Our CMB Motion: The Local Void influence Voids Devoid of Dwarfs: Cosmology or Gastrophysics?

1. Our CMB Motion: The Local Void influenceVoids Devoid of Dwarfs: Cosmology or Gastrophysics? Brent Tully Institute for Astronomy University of Hawaii

2. Fact 1:Gastrophysics must be importantbecausethe faint end of the luminosity function of galaxies depends on environment More dynamically evolved regions have steeper faint-end luminosity functions

3. Fact 2: The Dwarfs in Dynamically Evolved Regions are Overwhelmingly dE N5353/4 Group Local Group velocity radius N5846 Group

4. Fact 2: The Dwarfs in Dynamically Evolved Regions are Overwhelmingly dE N5353/4 Group Local Group velocity radius N5846 Group Show me a concentration of dE galaxies and I’ll show you a place with large M/L

5. Fact 3: Groups of Dwarfs - Evidence for Dark Halos • All-sky census of dwarf galaxies and follow up observations with HST/ACS: • most dwarfs are in groups • most of the mass in small groups is invisible • gastrophysics inhibits the collection of gas and star formation in low mass halos or low density regions

6. Fact 4:The Local Void- a void extending 60 Mpc begins at the edge of the Local Group HI Parkes All Sky Survey Time Allocation Committees could have inferred the existence of the Local Void

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

8. green/yellow Vpec~0 red Vpec > +100 blue Vpec < -100 Fact 5:we are traveling with the Local Filament as a unit • co-moving motion of the • Local Group w.r.t. 159 galaxies • at 1.1 < d < 7 Mpc • is 9 km/s negligible!! • velocity dispersion about the • local expansion of groups • and galaxies outside of groups • is ~40 km/s • within the Local Filament • (Karachentsev et al. 2003, AA, 398, 479) • cold flow!!

9. Where is the Local Filament going?

10. Assume component toward Virgo Cluster: ~200 km/s => l = 282.9 sgl = 102.7 b = 74.5 sgb = -2.3 Subtract from Local Supercluster vector: ~211 km/s => l = 213 sgl = 12 b = -3 sgb = -75 attributed primarily to evacuation of Local Void vector decompositions 1

11. what does nothing look like? SGZ SGX SGY

12. The lonely dwarf galaxy ESO461-36 = KK246 at 9 Mpc within the Local Void has a peculiar velocity toward us of -216 km/s Our peculiar motion in the Local Supercluster of 298 km/s is almost in the same direction, so the peculiar motion out of the void of ESO461-36 = KK246 is at least 500 km/s with respect to the Local Supercluster A galaxy in the void MB=-14 TRGB HI KK246

13. Bulk Peculiar Velocities Virgo Leo Spur

14. Local Void local velocity anomaly milky way local filament 36o 8.9 Mpc 45o 211 km/s 56o ~6 Mpc 9.5 Mpc 7.8 Mpc -285 km/s -260 km/s -260 km/s NGC 2903 -400 km/s -510 km/s Leo spur UGC 3974 -540 km/s D634-03

15. vector decompositions 2 • CMB motion • Local Group frame:619 km/s • l = 275.2 b = 28.7 • sgl = 140.2 sgb= -32.2 • Subtract • Local Supercluster vector • leaves large-scale structure component:~446 km/s • l = 300 b = 15 • sgl = 163 sgb = -15 • Attributed to structure on scales > 3,000 km/s Assume component toward Virgo Cluster: ~200 km/s => l = 282.9 sgl = 102.7 b = 74.5 sgb = -2.3 Subtract from Local Supercluster vector: ~211 km/s => l = 213 sgl = 12 b = -3 sgb = -75 attributed primarily to evacuation of Local Void

16. (again)Where is the Local Filament going? ~446 km/s ~200 km/s attractors on large scales ~211 km/s Kocevski & Ebeling 2006, ApJ, 645, 1043

17. The ratio of dwarf to giant galaxies is highest in high density, dynamically evolved environments. In the standard hierarchical clustering paradigm, the ratio of low to high halo mass is higher in lowdensity, dynamically unevolved regions. Either the paradigm is wrong or gas & stars are preferentially excluded from low mass halos in low density regions. The evident existence of groups of dwarfs with extreme M/L suggest that gas & stars are excluded in these locals. It must be considered likely that the paucity of dwarfs in voids is due to the inability of halos to collect or retain gas in those environments. Conclusions:

18. The ratio of dwarf to giant galaxies is highest in high density, dynamically evolved environments. In the standard hierarchical clustering paradigm, the ratio of low to high halo mass is higher in lowdensity, dynamically unevolved regions. Either the paradigm is wrong or gas & stars are preferentially excluded from low mass halos in low density regions. The evident existence of groups of dwarfs with extreme M/L suggest that gas & stars are excluded in these locals. It must be considered likely that the paucity of dwarfs in voids is due to the inability of halos to collect or retain gas in those environments. The Local Filament within 7 Mpc is moving as a unit with low internal dispersion. The bulk motion of the filament is decomposed cleanly into 3 quasi-orthogonal components: a motion of ~200 km/s away from the Local Void, a motion of ~200 km/s toward the Virgo Cluster, and a motion of ~450 km/s toward clustering on large scales in the direction of Centaurus. While we are moving toward -SGZ, the adjacent filament south of the supergalactic equator called Leo Spur has a bulk peculiar motion toward +SGZ and consequently is converging with our filament (in co-moving coordinates). The lonely dwarf galaxy ESO 461-36 lies 9 Mpc away, 8 Mpc deep into the Local Void. The galaxy appears to be a normal dIrr, with HI and leisurely ongoing star formation. The galaxy has a LARGE peculiar velocity toward the boundary of the void of over 500 km/s. Conclusions: