Reconstructed density and velocity fields from the 2MASS Redshift Survey

November 2006 • 2006MNRAS.373...45E

Authors • Erdoǧdu, Pirin • Lahav, Ofer • Huchra, John P. • Colless, Matthew • Cutri, Roc M. • Falco, Emilio • George, Teddy • Jarrett, Thomas • Jones, D. Heath • Macri, Lucas M. • Mader, Jeff • Martimbeau, Nathalie • Pahre, Michael A. • Parker, Quentin A. • Rassat, Anaïs • Saunders, Will

Abstract • We present the reconstructed real-space density and the predicted velocity fields from the Two-Micron All-Sky Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23200 galaxies with extinction-corrected magnitudes brighter than K_s = 11.25. Our method is based on the expansion of these fields in Fourier-Bessel functions. Within this framework, the linear redshift distortions only affect the density field in the radial direction and can easily be deconvolved using a distortion matrix. Moreover, in this coordinate system, the velocity field is related to the density field by a simple linear transformation. The shot noise errors in the reconstructions are suppressed by means of a Wiener filter which yields a minimum variance estimate of the density and velocity fields. Using the reconstructed real-space density fields, we identify all major superclusters and voids. At 50 h^-1 Mpc, our reconstructed velocity field indicates a backside infall to the Great Attractor region of v_infall = (491 +/- 200) (β/0.5)kms^-1 in the Local Group frame and v_infall = (64 +/- 205) (β/0.5)kms^-1 in the cosmic microwave background (CMB) frame and β is the redshift distortion parameter. The direction of the reconstructed dipole agrees well with the dipole derived by Erdoǧdu et al. The misalignment between the reconstructed 2MRS and the CMB dipoles drops to 13° at around 5000 kms^-1 but then increases at larger distances.

Links

View on ADS

IPAC Authors
(alphabetical)

Roc Cutri

IPAC Deputy Director