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Wiener Reconstruction of the Galaxy Redshift Surveys

Wiener Reconstruction of the Galaxy Redshift Surveys. Pirin Erdogdu, Ofer Lahav, Saleem Zaroubi and the 2dFGRS Team. The Reconstructed Density Field of 2dFGRS in Declination Strips. We assign. Pirin Erdogdu and 2dFGRS Team, 2003, in preparation. Motivation.

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Wiener Reconstruction of the Galaxy Redshift Surveys

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  1. Wiener Reconstruction of the Galaxy Redshift Surveys Pirin Erdogdu, Ofer Lahav, Saleem Zaroubi and the 2dFGRS Team

  2. The Reconstructed Density Field of 2dFGRS in Declination Strips We assign Pirin Erdogdu and 2dFGRS Team, 2003, in preparation

  3. Motivation • Statistical Uncertainties due to Shot Noise • Incomplete Sky Coverage • Incomplete Galaxy Sampling • Recovering one field from another

  4. Underlying Signal (ΛCDM) Noise Wiener Filter (For details see Zaroubi et al 1995, ApJ, 449, 446)

  5. where the matrix WF is chosen such thatthe residual: is minimised. Hence: ~ prior/(prior + noise)

  6. Data –Data Correlation Matrix: Signal –Data Cross-Correlation Matrix: Density Reconstruction in Redshift Space : = Density Reconstruction in Real Space:

  7. Application to 2df Survey Pixelisation

  8. EACH GALAXY IS ASSIGNED THE WEIGHT: So the data vector is written as:

  9. 2dFGRS SGP SCGP01 VSGP02 VSGP01

  10. Density Threshold as A Function of Redshift

  11. VNGP27 SCNGP16 VNGP25 SCNGP18 SCNGP19 SCNGP17 2dFGRS NGP VNGP26

  12. 2dFGRS SGP SCSGP 21 SCSGP22

  13. Are these structures real?

  14. FUTURE WORK Large Scale Reconstruction from Peculiar Velocities And assuming

  15. Reconstruction from Mark III data. Zaroubi, Hoffman & Dekel 1999 ApJ,520, 412 Top Right panel : Mark III data Top Left Panel: IRAS data

  16. WORK IN PROGRESS

  17. Conclusions • WF is applied to the density reconstruction of 2dFGRS • Major superclusters and voids are identified. • WF can be used to reconstruct the density and velocity fields of 6dFGRS. • The reconstructed density fields can be used as an input to different analyses.

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