A brief introduction to QiTai radio Telescope (QTT) Hello everyone, I name is from Xinjiang observatory. It’s my pleasure bto be here to give a brief intro to QTT. Na Wang（王娜） Lang Cui（崔朗） Xinjiang Astronomical Observatory, CAS CAS-NWO Workshop, Beijing

Outline Project Overview Telescope Scheme QTT site – recent status Potential Collaborations

QTT Project Overview QiTai radio Telescope (QTT) a Steerable 110-m Aperture Radio Telescope (SmART) Active Surface Freq Range 150 MHz – 115 GHz Qitai Nanshan Urumqi Ulastai QTT is named after the site location, QiTai county in Xinjiang. QTT will be a

Telescope Scheme Receiver Arrangement Type Band (cm) RF Freq (GHz) Focus Feed Poln Science Goals Single Pixel 100 0.15 – 0.6 Primary Kildal Linear Pulsar, RRT 30 0.6 – 4 Horn Pulsar, RRT, HI, OH, Galaxies 5 2 – 12 Greg. Molecular spectrum, Galaxies; VLBI 1 12 – 36 Pulsar, H2O, NH3, VLBI 0.6 36 – 50 Molecular spectrum, High-z CO 0.3 72 – 115 Molecular spectrum, Galaxies Dual- 13/3.6 2.2 – 2.5 8 – 9 Circular VLBI, space exploration, System measurement (3.6cm) 3.6/0.9 30 – 34 VLBI, space exploration Multi- 15 1 – 2 PAF 80 – 115 Horn(7/13 Beam) There will be single pixel receivers, dual-band receivers and multibeam receivers To meet different science

Telescope Scheme Pointing Accuracy: 6mm wave length: blind pointing ≤ 5arcs, repeatability precision ≤ 2.5arcs (wind speed ≤ 4m/s, temperature drift ≤ 2℃/h, observation time: 69.5% ) 1cm wave length: ≤ 10arcs (wind speed ≤ 6m/s, temperature drift ≤ 3℃/h, observation time: 87.7% ) 5cm wave length: ≤ 25arcs (wind speed ≤ 10m/s, temperature drift ≤ 5℃/h, observation time: 97.9% )

Key technology studies Servo control and very accurate pointing Active surface: measurement and adjust: OOF, holography Reflector: parabolic dish vs. shaped design Dividing the main reflector and number of actuators Track and wheels: monolithic track & heavy load Structure and electronics: environment under －30℃ Rx: wide band, Multi-beam, PAF RFI shielding Some key technolgy studies are on going or completed 15° ring1…… ring22 5m2, 2856 12.5m2, 888

QTT site 1.5 kilometers long and 2 kilometers wide rectangle basin Altitude range from 1730 m to 2250 m Surrounding ridges form an isolated layer with outside region 刀条岭 北梁 中葛根河 马鞍山 天山山脉 The QTT site is a rectangle basin, located in the TianShan mountain hinterland, QTT site surroundings QTT site concept plan

QTT site elevation of mountain shelter This fig gives the el of mountain shelter, the max shelter el is about 12 degree in the east

QTT site Average annual rainfall of area: 180 mm to 200 mm (cf. average evaporation capacity of Xinjiang area is ~2000mm) Precipitable water vapor: Summer: ~19 mm Spring and Autumn: ~8 mm to 9.5 mm Winter: ~3 mm Temperature range: maximum +29.3 °, minimum -26.6 ° QTT site has good weather conditions for high frequency observations. The water vaper monitored in the site is about 3 mm in winter, 2 months Temperature drifting Ratio ≤ 5 ℃/hr 99.0% ≤ 3 ℃/hr 92.7% ≤ 2 ℃/hr 82.7%

QTT site Frequency distribution of extreme wind speed: Wind speed Ratio Qitai_Average Qitai_Day Qitai_Night GBT ≤4m/s (3 beaufort scale) 65.9% 48.9% 83.0% 45.9% ≤6m/s (4 beaufort scale) 83.6% 74.3% 92.9% 64.5% ≤8m/s (5 beaufort scale) 93.7% 91.0% 96.6% 79.2% ≤10m/s (6 beaufort scale) 97.5％ 96.7% 98.3% 88.9％ ≥17m/s (8 beaufort scale) 0.14% 0.21% 0.06% 0.5% Rare days with extreme wind speed

QTT site — Radio Quiet Zone Proposals for the legislative protection of radio quiet zone are on going core area (2.5 km × 4 km) restricted area (10 km × 15 km) coordination area (< 30 km) There are three levels of protection in 30 km area

QTT site — Infrastructure Progress Land acquisition: approved Road flattening: done Power: 10kV satisfy the infrastructure requirement Water supply plan: assessed Fiber connection: done for construction period

QTT Potential Collaborations Science Pulsar emission properties, and detection of gravitational waves with pulsar timing array (PTA ) Pulsar-like objects searching strategy Spectral lines and masers single-dish survey and VLBI follow-up Fine structures of AGNs and galaxies High accuracy VLBI astrometry, astrodynamics and space VLBI RRAT, FRB, Magnetar, and so on We suggest some potential collaborations with QTT.

QTT Potential Collaborations Receivers (1) Technique of developing the PAF receiver, 7/3mm multi-beam receiver Ultra-broad band OMT design and fabrication; Compact LO distributor design; Calibration signal distributor and calibration method; Design of the compact heterodyne receiver array. (2) Technique of developing broad band digital polarimeter

Summary QTT is a cooperative project between CAS & XJ built in an excellent site (easily accessible, radio quiet, good weather conditions) Outstanding and high sensitivity platform Site infrastructure is underway Telescope preliminary design to be finished Project approval: key period this year Collaborations welcome I wanna to give a short summary.

Thanks OK I stop here, Thank you for your attention.