Origin of Supersonic Drift Velocity between Baryons and Dark Matter from Spherical Overdensities
We show animations for the evolution of the radial mass and velocity profile versus comoving radius of an initially:
1. Point-like overdensity
2. Top-hat overdensity
Also, we show the evolution of Δ2v(k) and v-rms for Baryon, CDM and Drift velocities with:
a. spherical overdensities
b. the Planck-Primordial power spectrum[1]
For the animations click here
Here is a plot from work done by Eisenstein, et. al [2] where they demonstrate and explain the phenomena of point-like primordial overdensity.
Eisenstein, Seo & White (2007)
Transformation Derivation and Discussion
All the plots and animations have been made by suitable transforms of the transfer functions created by CAMB[3]. For a detailed derivation of the transformations, click here.
References
[1] Planck Collaboration, P. A. R., Aghanim, N., Armitage-Caplan, C., Arnaud, M., Ashdown, M., Atrio-Barandela, F., ... & Davis, R. J. (2014)
[2] Eisenstein, D. J., Seo, H. J., & White, M. (2007). On the robustness of the acoustic scale in the low-redshift clustering of matter. The Astrophysical Journal, 664(2), 660.
[3] Lewis, A., & Challinor, A. (2007). 21 cm angular-power spectrum from the dark ages. Physical Review D, 76(8), 083005.
Contact Information
For any questions, comments or more details, you can mail me at:
email: praful.gagrani@gmail.com
Praful Gagrani
Indian Institute of Technology, Delhi