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Zhu, Ming (on behalf of the FAST team) National Astronomical Observatories

FAST Project and its Science Goals. Five hundred meter Aperture Spherical radio Telescope. Zhu, Ming (on behalf of the FAST team) National Astronomical Observatories Chinese Academy of Sciences. 2012 April 2. content Introduction to the FAST project General technical specifications

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Zhu, Ming (on behalf of the FAST team) National Astronomical Observatories

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  1. FAST Project and its Science Goals Five hundred meter Aperture Spherical radio Telescope Zhu, Ming (on behalf of the FAST team) National Astronomical Observatories Chinese Academy of Sciences 2012 April 2

  2. content • Introduction to the FAST project • General technical specifications • Last Status • FAST Science

  3. Five hundred meter Aperture Spherical Telescope Unique Karst depression as the site Active main reflector Cable - parallel robot feed support

  4. Guiyang Site Surveying in Guizhou Location: N25.647222º E106.85583° Site: the Karst region in south Guizhou Province

  5. Quick Bird Fly Oct. 6, 2005

  6. 排水隧道 1.2km

  7. 2012-03-28

  8. FAST model construction process 1. tower 2. girder ring 4. cable & node 3. cement depression 5. actuator

  9. 2. General Technical Specification

  10. Sky coverage ZA 30 deg ZA 40 deg ZA 60 deg FAST Zenith Opening angle - sky coverage ZA 56 deg Sky coverage FAST vs. Arecibo

  11. Frequency range 0.13 0.327 1.42 3 4 5 (GHz) 8 In layout 2000 First phase Second phase HI surveying 70MHz EoR z~20 Pulsar 300MHz 5.2GHz VLBI HCOOH 17 Lines HC5N(4) CH(4) CH4 H2CO(6) CH3OH OH(4) SETI Water hole Space science S Band C Band X Band

  12. Observatory Receivers Measurements Observatory building Receivers Mark stone Backend Computing center Laser total station Disaster prevention Optical fiber Photogrammetry Field bus Tension monitoring Cables AB-rotator & Stewart Earth work Winches Drainage Capstan Elements Exploration Tower Main cable net Active Reflector Feed support Site 3.Technical plan – critical technology Site Active Reflector Feed support Measurements Receivers Observatory

  13. 下拉索 索节点 主索网 周边支承结构 地锚 背架结构 主索网 面板 下拉索 促动器 防躁墙 挡风墙 节点 健康监测系统 Structure of active reflector • 500m girder built around hills supported by • 50 pillars • Backup consists of ~7000 steel strands • actuated by ~2300 down tied cables driven by • winches anchored into ground • Errors 5.0 mm r.m.s in total

  14. Feed support • Three main parts of cabin suspension • Cable network - adjustable system • Stewart Platform - secondary adjustable system • Close loop control F=0.4665R Focus surface

  15. Dynamic experiment on Stewart stabilizer, Sept. 2002

  16. Measurement –precise, quick and in long distance • Task 1: 3-D spatial positions of focus cabin • Large working range up to 300 m • Errors ~1 mm • Sampling rate > 10 Hz Task 2: profiles of main reflector • Number of targets ~2400 • ~1000 in illuminated area • Accuracy 1~2mm • Sampling interval 10 sec ~ few min

  17. DGPS：10Hz；1cm CCD：20Hz；0.5cm Laser Tracker：1KHz；0.05mm IMU：0.1 Measuring Total station

  18. Photogrammetry Surveying reflector profile 1000 nodes within illuminated area to be scanned in real-time period ~ 1 min

  19. Main Control Computer Power Monitoring Feed Control Computer Reflector Control Computer Location Reference Time Reference Laser Measurement Cable Tension Measurement Inertial Measurement Reflector Measurement Cable Tension Measurement Main Control Diagram

  20. Receiver layout design (2000 & 2006)

  21. Feed + polarizer E/O O/E Mixer LNA Pulsar HI line VLBI SETI Receiver Diagnostics Receiver -- Schematic Diagram multi

  22. x y z L-band Multi-beamreceivers and its prototyping

  23. 接收机与终端- 2 密云模型观测情况 密云模型低频馈源 EMI测试

  24. 9 sets of FAST receivers NAOC - JBO

  25. HI was observed using 50m model in Sept 2006.

  26. FAST sciences • Neutral Hydrogen line (HI) survey • Pulsar research • VLBI network • Molecular line study (including recombination lines, masers) • Search for Extraterrestrial Intelligence (SETI)

  27. FAST all-sky HI survey • Using a 19 beam L-band receiver to map 2.3π sterradians FAST sky at 40 sec per beam, doable in 1-2 yrs. • Expect about 1 million detections (Duffy et al. 2008) with MHI< 1011 Mout to z ~ 0.15 in a range of environments including Coma, Hydra, Ursa Major, Persues-Pisces supercluster plus neighboring voids. • Large HI database for T-F relation, peculiar velocity study of the local universe with a larger volume. • Extend ALFALFA Sky coverage

  28. Duffy et al (2008) Number of galaxies to be detected per day (18h) using FAST 19 beams with different integration time ---- 6 sec ---- 60 sec ---- 600 sec ---- 6000 sec ---- 60000 sec

  29. Xuelei Chen Veff vs scale ¼ sky coverage survey by FAST ---- 6 s 44 days ---- 12 s 88 days ----1 min 440 days Duffy et al Spectra errors

  30. Deep mapping of Nearby Galaxies • To map a 4 square degree area, with an integration time of 10 minute per beam, in 10 hours we can reach a 3σ sensitivity of 1.5 x1017 cm-2 per 2.1 km/s channel. • Select regions of different environments, • void, big galaxies, clusters …

  31. Kacprzak et al. 2010 ΛCDM COSMOLOGICAL GALAXY SIMULATIONS

  32. How is gas accreted from the IGM onto galaxies? • low NHI gas seen around M 31 and M 33 Braun &Thilker 2004

  33. FAST WALLABY: NHI~2x10^19 cm-2 DINGO deep: NHI~2.6x 10^18 cm-2 DINGO u-deep: NHI~1.2x10^18 cm-2 Prochaska et al. 2010

  34. HI map of M31 Braun & Thilker 2003

  35. Xuelei Chen – Estimated FAST detection sensitivity of 1 min & 1 h Line width 30km/s,S/N -10 Kravtsov - Simulation on dark matter distribution in a normal galaxy

  36. Searching for High Z HI and OH Megamaser Arecibo 0.1 < z < 0.45 0◦ <  < 37◦ Smin ~0.6 mJy 53 OHM FAST 0.1 < z < 5 0◦ <  < 70◦ Smin ~0.1 mJy ～3000 OHM

  37. The simulated uv-coverage of EVN+FAST for sources of Declination 10 and 60 degree

  38. Search for binary SMBH • Galaxy mergers yield inspiraling, binary, and recoiling black holes that may be detectable with high resolution VLBI search for off-nuclear and binary SMBHs • FAST+VLBI

  39. Summary FAST has very high sensitivity and large coverage of the northern sky Good for searching for weak signals, low surface brightness structures FAST has the potential to make great contributions to HI and pulsar studies and VLBI observations First light expected in 2016 Website: fast.bao.ac.cn

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