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Tuesday Lunch New Windows on Star Formation in the Cosmos October 11-13, 2004 U. of Maryland The Dusty and Molecular Universe A prelude to HERSCHEL and.

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Presentation on theme: "Tuesday Lunch New Windows on Star Formation in the Cosmos October 11-13, 2004 U. of Maryland The Dusty and Molecular Universe A prelude to HERSCHEL and."— Presentation transcript:

1 Tuesday Lunch New Windows on Star Formation in the Cosmos October 11-13, 2004 U. of Maryland The Dusty and Molecular Universe A prelude to HERSCHEL and ALMA 27 - 29 October 2004, Paris ALMA Update Al Wootten NRAO New Windows on Star Formation in the Cosmos October 11-13, 2004 U. of Maryland The Dusty and Molecular Universe A prelude to HERSCHEL and ALMA 27 - 29 October 2004, Paris ALMA Update Al Wootten NRAO

2 Tuesday Lunch2 U. Of Md.

3 Tuesday Lunch3 Dusty04 http://aramis.obspm.fr/DUSTY04/plan.html

4 Tuesday Lunch4 Dusty04—Herschel Schedule

5 Tuesday Lunch5

6 6

7 7 HIFI

8 Tuesday Lunch8 PACS

9 Tuesday Lunch9 SPIRE

10 Tuesday Lunch10 ALMA: Current Definition 64 moveable 12-m antennas: ‘100-m class telescope’ Baselines from 15m to 15km –Angular resolution ~40 mas at 100 GHz (5mas at 900GHz) –Strong implications for atmospheric phase correction scheme Receivers: low-noise, wide-band (8GHz), dual-polarisation, SSB –Many spectral lines per band Digital correlator, >=8192 spectral channels, 4 Stokes –very high spectral resolution (up to 15kHz) Short spacing data provided by 12-m antennas in single-dish mode –Critical for objects bigger than the primary beam Requirements for star formation and high-z studies are remarkably similar!

11 Tuesday Lunch11 Summary of detailed requirements Frequency30 to 950 GHz (initially only 84-720 GHz) Bandwidth8 GHz, fully tunable Spectral resolution31.5 kHz (0.01 km/s) at 100 GHz Spatial resolution<0.01” (18.5 km baseline at 650 GHz) Dynamic range10000:1 (spectral); 50000:1 (imaging) Flux sensitivitySub-mJy in <10 min (median conditions) Antenna complement64 antennas of 12m diameter PolarizationAll cross products simultaneously

12 Tuesday Lunch12 Management – JAO Staffing Joint Alma Office (JAO) in Chile: – Director:Massimo Tarenghi – Project Manager:Tony Beasley – Project Engineer:Rick Murowinski – Project Scientist:Vacant – Project Controller:Richard Simon (interim) – Logistics Officer:Charlotte Hermant

13 Tuesday Lunch13 Agreement (2/2)

14 Tuesday Lunch - de Breuck14 Primary Scientific Requirements ALMA will be a flexible observatory supporting a wide range of scientific investigations in extragalactic, galactic and planetary astronomy. ALMA should be “easy to use” (i.e. you do not need to be an expert in aperture synthesis to produce images). Three scientific requirements drive the science planning. These are the “Primary Scientific Requirements”.

15 Tuesday Lunch15 Primary Scientific Requirements The ability to detect spectral line emission from CO or CII in a normal galaxy like the Milky Way at a redshift of 3, in less than 24 hours of observation. The ability to image the gas kinematics in protostars and protoplanetary disks around young Sun-like stars at a distance of 150 pc, enabling one to study their physical, chemical and magnetic field structures and to detect the gaps created by planets undergoing formation in the disks. (see John Richer’s talk) The ability to provide precise images at an angular resolution of 0.1”. Here the term ‘precise images’ means representing to within the noise level the sky brightness at all points where the brightness is greater than 0.1% of the peak image brightness. This requirement applies to all sources visible to ALMA that transit at an elevation greater than 20°.

16 Tuesday Lunch16 Detecting normal galaxies at z=3 CO emission now detected in 25 z>2 objects. To date only in luminous AGN and/or gravitationally lensed. Normal galaxies are 20 to 30 times fainter. Current millimeter interferometers have collecting areas between 500 and 1000 m 2.

17 Tuesday Lunch17 Detecting normal galaxies at z=3 ALMA sensitivity depends on: 1.Atmospheric transparency: Chajnantor plateau at 5000m altitude is superior to all existing mm observatories. 2.Noise performance of receivers: can be reduced by factor 2 (approaching quantum limit). Also gain √2 because ALMA will simultaneously measure both states of polarization. 3.Collecting area: remaining factor of 7 to 10 can only be gained by increasing collecting area to >7000 m 2.

18 Tuesday Lunch18 At z=3, the 10 kpc molecular disk of the Milky Way will be much smaller than the primary beam → single observation. Flux density sensitivity in image from an interferometric array with 2 simultaneously sampled polarizations and 95% quantum efficiency is: Aperture efficiencies 0.45<ε a <0.75 can be achieved (25 µm antenna surface accuracy). T sys depends on band, atmosphere, … for 115 GHz, T sys =67 K obtainable. Detecting normal galaxies at z=3

19 Tuesday Lunch19 Detecting normal galaxies at z=3 Total CO luminosity of Milky Way: L ’ co(1-0) = 3.7x10 8 K km s -1 pc 2 (Solomon & Rivolo 1989). COBE found slightly higher luminosities in higher transitions (Bennett et al 1994) → adopt L ’ co = 5x10 8 K km s -1 pc 2. At z=3 → observe (3-2) or (4-3) transition in the 84-116 GHz atmospheric band → need to correct, but also higher T CMB providing higher background levels for CO excitation. Different models predict brighter or fainter higher-order transitions. Few measurements of CO rotational transitions exist for distant quasars and ULIRGs, but these are dominated by central regions. → Assume L ’ co(3-2) / L ’ co(1-0) = 1.

20 Tuesday Lunch20 Detecting normal galaxies at z=3 For ΛCDM cosmology, Δv=300 km/s, the expected peak CO(3-2) flux density is 36 µJy. Require 5σ detection in 12h on source (16h total time). → ND 2 =7300 m 2. Achievable with N=64 antennas of D=12m diameter.

21 Tuesday Lunch21 Precise 0.1” resolution images 0.1” resolution needed to complement contemporary facilities: JWST, eVLA, AO with 8-10m telescopes, … High angular resolution and sensitivity complementary. High fidelity images require a sufficiently large number of baselines to fill >50% of the uv-plane. Short tracking (<2 hours) to reduce atmospheric variations → requires ND > 560 for a maximum baseline of 3 km. Achievable with 64 12m antennas.

22 Tuesday Lunch22 Precise 0.1” resolution images Array cannot measure smallest spatial frequencies (<D). Solve by having four antennas optimized for total power measurements (nutating secondaries). Remaining gap in uv-plane filled in by Atacama Compact Array (ACA): 12 antennas 7m diameter.

23 Tuesday Lunch23 Design Reference Science Plan 128 projects; full list available from http://www.alma.nrao.edu http://www.a Use ALMA sensitivity calculator: http://www.eso.org/projects/alma/science/bin /sensitivity.html Total time: 3-4 years of ALMA observing.

24 Tuesday Lunch24 Design Reference Science Plan

25 Tuesday Lunch25 Molecular line studies of submm galaxies >50% of the FIR/submm background are submm galaxies. Trace heavily obscured star-forming galaxies. Optical/near-IR identification very difficult. Optical spectroscopy: ~2.4. Confirmation needed with CO spectroscopy.

26 Tuesday Lunch26 Molecular line studies of submm galaxies ALMA will provide 0.1” images of submm sources found in bolometer surveys (LABOCA/APEX, SCUBA- 2/JCMT) or with ALMA itself. 3 frequency settings will cover the entire 84-116 GHz band → at least one CO line. (1h per source) Confirm with observation of high/lower order CO line. (1h per source)

27 Tuesday Lunch - end de Breuck27 Molecular line studies of submm galaxies Follow-up with ALMA: High resolution CO imaging to determine morphology (mergers?), derive rotation curves → M dyn, density, temperature,... (1h per source) Observe sources in HCN to trace dense regions of star-formation. (10h per source, 20 sources) Total: 12h per source, 170h for sample of 50 sources.

28 Tuesday Lunch - CC28 Millimeter VLBI – Imaging the Galactic center black hole (Falcke 2000) Kerr Schwarzschild Model: opt. thin synch 0.6 mm VLBI 16uas res 1.3 mm VLBI 33 uas res R _g = 3 uas

29 Tuesday Lunch - CC29 Enabling technology III: Wideband spectroscopy – Redshifts for obscured/faint sources: 8 - 32 GHz spectrometers on ALMA, LMT, GBT (Min Yun 04, Harris 04) L _FIR = 1e13 L _sun ALMA

30 Tuesday Lunch30

31 Tuesday Lunch31 Andre

32 Tuesday Lunch - JSR32 ALMA “Level 0” Requirements Image gas kinematics in protostars and protoplanetary disks around Sun-like stars at 140pc distance, enabling one to study their physical, chemical and magnetic field structures and to detect the gaps created by planets undergoing formation in the disk. Provide precise images at 0.1 arcsec resolution. Precise means representing within the noise level the sky brightness at all points where the brightness is greater than 0.1% of the peak image brightness. This applies to all objects transiting at >20 degree elevation.

33 Tuesday Lunch33 Good match to weather statistics and science

34 Tuesday Lunch34 Frequency band capabilities Band 3: 84-116GHz. FOV = 60 arcsec –Continuum: ff/dust separation, optically-thin dust, dust emissivity index, grain size –SiO maser, low excitation lines CO 1-0 (5.5K), CS 2-1, HCO + 1-0, N 2 H+… Band 6: 211-275GHz. FOV = 25 arcsec –Dust SED –Medium excitation lines: CO 2-1 (16K), HCN 3-2, … Band 7: 275-373GHz. FOV = 18 arcsec –Continuum: most sensitive band for dust. –Wave plate at 345GHz for precision polarimetry –Medium-high excitation lines: CO 3-2 (33K), HCN 4-3, N 2 D +, … Band 9: 602-720GHz. FOV = 9 arcsec –Towards peak of dust SED, away from Rayleigh Jeans; hence T(dust) –High excitation lines e.g. CO 6-5 (115K), HCN 8-7 in compact regions

35 Tuesday Lunch35 Diffraction limited imaging needs phase correction Water fluctuations typically 500m- 1000m above site Correct by Fast Switching of antennas to QSO, plus Water Vapor Radiometry

36 Tuesday Lunch - Walmsley36 Star Forming Regions are complex Such as DR21 at roughly 3 Kpc (Marston et al. IRAC)

37 Tuesday Lunch - Walmsley37 Serpens at 3mm and 100 microns (Testi priv.comm)

38 Tuesday Lunch38 Fundamental steps forward with Herschel PACS : Maps of star forming regions in continuum and OI 63 micron line SPIRE : Maps on the large scale (eg of galactic plane, see Molinari HIGAL poster) HIFI : Water and detailed kinematics of star forming regions

39 Tuesday Lunch39 Initial Conditions: Pre-collapse Cores L1498: Tafalla et al. Strong chemical gradients and clumpiness Indicates depletion and chemical evolution ALMA mosaic at 3mm: 100 pointings plus single- dish data needed ALMA can resolve 15AU scales in nearby cores, or study cores at 1000AU scales out to 10kpc

40 Tuesday Lunch40 Core dynamics: infall Di Francesco et al (2001) Small-scale Extended 0.1 - 0.3 pc Walsh et al

41 Tuesday Lunch41 Starless Core Chemistry: probing the depletion zones Complete CNO depletion within 2500AU? ALMA can study this region, in objects as far as the GC, in H 2 D + CS, CO, HCO + NH 3, N 2 H + H2D+D2H+H2D+D2H+ Walmsley et al. 2004; Caselli et al 2003 372GHz line 8,000AU 2,500AU 15,000AU

42 Tuesday Lunch42 Role of Magnetic Fields? (Figure by A. Chrysostomou) (Crutcher et al) L1544: Ward-Thompson et al 2000

43 Tuesday Lunch43 Star formation in crowded environments ALMA can resolve 15AU scales at Taurus Clump mass function down to 0.1 Jupiter masses Onset of multiplicity BD formation Internal structure of clumps Turbulence on AU scales Bate 2002 Protostars and Clumps in Perseus: Hatchell et al 2005.

44 Tuesday Lunch44 Molecular Outflows Origin of flows down to 1.5AU scales –10 mas resolution at 345 GHz: 24 hours gives 5K rms at 20 km/s resolution –Resolve magnetosphere: X or disk winds? –Flow rotation? Proper motions –0.2 arcsec per year for 100km/s at 100pc –Resolve the cooling length Resolve multiple outflow regions Beuther et al, 2002 Chandler & Richer 1999 170AU resolution

45 Tuesday Lunch45 Spatially-resolved Spectral Surveys 8GHz bandwidth Schilke et al Kuan et al 2004

46 Tuesday Lunch46 Kuan et al 2004 Looney et al, 2000 “Hot Core” chemistry around low mass protostars 300AU sized molecular structures around protostellar candidates Different chemical signatures

47 Tuesday Lunch47 Circumstellar Disks: Structure and Evolution Dutrey et al

48 Tuesday Lunch - Guilloteau48 Disk around young stars Current arrays have done about 20 sources... (e.g. IRAM PdB Survey) ALMA sensitivity 50 times better... ALMA could do hundreds of sources in continuum, to a much better level, and at much higher angular resolution

49 Tuesday Lunch - SG49 Zooming on inner disks Nice, circularly symmetric, Keplerian disks don’t really exist E.g. AB Aur 1.3 mm image at 0.6” resolution: “spiral” density enhancements 100 AU from the star (black: IR from Fukagawa et al 2004, White: mm from Piétu et al 2004) Are such phenomena common? Long-lived ?

50 Tuesday Lunch - SG50 Stellar Masses (and more) From the (Keplerian) rotation curve, measured from CO (Simon et al 2000) Temperature from CO isotopes (Dartois et al 2003) A sample of 40 sources, in CO and its isotopes at 0.2” resolution requires 2600 hours of ALMA !

51 Tuesday Lunch - SG51 Transition Disks ? ALMA can image the “débris” disks around (young) stars But also perhaps unveil the transition stage between proto-planetary disks and “débris” disks Small disks just being found: e.g. BP Tau (Dutrey et al 2003) But studies will require long integration time even with ALMA (>> 10 hours / object)

52 Tuesday Lunch - SG52 Long term schedule Proper motions can be measured with ALMA Clumps in “debris” disks (  evidence for planets ?) Orbital motions of proto-stellar condensations in massive star forming regions  Plan in advance and for the long term...

53 Tuesday Lunch - JSR53 Protoplanetary disk at 140pc, with Jupiter mass planet at 5AU ALMA simulation –428GHz, bandwidth 8GHz –total integration time: 4h –max. baseline: 10km Contrast reduced at higher frequency as optical depth increases Will push ALMA to its limits Wolf, Gueth, Henning, & Kley 2002, ApJ 566, L97 Imaging Protoplanetary Disks

54 Tuesday Lunch54 See Sebastian Wolf’s talk Direct detection of proto-Jovian planets? Wolf et al 2004

55 Tuesday Lunch55 “Debris” disk spectroscopy with Spitzer Rieke et al 2004

56 Tuesday Lunch56 “Debris” Disk imaging with ALMA Wyatt (2004) model: dust trapped in resonances by migrating planets in disk ALMA will revolutionise studies of the large cold grains in other planetary systems Vega (Holland et al) Fomalhaut (Greaves et al)

57 Tuesday Lunch57 ALMA could map one square degree at 350GHz in 180 hours to –0.7mJy sensitivity –This is 0.15 solar masses at 20K –confusion limited unless resolution high 1 arcsec beam (8500AU) would give –ΔT=0.6K at 1 km/s resolution Possible lines in 2x4GHz passband: –USB: SiO 8-7, H 13 CO + 4-3, H 13 CN 4-3, CO 3-2 –LSB: CH 3 CN, CH 3 OH –Or –USB: HCN 4-3, HCO + 4-3 –LSB: H 13 CN 4-3, CS 7-6, CO 3-2 Pierce-Price, Richer, et al 2000 SCUBA 850 micron: Pierce-Price et al 2000 SCUBA 450 micron Star Formation at the Galactic Centre

58 Tuesday Lunch58 Final Remarks ALMA’s unique role will be imaging down to few AU scales in nearby star forming regions with a sensitivity of a few Kelvin –Protostellar and protoplanetary disks –Accretion, rotation and outflow deep in the potential well –Chemistry and dust properties at high spatial resolution –Will require excellent operation on long baselines Study star formation across the Galaxy Modest resolution observations (0.5 arcsec or so) will be important too –Good brightness sensitivity ALMA has a narrow field of view –Need surveys with single dishes to feed ALMA Many targets extended over several primary beams –Need high-quality short spacing data to make precise images and for flux ratio experiments

59 Tuesday Lunch - JSR final59 Site – Road Construction 1 Road Construction There are 42Km of road being constructed between Highway 23 outside San Pedro de Atacama to the AOS via the OSF giving ALMA its own private road network. Initial construction started in 2003 and the road was opened in time for the Ground Breaking ceremony in November. Commencing in June 2004 the final construction is now taking place to consolidate the existing road and make it suitable for the main construction and operations phases.

60 Tuesday Lunch60

61 Tuesday Lunch61 GPS track on site image

62 Tuesday Lunch62 Right of Way Concession Site – Road Construction 2

63 Tuesday Lunch63 To AOS OSF Site Site – Road Construction 3

64 Tuesday Lunch64 Site – Road Construction 4 View West Road at 18Km View East

65 Tuesday Lunch65 ALMA Camp The permanent ALMA camp at the OSF is currently being used by members of the site IPT. Further expansion is planned over the following year to allow accommodation of all ALMA staff during the main integration phase. The camp will also be used during the operations phase and it is planned to augment the facilities with a Residence building housing about 100 visiting staff and observers. At the same time a Contractors camp is being built nearby to house the contractors workforce during the construction phase. Site – ALMA Camp 1

66 Tuesday Lunch66 Site – ALMA Camp 2 ALMA Camp – General View Inner Court Typical Office

67 Tuesday Lunch67 ALMA Board at ALMA Camp Grill

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69 Tuesday Lunch69 Site – OSF 1 Operations Support Facility The OSF is the main facility for operations and maintenance of the array. Situated at 2900m it will offer a modern, comfortable and safe environment from which both scientific observation and routine maintenance can be conducted. The design of the OSF encompasses workshop facilities, integration facilities and maintenance areas for both the current baseline ALMA and the enhanced design to include the contribution of Japan. In addition the array operations centre and associated observing facilities are all contained within the same campus.

70 Tuesday Lunch70 OSF Camps and Technical Facilities ALMA Camp Contractors Camp Visitors Center Access Road to Visitors Center Residence Area

71 Tuesday Lunch71 Site – AOS 1 Array Operation Site The AOS complex houses the Correlator and Local Oscillator equipment together with limited workshop facilities and emergency overnight accommodation. It is not intended to have any staff permanently stationed at the AOS and all operations will be conducted remotely from the AOS. The layout of the array foundations has been completed with a total of 216 pads. The original compliment of 256 pads has been reduced with no compromise to the ALMA science.

72 Tuesday Lunch72 Site – AOS Building 1

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