pygedm.yt2020

Python implementation of Yamasaki & Totani DM Halo model

References

[1] Yamasaki S, Totani T (2020), The Galactic Halo Contribution to the Dispersion Measure of Extragalactic Fast Radio Bursts The Astrophysical Journal, Volume 888, Issue 2, id.105

Notes

Adapted from S. Yamasaki’s DM_halo_yt2020_numerical.py command-line python code

pygedm.yt2020.calculate_halo_dm(l, b, component='both')

Compute halo DM

Parameters:

• l (float) – Galactic longitude, in degrees (-180 to +180)
• b (float) – Galactic latitude, in degrees (-90 to 90)
• component (str) – Compute ‘spherical’ component of halo, ‘disk’ component, or ‘both’ components.

Returns:

Dispersion measure in [pc/cm^3]

Return type:

DM (float)

pygedm.yt2020.calculate_halo_dm_analytic(l, b)

Calculate the DM contribution of the Galactic halo.

Uses an analytical formula for speed. Useful for all-sky mapping.

Parameters:

• l (float) – Galactic longitude, in degrees (-180 to +180)
• b (float) – Galactic latitude, in degrees (-90 to 90)

pygedm.yt2020.ne_disk(l, b, s)

Compute electron density for spherical component for (l, b) at distance s

Parameters:

• l (float) – Galactic longitude, in radians (-pi to +pi)
• b (float) – Galactic latitude, in radians (-pi/2 to pi/2)
• s (float) – Distance (kpc)

Returns:

electron density in cm^{-3}

Return type:

ne (float)

pygedm.yt2020.ne_sphe(l, b, s)

Compute electron density for spherical component for (l, b) at distance s

Parameters:

• l (float) – Galactic longitude, in radians (-pi to +pi)
• b (float) – Galactic latitude, in radians (-pi/2 to pi/2)
• s (float) – Distance (kpc)

Returns:

electron density in cm^{-3}

Return type:

ne (float)

pygedm.yt2020.s_max(l, b)

Compute integration limit s_max for given sky coordinates

Parameters:

• l (float) – Galactic longitude, in radians (-pi to +pi)
• b (float) – Galactic latitude, in radians (-pi/2 to pi/2)

Returns:

s_max (float), maximum integration limit corresponsing to r = r_vir