Presentation on theme: "Dome A THz Astronomy Ji Yang Purple Mountain Observatory,"— Presentation transcript:
1 Dome A THz Astronomy Ji Yang Purple Mountain Observatory, Workshop on Progress in Theoreticaland Observational CosmologyNov. 7-9, 2011, IHEP, BeijingDome A THz AstronomyJi YangPurple Mountain Observatory,Key Laboratory for Radio Astronomy,Chinese Academy of Sciences,Nanjing , China
2 Outlines Science Drive and Dome A THz Conditions Dome A 5m THz Telescope ConceptChallenges to the THz DevelopmentTechnological Availability & International Collaboration
3 Major Challenges in Astronomy End of Dark Age and Formation of First Generation StarsPrecision Cosmology dominated by Dark Energy & Dark MatterEcology in the Universe: ISM, Stars, GalaxiesOrigin of Planetary Systems & Life
4 THz Wavelengths: New Windows for Observing the Universe Cosmic SED peak at FIR/THz：THz as an important tracers to the distribution, structure, and motion at different levels. Intensive lines carrying important information on the origin of the universe, celestial bodies, and life.Dole, H. et al. 2006; Driver, et al. 2008Credit: Herschel Team
5 World Trends and Challenges in Ground based Astronomy (Optical, NIR, THZ) World trends for large fields of view, high sensitivities, high resolution and multi-wavelength coverage；Finding best sites for large facilities to achieve the best performance；Or, to put telescopes into space, under the cost of money and technological risks!Difficulty in finding world-class sites for optical/NIR/THz within China;Dome A as an potential opportunity for China was widely recognized.
6 Dome A: The SiteDome A，altitude 4100m (60km10km), a plateau of small fluctuation。Lowest Temp -83ºC。Site surveys under Panda Program suggest ：Dome A is a promising site for astronomy, particularly in THz & IR.Chinese inland expedition team reached Dome A.Astronomy follows on from 2007/2008 , by the 24th Chinese Antarctic Expedition)
7 The Pre-HEAT Collaboration (The High Elevation Antarctic Terahertz Telescope) Pre-HEAT measured the transparency of the sky above Dome A at submillimeter wavelengths using a high frequency heterodyne receiver at 0.66 THz. Installed by Chinese 25th antarctic expedition team and data were collected from Jan 24, 2008.Major Collaboration Institutes:University of Arizona, Exeter University, University of New South Wales, Polar Research Institute of China, & Purple Mountain Observatory.
8 The Pre-HEAT Measurements Stable over several weeks !!!best 25% weather at Mauna Kea国际大科学工程ALMA台址Dome A (partial time)Mauna Kea at HawaiiYang, H. et al. 2010, PASP, 122, 490mm windowsDome A (4000m, -83C)Measurement（ , Pre-HEATThe best site ever knewNew THz windows over m
9 Measurement of Atmospheric THz Transmission by FTS (Shi, S.-c., et al. , 2011, in preparation) In 2009，a FIR/THz FTS was developed & installed to measure the atmospheric transmission over THz, under the collaboration among PMO, CfA, and NAOJ, with remote operation support from NSWU.The results，combined with 660GHz radiometer measurement by Pre-HEAT，strongly suggest that Dome A is a unique site for ground-based THz observations. THz facilities for micron windows should be planned.
10 Targeted Science Drivers Uniqueness of Dome A AstronomySite：ExcellentScience： Unique & CompetitiveFacility: Synergy in WavelengthsTechnology：FeasibleTargeted Science DriversTime Domain- The Legacy of a Dynamic UniverseLarge FOV+High Resolution- Revealing the Dark UniverseNew THz/IR Window- Star Formation, Young Galaxies, Early Universe, & Origin of Celestial Life
11 Concepts for Dome A Observatory Phase I Taking the advantage of Dome A superior site conditions to build optical/IR, THz observing facilities, and to build efficient international collaborations;Two telescopes with competitive observing capabilities, proposed as National Mega-Science Facilities;Major science goals on dark energy and dark matter, exo-planets, time-domain sciences, formation & evolution of stars and galaxies;Self-supported observing mode under remote control;On-site bulk data storage, partially send back for timely analysis and follow-up observations；Instrument maintenance/upgrade and data retrieval by summer traverse.
12 2.5m Optical/NIR Telescope 5m THz Telescope Antarctic Support Platform Dome A Observatory: A Mega-Science Facility Proposed for Construction2.5m Optical/NIR Telescope5m THz TelescopeAntarctic Support PlatformTransportation & LogisticsOn-Site AssemblyRemote Operation
13 Dome A Observatory Development: A Roadmap 2006-2008Site Survey & Small Telescope+Site Testing & Middle-sizeTelescope2009-20115m THzDATE515m THz2011-2015Dome A Observatory Phase I2.5m Opt/NIRKDUST2016-2025Dome A Observatory Phase II6-8mOpt/NIR
14 Superconducting Mixer，Nb/NbN SIS&HEB Dome A THz Explorer（DATE5）AntRelayOpticsAnt OpticsTHz ReceiversTHz Mixers（Band1 &2）IF Proc.（6 chs）THz Digit LO（Band1 &2）Backend SpectralProc.Control & DACDATE5 System DiagramDATE5 Toy ModelOpticsSymmetric CassegrainMain Reflector5m paraboloidSurface Accuracy10m (rms)Pointing2“ (rms)FoV10′×10′ (350m), 5′×5′（200m）ReceiverSuperconducting Mixer，Nb/NbN SIS&HEBWavelength350m×6, 200m×2Power Consumption<= 3 kWDATE5 Specs
15 The Extreme Site Conditions as The Major Challenges to Dome A THz Development High altitude: 4000m;Low pressure: 570 hPa;Extremely low temperature & large temp difference:-58.4 C , (-10 C ~ -83 C);Harsh weather conditions： snow, ice, radiation;Transportation: complicatedInstallation/testing：limited working time/facilities;Operation: low-bandwidth communication;Logistics: limited summer support, no winter-over.
16 THz Astronomy Development at PMO 13.7m-100GHz, DelignhaPOST 30cm-492GHz1995-SMA Collaboration（ THz，Mauna Kea/Hawaii）ALMADome A THz Development2006-
17 The Superconducting Spectroscopic Array (SSAR): A mm-wave multi-beam receiver recently finished for Delingha 14m TelescopeSideband Separation SIS3x3 beams, 18 IFsAll digital System
18 DATE5: Conceptual Studies on Ant & Relay Optics (Lou, Z. et al. 2011) Roof mirror partition scheme for dividing the incoming beam into receivers of two bandsFar-field distribution for Band1(14) & Band2(12) beams, calculated by Physical Optics through numerical methods based on GPUFocal plane distribution for Band 1&2, calculated by GO
19 DATE5 Prototype SIS Mixers Developed by Shi, S. et al & International Collaborations1.3THz NbN SIS mixer chip & measured I-V curveOriginal design initiated from GHz band design during ALMA R&D collaborationsBand2 HEB mixer prototype chip & measured FTS Response
20 Prototype 2GHz Digital FFT Spectrometer based on FPGA (Yang, J. et al., 2011, under development)real-time pipeline FFT algorithm based on FPGA, 32k pointsBandwidth：2GHzFreq Resolution：61kHzDynamic Range：≥ 30dBStability：≥ 1000sFunction diagram for 2GHz real-time digital FFT spectrometer, as a prototype back-end signal processing solution to the Dome A THz telescope
21 Herschel Blue Array 2048 pixels Requirement for THz Focal Plane Imaging Detectors Call for International CollaborationHerschel Blue Array 2048 pixelsbackground limitNEP W/ Hz at Dome AFull sampling at Focal PlaneUndergoing Collaboration with world institutesDemo device available with next few years
22 SummaryStimulated by Polar Research activities, the site surveys at Dome A demonstrate its excellent observing conditions for ground-based astronomy;Small-scale instruments have been used at Dome A for continuing site survey and astronomical observations;Dome A was selected as one of the major goals of development for Chinese astronomy for the next decade; Major Instruments, including 5m THz telescope & 2.5m Opt/IR telescope, have been proposed;Dedicated teams are organized to study the 5m telescope and key technologies on receiver systems;International collaboration has been successful and should be encouraged in future for Dome A THz astronomy.
23 AcknowledgementsPart of the materials in this talk was contributed by Chinese Center for Antarctic Astronomy (CCAA) and The International Partner Group on Cosmic Star Formation.CCAA is a center jointly initiated by Chinese institutes and universities, including Purple Mountain Observatory, Nanjing Institute of Astronomical Optics and Technology, Polar Research Institute of China, Polar Research Institute of China, National Astronomical Observatories of Chinese Academy of Sciences, and Chinese universities. CCAA is based at Purple Mountain Observatory, Chinese Academy of Sciences.The International Partner Group on Cosmic Star Formation is a program supported by NSFC and CAS and affiliated to Purple Mountain Observatory.Materials of this talk are also based on international collaborators including UNSW, UoA, CfA, NAOJ, etc.
24 Antarctic Support Platforms for Remote Operation : Joint Developments AUS、CHN、US、UKJoint PLATOFunction：To supply power, communica-tion, remote operation and data storage/ manipulation capabilities.Results：PLATO operated over 204 days in 2008，and full winter over 。New design of ASP by PMO-SEU: higher power output & larger data storage, testing in Tibet in 2010 summer.2010 PMO-SEU Joint ASP