Radiative transfer in disc galaxies – III. The observed kinematics of dusty disc galaxies
Radiative transfer in disc galaxies – III. The observed kinematics of dusty disc galaxies
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DOI：
10.1046/j.1365-8711.2003.06770.x
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发表时间：
2003-04
影响因子：
4.8
通讯作者：
M. Baes;J. Davies;H. Dejonghe;S. Sabatini;S. Roberts;R. Evans;S. Linder;Rodney M. Smith;W. D. Blok
中科院分区：
文献类型：
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作者：
M. Baes;J. Davies;H. Dejonghe;S. Sabatini;S. Roberts;R. Evans;S. Linder;Rodney M. Smith;W. D. Blok
我们目前的裙子（恒星动力学包括辐射传输），一个新的蒙特卡罗辐射传输代码，可以计算观测到的恒星运动学的尘埃星系。该代码结合了星际尘埃颗粒的吸收和散射效应，并通过考虑发射恒星和单个散射尘埃颗粒的速度来精确计算新兴辐射的多普勒频移。该代码支持任意分布的灰尘通过细胞的方法，从而通过灰尘的集成是通过一种新的高效三线性插值技术进行优化。我们应用我们的建模技术来计算所观察到的尘埃盘星系的现实模型的运动学。我们发现，尘埃的平均投影速度和投影速度色散的影响是严重的边缘上的星系。对于那些偏离精确边缘超过几度的星系，这种影响已经大大减少了。因此，尘埃衰减不能作为一种可能的方法来调和观测到的低表面亮度星系的内部旋转曲线的浅斜率和冷暗物质宇宙学模型的预测之间的差异。对于面对星系，速度色散增加，由于散射的尘埃质量的增加，但效果是有限的，即使是扩展的尘埃分布。最后，我们表明，严重的错误时，个别的尘埃颗粒的速度被忽略的计算。
We present skirt (Stellar Kinematics Including Radiative Transfer), a new Monte Carlo radiative transfer code that allows the calculation of the observed stellar kinematics of a dusty galaxy. The code incorporates the effects of both absorption and scattering by interstellar dust grains, and calculates the Doppler shift of the emerging radiation exactly by taking into account the velocities of the emitting stars and the individual scattering dust grains. The code supports arbitrary distributions of dust through a cellular approach, whereby the integration through the dust is optimized by means of a novel efficient trilinear interpolation technique. We apply our modelling technique to calculate the observed kinematics of realistic models for dusty disc galaxies. We find that the effects of dust on the mean projected velocity and projected velocity dispersion are severe for edge-on galaxies. For galaxies which deviate more than a few degrees from exactly edge-on, the effects are already strongly reduced. As a consequence, dust attenuation cannot serve as a possible way to reconcile the discrepancy between the observed shallow slopes of the inner rotation curves of low surface brightness galaxies and the predictions of cold dark matter cosmological models. For face-on galaxies, the velocity dispersion increases with increasing dust mass owing to scattering, but the effects are limited, even for extended dust distributions. Finally, we show that serious errors can be made when the individual velocities of the dust grains are neglected in the calculations.