bluuebunny/crossref_metadata_2025 huggingface dataset:
Powering AI at the edge: A robust, memristor-based binarized neural network with near-memory computing and miniaturized solar cell
Authors: Jebali Fadi , Majumdar Atreya , Turck Clément , Harabi Kamel-Eddine , Faye Mathieu-Coumba , Muhr Eloi , Walder Jean-Pierre , Bilousov Oleksandr , Michaud Amadéo , Vianello Elisa , Hirtzlin Tifenn , Andrieu François , Bocquet Marc , Collin Stéphane , Querlioz Damien , Portal Jean-Michel
Published: January 2024

Memristor-based neural networks provide an exceptional energy-efficient platform for artificial intelligence (AI), presenting the possibility of self-powered operation when paired with energy harvesters. However, most memristor-based networks rely on analog in-memory computing, necessitating a stable and precise power supply, which is incompatible with the inherently unstable and unreliable energy harvesters. In this work, we fabricated a robust binarized neural network comprising 32,768 memristors, powered by a miniature wide-bandgap solar cell optimized for edge applications. Our circuit employs a resilient digital near-memory computing approach, featuring complementarily programmed memristors and logic-in-sense-amplifier. This design eliminates the need for compensation or calibration, operating effectively under diverse conditions. Under high illumination, the circuit achieves inference performance comparable to that of a lab bench power supply. In low illumination scenarios, it remains functional with slightly reduced accuracy, seamlessly transitioning to an approximate computing mode. Through image classification neural network simulations, we demonstrate that misclassified images under low illumination are primarily difficult-to-classify cases. Our approach lays the groundwork for self-powered AI and the creation of intelligent sensors for various applications in health, safety, and environment monitoring.
A drug-free cardiovascular stent functionalized with tailored collagen supports in-situ healing of vascular tissues
Authors: Wu Haoshuang , Yang Li , Luo Rifang , Li Li , Zheng Tiantian , Huang Kaiyang , Qin Yumei , Yang Xia , Zhang Xingdong , Wang Yunbing
Published: January 2024

Drug-eluting stent implantation suppresses the excessive proliferation of smooth muscle cells to reduce in-stent restenosis. However, the efficacy of drug-eluting stents remains limited due to delayed reendothelialization, impaired intimal remodeling, and potentially increased late restenosis. Here, we show that a drug-free coating formulation functionalized with tailored recombinant humanized type III collagen exerts one-produces-multi effects in response to injured tissue following stent implantation. We demonstrate that the one-produces-multi coating possesses anticoagulation, anti-inflammatory, and intimal hyperplasia suppression properties. We perform transcriptome analysis to indicate that the drug-free coating favors the endothelialization process and induces the conversion of smooth muscle cells to a contractile phenotype. We find that compared to drug-eluting stents, our drug-free stent reduces in-stent restenosis in rabbit and porcine models and improves vascular neointimal healing in a rabbit model. Collectively, the one-produces-multi drug-free system represents a promising strategy for the next-generation of stents.
Life-history stage determines the diet of ectoparasitic mites on their honey bee hosts
Authors: Han Bin , Wu Jiangli , Wei Qiaohong , Liu Fengying , Cui Lihong , Rueppell Olav , Xu Shufa
Published: January 2024

Ectoparasitic mites of the genera Varroa and Tropilaelaps have evolved to exclusively exploit honey bees as food sources during alternating dispersal and reproductive life history stages. Here we show that the primary food source utilized by Varroa destructor depends on the host life history stage. While feeding on adult bees, dispersing V. destructor feed on the abdominal membranes to access to the fat body as reported previously. However, when V. destructor feed on honey bee pupae during their reproductive stage, they primarily consume hemolymph, indicated by wound analysis, preferential transfer of biostains, and a proteomic comparison between parasite and host tissues. Biostaining and proteomic results were paralleled by corresponding findings in Tropilaelaps mercedesae, a mite that only feeds on brood and has a strongly reduced dispersal stage. Metabolomic profiling of V. destructor corroborates differences between the diet of the dispersing adults and reproductive foundresses. The proteome and metabolome differences between reproductive and dispersing V. destructor suggest that the hemolymph diet coincides with amino acid metabolism and protein synthesis in the foundresses while the metabolism of non-reproductive adults is tuned to lipid metabolism. Thus, we demonstrate within-host dietary specialization of ectoparasitic mites that coincides with life history of hosts and parasites.
Pulse irradiation synthesis of metal chalcogenides on flexible substrates for enhanced photothermoelectric performance
Authors: Zhang Yuxuan , Meng You , Wang Liqiang , Lan Changyong , Quan Quan , Wang Wei , Lai Zhengxun , Wang Weijun , Li Yezhan , Yin Di , Li Dengji , Xie Pengshan , Chen Dong , Yang Zhe , Yip SenPo , Lu Yang , Wong Chun-Yuen , Ho Johnny C.
Published: January 2024

High synthesis temperatures and specific growth substrates are typically required to obtain crystalline or oriented inorganic functional thin films, posing a significant challenge for their utilization in large-scale, low-cost (opto-)electronic applications on conventional flexible substrates. Here, we explore a pulse irradiation synthesis (PIS) to prepare thermoelectric metal chalcogenide (e.g., Bi2Se3, SnSe2, and Bi2Te3) films on multiple polymeric substrates. The self-propagating combustion process enables PIS to achieve a synthesis temperature as low as 150 °C, with an ultrafast reaction completed within one second. Beyond the photothermoelectric (PTE) property, the thermal coupling between polymeric substrates and bismuth selenide films is also examined to enhance the PTE performance, resulting in a responsivity of 71.9 V/W and a response time of less than 50 ms at 1550 nm, surpassing most of its counterparts. This PIS platform offers a promising route for realizing flexible PTE or thermoelectric devices in an energy-, time-, and cost-efficient manner.
Effective electrical manipulation of a topological antiferromagnet by orbital torques
Authors: Zheng Zhenyi , Zeng Tao , Zhao Tieyang , Shi Shu , Ren Lizhu , Zhang Tongtong , Jia Lanxin , Gu Youdi , Xiao Rui , Zhou Hengan , Zhang Qihan , Lu Jiaqi , Wang Guilei , Zhao Chao , Li Huihui , Tay Beng Kang , Chen Jingsheng
Published: January 2024

The electrical control of the non-trivial topology in Weyl antiferromagnets is of great interest for the development of next-generation spintronic devices. Recent studies suggest that the spin Hall effect can switch the topological antiferromagnetic order. However, the switching efficiency remains relatively low. Here, we demonstrate the effective manipulation of antiferromagnetic order in the Weyl semimetal Mn3Sn using orbital torques originating from either metal Mn or oxide CuOx. Although Mn3Sn can convert orbital current to spin current on its own, we find that inserting a heavy metal layer, such as Pt, of appropriate thickness can effectively reduce the critical switching current density by one order of magnitude. In addition, we show that the memristor-like switching behaviour of Mn3Sn can mimic the potentiation and depression processes of a synapse with high linearity—which may be beneficial for constructing accurate artificial neural networks. Our work paves a way for manipulating the topological antiferromagnetic order and may inspire more high-performance antiferromagnetic functional devices.
Clinical and molecular epidemiology of enterovirus D68 from 2013 to 2020 in Shanghai
Authors: Li Fei , Lu Rou-jian , Zhang Yu-han , Shi Peng , Ao Yuan-yun , Cao Lin-feng , Zhang Yu-lan , Tan Wen-jie , Shen Jun
Published: January 2024

Enterovirus D68 (EV-D68) is an emerging pathogen that has caused outbreaks of severe respiratory disease worldwide, especially in children. We aim to investigate the prevalence and genetic characteristics of EV-D68 in children from Shanghai. Nasopharyngeal swab or bronchoalveolar lavage fluid samples collected from children hospitalized with community-acquired pneumonia were screened for EV-D68. Nine of 3997 samples were EV-D68-positive. Seven of nine positive samples were sequenced and submitted to GenBank. Based on partial polyprotein gene (3D) or complete sequence analysis, we found the seven strains belong to different clades and subclades, including three D1 (detected in 2013 and 2014), one D2 (2013), one D3 (2019), and two B3 (2014 and 2018). Overall, we show different clades and subclades of EV-D68 spread with low positive rates (0.2%) among children in Shanghai between 2013 and 2020. Amino acid mutations were found in the epitopes of the VP1 BC and DE loops and C-terminus; similarity analysis provided evidence for recombination as an important mechanism of genomic diversification. Both single nucleotide mutations and recombination play a role in evolution of EV-D68. Genetic instability within these clinical strains may indicate large outbreaks could occur following cumulative mutations.
Methodology of generation of CFD meshes and 4D shape reconstruction of coronary arteries from patient-specific dynamic CT
Authors: Psiuk-Maksymowicz Krzysztof , Borys Damian , Melka Bartlomiej , Gracka Maria , Adamczyk Wojciech P. , Rojczyk Marek , Wasilewski Jaroslaw , Głowacki Jan , Kruk Mariusz , Nowak Marcin , Ostrowski Ziemowit , Bialecki Ryszard A.
Published: January 2024

Due to the difficulties in retrieving both the time-dependent shapes of the vessels and the generation of numerical meshes for such cases, most of the simulations of blood flow in the cardiac arteries use static geometry. The article describes a methodology for generating a sequence of time-dependent 3D shapes based on images of different resolutions and qualities acquired from ECG-gated coronary artery CT angiography. The precision of the shape restoration method has been validated using an independent technique. The original proposed approach also generates for each of the retrieved vessel shapes a numerical mesh of the same topology (connectivity matrix), greatly simplifying the CFD blood flow simulations. This feature is of significant importance in practical CFD simulations, as it gives the possibility of using the mesh-morphing utility, minimizing the computation time and the need of interpolation between boundary meshes at subsequent time instants. The developed technique can be applied to generate numerical meshes in arteries and other organs whose shapes change over time. It is applicable to medical images produced by other than angio-CT modalities.
An innovative machine learning based on feed-forward artificial neural network and equilibrium optimization for predicting solar irradiance
Authors: Xu Ting , Sabzalian Mohammad Hosein , Hammoud Ahmad , Tahami Hamed , Gholami Ali , Lee Sangkeum
Published: January 2024

As is known, having a reliable analysis of energy sources is an important task toward sustainable development. Solar energy is one of the most advantageous types of renewable energy. Compared to fossil fuels, it is cleaner, freely available, and can be directly exploited for electricity. Therefore, this study is concerned with suggesting novel hybrid models for improving the forecast of Solar Irradiance (IS). First, a predictive model, namely Feed-Forward Artificial Neural Network (FFANN) forms the non-linear contribution between the ISand dominant meteorological and temporal parameters (including humidity, temperature, pressure, cloud coverage, speed and direction of wind, month, day, and hour). Then, this framework is optimized using several metaheuristic algorithms to create hybrid models for predicting the IS. According to the accuracy assessments, metaheuristic algorithms attained satisfying training for the FFANN by using 80% of the data. Moreover, applying the trained models to the remaining 20% proved their high proficiency in forecasting the ISin unseen environmental circumstances. A comparison among the optimizers revealed that Equilibrium Optimization (EO) could achieve a higher accuracy than Wind-Driven Optimization (WDO), Optics Inspired Optimization (OIO), and Social Spider Algorithm (SOSA). In another phase of this study, Principal Component Analysis (PCA) is applied to identify the most contributive meteorological and temporal factors. The PCA results can be used to optimize the problem dimension, as well as to suggest effective real-world measures for improving solar energy production. Lastly, the EO-based solution is yielded in the form of an explicit formula for a more convenient estimation of the IS.
Protein interaction networks characterizing the A549 cells Klotho transfected are associated with activated pro-apoptotic Bim and suppressed Wnt/β-catenin signaling pathway
Authors: Matsumoto Mitsuo , Ogawa Naomi , Fukuda Tetsuya , Bando Yasuhiko , Nishimura Toshihide , Usuda Jitsuo
Published: January 2024

Invasive assays and lung tumor-bearing mice models using a human lung adenocarcinoma cell line A549 cells transfected with the Klotho (KL) gene, A549/KL cells, have confirmed that KL suppresses invasive/metastatic potential. This study aimed to identify the co-expression protein networks and proteomic profiles associated with A549/KL cells to understand how Klotho protein expression affects molecular networks associated with lung carcinoma malignancy. A two-step application of a weighted network correlation analysis to the cells’ quantitative proteome datasets of a total of 6,994 proteins, identified by mass spectrometry-based proteomic analysis with data-independent acquisition (DIA), identified one network module as most significantly associated with the A549/KL trait. Upstream analyses, confirmed by western blot, implicated the pro-apoptotic Bim (Bcl-2-like protein 11) as a master regulator of molecular networks affected by Klotho. GeneMANIA interaction networks and quantitative proteome data implicated that Klotho interacts with two signaling axes: negatively with the Wnt/β-catenin axis, and positively by activating Bim. Our findings might contribute to the development of future therapeutic strategies.
The use of whole body computed tomography does not lead to increased 24-h mortality in severely injured patients in circulatory shock
Authors: Hanzalova Ivana , Bourgeat Mylène , Demartines Nicolas , Ageron François-Xavier , Zingg Tobias
Published: January 2024

The Advanced Trauma Life Support (ATLS) approach is generally accepted as the standard of care for the initial management of severely injured patients. While whole body computed tomography (WBCT) is still considered a contraindication in haemodynamically unstable trauma patients, there is a growing amount of data indicating the absence of harm from cross sectional imaging in this patient group. Our study aimed to compare the early mortality of unstable trauma patients undergoing a WBCT during the initial workup with those who did not. Single-center retrospective observational study based on the local trauma registry including 3525 patients with an ISS > 15 from January 2008 to June 2020. We compared the 24-h mortality of injured patients in circulatory shock undergoing WBCT with a control group undergoing standard workup only. Inclusion criteria were the simultaneous presence of a systolic blood pressure < 100 mmHg, lactate > 2.2 mmol/l and base excess < − 2 mmol/l as surrogate markers for circulatory shock. To control for confounding, a propensity score matched analysis with conditional logistic regression for adjustment of residual confounders and a sensitivity analysis using inverse probability weighting (IPW) with and without adjustment were performed. Of the 3525 patients, 161 (4.6%) fulfilled all inclusion criteria. Of these, 132 (82%) underwent WBCT and 29 (18%) standard work-up only. In crude and matched analyses, no difference in early (24 h) mortality was observed (WBCT, 23 (17.4%) and no-WBCT, 8 (27.6%); p = 0.21). After matching and adjustment for main confounders, the odds ratio for the event of death at 24 h in the WBCT group was 0.36 (95% CI 0.07–1.73); p = 0.20. In the present study, WBCT did not increase the risk of death at 24 h among injured patients in shock. This adds to the growing data indicating that WBCT may be offered to trauma patients in circulatory shock without jeopardizing early survival.
Identification of gene signatures and molecular mechanisms underlying the mutual exclusion between psoriasis and leprosy
Authors: Lu You-Wang , Dong Rong-Jing , Yang Lu-Hui , Liu Jiang , Yang Ting , Xiao Yong-Hong , Chen Yong-Jun , Wang Rui-Rui , Li Yu-Ye
Published: January 2024

Leprosy and psoriasis rarely coexist, the specific molecular mechanisms underlying their mutual exclusion have not been extensively investigated. This study aimed to reveal the underlying mechanism responsible for the mutual exclusion between psoriasis and leprosy. We obtained leprosy and psoriasis data from ArrayExpress and GEO database. Differential expression analysis was conducted separately on the leprosy and psoriasis using DEseq2. Differentially expressed genes (DEGs) with opposite expression patterns in psoriasis and leprosy were identified, which could potentially involve in their mutual exclusion. Enrichment analysis was performed on these candidate mutually exclusive genes, and a protein–protein interaction (PPI) network was constructed to identify hub genes. The expression of these hub genes was further validated in an external dataset to obtain the critical mutually exclusive genes. Additionally, immune cell infiltration in psoriasis and leprosy was analyzed using single-sample gene set enrichment analysis (ssGSEA), and the correlation between critical mutually exclusive genes and immune cells was also examined. Finally, the expression pattern of critical mutually exclusive genes was evaluated in a single-cell transcriptome dataset. We identified 1098 DEGs in the leprosy dataset and 3839 DEGs in the psoriasis dataset. 48 candidate mutually exclusive genes were identified by taking the intersection. Enrichment analysis revealed that these genes were involved in cholesterol metabolism pathways. Through PPI network analysis, we identified APOE, CYP27A1, FADS1, and SOAT1 as hub genes. APOE, CYP27A1, and SOAT1 were subsequently validated as critical mutually exclusive genes on both internal and external datasets. Analysis of immune cell infiltration indicated higher abundance of 16 immune cell types in psoriasis and leprosy compared to normal controls. The abundance of 6 immune cell types in psoriasis and leprosy positively correlated with the expression levels of APOE and CYP27A1. Single-cell data analysis demonstrated that critical mutually exclusive genes were predominantly expressed in Schwann cells and fibroblasts. This study identified APOE, CYP27A1, and SOAT1 as critical mutually exclusive genes. Cholesterol metabolism pathway illustrated the possible mechanism of the inverse association of psoriasis and leprosy. The findings of this study provide a basis for identifying mechanisms and therapeutic targets for psoriasis.
Added value of dynamic contrast-enhanced MR imaging in deep learning-based prediction of local recurrence in grade 4 adult-type diffuse gliomas patients
Authors: Yoon Jungbin , Baek Nayeon , Yoo Roh-Eul , Choi Seung Hong , Kim Tae Min , Park Chul-Kee , Park Sung-Hye , Won Jae-Kyung , Lee Joo Ho , Lee Soon Tae , Choi Kyu Sung , Lee Ji Ye , Hwang Inpyeong , Kang Koung Mi , Yun Tae Jin
Published: January 2024

Local recurrences in patients with grade 4 adult-type diffuse gliomas mostly occur within residual non-enhancing T2 hyperintensity areas after surgical resection. Unfortunately, it is challenging to distinguish non-enhancing tumors from edema in the non-enhancing T2 hyperintensity areas using conventional MRI alone. Quantitative DCE MRI parameters such as Ktrans and Ve convey permeability information of glioblastomas that cannot be provided by conventional MRI. We used the publicly available nnU-Net to train a deep learning model that incorporated both conventional and DCE MRI to detect the subtle difference in vessel leakiness due to neoangiogenesis between the non-recurrence area and the local recurrence area, which contains a higher proportion of high-grade glioma cells. We found that the addition of Ve doubled the sensitivity while nonsignificantly decreasing the specificity for prediction of local recurrence in glioblastomas, which implies that the combined model may result in fewer missed cases of local recurrence. The deep learning model predictive of local recurrence may enable risk-adapted radiotherapy planning in patients with grade 4 adult-type diffuse gliomas.
An oxygen-coordinated cobalt single-atom electrocatalyst boosting urea and urea peroxide production
Authors: Zhang Shengbo , Jin Meng , Xu Hui , Zhang Xinyuan , Shi Tongfei , Ye Yixing , Lin Yue , Zheng Lirong , Wang Guozhong , Zhang Yunxia , Yin Huajie , Zhang Haimin , Zhao Huijun
Published: January 2024

An oxygen-coordinated cobalt single-atom catalyst was successfully fabricated, exhibiting exceptional electrocatalytic activity toward urea and H2O2 production. Subsequently, the value-added urea peroxide was efficiently synthesized.
Multiparametric modulation of magnetic transduction for biomolecular sensing in liquids
Authors: Sanz-de Diego Elena , Aires Antonio , Palacios-Alonso Pablo , Cabrera David , Silvestri Niccolo , Vequi-Suplicy Cinthia C. , Artés-Ibáñez Emilio J. , Requejo-Isidro José , Delgado-Buscalioni Rafael , Pellegrino Teresa , Cortajarena Aitziber L. , Terán Francisco J.
Published: January 2024

The transducing capacity of magnetic nanoparticles for biomarker detection in AC magnetometry lies in a number of modulating parameters. This is assessed through the variations of AC magnetic hysteresis area in absence (black colour, A0) and presence (violet colour, A) of analytes.
Borylated cyclobutanes via thermal [2 + 2]-cycloaddition
Authors: Prysiazhniuk Kateryna , Polishchuk Oleksandr , Shulha Stanislav , Gudzikevych Kyrylo , Datsenko Oleksandr P. , Kubyshkin Vladimir , Mykhailiuk Pavel K.
Published: January 2024

A one-step approach to borylated cyclobutanes from amides of carboxylic acids and vinyl boronates is elaborated. The reaction proceeds via the thermal [2 + 2]-cycloaddition of in situ-generated keteniminium salts.
An efficient and robust system for human following scenario using differential robot
Authors: Zhu Jiangchao , Ma Changjia , Xu Chao , Gao Fei
Published: January 2024

A novel system for human following using a differential robot, including an accurate 3‐D human position tracking module and a novel planning strategy that ensures safety and dynamic feasibility, is proposed. The authors utilise a combination of gimbal camera and LiDAR for long‐term accurate human detection. Then the planning module takes the target's future trajectory as a reference to generate a coarse path to ensure the following visibility. After that, the trajectory is optimised considering other constraints and following distance. Experiments demonstrate the robustness and efficiency of our system in complex environments, demonstrating its potential in various applications.
Update of SB9 orbits using HERMES/Mercator radial velocities
Authors: Merle T. , Pourbaix D. , Jorissen A. , Siopis C. , Van Eck S. , Van Winckel H.
Published: January 2024

Aims. By combining astrometric orbits (delivered in large numbers by the Gaίa mission) with spectroscopic orbits for systems with two observable spectra (SB2), it is possible to derive the masses of both stellar components. However, to get masses with a good accuracy requires accurate spectroscopic orbits, which is the primary aim of the present paper. A subsidiary aim is to discover SB2 systems hiding among known SB1 systems and even though this search may often prove unsuccessful, the acquired radial velocities may still be used to improve the existing spectroscopic orbits.

Methods. New radial velocities for 58 binary systems from the Ninth Catalogue of Spectroscopic Binary Orbits (SB9), obtained using the high-resolution HERMES spectrograph installed on the 1.2 m Mercator telescope, were used to possibly identify hitherto undetected SB2 systems. For SB1 systems with inaccurate orbits, we used these new radial-velocity measurements to improve the orbital accuracy.

Results. This study provides 51 orbits (41 SB1 and 10 SB2) that have been improved with respect to the solution listed in the SB9 catalogue, out of the 58 SB9 orbits studied, which belong to 56 stellar systems. Among them, there are five triple and four quadruple systems. Despite the high resolution of HERMES, the only system we detected as anew SB2 system is HIP 115142 A. The B component of the visual binary HIP 92726 has now been found to be a spectroscopic system as well, which makes HIP 92726 a newly discovered quadruple system (SB 1+SB 1). Moreover, the high resolution of HERMES has enabled us to better isolate the signature of the secondary component of HIP 12390, HIP 73182, and HIP 111170. Thus, we derived more accurate masses for them. Among the 30 SB also present in Gaia Data Release 3 (DR3), with periods shorter than the Gaia DR3 time span (~1000 d), only five had been flagged as binaries by DR3. Various DR3 selection criteria are responsible for this discrepancy.
Adaptive data reduction workflows for astronomy: The ESO Data Processing System (EDPS)
Authors: Freudling W. , Zampieri S. , Coccato L. , Podgorski S. , Romaniello M. , Modigliani A. , Pritchard J.
Published: January 2024

Context. Astronomical data reduction is usually done via processing pipelines that consist of a series of individual processing steps that can be executed one at a time. These processing steps are then strung together into workflows and fed with data to address a particular processing goal. Examples of such pipeline processing goals are the quality control of incoming data from telescopes, unsupervised production of science and calibration products for an archive, and supervised data reduction to serve the specific science goals of a scientist. For each of these goals, individual workflows need to be developed. These workflows need to evolve when the pipeline, observing strategies, or calibration plans change. Writing and maintaining such a collection of workflows is therefore a complex and expensive task.

Aims. In this paper we propose a data processing system that automatically derives processing workflows for different use cases from a single specification of a cascade of processing steps.

Methods. The system works by using formalised descriptions of data processing pipelines that specify the input and output of each processing step. Inputs can be existing data or the output of a previous step. The rules for selecting the most appropriate input data are directly attached to the description.

Results. A version of the proposed system has been implemented as the ESO Data Processing System (EDPS) in the Python language. The specification of processing cascades and data organisation rules use a restrictive set of Python classes, attributes, and functions.

Conclusions. The EDPS implementation of the proposed system was used to demonstrate that it is possible to automatically derive from a single specification of a pipeline processing cascade the workflows that the European Southern Observatory uses for quality control, archive production, and specialised science reduction. The EDPS will be used to replace all data reduction systems using different workflow specifications that are currently in use at the European Southern Observatory.
A search for high-redshift direct-collapse black hole candidates in the PEARLS north ecliptic pole field
Authors: Nabizadeh Armin , Zackrisson Erik , Pacucci Fabio , Peter Maksym Walter , Li Weihui , Civano Francesca , Cohen Seth H. , D’Silva Jordan C. J. , Koekemoer Anton M. , Summers Jake , Windhorst Rogier A. , Adams Nathan , Conselice Christopher J. , Coe Dan , Driver Simon P. , Frye Brenda , Grogin Norman A. , Jansen Rolf A. , Marshall Madeline A. , Nonino Mario , Pirzkal Nor , Robotham Aaron , Rutkowski Michael J. , Ryan Russell E. , Tompkins Scott , Willmer Christopher N. A. , Yan Haojing , Diego Jose M. , Cheng Cheng , Finkelstein Steven L. , Willner Steven P. , Wang Lifan , Zitrin Adi , Smith Brent M. , Bhatawdekar Rachana , Gim Hansung B.
Published: January 2024

Direct-collapse black holes (DCBHs) of mass ∼104 − 105 M⊙ that form in HI-cooling halos in the early Universe are promising progenitors of the ≳109 M⊙ supermassive black holes that fuel observed z ≳ 7 quasars. Efficient accretion of the surrounding gas onto such DCBH seeds may render them sufficiently bright for detection with the JWST up to z ≈ 20. Additionally, the very steep and red spectral slope predicted across the ≈1 − 5 μm wavelength range of the JWST/NIRSpec instrument during their initial growth phase should make them photometrically identifiable up to very high redshifts. In this work, we present a search for such DCBH candidates across the 34 arcmin2 in the first two spokes of the JWST cycle-1 PEARLS survey of the north ecliptic pole time-domain field covering eight NIRCam filters down to a maximum depth of ∼29 AB mag. We identify two objects with spectral energy distributions consistent with theoretical DCBH models. However, we also note that even with data in eight NIRCam filters, objects of this type remain degenerate with dusty galaxies and obscured active galactic nuclei over a wide range of redshifts. Follow-up spectroscopy would be required to pin down the nature of these objects. Based on our sample of DCBH candidates and assumptions on the typical duration of the DCBH steep-slope state, we set a conservative upper limit of ≲5 × 10−4 comoving Mpc−3 (cMpc−3) on the comoving density of host halos capable of hosting DCBHs with spectral energy distributions similar to the theoretical models at z ≈ 6 − 14.
The Lockman–SpReSO project
Authors: González-Otero Mauro , Padilla-Torres Carmen P. , González-Serrano José Ignacio , Cepa Jordi , María Pérez García Ana , Jesús González J. , Benítez Erika , Bongiovanni Ángel , Cerviño Miguel , Cruz-González Irene , Gallego Jesús , Herrera-Endoqui Martín , Ibarra-Medel Héctor J. , Krongold Yair , Lara-López Maritza A. , Nadolny Jakub , Alenka Negrete Castalia , Pérez-Martínez Ricardo , Pović Mirjana , Sánchez-Portal Miguel , Cedrés Bernabé , de Diego José A. , Hernández-Toledo Héctor , Navarro Martínez Rocío
Published: January 2024

Context. The Lockman–SpReSO project is an optical spectroscopic survey of 956 far-infrared (FIR) objects within the Lockman Hole field limited by magnitude RC(AB) < 24.5. Fe II and Mg II absorption lines have been detected in 21 out of 456 objects with a determined spectroscopic redshift in the catalogue. The redshifts of these objects are in the range 0.5 ≲ z ≲ 1.44.

Aims. The aim of this study is to investigate material ejection from star-forming regions and material infall into galaxies by analysing the Fe II and Mg II absorption lines. Additionally, we explore whether the correlations found in previous studies between these galactic wind velocities, line equivalent widths (EWs), and galaxy properties such as stellar mass (M*), star formation rate (SFR), and specific star formation rate (sSFR) are valid for a sample with FIR-selected objects. The objects analysed span an M* range of 9.89 < log(M*/M⊙) < 11.50 and an SFR range of 1.01 < log(SFR) < 2.70.

Methods. We performed measurements of the Mg IIλλ2796, 2803, Mg Iλ2852, Fe IIλλ2374, 82, Fe IIλλ2586, 2600, and Fe IIλ2344 spectral lines present in the spectra of the selected sample to determine the EW and velocity of the flows observed in the star-forming galaxies. Subsequently, we conducted 107 bootstrap simulations using the Spearman’s rank correlation coefficient (ρs) to explore correlations with galaxy properties. Furthermore, we calculated the covering factor, gas density, and optical depth for the measured Fe II doublets.

Results. Our analysis reveals strong correlations between the EW of Mg II lines and both M* (ρs = 0.43, 4.5σ) and SFR (ρs = 0.42, 4.4σ). For the Fe II lines, we observed strong correlations between the EW and SFR (ρs ∼ 0.65, > 3.9σ), with a weaker correlation for M* (ρs ∼ 0.35, > 1.9σ). No notable correlations were found between velocity measurements of the Mg II line and M*, SFR, or sSFR of the objects (ρs ∼ 0.1). However, a strong negative correlation was found between the velocity of the Fe II lines and the SFR of the galaxies (ρs ∼ −0.45, ∼3σ). Our results align with those of previous studies, although only FIR-selected objects are investigated here. Finally, we detect a candidate ‘loitering outflow’, a recently discovered subtype of the iron low-ionisation broad absorption line (FeLoBAL) quasars, at a redshift of z = 1.4399, exhibiting emission in C III] and low line velocities (|v|≲200 km s−1).
TIPSY: Trajectory of Infalling Particles in Streamers around Young stars
Authors: Gupta Aashish , Miotello Anna , Williams Jonathan P. , Birnstiel Til , Kuffmeier Michael , Yen Hsi-Wei
Published: January 2024

Context. Elongated trails of infalling gas, often referred to as “streamers,” have recently been observed around young stellar objects (YSOs) at different evolutionary stages. This asymmetric infall of material can significantly alter star and planet formation processes, especially in the more evolved YSOs.

Aims. In order to ascertain the infalling nature of observed streamer-like structures and then systematically characterize their dynamics, we developed the code TIPSY (Trajectory of Infalling Particles in Streamers around Young stars).

Methods. Using TIPSY, the streamer molecular line emission is first isolated from the disk emission. Then the streamer emission, which is effectively a point cloud in three-dimensional (3D) position–position–velocity space, is simplified to a curve-like representation. The observed streamer curve is then compared to the theoretical trajectories of infalling material. The best-fit trajectories are used to constrain streamer features, such as the specific energy, the specific angular momenta, the infall timescale, and the 3D morphology.

Results. We used TIPSY to fit molecular-line ALMA observations of streamers around a Class II binary system, S CrA, and a Class I/II protostar, HL Tau. Our results indicate that both of the streamers are consistent with infalling motion. For the S CrA streamer, we could constrain the dynamical parameters well and find it to be on a bound elliptical trajectory. On the other hand, the fitting uncertainties are substantially higher for the HL Tau streamer, likely due to the smaller spatial scales of the observations. TIPSY results and mass estimates suggest that S CrA and HL Tau are accreting material at a rate of ≳27 Mjupiter Myr–1 and ≳5 Mjupiter Myr–1, respectively, which can significantly increase the mass budget available to form planets.

Conclusions. TIPSY can be used to assess whether the morphology and kinematics of observed streamers are consistent with infalling motion and to characterize their dynamics, which is crucial for quantifying their impact on the protostellar systems.
Circumstellar interaction models for the early bolometric light curve of SN 2023ixf
Authors: Martinez L. , Bersten M. C. , Folatelli G. , Orellana M. , Ertini K.
Published: January 2024

Type II supernovae (SNe II) show growing evidence of an interaction with circumstellar material (CSM) surrounding their progenitor stars as a consequence of enhanced mass loss during the last years of the progenitor’s life, although the exact mechanism is still unknown. We present an analysis of the progenitor mass-loss history of SN 2023ixf, a nearby SN II showing signs of an interaction. First, we calculated the early-time (< 19 days) bolometric light curve for SN 2023ixf based on the integration of the observed flux covering ultraviolet, optical and near-infrared bands, and black-body extrapolations for the unobserved flux. Our calculations detected the sudden increase to maximum luminosity and temperature, in addition to the subsequent fall, displaying an evident peak. This is the first time that this phase can be precisely estimated for a SN II. We used the early-time bolometric light curve of SN 2023ixf to test the calibrations of bolometric corrections against colours from the literature. In addition, we included the observations of SN 2023ixf into some of the available calibrations to extend their use to earlier epochs. A comparison of the observed bolometric light curve to SN II explosion models with CSM interaction suggests a progenitor mass-loss rate ofṀ= 3 × 10−3M⊙yr−1confined to 12 000R⊙(∼8 × 1014cm) and a wind acceleration parameter ofβ= 5. This model reproduces the early bolometric light curve, expansion velocities, and the epoch of disappearance of interacting lines in the spectra. This model indicates that the wind was launched ∼80 yr before the explosion. If the effect of the wind acceleration is not taken into account, the enhanced wind must have developed over the final months to years prior to the SN, which may not be consistent with the lack of outburst detection in pre-explosion images over the last ∼20 yr before explosion.
Numerical simulations of turbulence in prominence threads induced by torsional oscillations
Authors: Díaz-Suárez Sergio , Soler Roberto
Published: January 2024

Context.Threads are the main constituents of prominences. They are dynamic structures that display oscillations, usually interpreted as magnetohydrodynamic (MHD) waves. Moreover, instabilities such as the Kelvin–Helmholtz instability (KHI) have also been reported in prominences. Both waves and instabilities may affect the thermodynamic state of the threads.

Aims.We investigate the triggering of turbulence in prominence threads caused by the nonlinear evolution of standing torsional Alfvén waves. We study the heating in the partially ionized prominence plasma as well as possible observational signatures of this dynamics.

Methods.We modeled a prominence thread as a radially and longitudinally nonuniform cylindrical flux tube with a constant axial magnetic field embedded in a much lighter and hotter coronal environment. We perturbed the flux tube with the longitudinally fundamental mode of standing torsional Alfvén waves. We numerically solved the three-dimensional (3D) MHD equations to study the temporal evolution in both ideal and dissipative scenarios. In addition, we performed forward modeling to calculate the synthetic Hαimaging.

Results.The standing torsional Alfvén waves undergo phase-mixing owing to the radially nonuniform density. The phase-mixing generates azimuthal shear flows, which eventually trigger the KHI and, subsequently, turbulence. When nonideal effects are included, the obtained plasma heating is very localized in an annulus region at the thread boundary and does not increase the temperature in the cool core. Instead, the average temperature in the thread decreases owing to the mixing of internal and external plasmas. In the synthetic observations, first we observe periodic pulsations in the Hαintensity caused by the integration of the phase-mixing flows along the line of sight. Later, fine strands that may be associated with the KHI vortices are seen in the synthetic Hαimages.

Conclusions.Turbulence can be generated by standing torsional Alfvén waves in prominence threads after the triggering of the KHI, although this mechanism is not enough to heat such structures. Both the phase-mixing stage and the turbulent stage of the simulated dynamics could be discernible in high-resolution Hαobservations.
KMT-2023-BLG-0416, KMT-2023-BLG-1454, KMT-2023-BLG-1642: Microlensing planets identified from partially covered signals
Authors: Han Cheongho , Udalski Andrzej , Lee Chung-Uk , Zang Weicheng , Albrow Michael D. , Chung Sun-Ju , Gould Andrew , Hwang Kyu-Ha , Jung Youn Kil , Ryu Yoon-Hyun , Shvartzvald Yossi , Shin In-Gu , Yee Jennifer C. , Yang Hongjing , Cha Sang-Mok , Kim Doeon , Kim Dong-Jin , Kim Seung-Lee , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. , Mróz Przemek , Szymański Michał K. , Skowron Jan , Poleski Radosław , Soszyński Igor , Pietrukowicz Paweł , Kozłowski Szymon , Rybicki Krzysztof A. , Iwanek Patryk , Ulaczyk Krzysztof , Wrona Marcin , Gromadzki Mariusz , Mróz Mateusz
Published: January 2024

Aims. We investigate the 2023 season data from high-cadence microlensing surveys with the aim of detecting partially covered shortterm signals and revealing their underlying astrophysical origins. Through this analysis, we ascertain that the signals observed in the lensing events KMT-2023-BLG-0416, KMT-2023-BLG-1454, and KMT-2023-BLG-1642 are of planetary origin.

Methods. Considering the potential degeneracy caused by the partial coverage of signals, we thoroughly investigate the lensing-parameter plane. In the case of KMT-2023-BLG-0416, we have identified two solution sets, one with a planet-to-host mass ratio of q ~ 10−2 and the other with q ~ 6 × 10−5, within each of which there are two local solutions emerging due to the inner-outer degeneracy. For KMT-2023-BLG-1454, we discern four local solutions featuring mass ratios of q ~ (1.7−4.3) × 10−3. When it comes to KMT-2023-BLG-1642, we identified two locals with q ~ (6 − 10) × 10−3 resulting from the inner-outer degeneracy.

Results. We estimate the physical lens parameters by conducting Bayesian analyses based on the event time scale and Einstein radius. For KMT-2023-BLG-0416L, the host mass is ~0.6 M⊙, and the planet mass is ~(6.1−6.7) MJ according to one set of solutions and ~0.04 MJ according to the other set of solutions. KMT-2023-BLG-1454Lb has a mass roughly half that of Jupiter, while KMT-2023-BLG-1646Lb has a mass in the range of between 1.1 to 1.3 times that of Jupiter, classifying them both as giant planets orbiting mid M-dwarf host stars with masses ranging from 0.13 to 0.17 solar masses.
Indication of a fast ejecta fragment in the atomic cloud interacting with the southwestern limb of SN 1006
Authors: Giuffrida R. , Miceli M. , Ravikularaman S. , Phan V. H. M. , Gabici S. , Mertsch P. , Orlando S. , Bocchino F.
Published: January 2024

Context. Supernova remnants interacting with molecular and atomic clouds are interesting X-ray sources for studies of broadband nonthermal emission. X-ray line emission in these systems can be produced by different processes, such as low-energy cosmic rays (LECRs) interacting with the cloud and fast ejecta fragments moving in the cloud.

Aims. This paper is aimed at studying the origin of the non-thermal X-ray emission of the southwestern limb of SN 1006 beyond the main shock to determine whether the emission is due to LECRs diffusing in the cloud or to ejecta knots moving into the cloud.

Methods. We analyzed the X-ray emission of the southwestern limb of SN 1006, where the remnant interacts with an atomic cloud, using three different X-ray telescopes: NuSTAR, Chandra, and XMM-Newton. We also performed a combined spectro-imaging analysis of this region.

Results. Our analysis of the nonthermal X-ray emission of the southwestern limb of SN 1006 interacting with an atomic cloud has led to the detection of an extended X-ray source in the atomic cloud, approximately 2 pc upstream of the shock front. The source is characterized by a hard continuum (described by a power law with photon index Γ ∼ 1.4) and by Ne, Si, and Fe emission lines. The observed flux suggests that the origin of the X-ray emission is not associated with LECRs interacting with the cloud. On the other hand, the spectral properties of the source, together with the detection of an IR counterpart visible with Spitzer-MIPS at 24 μm, are in good agreement with the general expectations for a fast ejecta fragment moving within the atomic cloud.

Conclusions. We detected X-ray and IR emission from a possible ejecta fragment, with an approximate radius of 1 × 1017 cm and approximate mass of 10−3 M⊙ at about 2 pc out of the shell of SN 1006, in the interaction region between the southwestern limb of the remnant and the atomic cloud.
Efficiency of solar microflares in accelerating electrons when rooted in a sunspot
Authors: Saqri Jonas , Veronig Astrid M. , Battaglia Andrea Francesco , Dickson Ewan C. M. , Gary Dale E. , Krucker Säm
Published: January 2024

Context. The spectral shape of the X-ray emission in solar flares varies with the event size, with small flares generally exhibiting softer spectra than large events, indicative of a relatively lower number of accelerated electrons at higher energies.

Aims. We investigate two microflares of GOES classes A9 and C1 (after background subtraction) observed by STIX onboard Solar Orbiter with exceptionally strong nonthermal emission. We complement the hard X-ray imaging and spectral analysis by STIX with co-temporal observations in the (E)UV and visual range by AIA and HMI to investigate what makes these microflares so efficient in high-energy particle acceleration.

Methods. We made a preselection of events in the STIX flare catalog based on the ratio of the thermal to nonthermal quicklook X-ray emission. The STIX spectrogram science data were used to perform spectral fitting to identify the non-thermal and thermal components. The STIX X-ray images were reconstructed to analyze the spatial distribution of the precipitating electrons and the hard X-ray emission they produce. The EUV images from SDO/AIA and SDO/HMI LOS magnetograms were analyzed to better understand the magnetic environment and the chromospheric and coronal response. For the A9 event, EOVSA microwave observations were available, allowing for image reconstruction in the radio domain.

Results. We performed case studies of two microflares observed by STIX on October 11, 2021 and November 10, 2022, which showed unusually hard microflare X-ray spectra with power-law indices of the electron flux distributions of δ = (2.98 ± 0.25) and δ = (4.08 ± 0.23), during their non-thermal peaks and photon energies up to 76 keV and 50 keV, respectively. For both events under study, we found that one footpoint is located within a sunspot covering areas with mean magnetic flux densities in excess of 1500 G, suggesting that the hard electron spectra are caused by the strong magnetic fields the flare loops are rooted in. Additionally, we revisited a previously published unusually hard RHESSI microflare and found that in this event, there was also one flare kernel located within a sunspot, which corroborates the result from the two hard STIX microflares under study in this work.

Conclusions. The characteristics of the strong photospheric magnetic fields inside the sunspot umbrae and penumbrae where flare loops are rooted play an important role in the generation of exceptionally hard X-ray spectra in these microflares.