Astronomy Reports最新文献_第9页

On the Influence of Angular Momentum and Dynamical Friction on Structure Formation: III. The Effect of Dark Energy 角动量和动力摩擦对结构形成的影响：III.暗能量的影响

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700021

Antonino Del Popolo

引用次数: 0

Study of Solar Motion and Galactic Kinematical Characteristics Using Recent Gaia Data 利用最新盖亚数据研究太阳运动和银河运动学特征

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S106377292470001X

N. Ayari, W. H. Elsanhoury

{"title":"Study of Solar Motion and Galactic Kinematical Characteristics Using Recent Gaia Data","authors":"N. Ayari, W. H. Elsanhoury","doi":"10.1134/S106377292470001X","DOIUrl":"10.1134/S106377292470001X","url":null,"abstract":"Our objective is to construct models of the velocity ellipsoid and the retrieved Solar motion for program stars with 4924 points within the Solar neighborhood (∼2 kpc). In which 1374 early types (B5, A0, A5, F0, and F5) and about 3550 late types (G0, G5, K0, and K5) with more recent data source with Gaia DR3. Based on space velocity vectors ((bar {U},bar {V},bar {W};;{text{km }}{{{text{s}}}^{{ - 1}}})), we have determined a velocity ellipsoid parameter for our program stars. We have derived the Solar velocity (({{S}_{ odot }})), which ranged from 13.39 ± 3.66 to 25.06 ± 5.06 km s–1, and other Solar elements (({text{i}}.{text{e}}.,;{{l}_{{text{A}}}},;{{b}_{{text{A}}}},;{{{{alpha }}}_{{text{A}}}},;{{{{delta }}}_{{text{A}}}})), the velocity dispersion (left( sigma right)), ranging from 26.65 ± 5.16 to 57.29 ± 7.57 km s–1 for considered program stars, the projected distances (({{X}_{ odot }},{{Y}_{ odot }},{{Z}_{ odot }};;{text{kpc}})), ratio of (left( {{{sigma }_{2}}{text{/}}{{sigma }_{1}}} right)), ranging from 0.52 to 0.92, which relates to Oort’s constants ((A,B;;{text{km}};{{{text{s}}}^{{ - 1}}}{text{ kp}}{{{text{c}}}^{{ - 1}}}),) and finally the ratio of (({{sigma }_{3}}{text{/}}{{sigma }_{1}})), ranging from 0.41 to 0.61.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1","pages":"80 - 88"},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937736","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

Image of a Black Hole Illuminated by a Parabolic Screen 抛物面屏幕照射下的黑洞图像

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700057

E. V. Mikheeva, S. V. Repin, V. N. Lukash

引用次数: 0

Prompt Cusp Formation and Angular Momentum 顶点形成与角动量

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700033

Antonino Del Popolo, Saeed Fakhry

{"title":"Prompt Cusp Formation and Angular Momentum","authors":"Antonino Del Popolo, Saeed Fakhry","doi":"10.1134/S1063772924700033","DOIUrl":"10.1134/S1063772924700033","url":null,"abstract":"In this study, we expand on White’s model proposed in [1], which explores the post-collapse evolution of density peaks while incorporating the influence of angular momentum. Within a time scale smaller than the peak collapse, denoted as ({{t}_{0}}), the inner regions of the peak reach an equilibrium state, forming a cuspy profile, consistent with White’s findings. However, the power-law density profile is slightly flatter, specifically (rho propto {{r}^{{ - 1.52}}}), due to the incorporation of the specific angular momentum (J) obtained from theoretical models of its evolution in CDM universes, represented as (J propto {{M}^{{2/3}}}). The outcome above demonstrates the impact of angular momentum on the slope of the density profile, allowing us to reproduce a slightly flatter profile similar to the one observed in high-resolution numerical simulations, where (rho propto {{r}^{alpha }}) with (alpha simeq - 1.5). Notably, our model, like the simulations, does not account for adiabatic contraction. Therefore, conducting more comprehensive simulations may yield different values for the slope of the density profile, presenting an opportunity to enhance and refine our model.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1","pages":"19 - 26"},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937744","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

Rotation of the Apsidal Line in the Eclipsing System V1059 Cep 日蚀系统 V1059 Cep 中的天体旋转线

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700148

V. S. Kozyreva, F. B. Khamrakulov, O. A. Burkhonov, A. I. Bogomazov, B. L. Satovskiy

引用次数: 0

Gnevyshev–Ohl Rule: Current Status 格涅维舍夫-奥赫尔规则：现状

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700069

Yu. A. Nagovitsyn, A. A. Osipova, V. G. Ivanov

引用次数: 0

Orbital Period Changes of the Eclipsing Binaries RW Cap, BG Peg, and CU Peg 食双星 RW Cap、BG Peg 和 CU Peg 的轨道周期变化

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700094

A. I. Khaliullina

引用次数: 0

Modeling of the Exoplanet HAT-P-11b Magnetosphere 系外行星 HAT-P-11b 磁层建模

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700045

E. S. Belenkaya, I. I. Alexeev, V. V. Kalegaev

引用次数: 0

MHD Modeling of the Molecular Filament Evolution 分子丝演变的 MHD 模型

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700070

I. M. Sultanov, S. A. Khaibrakhmanov

{"title":"MHD Modeling of the Molecular Filament Evolution","authors":"I. M. Sultanov, S. A. Khaibrakhmanov","doi":"10.1134/S1063772924700070","DOIUrl":"10.1134/S1063772924700070","url":null,"abstract":"We perform numerical magnetohydrodynamic (MHD) simulations of the gravitational collapse and fragmentation of a cylindrical molecular cloud with the help of the FLASH code. The cloud collapses rapidly along its radius without any signs of fragmentation in the simulations without magnetic field. The radial collapse of the cloud is stopped by the magnetic pressure gradient in the simulations with parallel magnetic field. Cores with high density form at the cloud’s ends during further evolution. The core densities are (n approx 1.7 times {{10}^{8}}) and (2 times {{10}^{7}}) cm–3 in the cases with initial magnetic field strengths (B = 1.9 times {{10}^{{ - 4}}}) and (6 times {{10}^{{ - 4}}}) G, respectively. The cores move toward the cloud’s center with supersonic speeds (left| {{{{v}}_{z}}} right| = 3.6) and (5.3) km/s. The sizes of the cores along the filaments radius and filament’s main axis are ({{d}_{r}} = 0.0075) pc and ({{d}_{z}} = 0.025) pc, ({{d}_{r}} = 0.03) pc and ({{d}_{z}} = 0.025) pc, respectively. The masses of the cores increase during the filament evolution and lie in range of ( approx {kern 1pt} (10{-} 20){kern 1pt} {{M}_{ odot }}). According to our results, the cores observed at the edges of molecular filaments can be a result of the filament evolution with parallel magnetic field.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1","pages":"60 - 66"},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937671","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 Brightness of the Sky of the Caucasian Mountain Observatory of MSU in the Near Infrared MSU 高加索山天文台天空的近红外亮度

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700082

A. M. Tatarnikov, S. G. Zheltoukhov, G. E. Nikishev, A. N. Tarasenkov, A. V. Sharonova

{"title":"The Brightness of the Sky of the Caucasian Mountain Observatory of MSU in the Near Infrared","authors":"A. M. Tatarnikov, S. G. Zheltoukhov, G. E. Nikishev, A. N. Tarasenkov, A. V. Sharonova","doi":"10.1134/S1063772924700082","DOIUrl":"10.1134/S1063772924700082","url":null,"abstract":"The results of measurements of background brightness in the near-infrared range (J, H, K bands), carried out in 2016–2023 at the Caucasus Mountain Observatory of Moscow State University was analyzed. It is shown that the instrumental background associated with the thermal radiation of the telescope is noticeable only in the (K) band, and at operating temperatures its contribution mainly determines the level of the overall background in this band. The coefficients of a polynomial taking into account the contribution of instrumental and extra-atmospheric backgrounds are presented. It is shown that the brightness of the sky background does not depend on air temperature, but a weak dependence on the water vapor content is observed, close to that expected from model calculations: in the (J) and (H) bands, the background brightness decreases at a rate of ( approx {kern 1pt} 1% {text{/}}1) mm, and in the (K) band it grows at a rate of ( approx {kern 1pt} 2.5% {text{/}}1) mm. The maximum amplitude of background brightness variability on short time scales (( sim {kern 1pt} 30) min) has been estimated: ( approx {kern 1pt} 10)% in the (J) and (K) bands and ( approx {kern 1pt} 30)% in the (H) band. The maximum contribution of Moon’s radiation scattered in the atmosphere to the overall background level has been determined. It is shown that this contribution can be ignored at an angular distance from the Moon greater than ( sim {kern 1pt} 10^circ ) even during a full moon. The average background surface brightness mag/arcsec2 in the J, H, and (K) bands was calculated: ({{m}_{J}} = 15.7), ({{m}_{H}} = 13.9), and ({{m}_{K}} = 13.1).","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1","pages":"67 - 79"},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937743","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