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Myung Gyoon LEE (K-GMT SWIG/Seoul National University) GMT2010:Opening New Frontiers with the GMT 2010.10.4-6, Seoul National University, Korea 1.

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Presentation on theme: "Myung Gyoon LEE (K-GMT SWIG/Seoul National University) GMT2010:Opening New Frontiers with the GMT 2010.10.4-6, Seoul National University, Korea 1."— Presentation transcript:

1 Myung Gyoon LEE (K-GMT SWIG/Seoul National University) GMT2010:Opening New Frontiers with the GMT , Seoul National University, Korea 1

2  Structure & dynamics of the Universe  Structure formation ◦ Mass assembly & Star formation  Dark matter  Dark energy 2 Komatsu et al (2008, 2010)

3  ΛCDM + Hierarchical Merging Model ◦ Successful for large-scale structures and CMBR 3 N-body simulation By Park (2005) Power spectrum (Tegmark et al 2004)

4  Structure & dynamics of the U?  Small-scale structure formation ◦ Mass assembly & Star formation  Dark matter  Dark energy? 4

5  LCDM + Hierarchical Merging model ◦ But, problems for small-scales ◦ Small-scale problems are not at all small, but big! 5 Power spectrum (Tegmark et al(2004))

6  Problems in ΛCDM+HM model 1) Missing satellite problem 2) Star formation problem 3) Galaxy core/cusp problem 4) Thin disk galaxy problem 6

7  To over current barriers with the power of the GMT  High resolution deep imaging+spectroscopy ◦ (NIRMOS, GMACS, GCLEF, GMTNIRS, GMTIFS etc) ◦ To complement with Skymapper, DES, LSST, JWST, etc.  Targets: dwarf galaxies and globular clusters 7

8  Dwarf galaxies ◦ are dark-matter dominated ◦ are made of various stellar pops ◦ can be studied in most detail  Cosmological topics with dwarf galaxies ◦ To study dark matter ◦ To study the early star formation history ◦ To find the first objects in the universe 8

9  Globular clusters ◦ are a good tracer of dark matter ◦ have a large range of metallicity ◦ are found in galaxies & between galaxies ◦ are bright: an efficient tool for local galaxies  Cosmological topics with globular clusters ◦ To study dark matter in galaxies and clusters ◦ To study the formation of their host galaxies ◦ To find the first objects in the universe 9

10 1) Dwarf galaxy cosmology 2) Globular cluster cosmology 10

11  Dark matter ◦ To understand the missing satellite problem ◦ 1) N(obs satellites) >> N(mini-halo in model) ◦ 2) M min (obs satellites) >>M min (mini-halo) 11 Comparison of mass functions for the MW dSphs and Via Lactea II simulation (Bullock 2010)

12  Segue 1: the darkest galaxy with M/L=3400 (M~10 6 Mo, but L=340 Lo), very small (r e =30 pc),  very metal poor ([Fe/H]=-2.5) 12 Geha et al (2009), Simon et al (2010), Martinez et al (2010 )

13  Dark galaxies have low surface brightness, small size, but some mass!  They may be ‘satellites of (dead) satellites’ (Belokurov et all 2009) 13 Mv-log r e (pc) for dwarf galaxies, globular clusters, and UCDs. Most of the new dwarfs (filled circles) are from SDSS. (???? 2010) GC UCD dSph Log r e [pc] Mv

14  M/L increases as dSph galaxies get less massive, smaller, and fainter. 14 Tellerud et al (2010) dSph

15  MW satellites mostly in the northern sky (POSS, SDSS)  Where are missing satellites?  To survey the southern sky ◦ Soon: Stromlo Missing Satellite Survey (SMSS) with Skymapper ◦ Later: DES, LSST 15 Distribution of MW satellites (Jerjen 2010)

16 16  Detection: wide field imaging for survey (LSST etc)  GMT follow-up: deep photometry & spectroscopy (member selection, age, metallicity, kinematics, mass, etc) N(R<400 kpc) Distance [kpc] GMT targets

17  Star formation history ◦ To understand star formation problem  The duration of the first star formation in dwarf galaxies is extended (e.g., Lee et al 2009, Monelli et al 2010). ◦ To find when and how long the first stars form 17 S FH of MW dSphs (Grebel 2005)

18  LCID: Deep HST  photometry of six  isolated galaxies  (Monelli etal (2010),  Tolstoy etal (2009))  Go deeper with the GMT  to derive the first star formation precisely!  Why not 100m- 1000m telescopes?  Time to start for them? 18

19  Still tough, but can dig older stars with the GMT! 19 Tolstoy etal (2009) Very metal poor!

20  The First Objects (Pop III?) ◦ To find the most metal-free stars (the oldest stars?) ◦ Where are they?  In the outskirts or center of a massive galaxy?  In dwarf galaxies?  In globular clusters? 20

21  Where are the most metal-poor stars?  [Fe/H], M/L/, M versus L for MW dSphs indicates  In the faintest dSphs (the most dark-matter dominated)! 21 (2009)

22  Frebel 2010’s prediction: 22

23 ◦ To study dark matter in galaxies and clusters ◦ To study the formation of their host galaxies ◦ To find the first objects 23

24  Dark matter in Galaxies ◦ Kinematics-> Dark matter distribution in their host galaxies ◦ Age & metallicity -> formation of their host galaxies 24

25 Harris (2009) CFHT/Megaprime: 1d x 1d for M87 ◦ 25  A summary of gE GC kinematics: diversity (Lee et al (2010a)  GMT spectroscopy of GCs (radial velocity, [Fe/H], [alpha/H]) SDSS IGC GMT spec GC

26  Dark matter in Galaxy Clusters ◦ Kinematics of intracluster globular clusters (IGCs)-> Dark matter distribution in galaxy clusters 26

27 27  Large scale structure of GCs in Galaxy Clusters ◦ (Lee et al 2010b, Science) ◦ GMT spectroscopy of IGCs ◦ (radial velocity, age, metallicity)

28  To find the first objects  Some of the IGCs may be the first objects!  GMT Spectroscopy and deep photometry 28

29

30 *HST/ACS images: They are genuine GCs! - Williams et al (2007) 4 IGCs in Area 4 -Lee, Lim, et al (2010, in prep) several new IGCs Are they really GCs? How about compact dwarfs (UCDs, DTGCs)? 30

31  Do they belong to the same class?  Which of them are the first objects? 31 Faber-Jackson relations from GCs to galaxy clusters. (Tellerud et al 2010) GC dSph UCD

32 32  1968 Peebles and Dicke’s suggestion.  With the GMT, we can test it!

33 With the GMT observations (GMACS, NIRMOS, Gclef, GMTNIRS, GMTIFS, etc) of dwarf galaxies and globular clusters, we can 1) study dark matter in galaxies and clusters 2) study the early star formation history 3) find the first objects in the universe 33


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