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Mini-outburst of black hole X-ray binary GX 339-4 in 2004 2004年黑洞X射线双星GX 339-4的小型爆发
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-02-01 DOI: 10.1002/asna.20230185
Xue-Kun Zhang, Wei-Long He, Wei-Jia Yang, Ai-Jun Dong
{"title":"Mini-outburst of black hole X-ray binary GX 339-4 in 2004","authors":"Xue-Kun Zhang, Wei-Long He, Wei-Jia Yang, Ai-Jun Dong","doi":"10.1002/asna.20230185","DOIUrl":"10.1002/asna.20230185","url":null,"abstract":"<p>The mini-outburst of black hole X-ray binaries (BHXBs) is a re-bright event of light curve, which is often detected in BHXBs with the low orbital period, such as XTE J1650-500 (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>P</mi>\u0000 <mi>orb</mi>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>7.69</mn>\u0000 <mo>±</mo>\u0000 <mn>0.02</mn>\u0000 <mspace></mspace>\u0000 <mi>hr</mi>\u0000 </mrow>\u0000 <annotation>$$ {P}_{mathrm{orb}}approx 7.69pm 0.02kern0.22em mathrm{hr} $$</annotation>\u0000 </semantics></math>), GRO J0422+32 (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>P</mi>\u0000 <mi>orb</mi>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>5.091850</mn>\u0000 <mo>±</mo>\u0000 <mn>0.000005</mn>\u0000 <mspace></mspace>\u0000 <mi>hr</mi>\u0000 </mrow>\u0000 <annotation>$$ {P}_{mathrm{orb}}approx 5.091850pm 0.000005kern0.22em mathrm{hr} $$</annotation>\u0000 </semantics></math>) and Swift J1753.5-0127 (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>P</mi>\u0000 <mi>orb</mi>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>3.244</mn>\u0000 <mo>±</mo>\u0000 <mn>0.001</mn>\u0000 <mspace></mspace>\u0000 <mi>hr</mi>\u0000 </mrow>\u0000 <annotation>$$ {P}_{mathrm{orb}}approx 3.244pm 0.001kern0.22em mathrm{hr} $$</annotation>\u0000 </semantics></math>). Because of its low X-ray luminosity, the physics properties of mini-outburst is still unclear. GX 339-4 is a famous BHXBs with the orbital period <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>P</mi>\u0000 <mi>orb</mi>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>16.9</mn>\u0000 <mspace></mspace>\u0000 <mi>hr</mi>\u0000 </mrow>\u0000 <annotation>$$ {P}_{mathrm{orb}}=16.9kern0.22em mathrm{hr} $$</annotation>\u0000 </semantics></math> and present many normal outburst and failed outburst over the past decades. However, the mini-outburst is not still detected in GX 339-4. In this work, using the Rossi X-ray Timing Explorer (RXTE) observations, we investigated the energy spectrum properties of the GX 339-4 outburst in 2004 and confirmed that the outburst in 2004 is a mini-outburst. It is very interest that the mini-outburst has been through a whole state transition from Low/Hard state to High/Soft state. We also give a comparison between the normal outburst in 2002 and the mini-outburst in 2004. ","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139679630","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}
引用次数: 0
Studies of bright flat-spectrum radio quasar 3C 454.3 at high and very-high-energies 在高能和甚高能下对明亮平谱射电类星体 3C 454.3 的研究
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-02-01 DOI: 10.1002/asna.20240007
Vera G. Sinitsyna, Vera Y. Sinitsyna, Sergey Borisov
{"title":"Studies of bright flat-spectrum radio quasar 3C 454.3 at high and very-high-energies","authors":"Vera G. Sinitsyna,&nbsp;Vera Y. Sinitsyna,&nbsp;Sergey Borisov","doi":"10.1002/asna.20240007","DOIUrl":"10.1002/asna.20240007","url":null,"abstract":"<p>Blazars are the subclass of active galactic nuclei (AGNs) which includes the Flat Spectrum Radio Quasars (FSRQ) and BL Lacertae (BL Lac) objects. Variability on the short- and long-time scale in all the wide energy ranges from radio up to gamma-ray emission is a special characteristic of blazars. Multi-wavelength studies of the flaring activity and variability of blazars can serve as a tool to probe the physical properties of the near the core regions and processes responsible for the observed features. 3C 454.3 is a bright FSRQ that is intensively studied through the wide range of electromagnetic spectrum. It has shown remarkably high activity since 2000. The long-term observations of 3C 454.3 at 800 GeV–100 TeV energies with the SHALON telescope were started in 1998 year. A number of activity periods were found. The most significant flaring state of 3C 454.3 at TeV energies was detected in the SHALON observational period of November–December 2010. This increase is correlated with the flares at a lower energy range in observations of Fermi-LAT. The direct association of the significant changes of gamma-ray flux with strong core radio flares are not clear but observed correlations and lags in multi-wavelength activity may point to the complexity of the emission processes in blazars connected with disturbance propagating in the jet.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139686785","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}
引用次数: 0
The Ushnus in the astronomy of the Inca culture 印加文化天文学中的乌斯努斯女神
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-02-01 DOI: 10.1002/asna.20230181
Milton Rojas Gamarra, Mônica Baptista Pereira Estrázulas, Steven R. Gullberg, César A. Zen Vasconcellos
{"title":"The Ushnus in the astronomy of the Inca culture","authors":"Milton Rojas Gamarra,&nbsp;Mônica Baptista Pereira Estrázulas,&nbsp;Steven R. Gullberg,&nbsp;César A. Zen Vasconcellos","doi":"10.1002/asna.20230181","DOIUrl":"10.1002/asna.20230181","url":null,"abstract":"<p>Inferences are made about the relationship that existed between the <i>Ushnus</i>, pyramid-shaped, terraced structures used by the Incas in the most important ceremonies of the <i>Tawantinsuyo</i>, and Inka Astronomy. We draw attention to <i>Ayni</i>, <i>Kawsaypacha</i>, <i>Duality</i>, and <i>Tinkuy</i> principles, multidimensional codes of conduct and wisdom that are at the root of the Andean cosmovision and on their perception of the world and the Cosmos. These principles, examined as postulates, allow to elaborate axiomatic propositions to identify the <i>Ushnus</i> with ancient Astronomy practices. In a complementary statement, starting from a bi-conditional proposition, we may infer through reciprocal corollaries that the Inka earliest roots to a holistic learning and educational ambient in the <i>Tawantinsuyo</i> was not elitist, instead it was based on a epistemological construct that differs from the corresponding Western educational ambients. An epistemological and cognitive approach allows to identify an ancient elaborate process of knowledge construction, based on the four fundamental principles, corresponding to different levels of assimilation and comprehension. As a complementary aspect, we identify some of the most preserved <i>Ushnus</i> of the Inka “Empire.” Then we complement this contribution with a broader interpretation for the <i>Ushnus</i>.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139883987","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}
引用次数: 0
The deep eclipses of RW Aur revisited by long-term photometric and spectroscopic monitoring 通过长期光度和光谱监测重新审视 RW Aur 的深食
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-31 DOI: 10.1002/asna.20230118
Oliver Lux, Markus Mugrauer, Richard Bischoff
{"title":"The deep eclipses of RW Aur revisited by long-term photometric and spectroscopic monitoring","authors":"Oliver Lux,&nbsp;Markus Mugrauer,&nbsp;Richard Bischoff","doi":"10.1002/asna.20230118","DOIUrl":"https://doi.org/10.1002/asna.20230118","url":null,"abstract":"<p>RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow-up observations. We performed multiband (BVRI) photometry of the system with the <i>Cassegrain-Teleskop-Kamera II</i> and the <i>Schmidt-Teleskop-Kamera</i> between September 2016 and April 2019, as well as spectroscopy, using the <i>Fibre Linked ÉCHelle Astronomical Spectrograph</i> between September 2016 and April 2018. We present the apparent photometry of RW Aur, which is consistent with and complementary to photometric data from the <i>American Association of Variable Star Observers</i>. The V-band magnitude of RW Aur changed by up to three magnitudes during the timespan of our monitoring campaign. For the observing epochs 2016/2017 and 2017/2018 we report a decreasing brightness, while in the epoch 2018/2019 the system remained in a relatively constant bright state. In the color-magnitude diagram, we see that RW Aur lies close to a track for grey extinction. The spectra show a decreasing equivalent width (EW) of the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>H</mi>\u0000 <mi>α</mi>\u0000 </mrow>\u0000 <annotation>$$ mathrm{H}alpha $$</annotation>\u0000 </semantics></math> emission line for decreasing brightness, whereas the EW of the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mo>[</mo>\u0000 <mrow>\u0000 <mi>O</mi>\u0000 <mi>I</mi>\u0000 </mrow>\u0000 <mo>]</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$$ left[mathrm{O}Iright] $$</annotation>\u0000 </semantics></math> line increases, indicating an increased outflow activity during the obscuration. Both give further evidence for the favored theory that the obscurations are caused by a hot dusty wind emerging from the inner disk.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 4","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20230118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140844984","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}
引用次数: 0
Measurements of visual double stars with PISCO2 at the Nice 76-cm refractor in 2016–2017 2016-2017 年利用 PISCO2 在尼斯 76 厘米折射镜测量目视双星
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-30 DOI: 10.1002/asna.20230140
Jean-Louis Prieur, René Gili, Jean-Pierre Rivet, Farrokh Vakili, Marco Scardia, Luigi Pansecchi, Robert W. Argyle, Josefina F. Ling, Luca Piccotti, Eric Aristidi, Laurent Koechlin, Daniel Bonneau, Luca Maccarini, Jocelyn Serot
{"title":"Measurements of visual double stars with PISCO2 at the Nice 76-cm refractor in 2016–2017","authors":"Jean-Louis Prieur,&nbsp;René Gili,&nbsp;Jean-Pierre Rivet,&nbsp;Farrokh Vakili,&nbsp;Marco Scardia,&nbsp;Luigi Pansecchi,&nbsp;Robert W. Argyle,&nbsp;Josefina F. Ling,&nbsp;Luca Piccotti,&nbsp;Eric Aristidi,&nbsp;Laurent Koechlin,&nbsp;Daniel Bonneau,&nbsp;Luca Maccarini,&nbsp;Jocelyn Serot","doi":"10.1002/asna.20230140","DOIUrl":"10.1002/asna.20230140","url":null,"abstract":"<p>We present relative astrometric and photometric measurements of visual double stars made in 2016–2017, with PISCO2 installed at the 76-cm refractor of Côte d'Azur Observatory in Nice (France). Our observing list contains orbital couples as well as double stars whose motion is still uncertain. Three different techniques were used for obtaining measurements: Lucky Imaging, Speckle Interferometry and the direct vector autocorrelation (DVA) method. From our observations of 1,510 multiple stars, we obtained 2,918 new measurements with angular separations in the range 0″.1–20″ and an average accuracy of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>0.019</mn>\u0000 </mrow>\u0000 <annotation>$$ 0.019 $$</annotation>\u0000 </semantics></math>. The mean error on the position angles is 1°.1. Most of the position angles were determined without the usual 180° ambiguity with the application of the DVA technique and/or by inspection of the Lucky images or the long integration files. We managed to routinely monitor faint systems (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>m</mi>\u0000 <mi>V</mi>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>9</mn>\u0000 <mo>−</mo>\u0000 <mn>12</mn>\u0000 </mrow>\u0000 <annotation>$$ {m}_Vapprox 9-12 $$</annotation>\u0000 </semantics></math>) with large magnitude differences (up to <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <msub>\u0000 <mi>m</mi>\u0000 <mi>V</mi>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>4.5</mn>\u0000 </mrow>\u0000 <annotation>$$ Delta {m}_Vapprox 4.5 $$</annotation>\u0000 </semantics></math>). We have thus been able to measure six systems containing red dwarf stars that had been poorly monitored since their discovery, from which we estimated the stellar masses thanks to Gaia measurements. We also measured the magnitude difference of the two components of 593 double stars with a mean error of 0.1 mag. Thanks to good seeing images and with the use of high-contrast numerical filters, we have also been able to obtain 46 measurements with an angular separation smaller than the diffraction limit of our instrumentation. Except for a few objects that have been discussed, our measurements are in good agreement with the ephemerides computed with published orbital elements, even for the double stars whose separation is smaller than the diffraction limit. We also report the measurements of 205 new double stars that we found in the files obtained during the observations.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 4","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139647333","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}
引用次数: 0
On CCGG, the De Donder-Weyl Hamiltonian formulation of canonical gauge gravity 关于 CCGG,典型规规引力的 De Donder-Weyl Hamiltonian 公式
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-25 DOI: 10.1002/asna.20230154
David Vasak, Johannes Kirsch, Armin van de Venn, Vladimir Denk, Jürgen Struckmeier
{"title":"On CCGG, the De Donder-Weyl Hamiltonian formulation of canonical gauge gravity","authors":"David Vasak,&nbsp;Johannes Kirsch,&nbsp;Armin van de Venn,&nbsp;Vladimir Denk,&nbsp;Jürgen Struckmeier","doi":"10.1002/asna.20230154","DOIUrl":"10.1002/asna.20230154","url":null,"abstract":"<p>This short paper gives a brief overview of the manifestly covariant canonical gauge gravity (CCGG) that is rooted in the De Donder-Weyl Hamiltonian formulation of relativistic field theories, and the proven methodology of the canonical transformation theory. That framework derives, from a few basic physical and mathematical assumptions, equations describing generic matter and gravity dynamics with the spin connection emerging as a Yang Mills-type gauge field. While the interaction of any matter field with spacetime is fixed just by the transformation property of that field, a concrete gravity ansatz is introduced by the choice of the free (kinetic) gravity Hamiltonian. The key elements of this approach are discussed and its implications for particle dynamics and cosmology are presented. New insights: Anomalous Pauli coupling of spinors to curvature and torsion of spacetime, spacetime with (A)dS ground state, inertia, torsion and geometrical vacuum energy, Zero-energy balance of the Universe leading to a vanishing cosmological constant and torsional dark energy.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20230154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139264231","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}
引用次数: 0
The magnetar crustal magneto-thermal evolution 磁星地壳磁热演化
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-25 DOI: 10.1002/asna.20240011
Hui Wang, Zhi Bing Li, Xiao Feng Yang, Dong Ling Song
{"title":"The magnetar crustal magneto-thermal evolution","authors":"Hui Wang,&nbsp;Zhi Bing Li,&nbsp;Xiao Feng Yang,&nbsp;Dong Ling Song","doi":"10.1002/asna.20240011","DOIUrl":"10.1002/asna.20240011","url":null,"abstract":"<p>Magnetars are a type of pulsars powered by magnetic field energy. Part of the X-ray luminosities of magnetars in quiescence have a thermal origin and can be fitted by a blackbody spectrum with the surface temperature, much higher than the typical values for rotation-powered pulsars. The persistent thermal emissions and bursts of magnetars indicate the presence of some internal heat sources in their outer crusts. In this work, we have formulated the energy balance equation and applied it to investigate the thermal evolution in the magnetar crust, taking into account the heating mechanisms of Ohmic decay and electron capture processes. This model can explain the changes in the X-ray luminosity of the magnetars.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139585143","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}
引用次数: 0
Non-symmetrical sparking may hint “zits” on a pulsar surface 非对称火花可能暗示脉冲星表面有 "青春痘"
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-24 DOI: 10.1002/asna.20240010
Zhengli Wang, Jiguang Lu, Jingchen Jiang, Shunshun Cao, Weiyang Wang, Enwei Liang, Renxin Xu
{"title":"Non-symmetrical sparking may hint “zits” on a pulsar surface","authors":"Zhengli Wang,&nbsp;Jiguang Lu,&nbsp;Jingchen Jiang,&nbsp;Shunshun Cao,&nbsp;Weiyang Wang,&nbsp;Enwei Liang,&nbsp;Renxin Xu","doi":"10.1002/asna.20240010","DOIUrl":"10.1002/asna.20240010","url":null,"abstract":"<p>Pulsar electrodynamics could be relevant to the physics of stellar surface, which remains poorly understood for more than half a centenary and is difficult to probe due to the absence of direct and clear observational evidence. Nevertheless, highly sensitive telescopes (e.g., China's Five-hundred-meter Aperture Spherical radio Telescope, FAST) may play an essential role to solve the problem since the predicted surface condition would have quite different characteristics in some models of pulsar structure, especially after the establishment of the standard model of particle physics. For instance, small hills (or “zits”) may exist on solid strangeon star surface with rigidity, preferential discharge, that is, gap sparking, may occur around the hills in the polar cap region. In this work, with the 110-min polarization observation of PSR B0950<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>+</mo>\u0000 </mrow>\u0000 <annotation>$$ + $$</annotation>\u0000 </semantics></math>08 targeted by FAST, we report that the gap sparking is significantly non-symmetrical to the meridian plane on which the rotational and magnetic axes lie. It is then speculated that this asymmetry could be the result of preferential sparking around zits which might rise randomly on pulsar surface. Some polarization features of both single pulses and the mean pulse, as well as the cross-correlation function of different emission regions, have also been presented.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554804","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}
引用次数: 0
Singularity attenuation with quantum-mechanically revisited metric tensor 量子力学重访度量张量的奇点衰减
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-24 DOI: 10.1002/asna.20240003
Abdel Nasser Tawfik, Tahia F. Dabash, Azzah Elshehri
{"title":"Singularity attenuation with quantum-mechanically revisited metric tensor","authors":"Abdel Nasser Tawfik,&nbsp;Tahia F. Dabash,&nbsp;Azzah Elshehri","doi":"10.1002/asna.20240003","DOIUrl":"10.1002/asna.20240003","url":null,"abstract":"<p>The space and initial singularities are reexamined in the most reliable solutions to the Einstein's field equations (EFE), that is, the Einstein–Gilbert–Straus (EGS) metric. In discretized Finsler geometry, additional curvatures and thereby geometric structures likely emerge, which are distinct from the conventional spacetime curvatures and geometric structures that the Einstein's theory of general relativity introduced. The generalized fundamental tensor, which is obtained in the Fisleriean geometry, imposes quantum-mechanically revisions on the Landau–Raychaudhuri evolution equations. The time-like geodesic congruence in EGS metric is then analyzed, analytically and numerically. The evolution of a family of trajectories whose congruence is defined by the flow lines generated by velocity fields is determined. We conclude that both two types of singularities seem to be attenuated or even regulate. With the singularity attenuation, we refer to the fundamental nature of the additional curvatures at quantum relativistic scales.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 2-3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554744","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}
引用次数: 0
Bright spectroscopic binaries: III. Binary systems with orbital periods of P > 500 days 明亮的分光双星III.轨道周期 P > 500 天的双星系统
IF 0.9 4区 物理与天体物理
Astronomische Nachrichten Pub Date : 2024-01-22 DOI: 10.1002/asna.20230123
Dennis Jack, Missael Alejandro Hernández Huerta, Faiber Danilo Rosas-Portilla, Klaus-Peter Schröder
{"title":"Bright spectroscopic binaries: III. Binary systems with orbital periods of P > 500 days","authors":"Dennis Jack,&nbsp;Missael Alejandro Hernández Huerta,&nbsp;Faiber Danilo Rosas-Portilla,&nbsp;Klaus-Peter Schröder","doi":"10.1002/asna.20230123","DOIUrl":"10.1002/asna.20230123","url":null,"abstract":"<p>We present an analysis of nine bright spectroscopic binaries (HD 1585, HD 6613, HD 12390, HD 39923, HD 55201, HD 147430, HD 195543, HD 202699, HD 221643), which have orbital periods of <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 <mo>&gt;</mo>\u0000 <mn>500</mn>\u0000 </mrow>\u0000 <annotation>$$ P&gt;500 $$</annotation>\u0000 </semantics></math> days. These well-separated binaries are the last stars of our sample that we observed with the TIGRE telescope obtaining intermediate-resolution spectra of <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 <mo>≈</mo>\u0000 <mn>20,000</mn>\u0000 </mrow>\u0000 <annotation>$$ Rapprox mathrm{20,000} $$</annotation>\u0000 </semantics></math>. We applied the same method as described in our previous publication of this series. For the analysis of the radial velocity curves, we used the toolkit RadVel, which allowed us to determine all orbital parameters. Recently published orbital solutions of some systems from Gaia DR3 agree with our results. However, our solutions have much smaller uncertainties. We determined the basic stellar parameters of the primary stars with our automatic script using iSpec. The parameter determination allowed us to place all nine stars in the Hertzsprung–Russell diagram. We found that all stars have already evolved to the giant phase. A comparison with stellar evolution tracks of the Eggleton code was applied to determine the stellar masses and ages. As a result of our analysis, we were able to estimate the masses of the secondary stars and the orbital inclinations of the binary systems.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554359","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}
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