2MASS Tully-Fisher Survey Mapping the Mass in the Universe Tao Hong (NAOC, ICRAR, CAASTRO) 2MTF Team Large Scale Structure and Galaxy Flow Conference Quy Nhon, Vietnam, 2016-07-04

Motivation Most of the matter is dark Map all the matter in the local universe, by measuring the peculiar velocity field.

Peculiar velocity as a cosmological probe Dark matter Mass distribution, large-scale structure Dark energy Growth rate Test cosmological models ΛCDM Constrain cosmological parameters Ωm, σ8

Previous studies on PV field Bulk flow measurement Watkins et al., 2009 Depth ~ 50 h-1Mpc Vpec = 407 ± 81 km/s Inconsistent with ΛCDM at >98% confidence level Weyant et al., 2011 Nusser & Davis., 2011 Depth ~ 40 h-1Mpc Vpec = 333±38 km/s Consistent with ΛCDM Dai et al., 2011; Turnbull et al., 2012; Ma & Pan 2014…

Previous studies on PV field Velocity power spectrum Watkins & Feldman, 2007 Constrained shape parameter Γ “lower than, but consistent with, CMB data” Multipole components of PV field Feldman, Watkins & Hudson, 2010 shear and octupole moments measured “consistent with WMAP5 power spectrum”

Measure the Peculiar Velocity Using Tully-Fisher Relation Tully-Fisher relation provides the redshift independent distances for spirals. Unbiased matter tracer Trace both visible matter and dark matter

2MASS Tully-Fisher Survey Measure Tully-Fisher (TF) distances to nearby spirals Galaxies are selected from the 2MASS Redshift Survey (2MRS) Near Infrared magnitudes Optical redshifts High quality HI widths New observation + ALFALFA + Archival

2MTF bulk flow team Tao Hong (ICRAR/UWA, NAOC) Thomas Jarrett (University of Cape Town) Heath Jones (Monash University) Baerbel Koribalski (ATNF) David Lagattuta (Swinburne University) Lucas Macri (Texas A&M University) Karen Masters (University of Portsmouth) Christopher Springob (ICRAR/UWA) Lister Staveley-Smith (ICRAR/UWA)

Advantages of 2MTF Comparing with previous T-F surveys, we have: Uniform source selection & sky-coverage Better sample to measure the peculiar velocity field Smaller zone of avoidance (ZoA) 2MTF goes down to b = ±5° SFI++ covers to b = ±15° Near Infrared magnitudes Ks, H and J band magnitudes SFI++ used optical magnitudes – I band

Scientific Goal of 2MTF Reconstruct the matter field High quality Tully-Fisher distance catalog Test cosmological models Constrain cosmological parameters Ωm, σ8 Reconstruct the matter field compare with the field from 2MRS, 6dF. The 2MRS velocity field Erdogdu et al., 2006

Source Selection Selection criteria Select from 2MASS Redshift Survey Ks < 11.25 mag cz < 10,000 km/s b/a < 0.5 Morphology Selection limits on HI data εw/w < 10% S/N > 5

Observations & data collection Green Bank Telescope (Masters et al., 2014) Northern sky δ ≥ - 40◦ 1194 galaxies observed, 479 well detected Parkes Telescope (Hong et al., 2013) Southern sky δ < - 40◦ 305 galaxies observed, 151 well detected ALFALFA 576 galaxies used (final ALFALFA has been included in 2016) Archival data 1502 galaxies collected (mainly from Cornell archive) Newly observed by 2MTF team

Uniform Sky-coverage

Tully-Fisher calculation TF plot of 2018 2MTF galaxies Distances & peculiar velocity calculated

Bulk Flow estimation Least χ2 fitting with Gaussian windows Depth at 20, 30 and 40 h-1Mpc Fitting in the log-normal space Malmquist bias corrected Error estimated by Jackknife method Also adopted Maximum Likelihood Method (MLE; Kaiser 1998) & Minimum Variance method (MV; Watkins et al., 2009, Feldman et al., 2010)

Bulk Flow estimation Direction of the bulk flow Hong et al., 2014

Bulk Flow estimation Amplitude of the bulk flow Disagreement between previous results

Bulk Flow estimation Amplitude of the bulk flow Measured by 2MTF with χ2 method Hong et al., 2014

Bulk Flow estimation Compare with previous studies

Bulk Flow estimation Amplitude of the bulk flow Measured by 2MTF with minimum variance method Hong et al., 2014

Next steps Final ALFALFA data added 2062 2MTF galaxies after applying all criteria

Next steps Final ALFALFA data added 2062 2MTF galaxies after applying all criteria Bulk flow estimation for the full sample

Next steps Final ALFALFA data added 2062 2MTF galaxies after applying all criteria Bulk flow estimation for the full sample Multipole fitting applied on the sample

Data availability 2MASS/2MRS data published New GBT/Parkes data published Masters+ 2014; Hong+ 2013 ALFALFA mostly published online Peculiar velocities will be published later on: ict.icrar.org/2MTF to accompany final bulk flow paper in 2017

Conclusions 2MASS Tully-Fisher Survey More uniform sky-coverage Straightforward selection criteria Smaller “Zone of Avoidance” Distances for nearby spirals using T-F relation Good sample for cosmological studies Highly accurate bulk flow estimate Measurements indicate consistency with ΛCDM Full sample has been completed Further analysis ongoing