Enzo Branchini, Marc Davis, Adi Nusser
Using the nearly full sky Ks=11.75 2MASS Redshift Survey [2MRS]of ~45,000
galaxies we reconstruct the underlying peculiar velocity field and constrain
the cosmological bulk flow within ~100. These results are obtained by
maximizing the probability to estimate the absolute magnitude of a galaxy given
its observed apparent magnitude and redshift. At a depth of ~60 Mpc/h we find a
bulk flow Vb=(90\pm65,-230\pm65,50\pm65) km/s in agreement with the theoretical
predictions of the LCDM model. The reconstructed peculiar velocity field that
maximizes the likelihood is characterized by the parameter beta=0.323 +/- 0.08.
Both results are in agreement with those obtained previously using the ~23,000
galaxies of the shallower Ks=11.25 2MRS survey. In our analysis we find that
the luminosity function of 2MRS galaxies is poorly fitted by the Schechter form
and that luminosity evolves such that objects become fainter with increasing
redshift according to L(z)=L(z=0)(1+z)^(+2.7 +/-0.15).
View original:
http://arxiv.org/abs/1202.5206
No comments:
Post a Comment