The highz Universe with ALMA

1

• The high-z Universe with ALMA

Carlos De Breuck (ESO)
2
The ALMA project

• ALMA is a collaboration between Europe (ESO
  Spain), North America (US Canada), and Japan.
• It is the merger of individual projects to build
  a large (sub)millimeter interferometer.
• Located on a 5000m high plateau in Northern Chile
  to take advantage of the excellent sky
  transparency.
• ALMA will be Easy to use for non-experts.

3
The Location Chajnantor plateau
4
Configurations

• ALMA will consist of 50 operational antennas.
• Antennas can be moved to 185 different pads.
• Maximum baselines from 150m to 18km ? resolutions
  from 1 to lt0.01 at 850 µm.

5
Japanese contribution Atacama Compact Array

• Even at the shortest baselines (15m), ALMA will
  not be sensitive to large-scale structure.

• Japan will provide an array of 12 smaller (7m)
  antennas in a very compact configuration
• Also 4 single-dish 12m antennas to provide total
  power.
• First total power antennas arrive in Chile in
  September 2007.

6
Observing in different frequency bands

• 10 Frequency bands coincident with atmospheric
  windows have been defined.
• Bands 3, 6, 7 and 9 will be available from the
  start.
• Bands 4, 8 and 10 will be built by Japan.
• Some band 5 receivers built with EU funding.

7
Powerful receivers

• Receivers will have an 8 GHz instantaneous
  bandwidth.
• System temperatures ( sensitivity) close to
  quantum noise limit.
• Spectral resolution 31.5 kHz (0.01 km/s) at 100
  GHz.
• Will observe in dual polarization mode.

8
Timeline (1)

• Operation Support Facilty _at_2800m construction in
  progress.
• Array Operations Site _at_5000m construction starts
  on 1 Sept 2005.
• 12m wide road connecting both sites almost ready.

9
Timeline (2)

• First antenna delivered on site in September
  2007.
• Further antennas coming from July 2008 with new
  antenna every 2 months.

• First science end of 2008.
• Full completion 2012.

10
ULIRG SED dust and molecular lines
11
Dust continuum negative k-corrections

• At zgt1, the peak of thermal dust emission shifts
  to submm wavelengths.
• For a given luminosity, the observed flux density
  remains the same, or increases slightly for zgt1.

12
CO rotational transitions (ladders)

• Line ratios of CO rotational transitions depend
  on density and temperature.
• In Milky Way type galaxies low-order
  transitions are brighter ? low densities.
• In dense cores of starburst galaxies,
  higher-order transitions are brighter.
• Radio observations with eVLA, ATCA SKA will be
  needed (see Ron Ekers talk).

Weiss et al. astro-ph/0508037
13
Detecting normal galaxies at z3

• CO emission now detected in 25 zgt2 objects.
• To date only in AGN, starbursts and
  gravitationally lensed objects. Normal galaxies
  are 20 to 30 times fainter.
• Detecting CO or C in Milky Way type galaxies out
  to z3 in lt24h is one of the 3 primary science
  requirements of ALMA.
• Assuming LCO(3-2)5x108 K km/s pc2 (COBE
  results, Bennett et al 1994), MW galaxy at z3
  has 0.037 mJy km/s ? requires 24 hr with full
  array to get 3s detection

14
The CII 158µm line
Maiolino et al. astro-ph/0508064

• CII 158µm is the main coolant in the Milky
  Way.
• However, it is much fainter in ULIRGs.
• First detection in z6.4 QSO.
• With high-frequency ALMA bands ? observe CII
  158µm at 1ltzlt8.

15
Example ALMA deep field at 300 GHz

• 4 x 4 Field (3000² pixels).
• Sensitivity 0.1 mJy (5s).
• 30 minutes per field, 140 pointings ? total of 3
  days.
• 100-300 sources.
• Alternative deep bolometer surveys (wider
  fields, but lower sensitivity resolution).

16
HDF rich in nearby galaxies, poor in
distant galaxies.
Source K. Lanzetta, SUNY-SB
Nearby galaxies in HDF
Distant galaxies in HDF
17
ALMA deep field poor in nearby galaxies, rich
in distant galaxies.
Source Wootten and Gallimore, NRAO
Nearby galaxies in ALMA deep field
Distant galaxies in ALMA deep field
18
ALMA as a redshift machine

• ALMA will provide 0.1 images of submm sources.
• 3 frequency settings will cover the entire
  84-116 GHz band ? at least one CO line. (1h per
  source)
• At zgt3, at least 2 CO lines in a single band.
• Confirm with observation of high/lower order CO
  line. (1h per source)

19
Follow-up studies with ALMA

• High resolution high fidelity (comparable to
  HST) dust CO imaging to determine morphology
  (mergers?), derive rotation curves ? Mdyn,
  density, temperature, ...
• Observe sources in HCN to trace dense regions of
  star-formation.

• Expected results of an ALMA deep survey
• Fully resolve the cosmic IR background into
  individual sources and determine FIR properties
  of LBGs and EROs as well as SMGs
• Map the cosmic evolution of dusty galaxies and
  their contribution to the cosmic star
  formation history.

20
Dark matter and intervening absorbers

• Detailed kinematical studies of galaxies
• CO will provide reliable kinematics of galaxies
  (better than optical and HI 21cm) ? dark matter
  distribution.
• CO Tully-Fisher relation is more accurate
  because CO is less broadened by galaxy
  interactions than HI.

• Intervening absorbers
• With ALMAs sensitivity, the number of
  background continuum sources will increase by 2
  orders of magnitude ? studies of intervening
  absorbers becomes possible.
• Explore chemistry, CMB temperature, variations
  of the fine structure constant, as a function
  of redshift.

21
Sunyaev-Zelldovich effect

• ALMA will observe at frequencies where the SZE
  is the strongest.
• Increase in sensitivity combined with improved
  resolution will allow to map the SZE in less
  massive clusters out to higher z.
• ALMA will have the sensitivity to detect not
  only the thermal, but also the kinetic SZE.?
  trace possible cluster rotation.

22
Sunyaev-Zeldovich effect

• Most clusters will be detected in other
  experiments such as Planck, AMIBA, SZA, APEX.
• ALMA will provide (sub)arcsec resolution imaging
  of these clusters.
• SZE scientific goals include
• Constrain cosmological parameters w, Om, s8
  through cluster counts variation of TCMB as
  function of z.
• Study physics of clusters, by mapping their hot
  gas and radial velocity (kSZ), obtaining baryon
  fraction,

23
Ostriker-Vishniac effect

• Dark matter halos with M109M? have formed by
  z30 those with M1011M? by z9.
• Between initial re-ionization and complete
  baryonic condensation, most baryons in these
  halos are ionized gas.
• Typical diameters are D2.5 to 30 kpc,
  corresponding to 1 to 6 at z9-30 (Peebles
  Juszkiewicz 1998).
• Thomson scattering of the CMB by these
  structures will dominate its anisotropy at arcsec
  scale the OV-effect.
• For peculiar velocities 200 km/s, 6 beam
  (z9), ?T(rms)/T2x10-5, corresponding to 150µJy
  at 100GHz.
• Easily detectable with ALMA in a few hours.

24
For more information on the ALMA construction,
see the ALMA newsletter

http//www.eso.org/projects/alma/newsletter