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Transcript
1. What have you learned from this
workshop?
2. Where do you see the field going
in the next 5 years?
3. Which projects would be most
interesting as a graduate student
thesis?
Learn? Moi?
• The field is young and vibrant
• This proves there is much to learn! And hope.
• Clusters, dSph, & halo field subdwarfs are the 3 old metal-poor cospatial populations. How are/are they related? This remains
unclear. [later star formation in dSph is perhaps a separate problem]
• There are clear structural/dynamical/DM differences between dSph
and clusters  different formation?
• Do metal-poor GC’s trace PoPII? [Redefine Sn]
• Formation Models are developing extremely impressively: now good
enough they can be used as a research tool, to investigate what we
don’t yet know. This is a huge advance. Very impressive.
• But: still very much post-diction recipes to reproduce data, not yet an
investigation of parameter space. Is there any `if this is wrong
something important must be changed’ prediction?
Comments of my colleagues
For a model to be science, it must make falsifiable predictions.
Do they?
All these models tell me to relax, since all galaxy formation
problems are solved. Since all models differ, no wonder I’m
suspicious
Things are seen as they are since this is the best understood of all
possible worlds
Modulo variance. And physics.
Of course galaxy formation models are correct.
They have always been correct.
Just different than they used to be.
Models should be used to isolate and investigate what we
do not understand, not provide post hoc recipes to postdict data.
Next few years
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Gaia will revolutionise the subject: Launch 12/2011
Get ready to handle complex 3-D dynamical data…
`complete’ the dwarf census – help a wee bit only?
Quantify inner galaxy better: we focus on the outer galaxy since we can, not
because it is most significant. The reverse may be true: where are most
stars? Most angular momentum? Most metals?
More dynamics 1:– resolve core-cusp finally – probably no surprises, but
leaves pre-history (what is `no surprise’????)
More dynamics 2: outer parts and tides – is there anything fundamental
here? May be relevant for galaxy formation, not to study the nature of dark
matter?
Model-Building realistic LSB dwarfs?? Uniquely?
Understand the dSph orbits – what/where was Sgr 8 Gyr ago?
The bigger picture: linking the dSph to formation of the bulge, old thick
disk, thin disk, assorted debris,….
Clarify the environment [variance] dependence: loose groups vs clusters
What provided pre-enrichment? Re-ionisation?
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http://www.rssd.esa.int/index.php?project=GAIA&page=index
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• Several large kinematic studies: now is the
time to merge, publish, and make
consistent all the data: ----• The CTP manifesto
• An AVO-consistent dBase of stars,
kinematics, photometry, [spectra?].. for all
dSph: we’ll happily be part of this – and do
it. the Matt Walker opportunity? Add our
echelle spectra too, if wanted
• Access for contributors only at first?
A few viable problems
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Can anyone make reliable simulations for a variety of plausibly different
[W]DM models*???? Stay topical in LHC era!
Is small-scale feedback internal? External? Both? – limited by SFR(t) –
[quantify the limits better] & chemical element ratios
What `really’ would happen to DM in a baryon-dominated region – is it all
evacuated dynamically, creating cores? Or vice versa: is a smooth potential
adequate? Star cluster like model?
How did – or did? – small DM halos virialise?
What is the intermediate phase-mixing state as a star-forming region
evaporates into a dIrr/dSph environ (theory/obs)
Are there many small DM sub-halos in mid-sized dIrr galaxies (LMC-like) –
look for effect on HI/GMC.
Whatever caused the pre-enrichment*, might this (set of) processes affect
early structures
Where did the field halo form its stars? Mixing scale-length limits from
element ratio plus dynamics analysis. Why were all progenitors so exactly
similar (reionisation)? What is relation to rest of galaxy?
Galaxy cluster systems bi-modal in colour (age? Other?). Why bi, not tri?
Are most GC systems correlated with old (popII) halo field? Why?
Does every galaxy have a metal-poor PopII stellar halo – this would seem to
be a non-negotiable test of Lcdm substructure photoionisation models. Does
this apply to galaxies of every mass?
* this is a harder one…