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Carbon neutron star atmospheres

碳中子星大气层

基本信息

批准号：
258855794
负责人：
Professor Dr. Klaus Werner
金额：
--
依托单位：
Fysiikan ja tähtitieteen laitos
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/258855794?language=en
关键词：
Carbon neutron star atmospheres

项目摘要

The physical properties of super-dense matter in neutron-star (NS) cores is one of the most intriguing problems of modern physics. Also known as the NS equation-of-state problem, it cannot be resolved using theoretical considerations or laboratory experiments with heavy-ion collisions alone. A straightforward way for attacking this problem is the simultaneous mass and radius determination of NSs from X-ray spectroscopy. Despite of great progress in the last decade, this kind of measurements is still not sufficiently accurate to draw firm conclusions. Two of the main obstacles are generally unknown distances to NSs and unknown chemical compositions of NS atmospheres, however, accurate emergent spectra of NS model atmospheres (with appropriate composition) are crucially necessary for the measurement of basic neutron star parameters. We propose to use a particular subclass of NSs that allow to overcome this obstacles.NSs in supernova remnants (so-called Central Compact Objects, CCOs) are particularly interesting because for some of them distances (and ages) are sufficiently well known. In addition, there is no evidence for on-going accretion onto these objects so their gaseous upper layers are undisturbed and can be described by model stellar atmosphere methods. Recently, evidence was found from X-ray spectroscopy that some of the CCOs have atmospheres composed of carbon. Knowing distance and envelope composition of CCOs enables us to derive more precise NS parameters, provided the model atmospheres and emergent spectra can be computed with sufficiently high accuracy. The immediate aim of this project proposal is to investigate the potentially most important physical processes that can significantly affect existing theoretical carbon NS atmosphere spectra. As a final result we plan to compute new grids of accurate model spectra and use them for analyses of archival X-ray spectra of NSs with possible carbon atmospheres. These grids will be published so that future observations can be analysed with them. New, tight constraints on the equation-of-state in NS cores and also on neutrino-cooling physics will be obtained.

中子星（NS）核心中超稠密物质的物理特性是现代物理学中最有趣的问题之一。也称为 NS 状态方程问题，仅使用理论考虑或实验室重离子碰撞实验无法解决该问题。解决这个问题的一个直接方法是通过 X 射线光谱同时测定 NS 的质量和半径。尽管在过去十年中取得了巨大进步，但这种测量仍然不够准确，无法得出确切的结论。两个主要障碍通常是未知的中子星距离和未知的中子星大气化学成分，然而，准确的中子星模型大气（具有适当成分）的出现光谱对于测量基本中子星参数至关重要。我们建议使用特定的 NS 子类来克服这一障碍。超新星遗迹（所谓的中心致密天体，CCO）中的 NS 特别有趣，因为对于其中一些来说，距离（和年龄）是众所周知的。此外，没有证据表明这些物体正在不断吸积，因此它们的气态上层不受干扰，可以通过模型恒星大气方法来描述。最近，从 X 射线光谱中发现的证据表明，一些 CCO 的大气层由碳组成。了解 CCO 的距离和包络成分使我们能够得出更精确的 NS 参数，前提是可以以足够高的精度计算模型大气和出现光谱。该项目提案的直接目标是研究可能显着影响现有理论碳 NS 大气光谱的潜在最重要的物理过程。作为最终结果，我们计划计算新的精确模型光谱网格，并使用它们来分析可能存在碳大气的 NS 的档案 X 射线光谱。这些网格将被发布，以便可以用它们来分析未来的观测结果。将获得对 NS 核心状态方程以及中微子冷却物理的新的严格约束。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The direct cooling tail method for X-ray burst analysis to constrain neutron star masses and radii

DOI：
10.1093/mnras/stw3132
发表时间：
2016-11
期刊：
Monthly Notices of the Royal Astronomical Society
影响因子：
4.8
作者：
V. Suleimanov;J. Poutanen;J. Nattila;J. Kajava;M. Revnivtsev;K. Werner
通讯作者：
V. Suleimanov;J. Poutanen;J. Nattila;J. Kajava;M. Revnivtsev;K. Werner

Analysing neutron star in HESS J1731-347 from thermal emission and cooling theory

DOI：
10.1093/mnras/stv2204
发表时间：
2015-10
期刊：
Monthly Notices of the Royal Astronomical Society
影响因子：
4.8
作者：
D. Ofengeim;A. Kaminker;D. Klochkov;V. Suleimanov;D. Yakovlev
通讯作者：
D. Ofengeim;A. Kaminker;D. Klochkov;V. Suleimanov;D. Yakovlev

Probing the possibility of hotspots on the central neutron star in HESS J1731−347

DOI：
10.1051/0004-6361/201630028
发表时间：
2017-01
期刊：
Astronomy and Astrophysics
影响因子：
6.5
作者：
V. Suleimanov;V. Suleimanov;D. Klochkov;J. Poutanen;J. Poutanen;Klaus Werner
通讯作者：
V. Suleimanov;V. Suleimanov;D. Klochkov;J. Poutanen;J. Poutanen;Klaus Werner

Basic parameters of the helium-accreting X-ray bursting neutron star in 4U 1820−30

4U 1820â30中氦吸积X射线爆发中子星的基本参数