Interstellar X-ray Dust Scattering: Current Research and Future Prospects

金驰川（NAOC）, 2024-03-21

Colloquium

https://astro.tsinghua.edu.cn/info/1100/2779.htm

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Introduction

dust in MW -> dust in anywhere of Universe

Properties of Interstellar Dust

• sub-micron size
  • see grain size distribution for different species at Hensley & Draines 2018(?)
• Elemental building blocks
  • Si, Fe, 50% C, 30% O locked ...
• effects: extinction, scattering, polarization
  • astrophysics:
    • dust plays a crucial role through the lifecycle of ISM
    • AGN torus

X-ray Dust Scattering

• X-ray Dust Extinction

• the scenario:

• grain size distrubution $n(a)$

• cross-section $\frac{d \sigma}{d \Omega}$

scattering effects

halo

• radial profile

• halo shape as function of grain size and dust distance

  • these 2 parameter degenarate.

• application: depend on energy, should be calibrated in each energy band.

• time-lag of the scattering

ring

use to fit dust distribution.

Future Prospects of X-ray Dust Scattering

1. break degeneracy between grain size and distance
2. build 3D dust map via scattering
3. resolve the X-ray absorption fine structure (XAFS) of dust grains.
4. detect the scattering by the IGM dust.

Summary of dust scattering

Einstein Probe Mission

https://ep.bao.ac.cn/ep/