Galaxy Formation and Evolution by dffhrtcv3

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									  ALMA and the
Formation of Galaxies




        Pierre Cox
     IAS, Orsay, France
« The stellar systems are scattered through space as far
as telescopes can penetrate. We find them smaller and
fainter, in constantly increasing numbers, and we know
that we are reaching out into space, until, with the
faintest nebulae than can be detected with greatest
telescopes, we arrive at the frontiers of the known
Universe. »

Edwin Hubble, The Realm of the Nebulae (1936)
A Galaxy is a large Assemblage of Stars, Gas and Dust that is held
together by the mutual gravitational interaction between its
Constituents. Galaxies contain between a few million and about
ten trillion Stars together with differing proportions of interstellar
matter (Gas & Dust)




                       Spiral Galaxy NGC1512
     A Galaxy:the Tip of the Iceberg of Dark Matter

Angular Momentum of the Halo              Dark Matter Halo

                                                  M=1012 Msol
      Hot Gas
                                                  Old Stars




                                                Young Stars


       Cold Gas
                                         Supernova

                               100 kpc
8




Z=1000
             Hierarchical Formation


    Z = 10


     Today
        HOW WERE THE GALAXIES FORMED ?




300,000 yr after
                                   12 billion yr later
the Big Bang
                                COBE


The Early
Universe



                                       Boomerang
The last scattering surface of the
cosmic microwave background
reveals information on very low
amplitude density variations in
the dark matter 300,000 years
after the Big Bang, and on the
origin of these fluctuations
within the first 10-35 sec.
Simulations of the Developments of Large Scale Structures in
      the Universe: Dark Matter and Gas Dynamics
The Distribution of (invisible) Dark Matter can be mapped
using the (Gravitational Lens) Distortion of the Images of
Background Galaxies




      Foreground Cluster     Background Galaxies
      Abell 2218
                    Galaxy Evolution
Galaxies at z> 2 are multiple   Assembly of large Galaxies was
with evidence of merging        evidently completed at z<1
Visible (baryonic) Matter is at the
Center of the Gravitational Wells
The merging of two Galaxies
Stephan’s Quintet
The Center of the Milky Way

              Optical


  The Effect of Dust


 Submillimeter (SCUBA)
UV   Visible   Infrared   Submm/mm



           Add Dust
  Infrared/submm Spectrum of Galaxies: Dust & Gas



Dust: Graphite,
Silicates…..


Gas:
Atomic (H, C, O, N….)
Molecular (CO, HCO+…)
          M83
Optical     Carbon Monoxide CO(1-0)




                           SEST
             The Antennae Galaxy

HST Optical image        HST Optical image + CO
Optical is
 not the
 whole
  story




             Population of rare but
             high luminosity sources
             (1012 Lsun) matches
             energy output of UV-
             selected population at
             high z
         Cluster A1835




Z=2.55                   0.7<Z<2.5
                Dust and CO in
              BR1202-0725 at z=4.7




                            CO emission PdB & Nobeyama


1.2 mm Continuum MAMBO
       A next Generation mm/submm Telescope

                           ALMA
•a mm/submm equivalent of VLT, HST, NGST with corresponding high
sensitivity and angular resolution but unhindered by dust opacity
•a capability to see star-forming galaxies out to the highest redshifts
 Surveys of high redshift galaxies with ALMA

mm/submm sensitive searches to obscured, star-forming regions

             TODAY: about 200 sources known

             ALMA: many 100,000 sources


ALMA will detect objects to redshifts as high as 10-20

            Into the Reionization Epoch


            Morphology, Physical & Chemical Properties
      High Angular Resolution & Sensitivity

SCUBA resolution              ALMA resolution
Gravitational Lensing by a Cluster of Galaxies




   Submillimeter                 Optical
  ALMA will revolutionize our
understanding of the Formation
    of Galaxies in the early
           Universe



•mm/submm is a vital new window on the distant Universe
    –unobscured view of star-forming galaxies, at wavelengths
    containing most of the luminosity of the distant Universe
•ALMA’s sensitivity and angular resolution are essential to realize
this potential
•ALMA’s scientific contributions will include studies of the
earliest galaxies, an accounting of the bolometric luminosity of the
distant Universe, and the evolution of galaxies, quasars and the
elements over cosmic time
« We are, by definition, in the very center of the observable region.
We know our immediate neighborhood rather intimately. With
increasing distance, our knowledge fades, and fades rapidly.
Eventually, we reach the dim boundary, the utmost limits of our
Telescopes. There, we measure shadows, and we search among
ghostly errors of measurement for landmarks that are scarcely
more substantial.

The search will continue. Not until the empirical resources are
exhausted, need we pass on the dreamy realms of speculation. »

Edwin Hubble, The Realm of Nebulae (1936)

								
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