Epoch of Reionization 21-cm Signal Suman Majumdar Institute for - PowerPoint PPT Presentation

The Effect of Peculiar Velocities on the Epoch of Reionization 21-cm Signal Suman Majumdar Institute for Astronomy Stockholm University source:- arXiv:1209.4762

Collaborators o Somnath Bharadwaj (IIT Kharagpur, India) o Tirthankar Roy Choudhury (NCRA-TIFR, India)

Collaborators o Somnath Bharadwaj (IIT Kharagpur, India) o Tirthankar Roy Choudhury (NCRA-TIFR, India) o Garrelt Mellema (Stockholm University, Sweden) o Hannes Jensen (Stockholm University, Sweden) o Kanan Kumar Datta (Stockholm University, Sweden)

!!A Murder Mystery!! WHO? WHEN? HOW?

!!Time Travel!!  Direct Probe of Reionization  Timing and duration of EoR  Properties of EoR Sources  IGM Properties  Large scale HI 21-cm distribution of HI Radiation  Physical Processes involved

GMRT MWA LOFAR SKA

Radio Interferometry “Visibility” = FT of Sky Brightness Temp.

Power Spectrum of HI “Visibility” P(k) = |A(k)| 2 k = 2 Π /L

Redshift Space Distortion Line of Sight

Redshift Space Distortion Line of Sight

Redshift Space Distortion Line of Sight

Redshift space distortion Line of Sight

Power Spectrum in Redshift Space Observed power spectrum will be LoS dependent. k θ LoS

LoS HR HR-RS IR IR-RS

LoS HR HR-RS IR IR-RS

LoS HR HR-RS IR IR-RS

Our observations will always contain the effects of peculiar velocities.

Is that a bad news? Our observations will always contain the effects of peculiar velocities.

Brightness Tempereture from HI Underlying Matter Density Filed + State of Hydrogen

Brightness Tempereture from HI Cosmology Underlying Matter Density Filed + State of Hydrogen

Brightness Tempereture from HI Cosmology Underlying Matter Density Filed + State of Hydrogen Astrophysics

Brightness Tempereture from HI Cosmology Underlying Matter Density Filed + State of Hydrogen Astrophysics

Angle Averaged HI Power spectrum

Matter Power spectrum in Redshift Space o Kaiser, N., 1987, MNRAS, 227, 1 o Hamilton, A. J. S., 1992, APJL, 385, L5

Matter Power spectrum in Redshift Space Legendre Polynomial o Kaiser, N., 1987, MNRAS, 227, 1 o Hamilton, A. J. S., 1992, APJL, 385, L5

Matter Power spectrum in Redshift Space Angular Multipoles o Kaiser, N., 1987, MNRAS, 227, 1 o Hamilton, A. J. S., 1992, APJL, 385, L5

LoS HR HR-RS IR IR-RS

Model with Linear Approximations

Model with Linear Approximations Power Spectrum of DM Density Field

Model with Linear Approximations Power Spectrum of x HI Field

Model with Linear Approximations Cross-correlation between DM and x HI Field

Model with Linear Approximations o Bharadwaj, Nath and Sethi, 2001, JAA, 22, 21 o Bharadwaj and Ali, 2004, MNRAS, 352, 142 o Barkana and Loeb, 2005, ApJL, 624, L65

Model with Linear Approximations o Bharadwaj, Nath and Sethi, 2001, JAA, 22, 21 o Bharadwaj and Ali, 2004, MNRAS, 352, 142 o Barkana and Loeb, 2005, ApJL, 624, L65

It’s not a bad news!! Our observations will always contain the effects of peculiar velocities.

Monopole (l=0) and Quadrupole (l=2)

Monopole (l=0) and Quadrupole (l=2)

Monopole (l=0) and Quadrupole (l=2)

Monopole (l=0) and Quadrupole (l=2)

Hexadecapole (l=4) ???

Hexadecapole (l=4) ???

Tack!!