Astronomy Letters-A Journal of Astronomy and Space Astrophysics最新文献_第7页

Neutrino Emission of Neutron-Star Superbursts 中子星超级爆发的中微子发射

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S1063773723120034

A. D. Kaminker, A. Yu. Potekhin, D. G. Yakovlev

引用次数: 0

Reverberation of the Vela Pulsar Wind Nebula 维拉脉冲星风星云的混响

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S106377372312006X

A. E. Petrov, K. P. Levenfish, G. A. Ponomaryov

引用次数: 0

Current Sheet as an Optimal Synchrotron Maser on a Radio Pulsar 作为射电脉冲星最佳同步加速器的电流片

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S1063773723120046

S. A. Koryagin

引用次数: 0

Investigation of the Ultraluminous X-ray Source VII Zw 403 ULX in the X-ray and Optical Ranges 超光速 X 射线源 VII Zw 403 ULX 的 X 射线和光学范围研究

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S1063773723120083

A. S. Vinokurov, K. E. Atapin, A. E. Kostenkov, Yu. N. Solovyeva

引用次数: 0

Angles between the Magnetic Moment and the Rotation Axis in Radio Pulsars with Hard Emission 硬发射射电脉冲星的磁矩与旋转轴之间的角度

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S1063773723120071

M. A. Timirkeeva, I. F. Malov

{"title":"Angles between the Magnetic Moment and the Rotation Axis in Radio Pulsars with Hard Emission","authors":"M. A. Timirkeeva, I. F. Malov","doi":"10.1134/S1063773723120071","DOIUrl":"10.1134/S1063773723120071","url":null,"abstract":"We have performed a comparative analysis of the angles (beta) between the rotation axis and the magnetic moment in three groups of radio pulsars: sources in which only radio emission is observed, pulsars with detected X-ray emission, and radio-loud gamma-ray pulsars. For this purpose, we have calculated the values of the angle (beta) separately for objects from each group by two different methods. It has turned out that in pulsars with hard emission the mean values of this angle (28.2({}^{circ}) and 28.8({}^{circ})) are higher than those for quiet radio pulsars (12.9({}^{circ})). However, using the Kolmogorov–Smirnov test, we have shown that the revealed difference is insignificant with a high probability. Consequently, the structures of the magnetospheres in the three groups of pulsars considered do not differ significantly, while their difference is attributable to the values of the magnetic field on the light cylinder that switches on the hard non-thermal emission mechanism in pulsars with detected X-ray and/or gamma-ray emission but is not enough for this in radio pulsars without hard emission.","PeriodicalId":55443,"journal":{"name":"Astronomy Letters-A Journal of Astronomy and Space Astrophysics","volume":"49 12","pages":"796 - 805"},"PeriodicalIF":1.1,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140201992","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

Influence of a Small-Scale Magnetic Field on the Heating of the Polar Cap of the Radio Pulsar J0901–4046 小尺度磁场对射电脉冲星 J0901-4046 极冠加热的影响

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-22 DOI: 10.1134/S1063773723120010

D. P. Barsukov, I. K. Morozov, A. N. Popov

引用次数: 0

X-ray Properties of the Luminous Quasar PG 1634+706 at (z=1.337) from SRG and XMM-Newton Data 根据 SRG 和 XMM-Newton 数据得出的位于 $$z=1.337$$ 的发光类星体 PG 1634+706 的 X 射线特性

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-17 DOI: 10.1134/S1063773723110099

G. S. Uskov, S. Yu. Sazonov, M. R. Gilfanov, I. Yu. Lapshov, R. A. Sunyaev

{"title":"X-ray Properties of the Luminous Quasar PG 1634+706 at (z=1.337) from SRG and XMM-Newton Data","authors":"G. S. Uskov, S. Yu. Sazonov, M. R. Gilfanov, I. Yu. Lapshov, R. A. Sunyaev","doi":"10.1134/S1063773723110099","DOIUrl":"10.1134/S1063773723110099","url":null,"abstract":"In the fall of 2019, during the in-flight calibration phase of the SRG observatory, the onboard eROSITA and Mikhail Pavlinsky ART-XC telescopes carried out a series of observations of PG 1634+706 — one of the most luminous (an X-ray luminosity ({sim}10^{46}) erg s({}^{-1})) quasars in the Universe at (z<2). Approximately at the same dates this quasar was also observed by the XMM-Newton observatory. Although the object had already been repeatedly studied in X-rays previously, its new observations allowed its energy spectrum to be measured more accurately in the wide range 1–30 keV (in the quasar rest frame). Its spectrum can be described by a two-component model that consists of a power-law continuum with a slope (Gammaapprox 1.9) and a broadened iron emission line at an energy of about 6.4 keV. The X-ray variability of the quasar was also investigated. On time scales of the order of several hours (here and below, in the source rest frame) the X-ray luminosity does not exhibit a statistically significant variability. However, it changed noticeably from observation to observation in the fall of 2019, having increased approximately by a factor of 1.5 in 25 days. A comparison of the new SRG and XMM-Newton measurements with the previous measurements of other X-ray observatories has shown that in the entire 17-year history of observations of the quasar PG 1634+706 its X-ray luminosity has varied by no more than a factor of 2.5, while the variations on time scales of several weeks and several years are comparable in amplitude.","PeriodicalId":55443,"journal":{"name":"Astronomy Letters-A Journal of Astronomy and Space Astrophysics","volume":"49 11","pages":"621 - 638"},"PeriodicalIF":1.1,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150298","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

Nature of the Eclipsing Polar 1RXS J184542.4(+)483134 食极体 1RXS J184542.4 $$+$$ 483134 的性质

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-17 DOI: 10.1134/S1063773723110051

V. Yu. Kochkina, A. I. Kolbin, N. V. Borisov, I. F. Bikmaev

{"title":"Nature of the Eclipsing Polar 1RXS J184542.4(+)483134","authors":"V. Yu. Kochkina, A. I. Kolbin, N. V. Borisov, I. F. Bikmaev","doi":"10.1134/S1063773723110051","DOIUrl":"10.1134/S1063773723110051","url":null,"abstract":"We have carried out a comprehensive study of the poorly investigated eclipsing polar 1RXS J184542.4(+)483134 with a short orbital period (P_{textrm{orb}}approx 79) min. An analysis of its long-term light curves points to a change in the position and sizes of the accretion spot as the accretion rate changes. Narrow and broad components, which are probably formed on the ballistic segment of the accretion stream and on the magnetic trajectory, respectively, are identified in the emission line profiles. An inversion of the line profiles from emission to absorption due to the obscuration of the accretion spot by the accretion stream is observed. Based on the eclipse duration and the radial velocities of the narrow line component, we impose constraints on the white dwarf mass, (0.49leq M_{1}/;M_{odot}leq 0.89), and the orbital inclination, (79.7^{circ}leq ileq 84.3^{circ}). An analysis of the cyclotron spectra points to the presence of two accretion spots with magnetic field strengths (B_{1}=28.4^{+0.1}_{-0.2}) MG and (B_{2}=30{-}36) MG. The main spot has a complex structure that apparently has a dense core and a less dense periphery emitting a spectrum with cyclotron harmonics. Polarization observations reveal a circular polarization sign reversal during the orbital period and an anticorrelation of the polarization with the brightness of the polar. Our modeling of polarization observations using the simple model of an accreting white dwarf shows that the polarization properties can be interpreted in terms of two-pole accretion with different optical depths of the accretion spots ((tau_{1}/tau_{2}sim 10)). An analysis of the Swift/XRT observations points to a predominance of bremsstrahlung in the X-ray radiation from the system.","PeriodicalId":55443,"journal":{"name":"Astronomy Letters-A Journal of Astronomy and Space Astrophysics","volume":"49 11","pages":"706 - 721"},"PeriodicalIF":1.1,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150309","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

Theoretical Period–Radius and Period–Luminosity Relations for Mira Variables with Solar Metallicity 具有太阳金属性的米拉变星的理论周期-半径和周期-光度关系

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-17 DOI: 10.1134/S1063773723110014

Yu. A. Fadeyev

{"title":"Theoretical Period–Radius and Period–Luminosity Relations for Mira Variables with Solar Metallicity","authors":"Yu. A. Fadeyev","doi":"10.1134/S1063773723110014","DOIUrl":"10.1134/S1063773723110014","url":null,"abstract":"Evolutionary sequences of AGB stars with initial masses on the main sequence (M_{textrm{ZAMS}}=1.5;M_{odot}), (2;M_{odot}), and (3;M_{odot}) were computed for the initial metallicity (Z=0.014). Selected models of evolutionary sequences with envelopes under thermal equilibrium were used as initial conditions for calculation of nonlinear stellar pulsations. The hydrodynamic models of each evolutionary sequence are shown to concentrate along the continuous line in the period–radius and period–luminosity diagrams. The theoretical period–radius and period–luminosity relations differ from one another for different main–sequence star masses because the stellar luminosity of AGB stars depends on the degenerate carbon core mass which increases with increasing (M_{textrm{ZAMS}}). In hydrodynamic models of evolutionary sequences (M_{textrm{ZAMS}}=2) and (3;M_{odot}) the periods of the first overtone pulsators are (86leqPileq 123textrm{d}) and (174leqPileq 204textrm{d}), whereas all models of the evolutionary sequence (M_{textrm{ZAMS}}=1.5;M_{odot}) oscillate in the fundamental mode. Fairly regular radial oscillations exist in stars with pulsation periods (Pilesssim 500) d. In models with longer periods the amplitude rapidly increases with increasing (Pi) and oscillations become irregular.","PeriodicalId":55443,"journal":{"name":"Astronomy Letters-A Journal of Astronomy and Space Astrophysics","volume":"49 11","pages":"722 - 730"},"PeriodicalIF":1.1,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150395","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

Investigation of the Disk of the Be Star in the High-Mass X-ray Binary IGR J21343+4738 对高质 X 射线双星 IGR J21343+4738 中 Be 星星盘的研究

IF 1.1 4区物理与天体物理

Astronomy Letters-A Journal of Astronomy and Space Astrophysics Pub Date : 2024-03-17 DOI: 10.1134/S1063773723110075

E. A. Nikolaeva, I. F. Bikmaev, E. N. Irtuganov, M. A. Gorbachev, M. V. Suslikov, R. I. Gumerov, N. A. Sakhibullin

引用次数: 0