Reconstructed density and velocity fields from the 2MASS Redshift Survey

Erdogdu, 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, Anaid
Saunders, Will
W 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 23 200 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) (ss/0.5) km s(-1) in the Local Group frame and v(infall) = (64 +/- 205) (ss/0.5) km s(-1) in the cosmic microwave background (CMB) frame and ss is the redshift distortion parameter. The direction of the reconstructed dipole agrees well with the dipole derived by Erdogdu et al. The misalignment between the reconstructed 2MRS and the CMB dipoles drops to 13 degrees at around 5000 km s(-1) but then increases at larger distances.

Citation Formats
P. Erdogdu et al. , “Reconstructed density and velocity fields from the 2MASS Redshift Survey,” MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, vol. 373, no. 1, pp. 45–64, 2006, Accessed: 00, 2020. [Online]. Available: