Odessa Astronomical Publications最新文献_第10页

PHOTOMETRY AND THE BLAZHKO EFFECT IN THE RR Lyr VARIABLE STAR Y Vul 天琴座RR变星Y Vul的光度测定和BLAZHKO效应

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216279

S. Udovichenko, L. Keir

引用次数: 0

INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI 活动星系核中质子和α粒子的强通量诱导星际介质的本征γ射线发射

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216282

D. Doikov

{"title":"INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI","authors":"D. Doikov","doi":"10.18524/1810-4215.2020.33.216282","DOIUrl":"https://doi.org/10.18524/1810-4215.2020.33.216282","url":null,"abstract":". Cosmic-ray induced γ-ray emission in active galactic nuclei (AGN) has been examined in this study for the first time. Cross-sections for the formation of γ-quanta in such cosmic-ray collisions were selected in the 1-150 MeV energy range. Synthetic γ-ray spectra were computed for both interstellar gas and dust. At the same energies of particle collisions and induced emission of γ-quanta, energy intervals of diagnostic interest were determined. Specific characteristics of emission were detected in the energy ranges of 5-15 MeV and 23-30 MeV for most investigated elements. Diffuse continuous γ-ray spectra for the other energy ranges were less informative with regard to the determination of the chemical composition of interstellar gas. It has been shown that exploring cosmic-ray fluxes in the vicinity of galactic centres by employing the examined γ-ray spectra yields a pattern of their energy distribution. Diagrams of cross-sections for γ-quanta formation were computed for the α-process elements. Synthetic γ-ray spectra of interstellar gas and dust were calculated individually and collectively. It has been indicated that, under certain conditions in AGN, cross-sections for ionisation of atoms due to energy losses by cosmic-ray induced ionisation and γ-quanta emission resulting from collisions with cosmic rays are similar. It has been found that when the maximum of proton and α-particle energy distribution function falls within the investigated range of energies, it leads to the formation of the peak flux of γ-rays. This is particularly important for the interpretation of observations in the energy ranges of 5-15 MeV and 23-30 MeV. Synthetic induced γ-ray spectra of interstellar dust were computed, and methods of their observations for silicate and carbon-containing dust, which account for 80% and 20% of the interstellar-dust total mass, respectively, were determined. It has been deduced that the contribution of Compton processes to γ-quanta emission can be neglected at the investigated energies.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47796850","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

SPECTROSCOPIC INVESTIGATIONS OF THE POLARIS (α UMi) SYSTEM: RADIAL VELOCITY MEASUREMENTS, NEW ORBIT, AND COMPANION INFLUENCE FOR THE CEPHEID POLARIS Aa PULSATION ACTIVITY 北极星(α UMi)系统的光谱研究:径向速度测量，新轨道，以及造父变星北极星Aa脉动活动的伴星影响

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216289

I. Usenko, A. Miroshnichenko, S. Danford, V. Kovtyukh, D. Turner

引用次数: 0

PROBE OF THE MAGNETIC FIELD IN THE HOT SUPERGIANT ζ Per 热超巨星ζPer中磁场的探测

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216281

V. Butkovskaya, S. Plachinda

{"title":"PROBE OF THE MAGNETIC FIELD IN THE HOT SUPERGIANT ζ Per","authors":"V. Butkovskaya, S. Plachinda","doi":"10.18524/1810-4215.2020.33.216281","DOIUrl":"https://doi.org/10.18524/1810-4215.2020.33.216281","url":null,"abstract":"At the surface of ∼7% of single hot stars stable mainly dipolar strong magnetic fields have been detected. The main hypothesis today is that these magnetic fields are of fossil origin. In other words, these fields formed from the seed field in the molecular clouds from which the stars were formed. The recent observational and theoretical results confirm this theory: the properties of the observed fields correspond to those expected from fossil fields. Massive stars are stars whose initial mass exceeds about 8 solar masses. Massive stars play a significant role in the chemical and dynamical evolution of galaxies. However, much of their variability, particularly during their evolved supergiant stage, is poorly understood. To date magnetic field was registered only at three hot stars of I-II luminosity types: ρ Leo (B1 Ib), ζ Ori Aa (O9.2 Ib), and CMa (B1.5 II). We performed high-accuracy spectropolarimetric observation of the hot supergiant ζ Per (B1 Ib) over 26 nights from 1997 to 2012 with long-slit spectrograph mounted in the coude focus of 2.6-m reflector ZTSh at the Crimean Astrophysical Observatory. We also used circularly polarized spectra obtained during 2 nights in 2008 with echelle spectrograph ESPADONS mounted at 3.6m CFHT. Effective magnetic field Be (longitudinal component of the field integrated over visible hemisphere) of ζ Per was calculated in the line He I 6678.149 Å. Statistically significant longitudinal magnetic field (Be/σB > 3) was registered in 14 from 199 single measurements. These significant magnetic field values are all in the range from −145 to +148 G with the mean error 27 G. We suppose the supergiant ζ Per can be magnetic, but its magnetic field properties is difficult to detect likely due to the insufficient precision of the used spectropolarimetric measurements compared to the expected field strength.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49529504","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

SPECTROSCOPIC INVESTIGATIONS OF GALACTIC CLUSTERS WITH ASSOCIATED CEPHEID VARIABLES. IV. COLLINDER 220 AND UW CAR 造父变星相关星系团的光谱研究。4 .气缸220和气缸w

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216285

I. Usenko, A. Kniazev, I. Katkov, V. Kovtyukh, T. Mishenina, A. Miroshnichenko, D. Turner

{"title":"SPECTROSCOPIC INVESTIGATIONS OF GALACTIC CLUSTERS WITH ASSOCIATED CEPHEID VARIABLES. IV. COLLINDER 220 AND UW CAR","authors":"I. Usenko, A. Kniazev, I. Katkov, V. Kovtyukh, T. Mishenina, A. Miroshnichenko, D. Turner","doi":"10.18524/1810-4215.2020.33.216285","DOIUrl":"https://doi.org/10.18524/1810-4215.2020.33.216285","url":null,"abstract":"We present the results of a spectroscopic and photometric investigation of 18 probable members of the open cluster Collinder 220, which contains the Cepheid UW Car. Besides the Cepheid, we studied tree K-giants, two B-giants, and twelve B-A-F main sequence stars. Radial velocities (RV), v sin i, Teff , and log g were determined using spectroscopic model fitting and atmosphere models. We have derived color-excesses, reddenings, and intrinsic colors for these stars using their Teff and log g from comparison to the atmosphere models, especially for hot stars. Proper motions, RV, and the GAIA DR2 2018 parallaxes allowed us to determine their membership in the cluster and absolute magnitudes. We found that seven stars along with the Cepheid can be the cluster members with a high confidence. The parallaxes and reddenings of the 7 confident cluster members led to the distances in a range of 1900–2800 pc, while the other stars are probably foreground objects. All the members have [Fe/H] near 0.1 dex. The B-giant HD90435 located near the cluster’s “turn-off” point has a low projected rotational velocity, and this fact allows us to determine its chemical composition to compare with that of the Cepheid UW Car. The CNO abundances of HD90435 are nearly solar, while the Cepheid shows a deficit of carbon, an overabundance of nitrogen, a nearly solar oxygen, and an overabundance of sodium. The confident cluster member, K-supergiant CPD −57◦3199, has CNOand Na abundances close to those of UW Car.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45725004","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

HD 121135: FEATURES OF ITS CHEMICAL COMPOSITION Hd 121135:其化学成分的特征

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216277

T. Mishenina, I. Usenko, A. Kniazev, V. Kovtyukh

{"title":"HD 121135: FEATURES OF ITS CHEMICAL COMPOSITION","authors":"T. Mishenina, I. Usenko, A. Kniazev, V. Kovtyukh","doi":"10.18524/1810-4215.2020.33.216277","DOIUrl":"https://doi.org/10.18524/1810-4215.2020.33.216277","url":null,"abstract":". Low metallicity star HD121135 ([Fe/H] = -1.5) have been investigated spectroscopically. Its atmospheric parameters and elemental abundances have been determined, including elements of neutron (n-) capture processes, which are the keys in the study of early Galaxy enrichment. Na, Mg, Ni, Co, Sr, Y, Zr, Mo, Ba, La, Ce, Pr, Sm, Eu, Gd, Dy, Ho, Os, Th abundances were calculated using the synthetic spectrum method, factoring in the hy-perfine structure (HFS) for the Eu II lines. Si, Ca, Sc abundances were determined using the equivalent widths of their lines. The carbon content was computed by the molec-ular synthesis fitting for the region of CH (4300-4330 ÅÅ). For the abundances determinations of C, Na, Mg, Ba, and Th the NLTE corrections have been applied. We have determined for the first time the abundances of several n-capture elements and found that the behaviors of these elements do not show a significant trend with increasing atomic number. The elements ratios of [Eu/Fe] = 0.06, [Ba/Eu] = 0.13, [Sr/Ba] = - 0.05 do not support the HD121135 status as a r-process enrichment star. We have obtained the thorium abundance [Th/Fe] = 0.26. The carbon content confirms the effect of canonical additional mixing in this star.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48714992","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

DETECTION OF EMERGENCE OF MAGNETIC FLUX TUBES IN THE PHOTOSPHERES OF DWARF 61 Cyg A, SUBGIANT β Aql AND GIANT β Gem DWARF 61 Cyg A、亚巨星βAql和巨星βGem光球中磁通管的出现

Odessa Astronomical Publications Pub Date : 2020-11-14 DOI: 10.18524/1810-4215.2020.33.216284

S. Plachinda, V. Butkovskaya

{"title":"DETECTION OF EMERGENCE OF MAGNETIC FLUX TUBES IN THE PHOTOSPHERES OF DWARF 61 Cyg A, SUBGIANT β Aql AND GIANT β Gem","authors":"S. Plachinda, V. Butkovskaya","doi":"10.18524/1810-4215.2020.33.216284","DOIUrl":"https://doi.org/10.18524/1810-4215.2020.33.216284","url":null,"abstract":". Today, the study of stellar magnetic ﬁelds is one of the important research ﬁeld in astrophysics because it provides us, in addition to physics, with information about space weather in the orbits of Earth-like planets in stars other than the Sun. Local magnetic ﬁelds on stars with convective envelopes are small-scale magnetic ﬁelds diﬀerent in nature and structure from their global magnetic ﬁeld. Unlike the Sun, through direct measurements we are able to measure only the magnetic ﬁeld integrated over the visible disk of stars. However, we can register the magnetic ﬁeld in the leading spot during the time interval when the corresponding magnetic ﬂux tube already emerges on the surface of the star, and the magnetic ﬂux tube of the following spot is still hidden in the interior under the photosphere. Our research is based on the spectropolarimetric observations carried out with 2.6m Shajn telescope equipped with the echelle spectrograph ESPL, CCD, and the Stokesmeter as a circular polarization analyzer. For measuring stellar magnetic ﬁelds the Single Line (SL) technique was developed at CrAO. This technique is based on the calculation of Zeeman eﬀect in individual spectral lines. A key advantage of the SL technique is its ability to detect local magnetic ﬁelds on the surface of stars. Using SL technique emergence of large magnetic ﬂux tubes at the surface of stars of V-IV-III luminosity classes (61 Cyg A, β Aql, β Gem) were ﬁrst registered. We review the results of the study of local magnetic ﬁelds in these stars, including the results of modeling of magnetic ﬁeld ﬂux density and the size of their starspots. We also present the new results of spots modeling on β Aql. According to the","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46366469","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

INFRARED COUNTERPARTS OF X-RAY GALAXIES X射线星系的红外对应物

Odessa Astronomical Publications Pub Date : 2019-11-02 DOI: 10.18524/1810-4215.2019.32.182531

A. Tugay, S. Shevchenko

{"title":"INFRARED COUNTERPARTS OF X-RAY GALAXIES","authors":"A. Tugay, S. Shevchenko","doi":"10.18524/1810-4215.2019.32.182531","DOIUrl":"https://doi.org/10.18524/1810-4215.2019.32.182531","url":null,"abstract":"Population studies of the extragalac- tic objects are a major part of the universe large-scale structure study. Apart from radio, infrared, and visible wavelength bands, observations and further identification of extragalactic objects such as galaxies, quasars, blazers, liners, and active star burst regions are also conducted in the X-ray and gamma bands. In this paper we make identification and cross-correlate of the infrared and X-ray observational data, build a distribution of a selected sample sources by types and attempted to analyze types of the extragalactic objects at distances up to z = 0.1 using observational data of relevant space observatories. Data from a leading X-ray space observatory XMM-Newton were used to compile the largest catalog of X-ray sources. Current version of XMM SSC (Serendipitous Source Catalog) contains more than half a million sources. In our previous works we selected and analyzed a sample of 5021 X-ray galaxies observed by XMM-Newton. Identification and classification of these sources is essential next step of the study. In this study we used infrared apparent magnitudes from WISE catalog of AGN candidates. In 2010 space telescope WISE performed full sky survey in four infrared bands and detected 747 million sources. WISE catalog of AGN candidates amounts 4 million of possible extragalactic sources. We built infrared color-color diagram for our sample of X-ray galaxies and assessed their types using WISE telescope data. In this study we also analyzed large scale structure of the universe (distances up to z=0.1). This analysis revealed Coma galaxy cluster and SDSS Sloan Great Wall. In the further studies we are planning to investigate the distribution of different types of X-ray galaxies within the large-scale structures of the Universe.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49289943","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: 3

SOME COROLLARY FACTS OF THE N-POINT GRAVITATIONAL LENS EQUATION IN A COMPLEX FORM 复形式N点引力透镜方程的几个推论事实

Odessa Astronomical Publications Pub Date : 2019-11-02 DOI: 10.18524/1810-4215.2019.32.182518

O. A. Osmayev, Yu. S. Shuvalova, E. Bronza, K. I. Matvienko

{"title":"SOME COROLLARY FACTS OF THE N-POINT GRAVITATIONAL LENS EQUATION IN A COMPLEX FORM","authors":"O. A. Osmayev, Yu. S. Shuvalova, E. Bronza, K. I. Matvienko","doi":"10.18524/1810-4215.2019.32.182518","DOIUrl":"https://doi.org/10.18524/1810-4215.2019.32.182518","url":null,"abstract":"In the theory of the N-point gravita- tional lens equation, two groups of problems can be dis- tinguished. These are the so-called primal and inverse problems. Primal problems include problems of image definition in a specified lens for a specified source. In- verse problems include problems of determining a lens, source, or multiple images from one or more specified images. Inverse problem have an important applica- tions. We studied the equation of the N-point gravitational lens in a complex form. These studies became the basis for the solution of the inverse problem in the following formulation. N-point gravitational lens has specified. It is necessary to determine all other images from one of the images of a point source in N-point gravitational lens. Determine the necessary and sufficient conditions under which this problem has solutions. The algebraic formulation of the problem has the following form. The equation (of N-point gravitational lens) has specified. It is necessary to solve the problem of solutions unification (to express unequivocally all of the equation solutions through one parameter). To solve the inverse problem, we used methods of al- gebraic geometry and function theory. Branches equa- tions of any algebraic function admit unequivocal pa- rameterization by Puiseux series. The solutions of the N-point gravitational lens equation are algebraic functions defined by a certain irreducible polynomial. That polynomial has unequivocally defined by the N- point gravitational lens equation. Thus, the polyno- mial roots also admits parameterization by Puiseux se- ries. In simple cases, for lenses with a small number of point masses, the solution can be obtained in a sim- pler form. In particular, for the Schwarzschild lens and binary lens, the inverse problem has a solution in radicals.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42433624","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

INTERNATIONAL NUCLEAR DATA CENTERS NETWORK AND PROSPECTS OF ITS USE IN NUCLEAR POWER IN BELARUS 国际核数据中心网络及其在白俄罗斯核电中的应用前景

Odessa Astronomical Publications Pub Date : 2019-11-02 DOI: 10.18524/1810-4215.2019.32.182523

I. A. Serenkova, A. Pankov

{"title":"INTERNATIONAL NUCLEAR DATA CENTERS NETWORK AND PROSPECTS OF ITS USE IN NUCLEAR POWER IN BELARUS","authors":"I. A. Serenkova, A. Pankov","doi":"10.18524/1810-4215.2019.32.182523","DOIUrl":"https://doi.org/10.18524/1810-4215.2019.32.182523","url":null,"abstract":"We give a brief overview of the existing nuclear data base, and describe the structure of the International Nuclear Data Centres Network. Because the amount of experimental data in nuclear physics is extremely large, the note aims to show the way to modern methods of acquaintance with the char- acteristics of arrays of nuclei through the nuclear data banks accessible through the Web-technologies. In particular, the note describes the methods to extract information on the nuclei and nuclear reactions in nuclear data banks. The data include information on the masses and energies of the nuclei of the separation energy of nucleons and clusters, the spectra of states of nuclei, their spin, parity, isospin, charge and mass radii and densities, information about the shape of the nuclei, the cross sections of nuclear reactions, the decay of unstable nuclei. On the completeness and accuracy of the data depends on radiation and nuclear safety, and environmental acceptability of nuclear installations. Creating a nuclear databases in Belarus will monitor the quality of nuclear data supplied to consumers, and ensure that systems of constants, used in technical projects, the current international standards.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46932400","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