Astronomy and Computing最新文献

{"title":"pyC 2 Ray: A flexible and GPU-accelerated radiative transfer framework for simulating the cosmic epoch of reionization","authors":"P. Hirling ,&nbsp;M. Bianco ,&nbsp;S.K. Giri ,&nbsp;I.T. Iliev ,&nbsp;G. Mellema ,&nbsp;J.-P. Kneib","doi":"10.1016/j.ascom.2024.100861","DOIUrl":"10.1016/j.ascom.2024.100861","url":null,"abstract":"<div><p>Detailed modeling of the evolution of neutral hydrogen in the intergalactic medium during the Epoch of Reionization, <span><math><mrow><mn>5</mn><mo>≤</mo><mi>z</mi><mo>≤</mo><mn>20</mn></mrow></math></span>, is critical in interpreting the cosmological signals from current and upcoming 21-cm experiments such as the Low-Frequency Array (LOFAR) and the Square Kilometre Array (SKA). Numerical radiative transfer codes provide the most physically accurate models of the reionization process. However, they are computationally expensive as they must encompass enormous cosmological volumes while accurately capturing astrophysical processes occurring at small scales (<span><math><mrow><mo>≲</mo><mi>Mpc</mi></mrow></math></span>). Here, we present <span>pyC</span> <span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> <span>Ray</span>, an updated version of the massively parallel ray-tracing and chemistry code, <span>C</span> <span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> <span>-Ray</span>, which has been extensively employed in reionization simulations. The most time-consuming part of the code is calculating the hydrogen column density along the path of the ionizing photons. Here, we present the Accelerated Short-characteristics Octahedral ray-tracing (<span>ASORA</span>) method, a ray-tracing algorithm specifically designed to run on graphical processing units (GPUs). We include a modern <span>Python</span> interface, allowing easy and customized use of the code without compromising computational efficiency. We test <span>pyC</span> <span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> <span>Ray</span> on a series of standard ray-tracing tests and a complete cosmological simulation with volume size <span><math><msup><mrow><mrow><mo>(</mo><mn>349</mn><mspace></mspace><mi>Mpc</mi><mo>)</mo></mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span>, mesh size of <span><math><mrow><mn>25</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span> and approximately <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math></span> sources. Compared to the original code, <span>pyC</span> <span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> <span>Ray</span> achieves the same results with negligible fractional differences, <span><math><mrow><mo>∼</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>, and a speedup factor of two orders of magnitude. Benchmark analysis shows that <span>ASORA</span> takes a few nanoseconds per source per voxel and scales linearly for an increasing number of sources and voxels within the ray-tracing radii.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100861"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contribution of AI and deep learning in revolutionizing gravitational wave detection","authors":"Krishna Prajapati ,&nbsp;Snehal Jani ,&nbsp;Manisha Singh ,&nbsp;Ranjeet Brajpuriya","doi":"10.1016/j.ascom.2024.100856","DOIUrl":"https://doi.org/10.1016/j.ascom.2024.100856","url":null,"abstract":"<div><p>The fusion of cutting-edge computing techniques with physical detection of gravitational waves can be a potent solution for detecting and cleaning gravitational wave data, which further helps us in the identification of potential astrophysical sources. In this review article, we discuss the role of artificial intelligence approaches in the analysis of gravitational wave data. Below, we list both ground-based interferometers (like LIGO, VIRGO, etc.) and pulse timing arrays (like Parkes pulse timing array) as the current technologies used to find gravitational waves, along with their benefits and how they can be used to find different kinds of gravitational waves. We survey all four types of gravitational waves, each requiring a unique approach to both detection and data processing. We have extensively studied the use of deep learning techniques like convolutional neural networks, autoencoders, and LSTMs in the detection and parameter estimation of gravitational waves from various possible sources, including binary neutron star mergers and neutron star-black hole mergers, in detail. The review article also includes a thorough understanding of the noise and glitches in the real-time data of gravitational waves, as well as how the effective use of machine learning and deep learning techniques can be helpful in simulating waveforms and removing noise to quantify results.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100856"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141594495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of ground-based telescope control systems: A systematic mapping study","authors":"S. Carrasco ,&nbsp;P. Galeas ,&nbsp;A. Cravero","doi":"10.1016/j.ascom.2024.100854","DOIUrl":"https://doi.org/10.1016/j.ascom.2024.100854","url":null,"abstract":"<div><p>Telescope operation is exceptionally complex, generally with respect to specialized control and monitoring systems. World-class astronomical facilities usually choose tailored control solutions to meet their specific needs. However, many of these telescopes share a common control architecture composed of a three-layer architecture: a top level for services and communication between software components, an intermediate level for coordination and execution of tasks in real-time, and a low level where the end hardware devices live. The first generations of telescopes also implemented centralized and customized solutions, which later evolved to highly decentralized components based on industrial standards, middleware, and open protocols. This paper reviews control and monitoring technologies used in modern world-class terrestrial observatories.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100854"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213133724000696/pdfft?md5=a2eb6a5bc16e444858e933a463f56886&pid=1-s2.0-S2213133724000696-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"State Space Modelling for detecting and characterising gravitational waves afterglows","authors":"D. d’Antonio ,&nbsp;M.E. Bell ,&nbsp;J.J. Brown ,&nbsp;C. Grazian","doi":"10.1016/j.ascom.2024.100860","DOIUrl":"10.1016/j.ascom.2024.100860","url":null,"abstract":"<div><p>We propose the usage of an innovative method for selecting transients and variables. These sources are detected at different wavelengths across the electromagnetic spectrum spanning from radio waves to gamma-rays. We focus on radio signals and use State Space Models, which are also referred to as Dynamic Linear Models. State Space Models (and more generally parametric auto-regressive models) have been the mainstay of economic modelling for some years, but rarely they have been used in Astrophysics.</p><p>The statistics currently used to identify radio variables and transients are not sophisticated enough to distinguish different types of variability. These methods simply report the overall modulation and significance of the variability, and the ordering of the data in time is insignificant. State Space Models are much more advanced and can encode not only the amount and significance of the variability but also properties, such as slope, rise or decline for a given time <span><math><mi>t</mi></math></span>.</p><p>In this work, we evaluate the effectiveness of State Space Models for transient and variable detection including classification in time-series astronomy. We also propose a method for detecting a transient source hosted in a variable active galaxy, whereby the time-series of a static host galaxy and the dynamic nature of the transient in the galaxy are intertwined. Furthermore, we examine the hypothetical scenario where the target transient we want to detect is the gravitational wave source GW170817 (or similar).</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100860"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213133724000751/pdfft?md5=293df2efed325a14984b8d05aad55f6f&pid=1-s2.0-S2213133724000751-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light curve classification with DistClassiPy: A new distance-based classifier","authors":"S. Chaini ,&nbsp;A. Mahabal ,&nbsp;A. Kembhavi ,&nbsp;F.B. Bianco","doi":"10.1016/j.ascom.2024.100850","DOIUrl":"https://doi.org/10.1016/j.ascom.2024.100850","url":null,"abstract":"<div><p>The rise of synoptic sky surveys has ushered in an era of big data in time-domain astronomy, making data science and machine learning essential tools for studying celestial objects. While tree-based models (<em>e.g.</em> Random Forests) and deep learning models dominate the field, we explore the use of different distance metrics to aid in the classification of astrophysical objects. We developed <span>DistClassiPy</span>, a new distance metric based classifier. The direct use of distance metrics is unexplored in time-domain astronomy, but distance-based methods can help make classification more interpretable and decrease computational costs. In particular, we applied <span>DistClassiPy</span> to classify light curves of variable stars, comparing the distances between objects of different classes. Using 18 distance metrics on a catalog of 6,000 variable stars across 10 classes, we demonstrate classification and dimensionality reduction. Our classifier meets state-of-the-art performance but has lower computational requirements and improved interpretability. Additionally, <span>DistClassiPy</span> can be tailored to specific objects by identifying the most effective distance metric for that classification. To facilitate broader applications within and beyond astronomy, we have made <span>DistClassiPy</span> open-source and available at <span>https://pypi.org/project/distclassipy/</span><svg><path></path></svg>.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100850"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141540252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two Fluids in f(T) Gravity with Observational Constraints","authors":"D.D. Pawar ,&nbsp;P.S. Gaikwad ,&nbsp;Shah Muhammad ,&nbsp;Euaggelos E. Zotos","doi":"10.1016/j.ascom.2024.100863","DOIUrl":"10.1016/j.ascom.2024.100863","url":null,"abstract":"<div><p>A locally rotationally symmetric Bianchi type-I model has been studied with two fluids within the framework of the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span> theory of gravity. Bianchi type-I is an immediate generalization of the Friedmann–Lemaître–Robertson–Walker (FLRW) metric. We have derived the exact field equations in <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span> gravity by considering the Bianchi type-I metric and applying the action for <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span> theory of gravity. We have utilized the torsion scalar <span><math><mi>T</mi></math></span> and the Lagrangian for matter. The field equations are obtained by taking the variation of the action with respect to the vierbein, leading to a set of equations that includes the energy–momentum tensor for two fluid sources: matter and radiation. We fit the <span><math><mrow><mi>H</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span> curve using 57 data points and the <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-test, achieving an <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> value of 0.9321, indicating a strong fit with the Observational Hubble Dataset (OHD). Cosmological parameters like energy density, pressure, and state finder diagnostics are also discussed.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100863"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motion of test particles and topological interpretation of generic rotating regular black holes coupled to non-linear electrodynamics","authors":"Abdelhay Salah Mohamed ,&nbsp;Euaggelos E. Zotos","doi":"10.1016/j.ascom.2024.100853","DOIUrl":"10.1016/j.ascom.2024.100853","url":null,"abstract":"<div><p>This research is devoted to investigate the dynamics of test particles and the intricate topological nature of generic rotating Regular Black Holes (RBHs). By applying the Hamilton–Jacobi formalism, we have presented the paths of test particles as they move around the RBHs, graphically. The dynamics of angular momentum and energy of particles in both counter-rotation and co-rotation are studied. As these particles move around RBH, we observe the interplay of forces shaping their journey. We observe how the effective force, effective potential, and Lyapunov exponent change over time. The Lyapunov exponent, a measure of chaos in their motion, evolves, hinting at the stability of their orbits. Moreover, we study the topological properties of a generic rotating RBH and determine their topological numbers, which are sums of winding numbers around defects and probe the fabric of spacetime itself. The winding number is an integer that indicates how many times a curve encircling a defect wraps around the origin. We find that the total topological number is equal to 0 which suggest a system in balance. As the value of degree of nonlinear electrodynamics parameter (<span><math><mi>μ</mi></math></span>) increases, the turning points in particle trajectories multiply and presenting the picture of more complexity. In a twist of topology, the interchange of winding numbers can cause a phase transition, reshaping the order parameter space’s topology.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100853"},"PeriodicalIF":1.9,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141395559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The AGILEScience mobile application for the AGILE space mission","authors":"N. Parmiggiani ,&nbsp;A. Bulgarelli ,&nbsp;M. Tavani ,&nbsp;C. Pittori ,&nbsp;L. Baroncelli ,&nbsp;M. Malaspina ,&nbsp;D. Beneventano ,&nbsp;L. Castaldini ,&nbsp;A. Di Piano ,&nbsp;R. Falco ,&nbsp;V. Fioretti ,&nbsp;F. Lucarelli ,&nbsp;G. Panebianco ,&nbsp;F. Verrecchia","doi":"10.1016/j.ascom.2024.100849","DOIUrl":"https://doi.org/10.1016/j.ascom.2024.100849","url":null,"abstract":"<div><p>AGILE is a space mission launched in 2007 to study X-ray and gamma-ray phenomena through data acquired by different payload instruments. The AGILE Team developed an application called AGILEScience that allows to visualize information about the AGILE space mission from mobile devices, such as smartphones and tablets. The AGILEScience application can be downloaded freely for iOS and Android devices.</p><p>Beside sharing information about the AGILE space mission with the public for outreach purposes, similarly to what other applications do, the AGILEScience app offers some new and unique features in gamma-ray astrophysics: (i) it gives public access in nearly real-time to the sky view of a gamma-ray satellite for the first time, (ii) it interacts with the AGILE remote gamma-ray data storage and analysis system, allowing data analysis to be sent and results to be visualized, and (iii) it allows the AGILE Team to access a password-protected section of the app to view detailed AGILE pipeline results and submit advanced analyses. The last two features are critical to allow remote and easy access to the results of the AGILE automated pipelines.</p><p>In particular, the ability to visualize results and execute manual data analysis from mobile devices is key during the follow-up of transient events and to easily monitor the satellite status via smartphone.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100849"},"PeriodicalIF":2.5,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141324364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observational constraints on the wet dark fluid model in the fractal gravity","authors":"D.D. Pawar ,&nbsp;D.K. Raut ,&nbsp;A.P. Nirwal ,&nbsp;Shaily ,&nbsp;J.K. Singh","doi":"10.1016/j.ascom.2024.100848","DOIUrl":"10.1016/j.ascom.2024.100848","url":null,"abstract":"<div><p>A flat Friedmann–Robertson–Walker (FRW) cosmological model with Wet Dark Fluid has been studied based on fractal gravity. The exact solution of the field equations is obtained using linear time-varying deceleration parameter (Akars̈u and Dereli, 2012) and assuming fractal parameter <span><math><mrow><mi>ξ</mi><mo>≠</mo><mn>0</mn></mrow></math></span>. The model parameters involved in the model have been constrained using the Hubble datasets <span><math><mrow><mi>H</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span> of 77 data points, known as cosmic chronometers (CC), recently published Pantheon, and the joint data (CC+Pantheon samples). Additionally, we compare our model with <span><math><mi>Λ</mi></math></span>CDM in standard cosmology via error bar trajectories. We study the physical and the cosmographic parameters, such as the Hubble parameter <span><math><mrow><mi>H</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>, deceleration parameter <span><math><mrow><mi>q</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>, and the higher derivatives of the deceleration parameter <span><math><mrow><mi>q</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>, etc. under cosmic observations. It is observed that our model transits from a decelerating state to an accelerating state at <span><math><mrow><mi>z</mi><mi>t</mi><mi>r</mi><mo>≈</mo><mn>2</mn><mo>.</mo><mn>764</mn></mrow></math></span>. The other astrophysical parameters such as the jerk parameter and snap parameter are also discussed. Finally, we conclude that our model is an accelerating quintessence dark energy model.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100848"},"PeriodicalIF":1.9,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141394730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerating universe with wet dark fluid in modified theory of gravity","authors":"P.R. Agrawal,&nbsp;A.P. Nile","doi":"10.1016/j.ascom.2024.100847","DOIUrl":"10.1016/j.ascom.2024.100847","url":null,"abstract":"<div><p>In the present work we have focused on the investigation of LRS Bianchi type –I metric within the framework of <span><math><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></mrow></math></span> theory of gravity filled with wet dark fluid as the candidate of dark energy. The solution of the metric is an accelerating universe, derived by assuming the negative constant deceleration parameter and utilizing a power law relation. Additionally, we have visually analyzed the metric's dynamical and geometrical properties through graphical representations.</p></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"48 ","pages":"Article 100847"},"PeriodicalIF":2.5,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}