New Astronomy最新文献

{"title":"Impact of modified gravitational theory on the viability of wormhole structures","authors":"M. Zeeshan Gul,&nbsp;M. Sharif,&nbsp;Iqra Kanwal","doi":"10.1016/j.newast.2024.102204","DOIUrl":"https://doi.org/10.1016/j.newast.2024.102204","url":null,"abstract":"<div><p>This paper explores the existence of viable traversable wormhole solutions in the framework of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span> theory, where <span><math><mi>R</mi></math></span> represents the Ricci scalar and <span><math><mi>G</mi></math></span> denotes the Gauss–Bonnet term. We study the wormhole geometry by focusing on a static spherical spacetime with anisotropic matter configuration. The suitable shape function for the static wormhole structure is developed through the Karmarkar condition. Using this developed shape function, we construct a wormhole geometry that fulfills all the required constraints and connects asymptotically flat regions of the spacetime. Energy bounds are examined for various <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span> models to analyze the existence of traversable wormhole geometry. We investigate the stability of the wormhole solutions using the Tolman–Oppenheimer–Volkoff equation. The rigorous analysis and satisfaction of necessary conditions lead to the conclusion that the viable traversable wormhole solutions exist in this framework, offering a deep understanding of the spacetime and the possible existence of traversable shortcuts in the universe.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102204"},"PeriodicalIF":2.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139737219","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":"Berkeley 76: An intermediate age open star cluster in Gaia Era","authors":"Deepak Bisht ,&nbsp;D. Bisht ,&nbsp;A. Raj ,&nbsp;Geeta Rangwal ,&nbsp;Devesh P. Sariya ,&nbsp;Mehul Manu","doi":"10.1016/j.newast.2024.102205","DOIUrl":"https://doi.org/10.1016/j.newast.2024.102205","url":null,"abstract":"<div><p>We studied the open star cluster Berkeley 76 using Gaia DR3 and 2MASS data sets. We obtained 314 most probable cluster members with a membership probability greater than 80%. We have found the cluster center as <span><math><mi>α</mi></math></span> = 106.67 ± 0.07 deg and <span><math><mrow><mi>δ</mi><mo>=</mo><mo>−</mo><mn>11</mn><mo>.</mo><mn>75</mn><mspace></mspace><mo>±</mo><mspace></mspace></mrow></math></span>0.07 deg. The mean PMs of cluster members in right ascension and declination are <span><math><mrow><mo>−</mo><mn>0</mn><mo>.</mo><mn>60</mn><mspace></mspace><mo>±</mo><mspace></mspace></mrow></math></span>0.22 and 1.35 ± 0.19 mas yr⁻¹, respectively. The radial density profile estimates the cluster’s radius to be 4.5 arcmin. The cluster’s heliocentric distance is estimated as 4.27<span><math><msup><mrow></mrow><mrow><mo>±</mo></mrow></msup></math></span>0.91 kpc, and its age is determined as <span><math><mrow><mn>1</mn><mo>.</mo><mn>60</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><mn>35</mn></mrow></math></span> Gyr. Using the most probable cluster members, we determined the mass function slope for Berkeley 76 as <span><math><mi>1.57 ± 0.19</mi></math></span>. This value is close to Salpeter’s slope within the uncertainty. Berkeley 76 is a dynamically relaxed cluster with a relaxation time of <strong>23.4</strong> Myr.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102205"},"PeriodicalIF":2.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139719349","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":"Role of modified Chaplygin gas in Little Rip phenomena from interaction between dark energy and dark matter","authors":"Rajani Shelote","doi":"10.1016/j.newast.2024.102203","DOIUrl":"https://doi.org/10.1016/j.newast.2024.102203","url":null,"abstract":"<div><p>In this article, an interacting dark energy (DE)- dark matter (DM) scenario has been considered in a flat Friedmann–Lemaitre–Robertson–Walker (FLRW) cosmological model, where DE has a variable equation-of-state that follows the modified Chaplygin-like equation of state (Eq. <span>(1)</span>) characterized by two time dependent parameters <span><math><mrow><mi>Λ</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mi>ω</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span> and DM has a non-zero equation of state <span><math><mrow><msub><mrow><mi>p</mi></mrow><mrow><mi>D</mi><mi>M</mi></mrow></msub><mo>=</mo><mover><mrow><mi>ω</mi></mrow><mrow><mo>̃</mo></mrow></mover><msub><mrow><mi>ρ</mi></mrow><mrow><mi>D</mi><mi>M</mi></mrow></msub></mrow></math></span>. Gravitational equations of motion for dark matter have been solved for two different cases of thermodynamic parameter <span><math><mover><mrow><mi>ω</mi></mrow><mrow><mo>̃</mo></mrow></mover></math></span> as <span><math><mrow><mover><mrow><mi>ω</mi></mrow><mrow><mo>̃</mo></mrow></mover><mo>=</mo><mi>c</mi><mi>o</mi><mi>n</mi><mi>s</mi><mi>t</mi><mi>a</mi><mi>n</mi><mi>t</mi></mrow></math></span> and <span><math><mrow><mover><mrow><mi>ω</mi></mrow><mrow><mo>̃</mo></mrow></mover><mo>≠</mo></mrow></math></span> constant. Also, it has been found that <span><math><mrow><mi>Λ</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>→</mo><mo>−</mo><mi>∞</mi></mrow></math></span> as <span><math><mrow><mi>t</mi><mo>→</mo><mi>∞</mi></mrow></math></span>, it shows that the fate of our universe depends on specific model parameters for the coupled dark energy and dark matter, and experiences Little Rip behavior. Also, it is observed that coupled dark energy and dark matter may inflate and expand the universe after the Big Bang in the far future.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102203"},"PeriodicalIF":2.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139737218","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":"Effect of perturbed potential of heterogeneous triaxial rigid bodies of N layers on the stability of libration points in the R3BP","authors":"Kumari Shalini ,&nbsp;Pankaj Sharma ,&nbsp;Kumari Ranjana","doi":"10.1016/j.newast.2024.102202","DOIUrl":"10.1016/j.newast.2024.102202","url":null,"abstract":"<div><p>In this paper, we investigate the motion of an infinitesimal mass <span><math><msub><mrow><mi>m</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> in the restricted three-body problem by taking both the primaries as heterogeneous triaxial rigid bodies with <em>N</em> layers. The potential of the proposed model and the equations of motion for the infinitesimal mass <span><math><msub><mrow><mi>m</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> are derived. Our findings reveal the existence of five libration points denoted as <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> <span><math><mrow><mo>(</mo><mi>i</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>,</mo><mn>4</mn><mo>,</mo><mn>5</mn><mo>)</mo></mrow></math></span> in the proposed model, with three being collinear and two being non-collinear. We observed that the collinear libration points <span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>i</mi></mrow></msub><mrow><mo>(</mo><mi>i</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>)</mo></mrow></mrow></math></span> are unstable, whereas the non-collinear libration points <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>4</mn><mo>,</mo><mn>5</mn></mrow></msub></math></span> are conditionally stable for the mass parameter <span><math><mrow><mi>μ</mi><mo>∈</mo><mrow><mo>(</mo><mn>0</mn><mo>,</mo><msub><mrow><mi>μ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span>, where <span><math><mrow><msub><mrow><mi>μ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>25681</mn><mspace></mspace><msub><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>−</mo><mn>1</mn><mo>.</mo><mn>31619</mn><mspace></mspace><msub><mrow><mi>k</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>−</mo><mn>2</mn><mo>.</mo><mn>24318</mn><mspace></mspace><msub><mrow><mi>k</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>−</mo><mn>6</mn><mo>.</mo><mn>10258</mn><mspace></mspace><msub><mrow><mi>k</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102202"},"PeriodicalIF":2.0,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139679418","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":"Structure of compact stars: A pure geometric approach","authors":"M.I. Wanas ,&nbsp;Samah A. Ammar ,&nbsp;Mona M. Foda","doi":"10.1016/j.newast.2024.102201","DOIUrl":"10.1016/j.newast.2024.102201","url":null,"abstract":"<div><p>This paper uses pure geometric field theory to construct a stellar model for a static spherically symmetric anisotropic compact star. The expression pure geometry means that all physical quantities and fields are defined in terms of the geometric objects of the geometry used. This implies the possibility of defining the material-energy tensor geometrically, not phenomenologically, from the geometry under consideration, absolute parallelism (AP-) geometry. Two solutions are obtained for the field equations of the theory, an interior solution and an exterior solution. The stellar model is obtained as an analytical solution of the field equations within the material distribution. An equation of state for anisotropic material distribution is derived from the model rather than being imposed on it. The vacuum solution of the field equations coincides with the Schwarzschild exterior solution. Matching the interior and exterior solutions at the boundary of the stellar configuration enables fixing the integration constants. The physical acceptability and stability analysis of the model are discussed, and the results show that the present model is suitable for studying the envelope region of a neutron star in a core-envelope type model. The model is investigated graphically using the estimated data of the pulsar 4U1820-30 with mass <span><math><mrow><mn>1</mn><mo>.</mo><mn>58</mn><mspace></mspace><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span> and radius 9.1 km. In conclusion, this study demonstrates the feasibility of constructing a pure geometric stellar model and highlights the benefits of using such an approach to understand stellar structure.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102201"},"PeriodicalIF":2.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666616","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":"Particle dynamics and thermodynamical analysis of the rotating ModMax black holes","authors":"Khurshid Karshiboev ,&nbsp;Farruh Atamurotov ,&nbsp;Ali Övgün ,&nbsp;Ahmadjon Abdujabbarov ,&nbsp;Eldor Karimbaev","doi":"10.1016/j.newast.2024.102200","DOIUrl":"10.1016/j.newast.2024.102200","url":null,"abstract":"<div><p><span>In this research paper, we investigate the structure of the horizon and ergosphere of a rotating ModMax black hole. The motion of test particles is analyzed by studying the characteristics of the innermost stable circular orbit (ISCO) and the behavior of the effective potential. Different values of the screening factor </span><span><math><mi>γ</mi></math></span> and the <span><math><mi>Q</mi></math></span><span> charge of the rotating ModMax black hole are explored in this study. Moreover, we also examine several thermodynamic quantities such as Enthalpy, Hawking temperature, Gibbs free energy, and entropy of the black hole. Additionally, the center-of-mass-energy (CM) generated by the collision of two particles (both in extremal and non-extremal cases) is briefly investigated for specific parameter values associated with this black hole.</span></p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102200"},"PeriodicalIF":2.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666836","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":"Gaia (DR3)-based astronomical analysis of the seven unstudied open star clusters","authors":"W.A. Badawy ,&nbsp;A.L. Tadross ,&nbsp;Y.H.M. Hendy ,&nbsp;M.N. Ismail ,&nbsp;A. Mouner","doi":"10.1016/j.newast.2024.102196","DOIUrl":"10.1016/j.newast.2024.102196","url":null,"abstract":"<div><p>The seven open star clusters FSR 0717, FSR 1698, Loden 2313, Ruprecht 49, Majaess 61, Mayer 2, and Teutsch 48, which are located near the Milky Way’s Galactic plane are studied in this article using the Gaia DR3 dataset. The estimated numbers of potential cluster members are 102, 362, 285, 197, 95, 116, 160, and 397, correspondingly. The calculated radius values are 3.10<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.20, 3.20<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.30, 5.10<!--> <span><math><mo>±</mo></math></span> <!--> <!--> <!-->0.10, 5.30<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.20, 4.50<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.40, 3.50<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.20, and 5.20<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.20 arcmin, respectively. The clusters’ log ages of 8.80<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.15, 7.80<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.05, 6.95<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.05, 8.00<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.10, 8.70<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.05, 7.95<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.10, and 8.95<!--> <span><math><mo>±</mo></math></span> <!--> <!-->0.05 yr are determined using solar metallicity isochrones. The distances of 3176.76<!--> <span><math><mo>±</mo></math></span> <!--> <!-->17.30, 2122.76<!--> <span><math><mo>±</mo></math></span> <!--> <!-->14.35, 1157.07<!--> <span><math><mo>±</mo></math></span> <!--> <!-->15.20, 3924.10<!--> <span><math><mo>±</mo></math></span> <!--> <!-->20.10, 2513.21<!--> <span><math><mo>±</mo></math></span> <!--> <!-->9.04, 3364.34<!--> <span><math><mo>±</mo></math></span> <!--> <!-->8.01, and 3505.36<!--> <span><math><mo>±</mo></math></span> <!--> <!-->7.93 pc that were obtained by the isochrone’s best fitting are comparable to the distances determined by inverting median parallaxes. The slopes of the mass function are matched the Salpeter mean value. Total masses are determined to be 128.55<!--> <span><math><mo>±</mo></math></span> <!--> <!-->11, 548.30<!--> <span><math><mo>±</mo></math></span> <!--> <!-->8, 254.57<!--> <span><math><mo>±</mo></math></span> <!--> <!-->7, 194.09<!--> <span><math><mo>±</mo></math></span> <!--> <!-->6, 92.32<!--> <span><math><mo>±</mo></math></span> <!--> <!-->15, 191.50<!--> <span><math><mo>±</mo></math></span> <!--> <!-->12, and 455.62<!--> <span><math><mo>±</mo></math></span> <!--> <!-->10 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, respectively.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102196"},"PeriodicalIF":2.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666463","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":"Decoupled charged anisotropic spherical solutions in Rastall gravity","authors":"M. Sharif ,&nbsp;M. Sallah","doi":"10.1016/j.newast.2024.102198","DOIUrl":"10.1016/j.newast.2024.102198","url":null,"abstract":"<div><p>This paper uses the gravitational decoupling through the minimal geometric deformation approach and extends a known isotropic solution for a self-gravitating interior to two types of anisotropic spherical solutions in Rastall gravity in the presence of electromagnetic field<span>. By deforming only the radial metric component, the field equations are decoupled into two sets, the first of which corresponds to an isotropic distribution of matter while the second set contains the anisotropic source. We obtain a solution of the first set by employing the charged isotropic Finch-Skea ansatz, whereas a solution for the second set is obtained by adopting two mimic constraints on the pressure and density. The matching conditions at the stellar surface<span> are explored with the exterior geometry given by the deformed Reissner–Nordström spacetime. For the two fixed values of the Rastall and charge parameters, we investigate physical features of both solutions through graphical analysis of the energy conditions, equation of state parameters, surface redshift and compactness function. The stability of both solutions is also studied through the Herrera cracking approach and causality condition. We deduce that while both solutions are physically viable, only the solution corresponding to the pressure-like constraint is stable.</span></span></p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102198"},"PeriodicalIF":2.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666613","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":"Detection of possible glycine precursor molecule methylamine towards the hot molecular core G358.93–0.03 MM1","authors":"Arijit Manna,&nbsp;Sabyasachi Pal","doi":"10.1016/j.newast.2024.102199","DOIUrl":"10.1016/j.newast.2024.102199","url":null,"abstract":"<div><p>The search for the simplest amino acid, glycine (<span><math><mrow><mtext>NH2CH2COOH</mtext></mrow></math></span><span><span>), in the interstellar medium (ISM) has become a never-ending story for </span>astrochemistry and astrophysics researchers because that molecule plays a possible connection between the Universe and the origin of life. In the last forty years, all searches for </span><span><math><mrow><mtext>NH2CH2COOH</mtext></mrow></math></span> in the ISM at millimeter and submillimeter wavelengths have failed. Since the detection of <span><math><mrow><mtext>NH2CH2COOH</mtext></mrow></math></span> in the ISM is extremely difficult, we aime to search for the possible precursors of <span><math><mrow><mtext>NH2CH2COOH</mtext></mrow></math></span>. Earlier, many laboratory experiments have suggested that methylamine (<span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span>) plays an important role in the ISM as a possible precursor of <span><math><mrow><mtext>NH2CH2COOH</mtext></mrow></math></span><span>. After spectral analysis using the local thermodynamic equilibrium (LTE) model, we identified the rotational emission lines of </span><span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> towards the hot molecular core G358.93–0.03 MM1 using the Atacama Large Millimeter/Submillimeter Array (ALMA). The column density of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> towards the G358.93–0.03 MM1 is estimated to be (1.10 ± 0.31)<span><math><mo>×</mo></math></span>10¹⁷ cm⁻² with an excitation temperature of 180.8 ± 25.5 K. The fractional abundance of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> with respect to <span><math><mrow><mtext>H2</mtext></mrow></math></span> towards the G358.93–0.03 MM1 is (8.80 ± 2.60)<span><math><mo>×</mo></math></span>10⁻⁸. The column density ratio of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> and <span><math><mrow><mtext>NH2CN</mtext></mrow></math></span> towards G358.93–0.03 MM1 is (1.86 ± 0.95)<span><math><mo>×</mo></math></span>10². The estimated fractional abundance of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> towards the G358.93–0.03 MM1 agrees fairly well with the previous three-phase warm-up chemical modelling abundance of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span>. We also discuss the possible formation mechanism of <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span>, and we find that <span><math><mrow><mtext>CH3NH2</mtext></mrow></math></span> is most probably formed via the reactions of radical <span><math><mrow><mtext>CH3</mtext></mrow></math></span> and radical <span><math><mrow><mtext>NH2</mtext></mrow></math></span> on the grain surface of G358.93–0.03 MM1.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102199"},"PeriodicalIF":2.0,"publicationDate":"2024-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587992","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":"Numerical solution of the coupled Lane–Emden–Fowler type equation using the variational iteration method and the Adomian polynomial","authors":"Vikash Kumar Sinha,&nbsp;Prashanth Maroju","doi":"10.1016/j.newast.2024.102195","DOIUrl":"10.1016/j.newast.2024.102195","url":null,"abstract":"<div><p>In this article, we introduce an efficient numerical approach for finding the numerical solution for coupled Lane–Emden–Fower type equations using the variational iteration method combined with the Adomian polynomial. The convergence analysis of the proposed approach is investigated under very general conditions. A couple of numerical examples are included and contrasted with the existing methods (Singh et al., 2021;Sinha et al., 2023;Duan et al., 2015) and the exact solution to check the robustness and effectiveness of the proposed approach. The present method shows faster convergence, computational efficiency, time efficiency and simplicity of implementation.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"109 ","pages":"Article 102195"},"PeriodicalIF":2.0,"publicationDate":"2024-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587958","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}