What’s New with Peculiar Velocities? hundreds of 5% distances within 6 Mpc galaxies gather in groups; few are isolated modest group masses; don’t account for much of mean matter density small dispersion in velocities on ~5 Mpc scales dynamically evolved clusters with large M/L significant streaming - local velocity anomaly suggests the existence of considerable mass associated with filaments but outside of groups

hundreds of 5% distances within 6 Mpc good at 3 Mpc hundreds of 5% distances within 6 Mpc marginal at 5 Mpc OK at 8 Mpc

good distances 2 a group of dwarf galaxies at 3 Mpc

good distances 3 a group at almost 8 Mpc with a large peculiar velocity VLG = 180 km/s Vpec= -380 km/s

good distances 4 all-sky inventory off POSS for dwarfs by Karachentseva and Karachentsev ; HI follow-up provides velocities about 200 of ~400 suspected to lie within ~7 Mpc now have good distances if you are ever on the HST TAC, give us time to do more!

galaxies gather in groups; few are isolated

galaxies gather in groups 2-point correlation signal dominated by groups like Local Group only dwarf groups

the local group quasi-virialized infall MW M31 31

galaxies at 1.1 - 3.2 Mpc |b|>30o [66 Mpc3] beyond Local Group 14+7 N4214 2.83 -17.1 U7577 2.55 -14.2 N4163 2.96 -13.8 U6817 2.56 -13.5 N3741 3.13 -13.2 U8508 2.59 -13.0 UA276 2.84 -11.7 14+8 U9240 2.79 -14.2 460 U8760 3.24 -13.2 210 U8651 3.02 -12.9 180 U8833 3.20 -12.4 260 dregs U9128 2.24 -12.5 300 U8091 2.10 -12.0 490 KKH86 2.52 -10.3 670 KK230 1.90 -8.6 700 KKR25 1.85 Mpc kpc 14+12 N3109 1.33 -15.5 310 Sex B 1.39 -14.0 450 Sex A 1.40 -13.8 210 Antlia 1.25 -9.3 350 KKH60 ? -7.8 ? 2x1011 M in 0.4 Mpc3 14+13 N 55 2.19 -17.9 190 N 300 1.87 -17.5 320 E407-18 2.14 -12.9 400 E410-05 1.92 -11.6 200 E294-10 2.00 -11.0 200 ----------------------- IC5152 2.07 -15.6 820 9x1011 M in 0.3 Mpc3 

modest group masses Omegam ~0.27 The mass in nearby groups of spirals is well below the level needed to explain the cosmic mean density

small dispersion in velocities on ~5 Mpc scales

dynamically evolved environments with large Vpec V=1779 km/s V= 558 km/s

significant streaming - the local velocity anomaly Milky Way plane of local filament -460 km/s -380 km/s 14+19 group VLG=182 km/s

Numerical Action Models Best models: only ~1/3 of mass distributed like galaxies considerable mass smoothly distributed on 5-10 Mpc scale

low velocity dispersion locally [~30 km/s] modest M/L in groups of spiral galaxies [< 100] large streaming motions between filaments [several x 100 km/s] global M/L assignments in NAM models in reasonable agreement with concordance model [~200] conclusion: Suggests the existence of considerable mass associated with filaments but outside of groups