The linear velocity field of 2MASS Redshift Survey, Ks= 11.75 galaxies: constraints on β and bulk flow from the luminosity function
Article first published online: 4 JUN 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 424, Issue 1, pages 472–481, July 2012
How to Cite
Branchini, E., Davis, M. and Nusser, A. (2012), The linear velocity field of 2MASS Redshift Survey, Ks= 11.75 galaxies: constraints on β and bulk flow from the luminosity function. Monthly Notices of the Royal Astronomical Society, 424: 472–481. doi: 10.1111/j.1365-2966.2012.21210.x
- Issue published online: 5 JUL 2012
- Article first published online: 4 JUN 2012
- Accepted 2012 April 30. Received 2012 April 7; in original form 2012 February 23
- cosmological parameters;
- dark matter;
- large-scale structure of Universe
Using the nearly full-sky Ks= 11.75 2MASS Redshift Survey (2MRS; Huchra et al.) of ∼45 000 galaxies, we reconstruct the underlying peculiar velocity field and constrain the cosmological bulk flow within ∼100 h−1 Mpc. 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 h−1 Mpc, we find a bulk flow in agreement with the theoretical predictions of the Λ cold dark matter model. The reconstructed peculiar velocity field that maximizes the likelihood is characterized by the parameter β= 0.32 ± 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.