February 2004 Five (or so) Easy Problems Douglas Richstone University of Michigan

February 2004 What is the most interesting attribute of a 30 meter space telescope? Resolution Spectral regime Photon rate

February Long ago and far away… Ô4 mas is ~20 nano radians

February 2004 Physical resolution vs distance (0.1arcsec vs 4mas)

February 2004 Because the angular size distance never exceeds 1.6 GPC, the resolution of a 30 meter space telescope is better than 30 parsecs anywhere in the universe. 0.1 arcsec

February 2004 Hdf

February 2004 The HDF was observed at a resolution of about.05 arcsec (about 200 parsecs)… The patch at left at 20 parsecs might look like the following pictures.

February 2004 Hcg87

February 2004 Hcg87big

February 2004 N1410

February 2004 “Go Deep” 1 ÔAny object in the HDF (or anywhere) can be studied with the physical resolution of current studies, of eg, the HCG 87 (or better) 2 subject only to surface brightness issues. 1Former Oakland quarterback Ken Stabler in reply to a question from President Reagan about whether to build the SSC. 2HCG 87 is at 100 Mpc.

February What about those pesky black holes?

February 2004 Likely BH mass and detection length-scale Based on the M bh ~  4 law and the radius of influence r i = GM/  2, We show r i for various bh masses. SigmaBhmassR_influe nce 10 km/s Msun E5 8.4E6 1.35E8 1.3E pc

February 2004 Nearby resolution

February 2004 Bhdetect distance versus M

February 2004 Black Holes ÔSee 10^9 Msun BH anywhere- can study the evolution of the BH fundamental plane and ‘Madau Plot’ for the biggest objects in the universe. ÔSee 1000 Msun BH anywhere in local group ÔInvestigate cDs with stellar dynamics ÔSee intermediate mass objects in Virgo cl.

February What does M31 look like?

February 2004 M31 at hst resolution.

February 2004 Resolution criterion ÔY = I  2 /f*, Y~1 is resolved, y>>1 isn’t.  I <~ m* + 5 log . I is mags/arcsec 2 at M31, I = = 11.5 at Virgo, I = = 17.5

February 2004 M31 GST

February 2004 M31gst big

February 2004 Those central populations ÔIn M32, and in many globular clusters, the physical collision time is not much longer than a Hubble time (in some cases much less)… find and characterize the collision products.

February What does our galaxy look like?

February The galaxy is kinematic Ô4 mas is 20 nanoradians ÔThis is 40au at 10kpc. - astrometry Ô100 km/sec ~10-4pc/yr, at 10kpc this is 10nr/yr. Can paint the halo with proper motions vectors. ÔDv/dt =v2/r ~v/10^8 yr - galaxy is kinematic, not dynamic (except very close to the center). ÔBack to those globular clusters… get pms there and have 5/6 of phase space.

February 2004 Its difficult to make predictions about the future