Astronomy and Computing最新文献

{"title":"Semi-analytical computation of commensurate semimajor axes of resonant orbits including second-order gravitational perturbations","authors":"Z.A. Mabrouk,&nbsp;F.A. Abd El-Salam,&nbsp;A. Owis,&nbsp;Wesam Elmahy","doi":"10.1016/j.ascom.2025.100940","DOIUrl":"10.1016/j.ascom.2025.100940","url":null,"abstract":"<div><div>This research work aims to understand how resonant geopotential harmonics affect the semi-major axis of GPS orbits. The study uses a second-order approximation to calculate iteratively the impact of higher zonal perturbations on the semi-major axis. In addition, Kaula's resonant perturbation theory is utilized to compute analytically the main resonant geopotential that can have significant effects on the motion. We derive and plot the drift rate as a function of the longitudinal position, aiming to identify stable and metastable positions at specific longitudes. The study also investigates motion around these points using the Poincare method, demonstrating the existence of periodic, quasi-periodic, and chaotic orbits near these positions.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100940"},"PeriodicalIF":1.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428083","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 using Bayesian Statistics and deep learning in Kaniadakis holographic dark energy","authors":"Kapil ,&nbsp;Lokesh Kumar Sharma ,&nbsp;Anil Kumar Yadav","doi":"10.1016/j.ascom.2025.100939","DOIUrl":"10.1016/j.ascom.2025.100939","url":null,"abstract":"<div><div>In this paper, we present the Kaniadakis holographic dark energy (KHDE) model with hybrid expansion law, which describes the Universe accelerating expansion in the flat Friedmann-Lema<span><math><mover><mrow><mi>i</mi></mrow><mrow><mo>̃</mo></mrow></mover></math></span>tre-Robertson-Walker Universe. The deceleration parameter obtained in the KHDE model depicts the expansion of the universe from decelerating to an accelerating phase. The KHDE model’s equation of state (EoS) parameter reproduces the Cosmos’ rich behaviour, such as the phantom division line spanning the quintessence era (<span><math><mrow><mi>ω</mi><mo>&gt;</mo><mo>−</mo><mn>1</mn></mrow></math></span>). We include the statefinder pair <span><math><mrow><mo>(</mo><mi>r</mi><mo>,</mo><mi>s</mi><mo>)</mo></mrow></math></span>, which emulates the <span><math><mi>Λ</mi></math></span> CDM model in the future. Bayesian Statistics and 57 Hubble data points, 6 baryonic acoustic oscillations <span><math><mrow><mo>(</mo><mi>B</mi><mi>A</mi><mi>O</mi><mo>)</mo></mrow></math></span> data points, and 1048 Pantheon Type Ia supernovae <span><math><mrow><mo>(</mo><mi>S</mi><mi>N</mi><mi>I</mi><mi>a</mi><mo>)</mo></mrow></math></span> data points are used to extract model constraints. Bayesian and <span><math><mrow><mi>A</mi><mi>N</mi><mi>N</mi></mrow></math></span> findings are also compared. CoLFI, an ANN-based parameter estimation approach is employed. CoLFI is more efficient for parameter estimation, especially for intractable likelihood functions or big, resource-intensive cosmological models. Some physical properties of the model are also discussed in detail.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100939"},"PeriodicalIF":1.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388097","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":"Exo-MerCat v2.0.0: Updates and open-source release of the Exoplanet Merged Catalog software","authors":"Eleonora Alei ,&nbsp;Silvia Marinoni ,&nbsp;Andrea Bignamini ,&nbsp;Riccardo Claudi ,&nbsp;Marco Molinaro ,&nbsp;Martina Vicinanza ,&nbsp;Serena Benatti ,&nbsp;Ilaria Carleo ,&nbsp;Avi Mandell ,&nbsp;Franziska Menti ,&nbsp;Angelo Zinzi","doi":"10.1016/j.ascom.2025.100936","DOIUrl":"10.1016/j.ascom.2025.100936","url":null,"abstract":"<div><div>Exoplanet research is at the forefront of contemporary astronomy recommendations. As more and more exoplanets are discovered and vetted, databases and catalogs are built to collect information. Various resources are available to scientists for this purpose, though every one of them has different scopes and notations. In Alei et al. (2020) we described <span>Exo-MerCat</span> a script that collects information from multiple sources and creates a homogenized table. In this manuscript, we announce the release of the <span>Exo-MerCat</span> v2.0.0 script as an upgraded, tested, documented and open-source software to produce catalogs. The main upgrades on the script concern: (1) the addition of the TESS Input Catalog and the K2 Input Catalog as input sources; (2) the optimization of the main identifier queries; (3) a more complex merging of the entries from the input sources into the final catalog; (4) some quality-of-life improvements such as informative flags, more user-friendly column headers, and log files; (5) the refactoring of the code in modules. We compare the performance of <span>Exo-MerCat</span> v2.0.0 with the previous version and notice a substantial improvement in the completeness of the sample, thanks to the addition of new input sources, and its accuracy, because of the optimization of the script.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100936"},"PeriodicalIF":1.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403321","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":"flashcurve: A machine-learning approach for the simple and fast generation of adaptive-binning light curves with Fermi-LAT data","authors":"T. Glauch ,&nbsp;K. Tchiorniy","doi":"10.1016/j.ascom.2025.100937","DOIUrl":"10.1016/j.ascom.2025.100937","url":null,"abstract":"<div><div>Gamma rays measured by the Large Area Telescope (LAT) on board the <em>Fermi Gamma-ray Space Telescope</em> tell us a lot about the processes taking place in high-energetic astrophysical objects. The fluxes coming from these objects are, however, extremely variable. Hence, gamma-ray light curves optimally use adaptive bin sizes in order to retrieve most information about the source dynamics and to combine gamma-ray observations in a multi-messenger perspective. However, standard adaptive binning approaches are slow, expensive and inaccurate in highly populated regions. Here, we present a novel, powerful, deep-learning-based approach to estimate the necessary time windows for adaptive binning light curves in <em>Fermi</em>-LAT data using raw photon data. The approach is shown to be fast and accurate. It can also be seen as a prototype to train machine-learning models for adaptive binning light curves for other astrophysical messengers.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100937"},"PeriodicalIF":1.9,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388300","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":"Exploring the impact of dark energy in Finslerian black hole dynamics and observational features","authors":"J. Praveen,&nbsp;S.K. Narasimhamurthy","doi":"10.1016/j.ascom.2025.100938","DOIUrl":"10.1016/j.ascom.2025.100938","url":null,"abstract":"<div><div>This study explores black hole dynamics within the framework of Finsler geometry, emphasizing the influence of the Finslerian constant <span><math><mi>η</mi></math></span> and the quintessence dark energy parameter <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span>. By extending the conventional black hole metric with Finslerian corrections, we employ the osculating Riemannian approach and Barthel connection to derive a novel black hole metric, termed the Finsler Black Hole metric. The research investigates the effects of these modifications on photon trajectories, gravitational lensing, and shadow formation. The findings indicate that increasing <span><math><mi>η</mi></math></span> enhances gravitational lensing, reduces the black hole shadow size, and produces distinct photon ring patterns. The analysis also reveals that the effective potential <span><math><mrow><mi>V</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow></mrow></math></span> significantly influences photon orbits, with higher <span><math><mi>η</mi></math></span> values pulling the photon sphere closer to the black hole. Furthermore, the study examines static and infalling spherical accretion models, showing that variations in <span><math><mi>η</mi></math></span> and <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> substantially impact the intensity distribution and geometry of black hole shadows. The inclusion of the Finslerian vector field <span><math><mi>β</mi></math></span> adds complexity to the gravitational dynamics. These modifications introduce observable features that distinguish Finslerian black holes from those predicted by General Relativity. Additionally, the incorporation of dark energy through <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> is shown to affect gravitational behavior and observable phenomena such as bending angles and critical impact parameters. This work provides a geometrical framework for understanding the interplay between Finsler geometry, dark energy, and black hole physics.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100938"},"PeriodicalIF":1.9,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377083","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":"cosmosage: A natural-language assistant for cosmology","authors":"Tijmen de Haan","doi":"10.1016/j.ascom.2025.100934","DOIUrl":"10.1016/j.ascom.2025.100934","url":null,"abstract":"<div><div><span>cosmosage</span> is a natural-language assistant intended for a wide audience, from laypersons interested in cosmology to students, teachers, and professional cosmologists. <span>cosmosage</span> provides a novel way to access knowledge and reason about cosmology. Leveraging the power of advanced large language models (LLMs), <span>cosmosage</span> has learned from a vast corpus of open-access source texts, including textbooks and papers. <span>cosmosage</span> is found to be state-of-the-art on the narrow task of answering questions about cosmology, outperforming all general-purpose models. The model parameters and code are publicly available.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100934"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143268283","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":"Dynamics of periodic orbits in the Copenhagen problem with non-spherical primaries","authors":"O.P. Meena ,&nbsp;P. Sachan ,&nbsp;R. Pratap ,&nbsp;P. Meena","doi":"10.1016/j.ascom.2025.100932","DOIUrl":"10.1016/j.ascom.2025.100932","url":null,"abstract":"<div><div>In the present investigation, we conduct an analysis of periodic orbits within the context of the Copenhagen problem, emphasizing the dynamical behavior of a test particle subjected to the gravitational influence of two primary bodies of equal mass, which are in continuous rotation characterized by a constant angular velocity. By expanding upon the classical framework, we treat the primary bodies as non-spherical entities, thereby introducing the phenomenon of oblateness into the dynamical system under consideration. Employing the methodology of Fourier series, we articulate the characteristics of periodic orbits in proximity to the libration points and systematically evaluate the influence of the orbital parameter <span><math><mi>ɛ</mi></math></span> on the spatial dimensions and temporal periods of these orbits. Through the incorporation of terms extending to the third order in Fourier series method, we present a comprehensive representation of the parameter’s influence on the orbital attributes. The findings indicate that with an increase in <span><math><mi>ɛ</mi></math></span>, the dimensions of periodic orbits experience a substantial expansion, while their temporal periods demonstrate non-linear fluctuations. Variational graphs elucidate the correlation between <span><math><mi>ɛ</mi></math></span> and the time period <span><math><mi>T</mi></math></span>, revealing distinct patterns for the various families of orbits under analysis. Moreover, the oblateness exhibited by the primary bodies engenders significant alterations in the geometrical characteristics, size, and time period of the orbits, thereby underscoring their pivotal influence on the dynamics of orbital motion.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100932"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144123","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 influence of spin in black hole triplets","authors":"A. Chitan ,&nbsp;A. Mylläri ,&nbsp;M. Valtonen","doi":"10.1016/j.ascom.2025.100933","DOIUrl":"10.1016/j.ascom.2025.100933","url":null,"abstract":"<div><div>Spin can influence the dynamics of the already chaotic black hole triplet system. We follow this problem in two sets of simulations: first, the Agekian–Anosova region (or region D), and second, using Pythagorean triangles. We use ARCcode, an N-body code that performs numerical integration of orbits. This code includes post-Newtonian corrections, which we include up to the 2.5th order. In set one of our simulations, we fix the masses of the black holes at 10⁶ M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. Then we run the simulations first without any spin added and after by initialising spin on one of the black holes. We find that after including spin into the system, 12.9% of the simulations changed outcomes. Either the systems went from having all black holes merging to having a black hole escaping the system, or vice versa. In the second set of simulations, we expanded into Pythagorean triangles as initial positions of black holes, stemming from Burrau’s three-body problem. We varied the masses of the black holes from 10⁰ M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>–10¹² M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. Black holes in these systems were given spin in normalised units ranging from 0 to <span><math><mo>∼</mo></math></span> 0.95. We find that intermediate mass black holes in the range of 10⁴ M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>–10⁵ M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, were influenced the most by spin, particularly in their lifetimes. We also find that simulations, initialised as 2-dimensional, become 3-dimensional.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100933"},"PeriodicalIF":1.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348555","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":"Emulators for stellar profiles in binary population modeling","authors":"Elizabeth Teng ,&nbsp;Ugur Demir ,&nbsp;Zoheyr Doctor ,&nbsp;Philipp M. Srivastava ,&nbsp;Shamal Lalvani ,&nbsp;Vicky Kalogera ,&nbsp;Aggelos Katsaggelos ,&nbsp;Jeff J. Andrews ,&nbsp;Simone S. Bavera ,&nbsp;Max M. Briel ,&nbsp;Seth Gossage ,&nbsp;Konstantinos Kovlakas ,&nbsp;Matthias U. Kruckow ,&nbsp;Kyle Akira Rocha ,&nbsp;Meng Sun ,&nbsp;Zepei Xing ,&nbsp;Emmanouil Zapartas","doi":"10.1016/j.ascom.2025.100935","DOIUrl":"10.1016/j.ascom.2025.100935","url":null,"abstract":"<div><div>Knowledge about the internal physical structure of stars is crucial to understanding their evolution. The novel binary population synthesis code <span>POSYDON</span> includes a module for interpolating the stellar and binary properties of any system at the end of binary <span>MESA</span> evolution based on a pre-computed set of models. In this work, we present a new emulation method for predicting stellar profiles, <em>i.e</em>., the internal stellar structure along the radial axis, using machine learning techniques. We use principal component analysis for dimensionality reduction and fully-connected feed-forward neural networks for making predictions. We find accuracy to be comparable to that of nearest neighbor approximation, with a strong advantage in terms of memory and storage efficiency. By providing a versatile framework for modeling stellar internal structure, the emulation method presented here will enable faster simulations of higher physical fidelity, offering a foundation for a wide range of large-scale population studies of stellar and binary evolution.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100935"},"PeriodicalIF":1.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348556","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":"Compression method for solar polarization spectra collected from Hinode SOT/SP observations","authors":"J. Batmunkh ,&nbsp;Y. Iida ,&nbsp;T. Oba ,&nbsp;H. Iijima","doi":"10.1016/j.ascom.2025.100929","DOIUrl":"10.1016/j.ascom.2025.100929","url":null,"abstract":"<div><div>The rapidly increasing volume of observational solar spectral data poses challenges for efficient and accurate analysis. To address this issue, we present a deep learning-based compression technique using the deep autoencoder (DAE) and 1D-convolutional autoencoder (CAE) models, developed for use on the Hinode SOT/SP data. This technique focuses on compressing Stokes I and V polarization spectra from sunspots in addition to the quiet Sun, offering a wider and more efficient avenue for spectral analyses.</div><div>Our findings reveal that the CAE model surpasses the DAE model in reconstructing Stokes profiles, exhibiting enhanced robustness and achieving reconstruction errors close to the observational noise level. The proposed technique is demonstrated to be effective in compressing Stokes I and V spectra from both the quiet Sun and sunspots, highlighting its potential for transformative applications in solar spectral analyses, including the identification of unique spectral signatures.</div></div>","PeriodicalId":48757,"journal":{"name":"Astronomy and Computing","volume":"51 ","pages":"Article 100929"},"PeriodicalIF":1.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144122","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}