Communications of the Byurakan Astrophysical Observatory最新文献_第10页

On the correlation between average velocities of galaxies and their average luminosities in the closest large clusters of galaxies 在最近的大星系团中，星系的平均速度和它们的平均光度之间的关系

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2019.66.1-25

H. Harutyunian, A. Grigoryan, A. Khasawneh

引用次数: 2

Saw-type shock fronts in several HII regions of southern hemisphere 南半球几个HII区域的锯齿型激波锋

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2019.66.1-20

A. Gyulbudaghian

引用次数: 1

No-z model: results and perspectives for accretion discs No-z模型:吸积盘的结果和前景

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.2-490

E. Mikhailov, M. V. Pashentsevay

引用次数: 0

Biermann battery mechanism and its role in evolution of astrophysical magnetic fields 比尔曼电池机制及其在天体物理磁场演化中的作用

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2020.67.2-281

E. Mikhailov, R. Andreasyan

引用次数: 1

Byurakan Astrophysical Observatory: 75 years of outstanding achievements 比拉坎天体物理天文台:75年的杰出成就

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.1-1

A. Mickaelian

引用次数: 2

Twenty years of the Armenian Astronomical Society (ArAS) 亚美尼亚天文学会(ArAS)二十年

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.2-400

A. Mickaelian, S. Farmanyan, G. Mikayelyan

引用次数: 0

Features of a Sample of Star-forming Galaxies in two Adjacent SBS Fields 两个相邻SBS场中恒星形成星系样本的特征

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.2-522

S. Hakopian

{"title":"Features of a Sample of Star-forming Galaxies in two Adjacent SBS Fields","authors":"S. Hakopian","doi":"10.52526/25792776-2021.68.2-522","DOIUrl":"https://doi.org/10.52526/25792776-2021.68.2-522","url":null,"abstract":"Some results are presented on studies of a sample of about hundred galaxies (“100SBS”) from two adjacent fields of SBS (Second Byurakan Survey), which have spectral data in SDSS (Sloan Digital SkySurvey-www.sdss.org ).The work is carried out as a part of the long-term program (Hakopian, 2013) forin-depth study of the galaxies in seven selected SBS fields (including the two under investigation).Comparative analysis was done between two classifications that the 100SBS objects got - from one side Starburst or Starforming in SDSS, from the other - SfGcont and SfGneb, with a possibility of further detailing in accordance to our scheme for SfG, i.e. star-forming galaxies. Obtained results showed good perspectives in using of our scheme for differentiation of activity phases of SfGs and for better statistics and comprehensive studies. Space distribution of 100SBS galaxies, what is important, homogeneously selected in continuous (32 sq.deg) area, was obtained using uniformly determined in SDSS redshift values. As it follows from the graphs plotted at 0.01 intervals the maximum of the distribution, with an equal number of Staforming and Starburst galaxies falls on the range 0.01<z<;0.019. The minimum of the distribution falls on the range 0.02<z<0.029 and more expressed for Starbursts. Also some difference is discerned in a diversity of morphological appearance of the galaxies composing two neighboring to it intervals.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131031931","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

On the kinematic interpretation of cosmological redshifts 宇宙学红移的运动学解释

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.1-12

G. Ter-Kazarian

{"title":"On the kinematic interpretation of cosmological redshifts","authors":"G. Ter-Kazarian","doi":"10.52526/25792776-2021.68.1-12","DOIUrl":"https://doi.org/10.52526/25792776-2021.68.1-12","url":null,"abstract":"We describe what is essentially a correct solution to the kinematic interpretation of cosmological redshifts in standard cosmological model. In the framework of \"stretching of space\" point of view of the spatially homogeneous and isotropic Robertson-Walker space-time of standard cosmological model, we study so-called \"lookforward\" history of expanding universe, subject to certain rules, in order to overcome the ambiguity of the parallel transport of source four-velocity along the null geodesic to an observer. We interpret the cosmological redshifts as the accumulation of a series of infinitesimal \"relative\" spectral shifts along the path of light consequent on recession. The crux of our solution is the kinetic recession velocity of comoving astronomical object, which is always subluminal even for large redshifts of order one or more, so that it does not violate the fundamental physical principle of causality. Our analysis establishes a straightforward kinematic relationship of overall cosmological redshift and kinetic recession velocity, which is utterly distinct from a familiar global Doppler shift formula. A difference of global Doppler velocity and kinetic recession velocity, for redshifts 0.9 ≤ z ≤ 800, is ≥ 0.072c, where a maximum value, 0.187c, is reached at redshifts z = 4.5 - 5.1. A general solution is reduced to a global Doppler shift along the null geodesic. We discuss the implications for the case of a zero-density cosmological model of Milne universe, whereas a correspondence to the more usual special relativity notion of relative speed retains. In Table 1, we are summing up kinetic recession velocities of some typical distant astronomical objects with spectroscopic redshift determinations collected from the literature.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131850701","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: 2

Space Activities in Armenia: past, present and future 亚美尼亚的空间活动:过去、现在和未来

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2019.66.2-191

A. Mickaelian, G. Mikayelyan

引用次数: 0

Investigation of DFBS late type stars at high galactic latitudes 高纬度星系DFBS晚型恒星的研究

Communications of the Byurakan Astrophysical Observatory Pub Date : 1900-01-01 DOI: 10.52526/25792776-2021.68.2-534

G. Kostandyan

{"title":"Investigation of DFBS late type stars at high galactic latitudes","authors":"G. Kostandyan","doi":"10.52526/25792776-2021.68.2-534","DOIUrl":"https://doi.org/10.52526/25792776-2021.68.2-534","url":null,"abstract":"We study in this thesis relatively bright late-type giants found in the First Byurakan Survey (FBS) data base. We present the 2nd version of the catalogue of FBS LTS with new data (FBS LTS v2), 1471 objects. It is a homogeneous and complete database for high- Galactic late-type stars, including M and C types. Since 2007, all FBS low-resolution spectral plates are digitized. All DFBS spectral plates are analyzed with FITSView and SAO Image ds9 and numerous relatively faint LTS were discovered. We have made cross-correlation with DFBS, USNO-B1.0, 2MASS, AllWISE, IRAS PSC/FSC, AKARI, ROSAT BSC/FSC, GCVS, SDSS and added updated SIMBAD data. For numerous new detected objects, we present accurate DSS2 positions, approximate spectral subtypes refined from the DFBS low-dispersion spectra, luminosity classes estimated from 2MASS colours, and available proper motions for 1471 FBS LTS. The Revised and Updated Catalogue v2 lists a large number of completely new objects, which promise to extend very significantly the census of M giants, faint N-type AGB carbon stars, CH-type carbon giants at high Galactic latitudes, also M dwarfs in the Solar vicinity up to 16.0m-17.0m in visual. Phase dependent light-curves from large sky area variability data bases such as Catalina Sky Survey (CSS) and All-Sky Automated Survey for Supernovae (ASAS-SN), and the early installment of the third Gaia data release (Gaia EDR3) photometric and astrometric data have been used to characterize our sample of 1100 M-type giants found and 130 C-type stars at high latitudes. We show the behaviour of our sample stars in a Gaia DR2 color–absolute magnitude diagram (CaMD), the Gaia-2MASS-diagram, including two alternative versions, and the logP-K-diagram. In this way we explore the potential of these diagrams and their combination for the analysis and interpretation of datasets of LPVs. We show the possibility to classify stars into M- and C-types and to identify the mass of the bulk of the sample stars.","PeriodicalId":412578,"journal":{"name":"Communications of the Byurakan Astrophysical Observatory","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126205662","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