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相关论文: NLTE Effects on Kilonova Expansion Opacities

200 篇论文

The coalescence of binary neutron stars can yield the expulsion of a fast-moving, quasi-isotropic material, which may induce thermal radiation and give rise to kilonova emission. Moreover, the interaction between the ejected material and…

高能天体物理现象 · 物理学 2024-02-29 Shao-Ze Li , Yun-Wei Yu , He Gao , Lin Lan

Detailed non-LTE calculations for red supergiant stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J-band. With their enormous brightness at J-band red supergiant stars are…

太阳与恒星天体物理 · 物理学 2015-06-04 Maria Bergemann , Rolf-Peter Kudritzki , Bertrand Plez , Ben Davies , Karin Lind , Zach Gazak

We investigate the early (t < 1 day) kilonova from the neutron star merger by deriving atomic opacities for all the elements from La to Ra (Z = 57 - 88) ionized to the states V - XI. The opacities at high temperatures for the elements with…

高能天体物理现象 · 物理学 2023-06-07 Smaranika Banerjee , Masaomi Tanaka , Daiji Kato , Gediminas Gaigalas

For the first time, a direct NLTE analysis of carbon and nitrogen lines in the spectra of nine RR Lyrae stars was carried out. We have determined the abundances of these elements together with oxygen, and have shown that the nitrogen…

太阳与恒星天体物理 · 物理学 2021-10-04 Sergei M. Andrievsky , Sergey A. Korotin , Valery V. Kovtyukh , Sergey V. Khrapaty , Yuri Rudyak

Following our solar work, we perform NLTE calculations of the Mn abundance for fourteen stars with [Fe/H] from 0 to -2.5, mainly to show how NLTE affects Mn abundances in cool stars of different metallicities.The spectrum synthesis and Mn…

天体物理学 · 物理学 2009-11-13 Maria Bergemann , Thomas Gehren

One of the major tasks in interpretation of data from large-scale stellar surveys is to determine the fundamental atmospheric parameters such as effective temperature, surface gravity, and metallicity. In most on-going and upcoming…

太阳与恒星天体物理 · 物理学 2015-06-16 L. Mashonkina

Ejected material from neutron star mergers give rise to electromagnetic emission powered by radioactive decays of r-process nuclei, which is so called kilonova or macronova. While properties of the emission are largely affected by opacities…

We study the formation of B I lines in a grid of cool stellar model atmospheres without the assumption of local thermodynamic equilibrium (LTE). The non-LTE modelling includes the effect of other lines blending with the B I resonance lines.…

天体物理学 · 物理学 2007-05-23 Dan Kiselman , Mats Carlsson

Non-local thermodynamical equilibrium (NLTE) line formation for Mg I and Mg II lines is considered in classical 1D-LTE model atmospheres of the Sun and 17 stars with reliable atmospheric parameters and in a broad range of spectral types:…

太阳与恒星天体物理 · 物理学 2018-10-31 Sofya Alexeeva , Tatiana Ryabchikova , Lyudmila Mashonkina , Shaoming Hu

Non-local thermodynamical equilibrium (NLTE) line formation for neutral and singly-ionized calcium is considered through a range of spectral types when the Ca abundance varies from the solar value down to [Ca/H] = -5. Departures from LTE…

天体物理学 · 物理学 2009-11-11 L. Mashonkina , A. J. Korn , N. Przybilla

We present detailed NLTE Ti~I calculations in model atmospheres of cool dwarf and giant stars. A fully self-consistent NLTE treatment for a Ti~I model atom with 395 levels and 5279 primary bound-bound transitions is included, and we discuss…

天体物理学 · 物理学 2016-08-30 Peter H. Hauschildt , France Allard , David R. Alexander , E. Baron

Kilonovae, the electromagnetic transients produced from two merging neutron stars, exhibit evolving spectral signatures in ultraviolet, visible, and infrared radiation. Starting around one week post-merger, equilibrium assumptions…

原子物理 · 物理学 2026-03-03 S. Bromley , E. Garbe , N. McElroy , C. Ballance , M. Fogle , P. Stancil , S. Loch

Kilonova is an optical-infrared transient powered by the radioactive decay of heavy nuclei from binary neutron star mergers. Its observational characteristics depend on the mass and the nuclide composition of meger ejecta, which are…

高能天体物理现象 · 物理学 2025-02-03 Wu-Zimo Qiumu , Meng-Hua Chen , Qiu-Hong Chen , En-Wei Liang

A merger of binary neutron stars creates heavy unstable elements whose radioactive decay produces a thermal emission known as a kilonova. In this paper, we predict the photometric and polarimetric behaviour of this emission by performing…

高能天体物理现象 · 物理学 2023-05-31 Manisha Shrestha , Mattia Bulla , Lorenzo Nativi , Ivan Markin , Stephan Rosswog , Tim Dietrich

We constructed a comprehensive model atom for C\ione\ -- C\ii\ using the most up-to-date atomic data available and evaluated the non-local thermodynamic equilibrium (NLTE) line formation for C\ione\ and C\ii\ in classical 1D models…

太阳与恒星天体物理 · 物理学 2016-08-17 S. A. Alexeeva , T. A. Ryabchikova , L. I. Mashonkina

Non-LTE calculations for Mg I in red supergiant stellar atmospheres are presented to investigate the importance of non-LTE for the formation of Mg I lines in the NIR J-band. Recent work using medium resolution spectroscopy of atomic lines…

太阳与恒星天体物理 · 物理学 2015-05-27 Maria Bergemann , Rolf-Peter Kudritzki , Zach Gazak , Ben Davies , Bertrand Plez

The material ejected from a binary neutron star merger produces "kilonova," a radioactively powered emission at ultraviolet, optical, and infrared wavelengths. The early-phase spectra of the kilonova AT2017gfo, following the gravitational…

高能天体物理现象 · 物理学 2026-04-08 Koya Chiba , Masaomi Tanaka , Shinya Wanajo , Sho Fujibayashi , Kyohei Kawaguchi , Kenta Hotokezaka

The double detonation is a widely discussed explosion mechanism for Type Ia supernovae, whereby a helium shell detonation ignites a secondary detonation in the carbon/oxygen core of a white dwarf. Even for modern models that invoke…

We present non-local thermodynamic equilibrium (NLTE) line formation calculations for Ca I and Ca II in B-F stars. The sign and the magnitude of NLTE abundance corrections depend on line and stellar parameters. We determine calcium…

太阳与恒星天体物理 · 物理学 2018-04-11 Tatyana Sitnova , Lyudmila Mashonkina , Tatyana Ryabchikova

Most of the physical information about astrophysical objects is obtained via the analysis of their electromagnetic spectra. Observed data coupled with radiation transfer models in physical conditions representative of stars, planets,…

太阳与恒星天体物理 · 物理学 2026-05-29 Maria Bergemann , Richard Hoppe