Imaging Cosmic Dawn: The Atacama Large Millimeter Array Christine Wilson Canadian ALMA Project Scientist McMaster University SMA meeting June 2005 (Original slides: Al Wootten)
Download ReportTranscript Imaging Cosmic Dawn: The Atacama Large Millimeter Array Christine Wilson Canadian ALMA Project Scientist McMaster University SMA meeting June 2005 (Original slides: Al Wootten)
Imaging Cosmic Dawn: The Atacama Large Millimeter Array Christine Wilson Canadian ALMA Project Scientist McMaster University SMA meeting June 2005 (Original slides: Al Wootten) The Millimeter Spectrum • Millimeter/submillimeter photons are the most abundant photons in the spectrum of the Milky Way, most spiral galaxies, and the cosmic background. • After the 3K cosmic background radiation, millimeter/submillimeter photons carry most of the energy in the Universe (40% of the energy in the Milky Way Galaxy). • These photons dominate the spectrum of planets, young stars, and many distant galaxies • ALMA will observe wavelengths from 1cm to 0.3 mm. SMA meeting June 2005 ALMA Science Requirements • • • • • • • • • High Fidelity Imaging Precise Imaging at 0.1” Resolution Routine Sub-mJy Continuum Sensitivity Routine mK Spectral Sensitivity Wideband Frequency Coverage Wide Field Imaging Mosaics Submillimeter Receiver System Full Polarization Capability System Flexibility (Total Power capability on ALL antennas) Top rated project in 1990 decadal review SMA meeting June 2005 Chajnantor SW from Cerro Chajnantor, 1994 May SMA meeting June 2005 AUI/NRAO S. Radford Complete Frequency Access Note: Band 1 (31.3-45 GHz) not shown SMA meeting June 2005 ALMA Specifications • 64 12-m antennas, at 5000 m altitude site • Surface accuracy 25 m, 0.6” reference pointing in 9m/s wind, 2” absolute pointing all-sky • Array configurations between 150m to ~15km • 10 bands in 31-950 GHz + 183 GHz WVR. Initially: • • • • • • • • • • • 86-119 GHz 125-163 GHz 211-275 GHz 275-370 GHz 385-500 GHz 602-720 GHz “3” “4” “6” “7” “8” “9” 8 GHz BW, dual polarization Interferometry, mosaics, & total-power observing Correlator: 4096 channels/IF (multi-IF), full Stokes Data rate: 6Mb/s average; peak 60Mb/s SMA meeting June 2005 All data archived (raw + images); pipeline to process Science with ALMA • • • • Formation of Galaxies and Clusters Formation of Stars Formation of Planets Creation of the Elements – Old stellar atmospheres – Supernova ejecta • Low temperature thermal science – Planetary composition, weather – Interstellar gas and dust – Astrochemistry, origins of life SMA meeting June 2005 Wilson et al. 2000 Making an ALMA Deep Field Step 1: 300 GHz Continuum Survey • 4’ x 4’ Field (3000x3000 pixels) • Sensitivity: 0.1 mJy (5s) – 30 minutes per field – 140 pointings – A total of 3 days • 100-300 sources 850 um 170 um 15 um Determine the contribution of LBGs to the IR background SMA meeting June 2005 Lewis et al. 2005 Galaxies at High Redshift • For distant galaxies, dimming due to distance is offset by the brighter part of the spectrum redshifting into an ALMA band • Result is galaxies have relatively similar brightness out to large distances SMA meeting June 2005 M82 from ISO, Beelen and Cox, in prep. Hubble Deep Field Rich in Nearby Galaxies, Poor in Distant Galaxies K. Lanzetta, SUNY-SB Nearby galaxies in HDF Distant galaxies in HDF SMA meeting June 2005 ALMA Deep Field Poor in Nearby Galaxies, Rich in Distant Galaxies Wootten and Gallimore, NRAO Nearby galaxies in ALMA Distant galaxies in ALMA SMA meeting June 2005 Deep Field Deep Field ALMA Deep Field Step 2: 100 GHz Spectroscopic Survey • 4’ x 4’ Field ( 1000x1000 pixels) • Sensitivity: 7.5 mJy continuum and 0.02 Jy km/s for a 300 km/s line (5s) – 12 hrs per field – 16 pointings (a total of 8 days) – 4 tunings • One CO line for all sources at z>2 and two or more at z>6 --> obtain spectroscopic redshifts • Photometric redshifts SMA meeting June 2005 Gas Distribution and Kinematics SMA meeting June 2005 Chapman et al. (2004) Formation of Stars • A key observation is infalling gas seen in absorption against the background protostar • Achievable now only toward a handful of sources, i.e., in the binary source NGC1333 IRAS 4A/B • ALMA will carry out similar experiments towards much weaker sources, with higher (.05 vs .16 km/s) velocity resolution and spatial resolution of ~1” SMA meeting June 2005 Di Francesco et al. 2001 Protoplanet Formation Mplanet / Mstar = 0.5MJup / 1.0 Msun Maximum baseline: 10km, tint=8h, Orbital radius: 5 AU 30deg phase noise Disk mass as in the circumstellar disk as around the Butterfly Star in Taurus Tsys = 1200K (333mu) / 220K (870mu) pointing eror 0.6“ Sebastian Wolf (2005) l = 333m l = 870m 50 pc 100 pc SMA meeting June 2005 50 pc Close-up view: Planetary region Mplanet / Mstar = 0.5 MJup / 1 Msun 50 pc Orbital radius: 5 AU Disk mass as in the circumstellar disk as around the Butterfly Star in Taurus 100 pc SMA meeting June 2005 Wolf & D’Angelo (2005) Maximum baseline: 10km, l=333m, tint=8h, 30deg phase noise astro-ph / 0410064 Highlights in 2004/5 • Entry of Japan into ALMA Project, bringing – – – • • • • • • Atacama Compact Array (ACA): 12 x 7m antenna 4x12m antennas for total power two or three additional receiver bands Construction of a working ALMA Camp at 2900m, road to 5000m level well underway Establishment of JAO in Santiago, decision for permanent office at ESO Prototype Integration of ALMA components into a functioning whole is ongoing Planning and formation of the North American, European ALMA Science Centers proceeding Operations Plan Version A approved Antenna Contract hopefully this year … SMA meeting June 2005 5000m Chajnantor site APEX CBI ALMA Site Char SMA meeting June 2005 View from the Highway To AOS (43km) Road construction (28km) SMA meeting June 2005 OSF Site (15km) ALMA Camp SMA meeting June 2005 Antenna Configurations (min) 150 m SMA meeting June 2005 Antenna Configurations (max) 10,000m 4 mas @ 950 GHz Site infrastructure (AOS/OSF) + inner array completed 2008 SMA meeting June 2005 ALMA Test Facility SMA meeting June 2005 Front End assembly SMA meeting June 2005 Cartridges (Bands 3 & 6) 3 SMA meeting June 2005 6 ALMA Regional Centers The JAO will have user interfaces known as “ARCs” in each of the three partner regions: North America, Europe, & Japan. The ARCs will conduct activities needed to receive and process proposals from observers and return data to users, all archive based and organized. The ARC archives are mirror archives of the central archive in Santiago; they all contain the same data, all the data. SMA meeting June 2005 The North American ALMA Science Center Interim Director, Paul A. van den Bout SMA meeting June 2005 NAASC: Beyond the NA ARC • • • • • • • • Data analysis grants program ALMA Fellows Pre-doctoral & co-op students Astronomers – archive functions EPO program Systems Admin. Business & library services Office of Chile Affairs SMA meeting June 2005 Schedule June 1998 Phase I: Design & Development November 2001 Prototype antennas at VLA site December 2001 US/European ALMA Agreement September 2004 Enhanced ALMA Agreement 2005 Antenna Contract Awarded 2005 Prototype System Testing 2007 AOS/OSF completed 2007 - 2009 Commissioning & early science operations 2012 Full Operations SMA meeting June 2005 ALMA will help to revolutionize our understanding of the Origin of Structure in the Universe Ivison et al. 2000 D. Wilner For more information: www.alma.info www.alma.nrao.edu www.almatelescope.ca SMA meeting June 2005