Large Scale Structure in 2MRS & 6dF Ofer Lahav (University
College London) 6dF workshop, AAO/Sydney, 26-27 April 2005 Slide 2
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 Slide 3 F
2MASS Galactic chart Slide 4 The Near IR Local Universe Slide 5
2MRS + mock ZoA ~25000 galaxies K s < 11.25 Huchra &
2MRS/6dF teams Random ZoA Interpolated ZoA Slide 6 2MRS vs. PSCz
radial selection fn Slide 7 Spectral PCA types in 2MASS 62% Es in
2MASS 35% Es in 2dF Madgwick, OL et al. Slide 8 Dipole weighting
schemes m 0.6 /b g / L/ (4 r 2 ) L = (7.67+- 1.02) x 10 8 L_sun h
Mpc -3 Slide 9 Number and Flux dipoles in the LG frame 15 o @ 50
Mpc/h 24 o @ 130 Mpc/h m < 0.37+- 0.20 < 0.57 +- 0.07 b 2mrs
> 0.85 +- 0.15 (for m = 0.30) Erdogdu et al., In preparation
Slide 10 Out to 200 Mpc/h- LG frame Slide 11 Number and Flux
dipoles in the CMB frame Slide 12 Out to 200 Mpc/h CMB frame Slide
13 Dipole Wiener reconstruction 0.4 0.6 Slide 14 2MRS dipole
directions @ 130 Mpc/h Slide 15 Spherical harmonics Slide 16 Wiener
filtering ) Redshift distortion Signal/(Signal+Noise) Fisher, OL et
al (1995) Slide 17 WF 2MRS @ 2000 km/sec Erdogdu et al. Slide 18 WF
2MRS @ 4000 km/sec Slide 19 WF 2MRS @ 6000 km/sec Slide 20 WF 2MRS
@ 10000 km/sec Slide 21 WF 2MRS velocity field CMB frame Erdogdu et
al. Slide 22 WF 2MRS velocity field LG frame Slide 23 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 Slide 24
Photometric redshifts Slide 25 Slide 26 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, Slide 27 Artificial Neural Network Output:
redshift Input: magnitudes Slide 28 SDSS data (ugriz; r < 17.77)
ANNz (5:10:10:1) HYPERZ Slide 29 DES (griz) 5-yr aloneDES + VISTA
(YJHKs) Photo-z with ANNz z = 0.13 z =0.08 Slide 30 2MASS + photo-z
z = 0.02 z=0 cyan z=0.05 yellow z=0.08 red Collister & Lahav,
ANNz Slide 31 The 2dFGRS Team Members I.J. Baldry, C.M. Baugh, J.
Bland-Hawthorn, T.J. Bridges, R.D. Cannon, S. Cole, C.A. Collins,
M. Colless (PI),W.J. Couch, N.G.J. Cross, G.B. Dalton, R.
DePropris, S.P. Driver, G. Efstathiou, R.S. Ellis, C.S. Frenk, K.
Glazebrook, E. Hawkins, C.A. Jackson, O. Lahav, I.J. Lewis, S.L.
Lumsden, S. Maddox (PI), D.S. Madgwick, S. Moody, P. Norberg, J.A.
Peacock (PI), B.A. Peterson, W. Sutherland, K. Taylor
http://www.mso.anu.edu.au/2dFGRS/ On 2dF Sociology see OL,
astro-ph/0105351 Slide 32 2dFGRS PhD students & collaborators
Spectral classification (PCA): S. Folkes, S. Ronen, D. Madgwick
Biasing from 2dF+CMB: S. Bridle Neutrino mass: O. Elgaroy Wiener
Reconstruction: P. Erdogdu Stochastic Biasing: V. Wild Testing the
halo model: A. Collister Ofer Lahav, UCL Slide 33 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 Slide 34 Clustering of Red vs. Blue 2dF
galaxies Madgwick, Hawkins, Lahav & 2dFGRS team,
astro-ph/0303668 Slide 35 Whats next? The 6dF NIR Galaxy Survey
2MASS NIR selected 150k redshifts (Southern hemisphere) Peculiar
Velocities for 15k galaxies Reconstruction of the MASS distribution
Slide 36 Great Walls of the Universe Slide 37 The 2dFGRS Power
Spectrum 50 Mpc/h8 Mpc/h Linear Non- linear Slide 38 The
latest2dFGRS power spectrum Cole et al. 2005 Slide 39 The SDSS LRG
correlation fn (Eisenstein et al 2005) Slide 40 Weighing Neutrinos
with 2dFGRS Free streaming effect: / m < 0.13 Total mass M<
1.8 eV (Oscillations) (2dF) a Four-Component Universe ? Elgaroy,
Lahav & 2dFGRS team, astro-ph/0204152, PRL = 0.05 0.01 0.00
Slide 41 Absolute Masses of Neutrinos Based on measured squared
mass differences from solar and atmospheric oscillations Assuming m
1 < m 2 < m 3 Elgaroy& Lahav, JCAP 03 Slide 42 Ratio of
bulk flows with massive neutrinos =0.04 Elgaroy&Lahav, NJP,
2005 Slide 43 Principal Component Analysis Projections on the First
two eigen- spectra Cf. traditional line indices Slide 44 PCA for
data compression (by a factor ~1000) = 0.5 pc 1 pc 2 Madgwick, OL
et al. Slide 45 Correlation Function per Type Madgwick & 2dFGRS
Why a power law? dP / n [1+ (r)] dV r) = (r/r 0 ) - Slide 46 An
empirical test of the halo model P gal (k) = P gal (1h) (k) + P gal
(2h) (k) The 1-halo term depends on the halo mass function, the
halo occupation number the radial distribution of the galaxies
within the halo The 2-halo also term depends on the above, roughly
P gal (2h) (k)= b gal 2 P dm (lin) (k) Each of the three terms can
actually be measured directly from e.g 2dFGRS: Is the model
satisfied for all, blue and red galaxies? Collister & OL,
astro-ph/0412516 Slide 47 2dFGRS galaxy groups Eke et al. 2004
Slide 48 An empirical test of the halo model Non-linear clustering
P(k) = P lin (k) + P halo (k) Co-added profile of 2dF groups
Truncated NFW fit with C = 2.4 +- 0.3 A. Collister & OL,
astro-ph/0412516 Slide 49 The halo model P(k) = P lin (k) + P halo
(k) Blue galaxies Red galaxies = (M/M 0 ) for M > M cut 1.05
0.19 = 0.88 0.17 C=3.9 0.5 C=1.3 0.2 Slide 50 Relative biasing
(Blue/Red) Slide 51 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 Slide 52 University College London http://www.star.ucl.ac.uk
http://www.star.ucl.ac.uk ASTROPHYSICS @ UCL 20 academic staff, 15
pos-docs, 35 PhDs, 15 support stuff Research Stellar Astrophysics,
Star formation, Cosmology, Astro-Chemistry, Atmospheric Physics,
Astro-biology, Instrumentation, Mill Hill Observatory & the
MSSL Department
