# Difference between revisions of "MapBasedR"

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== Foreground removal == | == Foreground removal == | ||

− | We run a map-based bayesian foreground-removal code on the simulations. The code samples the fully-resolved amplitudes of the three different components as well as spectral parameters (<math>\beta_s,\,\beta_d</math> and <math>T_d</math>). The latter are assumed constant on larger pixels, with HEALPix resolution <math>N_{\rm side}=16</math> (corresponding to ~4 deg). Fig. below shows the B-mode map at 145 MHz (left) and the mean CMB-only B-mode map output by the code. | + | We run a map-based bayesian foreground-removal code on the simulations. The code samples the fully-resolved amplitudes of the three different components as well as spectral parameters (<math>\beta_s,\,\beta_d</math> and <math>T_d</math>). The latter are assumed constant on larger pixels, with HEALPix resolution <math>N_{\rm side}=16</math> (corresponding to ~4 deg). Fig. below shows the B-mode map at 145 MHz (left) and the mean CMB-only B-mode map output by the code (right). |

− | [[File: | + | [[File:bmapfg.png|600px]] |

− | [[File: | + | [[File:bmap.png|600px]] |

== Estimating r == | == Estimating r == |

## Revision as of 16:28, 18 May 2016

## Summary

We checked the case in Victor's forecasts using our map-based code on PySM simulations. Bullet-point results (details below):

- Assuming no delensing:
- Assuming a 0.25 delensing factor:

## Simulations

We used PySM to generate full-sky simulations including:

- Power-law synchrotron (spatially-varying spectral index).
- Single-component thermal dust (spatially-varying temperature and spectral index).
- , partially de-lensed CMB.
- Noise levels compatible with Victor's case.

The simulations are cut using a map defined by selecting the cleanest 4000 sq-deg of the sky in polarization.

## Foreground removal

We run a map-based bayesian foreground-removal code on the simulations. The code samples the fully-resolved amplitudes of the three different components as well as spectral parameters ( and ). The latter are assumed constant on larger pixels, with HEALPix resolution (corresponding to ~4 deg). Fig. below shows the B-mode map at 145 MHz (left) and the mean CMB-only B-mode map output by the code (right).

## Estimating r

We compute the B-mode power spectrum for each simulation and fit a primordial + lensing template with amplitudes for both components (the first one being ). For this we only use multipoles . See result below for the no-delensing and 0.25-delensing cases.