论文标题
Kerr-Taub-Nut时空中的相对论增生流量的研究
Study of relativistic accretion flow in Kerr-Taub-NUT spacetime
论文作者
论文摘要
我们研究了相对论,稳定,轴对称性,低角度动量,无粘性,对流,几何薄的吸积流(Kerr-taub-nut(KTN)时空,其特征在于Kerr参数($ a _ _ _ _ _ {\ rm k} $)和nut参数($ n $)。根据$ a _ {\ rm k} $和$ n $ value,ktn spacetime代表黑色或裸体奇异性。我们解决了ktn时空中描述相对论积聚流的管理方程,并根据能量$({\ cal e})$和Angular Mommentum $(λ)$来获取KTN黑洞周围所有可能的全球透射积聚解决方案。我们在$λ-{\ cal e} $平面中确定参数空间的区域,该区域承认该流量具有KTN黑洞的多个关键点。我们检查了由于$ a _ {\ rm k} $和$ n $而导致的参数空间的修改,并发现$ a _ {\ rm k} $的作用在确定参数空间相反。这清楚地表明,螺母参数$ n $有效地减轻了黑洞旋转在决定积聚流结构中的影响。此外,我们计算与KTN黑洞周围的积聚解决方案以及给定的$ a _ {\ rm k} $和$ n $的最大光盘光度($ l _ {\ rm max} $)。此外,我们还研究了裸露奇点周围的所有可能的流拓扑,发现裸奇异性周围存在一个区域,而流动仍无法访问。我们研究了裸奇异点的临界点特性,并发现该流量最多具有四个临界点。最后,我们为裸奇异性获得了多个关键点的参数空间,并发现参数空间缩小并转移到$λ$,$ {\ cal e} $ side作为$ a _ {\ rm k} $增加,最终消失了。
We study the properties of the relativistic, steady, axisymmetric, low angular momentum, inviscid, advective, geometrically thin accretion flow in a Kerr-Taub-NUT (KTN) spacetime which is characterized by the Kerr parameter ($a_{\rm k}$) and NUT parameter ($n$). Depending on $a_{\rm k}$ and $n$ values, KTN spacetime represents either a black or a naked singularity. We solve the governing equations that describe the relativistic accretion flow in KTN spacetime and obtain all possible global transonic accretion solutions around KTN black hole in terms of the energy $({\cal E})$ and angular momentum $(λ)$ of the flow. We identify the region of the parameter space in $λ-{\cal E}$ plane that admits the flow to possess multiple critical points for KTN black hole. We examine the modification of the parameter space due to $a_{\rm k}$ and $n$ and find that the role of $a_{\rm k}$ and $n$ in determining the parameter space is opposite to each other. This clearly indicates that the NUT parameter $n$ effectively mitigates the effect of black hole rotation in deciding the accretion flow structure. Further, we calculate the maximum disc luminosity ($L_{\rm max}$) corresponding to the accretion solutions around the KTN black hole and for a given set of $a_{\rm k}$ and $n$. In addition, we also investigate all possible flow topologies around the naked singularity and find that there exists a region around the naked singularity which remains inaccessible to the flow. We study the critical point properties for naked singularities and find that the flow possesses maximum of four critical points. Finally, we obtain the parameter space for multiple critical points for naked singularity and find that parameter space is shrunk and shifted to lower $λ$ and higher ${\cal E}$ side as $a_{\rm k}$ is increased which ultimately disappears.