheng , Ge Xue , Ho Luis C. , Gao Yulong , Chen Zhengyi , Xu Ke , Zhang Zhi-Yu , Shi Yong , Yuan Qirong , Bao Min 
Published: March 2022

Abstract
Comparing the inactive and gas-poor normal lenticular galaxies (S0s) in the local universe, we study a barred star-forming S0 galaxy, PGC 34107, which has been observed by the Centro Astronómico Hispano Alemán 3.5 m telescope and the Northern Extended Millimeter Array. The spatially resolved ionized gas and molecular gas traced by 12CO(1–0), hereafter CO(1–0), show similar distribution and kinematics to the stellar component with an off-center star-forming region, ∼380 pc away from the center. The resolved kinematics of molecular CO(1–0) emission reveals that there is a blueshifted (redshifted) velocity component on the receding (approaching) side of the galaxy along the stellar bar. This might provide plausible evidence of noncircular motion, such as the bar-induced molecular gas inflow. The velocity of the molecular gas inflow decreases when approaching toward the peak of the off-center star formation in the north, which might be associated with the inner Lindblad resonance. In addition to CO(1–0), we also detect the isotopic line of 13CO(1–0). For most Hα, CO(1–0) and 13CO(1–0) emissions are concentrated on this northern star-forming region. We find that PGC 34107 follows the local stellar mass–metallicity relation, star-forming main sequence, and the Kennicutt–Schmidt law. The resolved and integrated molecular gas main sequence suggests that there is a higher gas fraction in the central region of the galaxy, which supports a scenario that the bar-induced gas reservoir provides the raw material, and subsequently triggers the central star formation.
Methanol Mapping in Cold Cores: Testing Model Predictions*
Authors: Punanova Anna , Vasyunin Anton , Caselli Paola , Howard Alexander , Spezzano Silvia , Shirley Yancy , Scibelli Samantha , Harju Jorma 
Published: March 2022

Abstract
Chemical models predict that in cold cores gas-phase methanol is expected to be abundant at the outer edge of the CO depletion zone, where CO is actively adsorbed. CO adsorption correlates with volume density in cold cores, and, in nearby molecular clouds, catastrophic CO freeze-out happens at volume densities above 104 cm−3. The methanol production rate is maximized there and its freeze-out rate does not overcome its production rate, while the molecules are shielded from UV destruction by gas and dust. Thus, in cold cores, methanol abundance should generally correlate with visual extinction, which depends on both volume and column density. In this work, we test the most basic model prediction that maximum methanol abundance is associated with a local
A

V
∼ 4 mag in dense cores and constrain the model parameters with the observational data. With the IRAM 30 m antenna, we mapped the CH3OH (2–1) and (3–2) transitions toward seven dense cores in the L1495 filament in Taurus to measure the methanol abundance. We use the Herschel/SPIRE maps to estimate visual extinction, and the C18O(2–1) maps from Tafalla & Hacar to estimate CO depletion. We explored the observed and modeled correlations between the methanol abundances, CO depletion, and visual extinction, varying the key model parameters. The modeling results show that hydrogen surface diffusion via tunneling is crucial to reproduce the observed methanol abundances, and the necessary reactive desorption efficiency matches the one deduced from laboratory experiments.
Discovery of Three Candidate Magnetar-powered Fast X-Ray Transients from Chandra Archival Data
Authors: Lin Dacheng , Irwin Jimmy A. , Berger Edo , Nguyen Ronny 
Published: March 2022

Abstract
It was proposed that a remnant stable magnetar could be formed in a binary neutron-star merger, leading to a fast X-ray transient (FXT) that can last for thousands of seconds. Recently, Xue et al. suggested that CDF-S XT2 was exactly such a kind of source. If confirmed, such emission can be used to search for electromagnetic counterparts to gravitational wave events from binary neutron-star mergers that have short gamma-ray bursts and the corresponding afterglows seen off-axis and thus too weak to be detected. Here we report the discovery of three new FXTs, XRT 170901, XRT 030511, and XRT 110919, from a preliminary search over Chandra archival data. Similar to CDF-S XT2, these new FXTs had a very fast rise (less than a few tens of seconds) and a plateau of X-ray flux of ∼1.0 × 10−12 erg s−1 cm−2 lasting for 1–2 ks, followed by a steep decay. Their optical/IR counterparts, if present, are very weak, arguing against a stellar flare origin for these FXTs. For XRT 170901, we identified a faint host galaxy with the source at the outskirts, very similar to CDF-S XT2. Therefore, our newly discovered FXTs are also strong candidates for magnetar-powered X-ray transients resulting from binary neutron star mergers.
How Many Elements Matter?
Authors: Ting 丁 Yuan-Sen 源森 , Weinberg David H. 
Published: March 2022

Abstract
Some studies of stars’ multielement abundance distributions suggest at least 5–7 significant dimensions, but others show that many elemental abundances can be predicted to high accuracy from [Fe/H] and [Mg/Fe] (or [Fe/H] and age) alone. We show that both propositions can be, and are, simultaneously true. We adopt a machine-learning technique known as normalizing flow to reconstruct the probability distribution of Milky Way disk stars in the space of 15 elemental abundances measured by APOGEE. Conditioning on T
eff and

log

g

minimizes the differential systematics. After further conditioning on [Fe/H] and [Mg/Fe], the residual scatter for most abundances is σ
[X/H] ≲ 0.02 dex, consistent with APOGEE’s reported statistical uncertainties of ∼0.01–0.015 dex and intrinsic scatter of 0.01–0.02 dex. Despite the small scatter, residual abundances display clear correlations between elements, which we show are too large to be explained by measurement uncertainties or by the finite sampling noise. We must condition on at least seven elements to reduce the correlations to a level consistent with the observational uncertainties. Our results demonstrate that cross-element correlations are a much more sensitive probe of a hidden structure than dispersion, and they can be measured precisely in a large sample even if the star-by-star measurement noise is comparable to the intrinsic scatter. We conclude that many elements have an independent story to tell, even for the mundane disk stars and elements produced by the core-collapse and Type Ia supernovae. The only way to learn these lessons is to measure the abundances directly, and not merely infer them.
Chemical Feedback of Pebble Growth: Impacts on CO depletion and C/O ratios
Authors: Van Clepper Eric , Bergner Jennifer B. , Bosman Arthur D. , Bergin Edwin , Ciesla Fred J. 
Published: March 2022

Abstract
Observations of protoplanetary disks have revealed them to be complex and dynamic, with vertical and radial transport of gas and dust occurring simultaneously with chemistry and planet formation. Previous models of protoplanetary disks focused primarily on chemical evolution of gas and dust in a static disk, or dynamical evolution of solids in a chemically passive disk. In this paper, we present a new 1D method for modeling pebble growth and chemistry simultaneously. Gas and small dust particles are allowed to diffuse vertically, connecting chemistry at all elevations of the disk. Pebbles are assumed to form from the dust present around the midplane, inheriting the composition of ices at this location. We present the results of this model after 1 Myr of disk evolution around a 1M
⊙ star at various locations both inside and outside the CO snowline. We find that for a turbulent disk (α = 10−3), CO is depleted from the surface layers of the disk by roughly 1–2 orders of magnitude, consistent with observations of protoplanetary disks. This is achieved by a combination of ice sequestration and decreasing UV opacity, both driven by pebble growth. Further, we find the selective removal of ice species via pebble growth and sequestration can increase gas phase C/O ratios to values of approximately unity. However, our model is unable to produce C/O values of ∼1.5–2.0 inferred from protoplanetary disk observations, implying selective sequestration of ice is not sufficient to explain C/O ratios >1.
The Solar Wind at (16) Psyche: Predictions for a Metal World
Authors: Collinson Glyn A. , Chen Li-Jen , Jian Lan K. , Dorelli John 
Published: March 2022

Abstract
NASA’s Psyche spacecraft will carry a magnetometer to main-belt asteroid (16) Psyche to search for remanent magnetic fields, and to attempt electromagnetic sounding of the interior. However, the Psyche spacecraft does not carry an instrument to measure solar wind plasmas. We thus combine data from five missions that have measured the solar wind at the orbit of asteroid (16) Psyche. We characterize these upstream conditions for future modeling and reference. We consider the implications of these ambient conditions for the interaction between (16) Psyche and the solar wind, outlining four possible resulting magnetospheres. Any magnetosphere would be dominated by ion-scale (Hall) physics and exotic electron-scale physics, requiring sophisticated physical modeling to describe. Under these different regimes, plasma generates additional electromagnetic fields, resulting in complex magnetism which may complicate the magnetic environment near asteroid (16) Psyche. Future missions to asteroids would benefit from combined magnetic field and plasma measurements.
Evidence for X-Ray Emission in Excess to the Jet-afterglow Decay 3.5 yr after the Binary Neutron Star Merger GW 170817: A New Emission Component
Authors: Hajela A. , Margutti R. , Bright J. S. , Alexander K. D. , Metzger B. D. , Nedora V. , Kathirgamaraju A. , Margalit B. , Radice D. , Guidorzi C. , Berger E. , MacFadyen A. , Giannios D. , Chornock R. , Heywood I. , Sironi L. , Gottlieb O. , Coppejans D. , Laskar T. , Cendes Y. , Duran R. Barniol , Eftekhari T. , Fong W. , McDowell A. , Nicholl M. , Xie X. , Zrake J. , Bernuzzi S. , Broekgaarden F. S. , Kilpatrick C. D. , Terreran G. , Villar V. A. , Blanchard P. K. , Gomez S. , Hosseinzadeh G. , Matthews D. J. , Rastinejad J. C. 
Published: March 2022

Abstract
For the first ∼3 yrs after the binary neutron star merger event GW 170817, the radio and X-ray radiation has been dominated by emission from a structured relativistic off-axis jet propagating into a low-density medium with n < 0.01 cm−3. We report on observational evidence for an excess of X-ray emission at δt > 900 days after the merger. With L

x
≈ 5 × 1038 erg s−1 at 1234 days, the recently detected X-ray emission represents a ≥3.2σ (Gaussian equivalent) deviation from the universal post-jet-break model that best fits the multiwavelength afterglow at earlier times. In the context of JetFit afterglow models, current data represent a departure with statistical significance ≥3.1σ, depending on the fireball collimation, with the most realistic models showing excesses at the level of ≥3.7σ. A lack of detectable 3 GHz radio emission suggests a harder broadband spectrum than the jet afterglow. These properties are consistent with the emergence of a new emission component such as synchrotron radiation from a mildly relativistic shock generated by the expanding merger ejecta, i.e., a kilonova afterglow. In this context, we present a set of ab initio numerical relativity binary neutron star (BNS) merger simulations that show that an X-ray excess supports the presence of a high-velocity tail in the merger ejecta, and argues against the prompt collapse of the merger remnant into a black hole. Radiation from accretion processes on the compact-object remnant represents a viable alternative. Neither a kilonova afterglow nor accretion-powered emission have been observed before, as detections of BNS mergers at this phase of evolution are unprecedented.
Nuclear-optical converters for detecting intense neutron
Authors: Baskov Pyotr B. , Marichev Gleb V. , Sakharov Vyacheslav V. , Stepanov Vladimir A. 
Published: March 2022

In the design of nuclear-optical converters (NOC) for detecting intense neutron fields (fluxes over 1015 cm–2·s–1), it is proposed to use hybrid gas ionization chambers (IC), in which electrical and optical neutron detecting methods are combined. For hybrid ICs, a technology is proposed for obtaining radiation-resistant and mechanically strong radiator materials capable of operating at temperatures of up to 1000 °C. This technology is based on solid-phase boron diffusion saturation of steel. It is shown that, at thermal neutron fluxes of 1×1010 n/(cm2·s) and higher, the integral intensity of argon luminescence as a result of ionization by α-particles and 7Li ions from layers of boride phases is sufficient for detection.
The combination of optical and radiation properties of multicomponent fluoride glasses makes it possible to use them as condensed active substances of NOCs. Choosing the elemental and isotopic composition, it becomes possible to use fluoride glasses for multichannel neutron detection as well as to significantly simplify the procedure for separating gamma and neutron components of radiation under conditions of intense radiation fluxes. It has been experimentally shown that in irradiation with a neutron flux of 1×1017 n/(cm2·s), the intensity of Nd IR luminescence in glasses based on zirconium fluoride (ZBLAN) increases in the presence of Gd, which interacts with neutrons.
Portfolio choice and mental accounts: A comparison with traditional approaches
Authors: Hübner Georges , Lejeune Thomas 
Published: March 2022

Cet article analyse dans quelle mesure un modèle réaliste de comptabilité mentale pour les choix de portefeuille est capable de concurrencer des alternatives d’utilité traditionnelles. Il s’agit du modèle de comptabilité mentale étendu aux dimensions d’horizon d’investissement et d’asymétrie présenté dans Hübner et Lejeune (2021). Das, Markowitz, Scheid, et Statman (2010) et Hübner et Lejeune (2021) ont démontré que le référentiel de comptabilité mentale incorpore des allocations optimales dérivées d’optimisation de l’utilité quadratique et/ou de l’hypothèse de la distribution Gaussienne. Nous complémentons leur travail en démontrant ici la flexibilité et la supériorité numérique des outputs d’optimisation qu’une version non-Gaussienne du modèle HAMA (Horizon-Asymmetry Mental Accounting) génère par rapport à deux règles traditionnelles de maximisation de l’utilité espérée produisant un spectre large et pertinent de règles d’allocation de portefeuille pour divers types d’investisseurs : l’approche du taux de décroissance de Stutzer (2003), qui est similaire à la maximisation de l’utilité espérée, et la classe des fonctions d’utilité flexibles à trois paramètres (FTP) introduite par Conniffe (2007) qui englobe un large ensemble de fonctions d’utilité.
Sustainable and Green Drilling Fluid Additives Development
Authors: Ramasamy Jothibasu , Arfaj Mohammad K. 
Published: March 2022

Abstract
Oil and gas drilling requires several components work simultaneously to ensure smooth and safe drilling. Drilling fluid or mud is an inseparable part of drilling oil and gas wells and circulated through out theh drilling operation. Drilling fluid contains a variety of additives or chemicals to provide various properties to drilling fluid namely viscosity, fluid loss control, emulsion stability, lubricity, etc. Developing environment friendly chemicals to provide the above-mentioned drilling fluid properties is a significant step taken towards sustainability and reducing carbon footprint besides suitability for aquifers and offshore environments. Several fatty acid-based chemicals used in drilling fluids as fatty acids offer eco-friendly and bio-degradable properties besides required drilling fluid properties. Vegatable oil contains triglycerides which is a potential source of fatty acids and their derivatives. Waste vegetable oil (WVO) provides a perpetual and sustainable source of raw material for various types of eco-friendly additives development. Waste vegetable oil is subjected to simple chemical modification of base hydrolysis process and mixtures of fatty acids have been obtained after finishing a sequence of clean-up process of reaction mixture. The fatty acids obtained are environment-friendly, bio-degradable and non-toxic. Due to technical, economic and environmental advantages of products derived from waste vegetable oils, we have undertaken several research projects to produce various chemicals from waste vegetable oil for oil and gas field applications. Fatty acid-based products mainly used in drilling fluids as lubricants to reduce torque and drag for water-based mud. In case of oil-based mud systems, fatty acid derived products are used as emulsifiers, wetting agents and rheology modifiers. However, these products have been either mixture of fatty acids and their derivatives or only derivatives of fatty acids. In our study, we have used the mixture of fatty acids obtained from chemical conversion of WVO for applications as lubricant for water-based mud and emulsifier and rheology modifier for invert emulsion oil-based mud systems. In this paper, we described the chemicals process for converting waste vegetable oil to fatty acids by base hydrolysis reaction in the first section. Application of synthesized fatty acids for water-based and oil-based mud formulation as lubricants, emulsifiers and rheology modifiers have been discussed in the second part of the paper.
3-D Micromodel for Visualization & Experimental Analysis of Flow Behavior, Surface Tension and Polymer Concentration on Enhanced Oil Recovery
Authors: Tandon Apoorv , Khan Fahad , Shukla Raman , Saxena Amit , Sharma Shivanjali , Biswas Koushik Guha 
Published: March 2022

Abstract
Oil recovery is a complex process involving physical and chemical interactions within the pore spaces of the reservoir. The oil recovery improves by injecting viscous and wettability-altering fluids into the reservoir. The present work aims to study the improvement in the recovery using surfactant polymer (SP) slug and discuss the mechanisms behind the oil mobilization process by visualizing the oil recovery using a glass tube filled with glass beads. Fluids were injected using a syringe pump, and the interaction of the fluid was visualized using a high-speed camera. Initially, the oil was displaced using brine which was followed by the injection of SP slug formulated using Sodium Dodecyl Sulphate (SDS) and Poly Acrylamide (PAM). The effect of the composition of the slug was studied at different concentrations 125ppm, 250ppm, 375ppm, and 500ppm. After that, the effect of flow rate of SP slug on the oil recovery process was explored. Colored non-interacting dyes aided the visualization in the glass model. Images of the oil recovery process were captured to examine the fluid displacement mechanism during SP flooding.
The total oil recovery increases from 73.33% to 83.33%, as the polymer concentration was increased gradually from 125 ppm to 500 ppm at a flow rate of 100 µL/min which further increases to 90% for 500 ppm slug at 500 µL/min of flow rate. High-quality magnified images from the camera captured the flow path of each fluid injected through the glass bead-packed channel. The effect of various forces like capillary, gravity, and viscous forces were visualized and analyzed. The pore throat and pore-diameter calculations were done using the software. The low viscous slug was subjected to higher gravity force, rendering it ineffective in displacing the oil present at the channel's top. The gravity segregation was overpowered by high viscous slugs that mobilized the oil present in the channel. The understanding and analysis of the fluid motion under oil-brine interaction and SP slug-oil interactions was studied. The study helps improve the techno-economic feasibility of the whole recovery process by limiting the use of chemicals and maximizing the oil recovery in a controlled manner.
New Formulation of Ultra-Low Ift Surfactant for Potential Eor Application
Authors: Ahmad Wazir Norhidayah , Saadon Shazleen , Ramli Anita 
Published: March 2022

Abstract
The paper discussed the development of an Ultra-Low Interfacial Tension (IFT) foaming surfactant based on a combination of improved as-synthesized surfactant (CBH) consist of as-synthesized oleic amido propyl betaine with mixtures of co-solvents and PETRONAS’ in-house patented foaming-based surfactant (IVF) which consist of amphoteric and anionic surfactant; as well as the performance evaluation of the surfactant in Enhanced Oil Revery (EOR) application. CBH and PETRONAS (IVF) foam-based surfactants were used in the formulation as ultra-low IFT and foaming components, respectively. The surfactant's development has been highlighted, and the findings have been discussed in detail. Due to the good foaming and IFT output at ultra-low levels, the combination of 0.3wt.% IVF and CBH at a ratio of 2: 8 was suggested. The addition of a non-ionic scleroglucan polymer from the polysaccharide group was chosen to study the stabilizing effect to the foam and the ultra-low IFT value of the formulation. Based on the findings, the presence of scleroglucan in the formulation has a significant effect on the performance of IFT and foam of the formulation when compared to the original formulation.