Voids in the 6dF Galaxy Survey Tony Fairall University of Cape Town and the 6dF Team.
Large Scale Structure in 2MRS & 6dF
description
Transcript of Large Scale Structure in 2MRS & 6dF
Large Scale Structure in 2MRS & 6dF
Ofer Lahav (University College London)
6dF workshop, AAO/Sydney, 26-27 April 2005
LSS in 2MRS• The Local Group Dipole• Wiener reconstruction• Future work with 2MRS+2MASS+6dF
Pirin Erdogdu (Cambridge/Ankara), John Huchra (CfA), Ofer Lahav (UCL) & the 2MRS/6dF teams
The Near IR Local Universe
2MRS + mock ZoA
~25000 galaxiesKs < 11.25
Huchra & 2MRS/6dF teams
Random ZoA
Interpolated ZoA
2MRS vs. PSCz radial selection fn
Spectral PCA types in 2MASS
62% E’s in 2MASS35% E’s in 2dF
Madgwick, OL et al.
Dipole – weighting schemes
m0.6/b
g / <M/L> L/ (4 r2)
L = (7.67+- 1.02) x 108 L_sun h Mpc-3
Number and Flux dipolesin the LG frame
15o @ 50 Mpc/h
24o @ 130 Mpc/h
m < 0.37+- 0.20< 0.57 +- 0.07b2mrs > 0.85 +- 0.15
(for m = 0.30)
Erdogdu et al.,In preparation
Out to 200 Mpc/h – CMB frame
Dipole – Wiener reconstruction
0.40.6
2MRS dipole directions @ 130 Mpc/h
Spherical harmonics
Wiener filtering
) Redshift distortion Signal/(Signal+Noise)
Fisher, OL et al (1995)
WF 2MRS @ 2000 km/sec
Erdogdu et al.
WF 2MRS @ 4000 km/sec
WF 2MRS @ 6000 km/sec
WF 2MRS @ 10000 km/sec
WF 2MRS velocity fieldCMB frame
Erdogdu et al.
WF 2MRS velocity fieldLG frame
The Concordance Model
Bulk flows are expected to have in linear theory: • For m < 1 lower amplitude and larger coherence length than in m=1 universe • Bulk flows are not sensitive to Dark Energy
Photometric redshifts
Photometric redshifts
Photo-z Other work:
* HYPERZ: Bolozonella et al., 2000, A&A, 363, 476 * Csabai et al,. 2003, AJ, 125, 580
ANNz:
* Firth, Lahav & Somerville, 2003, MNRAS, 339, 1195 * Collister & Lahav, 2004, PASP, 116, 345
http://www.ast.cam.ac.uk/~aac Applications to: SDSS LRGs, Dark Energy Survey, 2MASS, …
Artificial Neural Network
Output:redshift
Input:magnitudes
SDSS data (ugriz; r < 17.77)
ANNz (5:10:10:1) HYPERZ
2MASS + photo-z
z = 0.02
z=0 cyan z=0.05 yellow
z=0.08 red
Collister & Lahav, ANNz
Future work and interests @ London
• Compare predicted 2MRS peculiar velocities with observed 6dF pec vel.
• Combine 2MRS with 2MASS photo-z and 6dF• Cosmological parameters • Halo model & biasing• The cosmic web• Galaxy spectral classification
Alexandra Abate, Sarah Bridle, Ofer Lahav, Anais Rassat
Clustering of Red vs. Blue 2dF galaxies
Madgwick, Hawkins, Lahav & 2dFGRS team, astro-ph/0303668
Great Walls of the Universe
Ratio of bulk flows with massive neutrinos =0.04
Elgaroy&Lahav, NJP, 2005Elgaroy&Lahav, NJP, 2005
An empirical test of
the halo model
Non-linear clusteringP(k) = Plin(k) + Phalo(k)
Co-added profile of 2dF groupsTruncated NFW fit with C = 2.4 +- 0.3A. Collister & OL, astro-ph/0412516
Future work and interests @ UCL
• Compare predicted 2MRS peculiar velocities with observed 6dF pec vel.
• Combine 2MRS with 2MASS photo-z
and 6dF• Cosmological parameters • Halo model & biasing• The cosmic web• Galaxy spectral
classification
Alexandra Abate, Sarah Bridle, Ofer Lahav, Anais Rassat