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Status of LAMOST The Large Sky Area Multi-Object Fiber Spectroscopic Telescope Structure of LAMOST Fiber Positioning MA mirror Fibers MB mirror Spectrographs CCDs Optical System Basic parameters of LAMOST 4.5m/6.3m Schmidt telescope The declination of observable sky area ranges from -10 to +90. 20 square degree of the FOV 4000 fibers Spectrum resolution: VPH (Volume Phase Holographic) Grating R=1000, 2000, 5000, 10000 General Situation of the Project The LAMOST project has its management under National Astronomical Observatories (hereafter NAOC) with its project office in the headquarter of NAOC, and its main workforce distributed in the Nanjing Institute of Astronomical Optics and Technology /NAOC in Nanjing, the Beijing part of NAOC and in the University of Science and Technology of China in Hefei. The project has its board and scientific and technical committee as usual. Xinglong Station, NAOC the site Beijing: NAOC Project HQ Instruments & Software Science Nanjing: NIAOT (NAOC) Telescope Instruments Hefei: USTC Science Schedules of LAMOST Project Proposal Feasibility Study Preliminary Design Detailed Design Construction First Light Reviewed Approved Nov. 1996 Jul. 1997 Apr.-May 1999 Apr. 1997 Aug. 1997 Jun. 1999 Sep. 2001 2001-2008 2008.10 MA: 5.72mx4.4m reflecting corrector (24 submirrors) MB: 6.67mx6.05m spherical mirror (37 submirrors) Technical Challenges of Active Optics A combination of segmented mirror active optics and thin deformable mirror active optics on one mirror Two large segmented mirrors needed to be actively controlled in the same time in the telescope. With hexagonal deformable sub-mirrors. Wave front sensing on a variable aperture Active optics & supporting MB 37sub-mirrors of MB (July 13,2008) 24 sub-mirrors of MA 24 sub-mirrors of MA (Sept. 10, 2008) Statistics 9 Oct. 8, 2008 8 7 6 5 Times EE80(arcsec) Image Quality vs Iteration 4 9 3 8 2 7 1 6 0 0.5 0.6 0.7 0.8 0.9 5 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 EE80(arcsec) 4 Image Quality vs Iteration 3 2.5 2 1 0 1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 Iterations Mean=1.14″, Maintenance Mean=1.00″ 80%=1.21″, 80% Maintenance=1.14″ EE80(arcsec) 2 1.5 1 0.5 0 1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 Iterations (每次迭代时间3.5分钟) At 5.2 degrees FOV multi-optical fiber positioning Fiber positioning unit 4000 fiber position units 16 Spectrographs LAMOST-LRS Optical System Blue (370~590nm) R5000/10000 R1000/2000 Red (570~900nm) R5000/10000 R1000/2000 Resolution powers Grating 1000 5000 Blue branch Red branch R binning 500 3700- 5700- - 1000 5900 Å 9000Å narrow slit narrow slit 2000 5100- 8300- 5400Å 8900Å 5000 10000 Spectrographs VPHG (Volume Phase Holographic Grating) E2V-CCD203 南京 兴隆 红区 蓝区 Resolution of the spectrum Operation software Input Catalog SSS OCS TCS ICS LAMOST DHS Spectr. Database Software for automatic observation & data processing DPS SSS catalogue processing OCS observation First light of the small system On May 20 2007 The LAMOST small system (about 2m in diameter and have 250 firbers) got its first spectrum! Sky 白天天光观测 5月25日15时 6月5日18时 天光光谱 Select the targets Field No. 9 June 22, 02h 203 targets 3600 123 Spectrum Component & Total Efficiency Efficieny 1.00 0.80 telescope fiber 0.60 Spectrograph 0.40 CCD 0.20 total 0.00 370 450 550 650 Wavelength(A) 750 850 Efficincy R波段 Observe data ( Sky):12.0% Theoretical value: 16.5% 中值为1 July 2008 MB: all 37 sub-mirrors MA: all 24 sub-mirrors Co-focus for MB: <0.4” To test active optics Spectrographs: 16 Fiber positioning units: 4000 Wireless control system has tested August 24:4000optical fibers completed August 30:16 spectrographs completed LAMOST completed all hardware Test spectra (Aug.5, No. 3号spectrograph) Blue Red Relative efficiency(No.6 spectrograph-blue) Efficiency of spectrograph 370~900nm Target :35%(peak) According to test on reach parts: 50% According to test on whole spectrograph: 43% Sept. 28 More than 2000 spectra got in one test observation Oct. 13 About 3000 spectra got in one test observation Spectra of stars(28/9/2008) Red Blue Plan 2009: Technical commission period 2010: Scientific commission period 2011: start regular spectroscopic survey 2009: Stability Efficiency Active optics Dome seeing Fibers Spectrographs CCDs Scientific observations Open clusters, M31, selected area survey, … regular spectroscopic survey 2010-2015 Working groups for Extragalactic survey Galactic survey input catalog for LAMOST (end of 2009) SDSS 2DF LAMOST Aperture 2.5m 4m 4m Field of View 3 2 5 Number of Fiber 640 400 4000 Spectral resolution 1800-2100 1000 1000-2000, 5000-10000 Spectral ranges(Å) 3900-6100 6000-9100 3600-8000 3700-6200 6000-9000 Diameter of Fiber 3 ”(180mu) 2.16”(140mu) 3 ”(320mu) Mini Distance of Fibers 55 ” 12 ” (30”) S/N 4.5/pix (g=20.2) 13/pix (mean) 11/pix (20.5, 1.5h) Limited Magnitude i=15-19.1,20.2(q) r<17.7(g) bj 18.25-20.85(q) B<20.5 Fiber Position Accuracy 0.5 ” bj 17-19.45(g) Sqrt(1 ”+0.25”^2)~1.03” 5100-5400 8300-8900 40 ” 0.5”(3 sigma) LAMOST will become the most effective spectroscopic survey telescope, and the most powerful facilities for researches of wide field of view and large sample astronomy. LAMOST is a National large astronomical instrument, it will open to all Chinese Astronomer. We make the first call for observational proposal (2008-04) How can we do better than 2dF and SDSS? Large Aperture Large field of view More fibers But XingLong station ?? Weather at Xinglong Site Average temperature 7~8℃, lowest -22.5℃, highest 33.0℃ 94%(332 days) daily temperature difference less than 12℃ Average wind speed 2.4m/s~3.1m/s . About 90 days in a year instant wind speed >8m/s Yearly average relative humidity 57%, about 5.7%(21 days), RH > 90%. Precipitate days ~20 days/yr Observing nights ~200 nights/yr Seeing by BATC Seeing by BATC Seeing ~ 2” -3” Extinction Kv ~0.1 -0.33 Sky Brightness Mv ~ 20.5 -21.5 /sq. degree Key Projects Extra-galactic spectroscopic survey — Galaxy and QSO redshift survey Stellar spectroscopic survey — Structure of the Galaxy, and so on. Cross identification of multi-waveband survey. Extra-galactic spectroscopic survey — Galaxy and QSO redshift survey Magnitude limited sample • North Galactic Pole region: ~7700 degree2 r<18.8 ~2.6X106 gal. • South Galactic Pole region: ~4000 degree2 r<19.5 ~2.6X106 gal. Redshift survey of Galaxy Low Resolution spectroscopy: • To obtain the spectra of faint celestial objects (Galaxy and AGN) with R=1000 spectral resolution, S/N=10. • Wavelength range: 370—900 nm • From SDSS DR6 data select about 2.6X106 galaxies Luminous Red Galaxy (LRG) galaxies survey: i< 20.0 ~1.5X106 gal. LRG sample Advantage to select LRG • Red color → easy to find the candidate • Most luminous galaxy → Map large cosmological volume • Correlated with cluster → To detect and study the clustering QSO survey • Combine the high quality digital image data of SDSS (5 colors) with powerful spectroscopic capabilities of LAMOST to conduct a deep wide field spectroscopic suevey for Quasars Deep survey • Select few 100 degree2 field deep spectroscopy survey to i~ 20.5 The mean redshift is about Z=0.3, Some of these sample could go to as deep as Z=0.5 Deep Field selected • • • • • RA (2000) COSMOS field: 10:00:00 AKARI NEP 18:00:00 Lockman-Hole field: 10:47:00 H1K field: 14:00:00 ELAIS-North1 field: 16:11:00 DEC(2000) 02:12:00 +66:36:00 58:02:00 00:00:00 55:00:00 A detailed scientific case – – – – – – Studies of large-scale structure Baryon Acoustics Oscillations => Dark energy Formation and evolution of galaxies AGN physics The relation between galaxies and the IGM Constrain dark energy from cluster counts and Alcock-Paczsynki test – Accurately measure luminosity functions & starformation rate densities with redshift & environment – Detailed studies of local low-luminosity galaxies The structure and Evolution of The Milk Way • To get spectrum of 5×106 stars. • Sloan Extension for Galactic Underpinnings and Evolution (SEGUE) obtain ~ 250,000 spectra of Galactic stars • Stellar spectroscopy plays a crucial role in the study of our Galaxy, not only providing a key component of the 6-dimensional phase space of stellar positions and velocities, but also providing much-needed information on the chemical composition of individual stars. Taken together, information on space motion and composition can be used to unravel the formation process of the Galaxy. LAMOST Accuracies and our Galaxy + Welcome you to use LAMOST in the future