arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2204.12949gr-qcastro-ph.HE
收藏

具有薄吸积盘的玻色子和Proca星的阴影

Shadows of boson and Proca stars with thin accretion disks

João Luís Rosa, Diego Rubiera-Garcia

摘要:

在这项工作中,我们得到的阴影图像的球对称标量玻色子和Proca星的数值解的解析拟合,当照明的几何薄吸积盘。我们选择了一个由四颗玻色子和四颗普罗卡星组成的样本,其半径范围从更紧凑的$R\sim 9M$配置到更稀的$R\sim 20M$配置,其中$M$是玻色子星的总质量。在这些配置中,没有光子球(不稳定束缚测地线的轨迹),使得这些恒星的光学外观由一个围绕中央亮度凹陷的光环所主导,并且没有其他光环可用。我们表明,如果一个人认为面对的意见和磁盘模型,其发射截断在一些有限的半径,在光度达到其最大值,无论是阴影的大小,以及亮度和明亮区域的深度,在很大程度上受到影响的发射轮廓,与我们的样本中的玻色子恒星的类型和参数的选择有一个次主导的影响。然而,当我们允许吸积盘延伸到足够靠近恒星中心的地方时,这些差异会被显著放大。我们的结果指出,即使玻色子星是无水平的,没有一个光子球,其中一些可能能够产生传统的黑洞阴影状的图像,只要他们的紧凑性是足够大的,从而可能与当前和未来的观测一致。

英文摘要:

In this work, we obtain the shadow images of spherically symmetric scalar boson and Proca stars using analytical fittings of numerical solutions, when illuminated by a geometrically thin accretion disk. We chose a sample of four boson and four Proca stars with radii ranging from more compact configurations with $R\sim 9M$ to more dilute configurations with $R\sim 20M$, where $M$ is the total mass of the bosonic star. In these configurations, the absence of the photon sphere (the locus of unstable bound geodesics) makes the optical appearance of these stars to be dominated by a single luminous ring enclosing a central brightness depression, and no further light rings are available. We show that if one considers face-on observations and a disk model whose emission is truncated at some finite radius at which the luminosity attains its maximum value, both the size of the shadow, as well as the luminosity and depth of the bright region, are heavily influenced by the emission profile, with the choice of the type and parameters of the bosonic stars in our samples having a sub-dominant influence. These differences are nonetheless significantly magnified when one allows the accretion disk to extend close enough to the center of the star. Our results point out that even though bosonic stars are horizonless and do not have a photon sphere, some of them may be able to produce conventional black hole shadow-like images provided that their compactness is large enough, thus being potentially consistent with current and future observations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑