3D photon conserving code for time-dependent general relativistic radiative transfer: CARTOON
3D photon conserving code for time-dependent general relativistic radiative transfer: CARTOON
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用于依赖时间的广义相对论辐射传输的 3D 光子守恒代码：CARTOON
DOI：
10.1093/mnras/stac2822
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发表时间：
2022
影响因子：
4.8
通讯作者：
Asahina Yuta
中科院分区：
文献类型：
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作者：
Takahashi Mikiya M;Ohsuga Ken;Takahashi Rohta;Ogawa Takumi;Umemura Masayuki;Asahina Yuta
我们在Takahashi和Uemura开发的二维码ARTIST的基础上改进开发了三维广义相对论辐射传输程序：CALICON(基于弯曲时空中光子数守恒的真实辐射传输计算程序)。在CARTOON中，用光子数守恒的方法求解频率积分的广义相对论辐射传输方程，并考虑了零角动量观测器(ZAMO)坐标系和流体静止坐标系中的各向同性和相干散射。通过计算光子的平均能量，也保证了辐射的能量守恒。通过对二维和三维空间的测试计算，证明了在CARTON守恒的情况下，黑洞时空中的波前传输是可以正确求解的。波前的位置与解析解一致，在波前到达事件视界之前，光子数保持不变。我们还求解了测地线到达观测者屏幕上的辐射传递方程。随着黑洞周围辐射场的时间变化，可以同时一致地计算出观测者屏幕上强度图的时间变化。此外，黑洞阴影可以在中等光学厚度的情况下重现。
We develop the three-dimensional general relativistic radiative transfer code:CARTOON(Calculation code of Authentic Radiative Transfer based On phOton Number conservation in curved space–time) which is improved from the two-dimensional code:ARTISTdeveloped by Takahashi & Umemura . InCARTOON, the frequency-integrated general relativistic radiative transfer equation is solved in a photon number-conserving manner, and the isotropic and coherent scattering in the zero angular momentum observers (ZAMO) frame and the fluid rest frame is incorporated. By calculating the average energy of photons, energy conservation of the radiation is also guaranteed. With the test calculations in two-dimensional and three-dimensional space, we have demonstrated that the wavefront propagation in black hole space–time can be correctly solved inCARTOONconserving photon numbers. The position of the wavefront coincides with the analytical solution and the number of photons remains constant until the wavefront reaches the event horizon. We also solve the radiative transfer equation on the geodesic reaching the observer’s screen. The time variation of the intensity map on the observer’s screen can be simultaneously and consistently calculated with the time variation of the radiation field around the black hole. In addition, the black hole shadow can be reproduced in moderately optically thin situations.