The BOLD Response Douglas C. Noll Department of Biomedical Engineering University of Michigan.
February 2004 Five (or so) Easy Problems Douglas Richstone University of Michigan.
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February 2004 Five (or so) Easy Problems Douglas Richstone University of Michigan
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Transcript of February 2004 Five (or so) Easy Problems Douglas Richstone University of Michigan.
February 2004
Five (or so) Easy Problems
Douglas RichstoneUniversity of Michigan
February 2004
What is the most interesting attribute of a 30 meter space
telescope? ResolutionSpectral regimePhoton rate
February 2004
1. Long ago and far away…
4 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
Any 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.
1 Former Oakland quarterback Ken Stabler in reply to a question from President Reagan about whether to build the SSC.
2 HCG 87 is at 100 Mpc.
February 2004
2. What about those pesky black holes?
February 2004
Likely BH mass and detection length-scale
Based on the Mbh~4 law and the radius of influence ri = GM/ 2,
We show ri for various bh masses.
Sigma Bhmass R_influence
10 km/s2050100200350
843 Msun135005.3E58.4E61.35E81.3E9
0.035 pc0.14 0.883.514.143.1
February 2004
Nearby resolution
February 2004
Bhdetect distance versus M
February 2004
Black Holes
See 10^9 Msun BH anywhere- can study the evolution of the BH fundamental plane and ‘Madau Plot’ for the biggest objects in the universe.
See 1000 Msun BH anywhere in local group
Investigate cDs with stellar dynamics See intermediate mass objects in Virgo
cl.
February 2004
3. What does M31 look like?
February 2004
M31 at hst resolution.
February 2004
Resolution criterion
Y = I 2 /f*, Y~1 is resolved, y>>1 isn’t. I <~ m* + 5 log. I is mags/arcsec2
at M31, I = 24 -12.5 = 11.5 at Virgo, I = 30 -12.5 = 17.5
February 2004
M31 GST
February 2004
M31gst big
February 2004
Those central populations
In 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 2004
4. What does our galaxy look like?
February 2004
4. The galaxy is kinematic
4 mas is 20 nanoradians This is 40au at 10kpc. - astrometry 100 km/sec ~10-4pc/yr, at 10kpc this is 10nr/yr. Can
paint the halo with proper motions vectors. Dv/dt =v2/r ~v/10^8 yr - galaxy is kinematic, not
dynamic (except very close to the center). Back to those globular clusters… get pms there and
have 5/6 of phase space.
February 2004
Its difficult to make predictions
about the future
