Status of LAMOST The Large Sky Area Multi-Object Fiber Spectroscopic Telescope

Structure of LAMOST MB mirror Fiber Positioning Fibers MA 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 Nanjing: NIAOT (NAOC) Telescope Instruments Hefei: USTC Science Beijing: NAOC Project HQ Instruments & Software Science

Schedules of LAMOST Project Reviewed Approved Proposal Nov Apr Feasibility Study Jul Aug Preliminary Design Apr.-May 1999 Jun Detailed Design Sep Construction First Light

M A : 5.72mx4.4m reflecting corrector (24 sub- mirrors) M B : 6.67mx6.05m spherical mirror (37 sub- mirrors)

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)

Oct. 8, 2008 Mean=1.14″, Maintenance Mean=1.00″ 80%=1.21″, 80% Maintenance=1.14″

At 5.2 degrees FOV

multi-optical fiber positioning

Fiber positioning unit

4000 fiber position units

16 Spectrographs

LAMOST-LRS Optical System R1000/2000 R5000/10000 R1000/2000 Blue (370~590nm) Red (570~900nm)

GratingBlue branch Red branch R Å Å binning narrow slit Å Å narrow slit Resolution powers

Spectrographs

VPHG (Volume Phase Holographic Grating)

E2V-CCD203

蓝区红区 南京 兴隆

Resolution of the spectrum

Operation software OCS SSS TCSICSDHS Input Catalog LAMOST Spectr. Database

Software for automatic observation & data processing catalogue processing observation OCS SSS DPS

First light of the small system On May 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 Spectrum

Component & Total Efficiency Wavelength(A) Efficieny telescope fiber Spectrograph CCD total

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 ） BlueRed

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 Active optics Dome seeing Efficiency Fibers Spectrographs CCDs Scientific observations Open clusters, M31, selected area survey, …

regular spectroscopic survey Working groups for Extragalactic survey Galactic survey  input catalog for LAMOST (end of 2009)

SDSS2DFLAMOST Aperture2.5m4m Field of View325 Number of Fiber Spectral resolution , Spectral ranges （ Å ） Diameter of Fiber 3 ”(180mu)2.16”(140mu)3 ”(320mu) Mini Distance of Fibers 55 ”12 ” (30”) 40 ” S/N 4.5/pix (g=20.2)13/pix (mean)11/pix (20.5, 1.5h) Limited Magnitude i= ,20.2(q) r<17.7(g) bj (q) bj (g ) B<20.5 Fiber Position Accuracy 0.5 ” Sqrt(1 ”+0.25”^2)~1.03” 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 ( )

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 ℃, 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 ~ 2” -3”

Extinction Kv ~

Sky Brightness Mv ~ /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 degree 2 r<18.8 ~2.6X10 6 gal. South Galactic Pole region: ~4000 degree 2 r<19.5 ~2.6X10 6 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 2.6X10 6 galaxies

Luminous Red Galaxy (LRG) galaxies survey: i< 20.0 ~1.5X10 6 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 degree 2 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) DEC(2000) COSMOS field ： 10:00:00 02:12:00 AKARI NEP 18:00:00 +66:36:00 Lockman-Hole field ： 10:47:00 58:02:00 H1K field ： 14:00:00 00:00:00 ELAIS-North1 field ： 16:11:00 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 & star- formation rate densities with redshift & environment –Detailed studies of local low-luminosity galaxies

The structure and Evolution of The Milk Way To get spectrum of 5×10 6 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.

Accuracies and our Galaxy LAMOST +

Welcome you to use LAMOST in the future