Communications of the Byurakan Astrophysical Observatory最新文献_第8页

Optical properties of variable radio sources from NVSS and FIRST 来自NVSS和FIRST的可变射电源光学特性

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-340

H. Abrahamyan, A. Mickaelian, G. Paronyan, G. Mikayelyan

引用次数: 0

First Byurakan Spectral Survey. Late-Type Stars. Dwarfs 第一次比拉坎光谱调查。晚型恒星。小矮人

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-207

K. Gigoyan, K. Gigoyan, A. Sarkissian, G. Kostandyan, E. Karapetyan, M. Meftah, N. Azatyan, F. Zamkotsian

{"title":"First Byurakan Spectral Survey. Late-Type Stars. Dwarfs","authors":"K. Gigoyan, K. Gigoyan, A. Sarkissian, G. Kostandyan, E. Karapetyan, M. Meftah, N. Azatyan, F. Zamkotsian","doi":"10.52526/25792776-22.69.2-207","DOIUrl":"https://doi.org/10.52526/25792776-22.69.2-207","url":null,"abstract":"A total of 18 lists of the First Byurakan Survey of Late-Type Stars (FBSLTS) were published between 1990 and 2016. The stars were found on FBS low-dispersion spectral plates. A systematic search and selection were carried out on a surface of ∼16 000deg2 on almost the whole area of the FBS. Since 2007, all FBS low-resolution spectral plates have been digitized. The second version of the “Revised And Updated Catalogue of the First Byurakan Survey of Late-Type Stars”, containing data for 1471 M and C (carbon) stars (130 C-type giants, 1105 M– giants, and 236 M dwarfs) was generated. Among the 236 M dwarfs selected, 176 are new discoveries. The Gaia EDR3 G broad-band magnitudes are in the range 11.3 < G < 17.1. New distance information by Bailer-Jones et al. (2021), which is based on the EDR3 parallaxes are used to estimate the G-band absolute magnitudes for M dwarfs. 9 FBS M dwarfs (out of 176 new discovered) lie within 25pc of the Sun. The object FBS 0909-082 is more distant (r = 780˙pc) M dwarf among the sample considered, for which G-band absolute magnitude M(G)=9.18, M= 0.59MSun, L=0.13597 LSun, and Teff = 3844 K. This object can be classified as M1-M2 subtype dwarf. The nearest object is FBS0250+167, a M7 subtype dwarf with very high proper motion (5.13 arcsec/yr) and is located at 3.83pc from the Sun. The TESS estimated masses lie in the range 0.095(±0.02)M⊙ ≤M≤0.7(±0.1)M⊙ and Teff in the range 4000K < Teff < 2790K for FBSM dwarfs. Color-absolute magnitude (CaMD) diagrams are constructed for the FBSM dwarfs based on Gaia EDR3 and TESS data.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114355542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of [CII] 158µm line widths to luminosities [CII] 158µm线宽与光度的比较

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-270

A. Samsonyan

引用次数: 0

On the Stability of “Stable Systems” in the Presence of Dark Energy 暗能量存在下“稳定系统”的稳定性

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-193

H. Harutyunian

{"title":"On the Stability of “Stable Systems” in the Presence of Dark Energy","authors":"H. Harutyunian","doi":"10.52526/25792776-22.69.2-193","DOIUrl":"https://doi.org/10.52526/25792776-22.69.2-193","url":null,"abstract":"The influence of dark energy on baryon objects and their system is considered. For such an analysis, the concept is adopted, according to which the entire baryonic Universe interacts with dark energy on all cosmic scales. It is shown that the interaction of baryonic objects with a carrier of dark energy inevitably leads to the injection of energy into the baryonic world with tangible physical consequences. The consequences seem quite dramatic, since the accumulation of energy in the baryonic world changes the virial theorem for all objects and systems, making them more and more unstable. This process of stability loss takes place at all spatial scales, including the micro world, where baryonic matter experiences the dark energy influence. It results decaying of all cosmic objects beginning with atomic nuclei and reaching the clusters of galaxies. Evolution under the influence of dark energy can take place in two different ways depending on the existence of the angular momentum of the body and its value. If the angular momentum is small, the object under the influence of dark energy obtains a more regular shape, otherwise at the equatorial plane would appear a structure consisting of less evolved matter.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115403086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New late-type stars found in the BAO Plate Archive 在BAO板块档案中发现了新的晚型恒星

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-343

G. Kostandyan, H. Abrahamyan, G. Mikayelyan, G. M. G. M Paronyan

引用次数: 0

Relative velocity in pseudo-Riemannian spacetime 伪黎曼时空中的相对速度

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-151

G. Ter-Kazarian

{"title":"Relative velocity in pseudo-Riemannian spacetime","authors":"G. Ter-Kazarian","doi":"10.52526/25792776-22.69.2-151","DOIUrl":"https://doi.org/10.52526/25792776-22.69.2-151","url":null,"abstract":"We give a coordinate independent definition of relative velocity of test particle in pseudo-Riemannian spacetime as measured along the observer’s line-of-sight in general and several instructive cases. In doing this, the test particle is considered as a luminous object, otherwise, if it is not, we assume that a light source is attached to it, which has neither mass nor volume. Then we utilize the general solution of independent definition of relative velocity of a luminous source in generic pseudo-Riemannian spacetime. As a corollary, we discuss the implications for the Minkowski metric, the test particle and observer at rest in an arbitrary stationary metric, the uniform gravitational field, the rotating reference frame, the Schwarzschild metric, the Kerr-type metrics, and the spatially homogeneous and isotropic Robertson-Walker (RW) spacetime of standard cosmological model. In the last case, it leads to cosmological consequence that the resulting, so-called, kinetic recession velocity of an astronomical object is always subluminal even for large redshifts of order one or more, so that it does not violate the fundamental physical principle of causality. We also calculate the measure of carrying away of a galaxy at redshift z by the expansion of space, which proves, in particular, that cosmological expansion of a flat 3D–space is fundamentally different from a kinematics of galaxies moving in a non-expanding flat 3D-space. So, it is impossible to mimic the true cosmological redshift by a Doppler effect caused by motion of galaxies in a non-expanding 3D-space, flat or curved. We also give a reappraisal of the `standard ́ kinematic interpretation of redshifts in RW spacetime as accumulated Doppler-shifts.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116930370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Astroinformatics: The Importance of Mining Astronomical Data in Binary Stars Catalogues 天体信息学:在双星表中挖掘天文数据的重要性

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-12-29 DOI: 10.52526/25792776-22.69.2-251

A. Abushattal, A. A. Alrawashdeh, A. Kraishan

{"title":"Astroinformatics: The Importance of Mining Astronomical Data in Binary Stars Catalogues","authors":"A. Abushattal, A. A. Alrawashdeh, A. Kraishan","doi":"10.52526/25792776-22.69.2-251","DOIUrl":"https://doi.org/10.52526/25792776-22.69.2-251","url":null,"abstract":"The field of Astroinformatics offers exciting new perspectives on astronomical discovery through the implementation of advanced data mining procedures. Data deluges transform research practices and methodologies across various scientific disciplines, including day-to-day astronomical research. It is essential to use innovative algorithms and methods to process astronomical data and its variety. Descriptive Data Mining was used in this study to clarify the importance and effectiveness of obtaining common data between three binary star catalogs. These catalogues are The Ninth Catalogue of Spectroscopic Binary Orbits (SB9), The Sixth Catalog of Orbits of Visual Binary Stars (6COVBS), and The Fourth Catalog of Interferometry Measurements of Binary Stars (4CIMBS). We collect scattered data from the Ninth Catalog in its latest edition in 2021, which contains astronomical information for approximately 4021 binary systems. Then we search for the orbits of these binary systems in the 6COVBS to calculate the physical and the orbital properties with high accuracy. After that, we use the 4CIMBS to look for new observations of these stars in 66,225 resolved stars in its latest edition 2020 to calculate new orbits. As a result of this research, we have found about 600 standard systems among these catalogues, which are valuable data to calculate many physical properties of such binary stars, starting from individual masses, by the combination of the spectroscopic orbital solution with the visual orbital solutions. Furthermore, calculate the orbital parallax for each system with high accuracy compared with those from space missions such as Gaia and Hipparcos give us a new and essential method to verify the validity of the data from those satellites.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116802152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Properties of interstellar matter and stellar population in two star-forming regions 两个恒星形成区的星际物质和恒星群的性质

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-09-02 DOI: 10.52526/25792776-22.69.1-83

E. Nikoghosyan

{"title":"Properties of interstellar matter and stellar population in two star-forming regions","authors":"E. Nikoghosyan","doi":"10.52526/25792776-22.69.1-83","DOIUrl":"https://doi.org/10.52526/25792776-22.69.1-83","url":null,"abstract":"This study aims to compare the properties of interstellar medium in two star-forming regions with\u0000different stellar content, with and without high-mass YSOs. The first region is an extended molecular\u0000cloud surrounding five IRAS sources: 05168+3634, 05184+3635, 05177+3636, 05162+3639, and IRAS\u000005156+3643. The second one is a physically connected pair of ultra compact HII regions, G45.07+0.13 &\u0000G45.12+0.13, associated with IRAS 19110+1045 and IRAS 19111+1048 sources, respectively. Using these\u0000two star formation regions as an example, one can see the relationship between the initial parameters of\u0000the parent molecular cloud (hydrogen column density, dust temperature), the process of star formation\u0000itself (external triggering shock or independent condensations), and the parameters of the stellar content.\u0000High-mass YSOs were obtained only in the G45.07+0.13 & G45.12+0.13 regions, in which, apparently,\u0000the initial density of the parent molecular cloud was higher and the star formation process was initiated\u0000by an external triggering shock. In addition, in the IRAS 05168+3634 region, there is a relationship\u0000between the density of the interstellar medium and the activity of the star formation process. In those\u0000subregions, where the mass and density of the initial, parent molecular cloud is greater, the process of\u0000star formation is likely to be more active and have a longer duration. In addition, in these sub-groups,\u0000on average, the mass of stars is larger.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"567 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127792867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Evolution of Stars and Astrophysics 恒星的演化和天体物理学

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-09-02 DOI: 10.52526/25792776-22.69.1-127

V. Ambartsumian

引用次数: 32

The Spectral Line Evolution in a Semi-infinite Atmosphere with Local Time-dependent Energy Sources 具有局地时变能量源的半无限大气中的谱线演化

Communications of the Byurakan Astrophysical Observatory Pub Date : 2022-09-02 DOI: 10.52526/25792776-22.69.1-25

A. Nikoghossian

引用次数: 2