Status of LAMOST

Status of LAMOST

ZHAO YonghengNational Astronomical Observatories of China

Structure of LAMOST

MB mirror

Fiber Positioning

Fibers

MA mirror

Spectrographs

CCDs

Ma: reflecting corrector (24 sub-mirrors) ~ 4.9m Mb: spherical mirror (37 sub-mirrors) ~ 6.1m

Basic parameters of LAMOST 4.9m/6.1m 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

Schedules of LAMOST Project

Reviewed Approved Proposal Nov. 1996 Apr. 1997 Feasibility Study Jul. 1997 Aug. 1997 Preliminary Design Apr.-May 1999 Jun. 1999 Detailed Design Sep. 2001 Construction 2001-2008 First Light 2008

Technical Challenges

Active optics Both thin mirror and segmented

mirror active optics in MA

segmented mirror active optics in MB

Fiber positioning 4000 fibers at LAMOST SDSS: 640 fibers 2dF: 400 fibers

LAMOST small system June 2007

6Ma and 9 Mb submirror ~ 2m LAMOST Small focus plane + 250 fibers 1 spectrograph

Active optics & supporting

Results of Close Loop Active Optics

第九号星闭环跟踪结果（ 2007.6.8 180组）

LAMOST- Positioning for 4000 fibers

Double arm scheme

Focal Plate for holding 4000 fibers

Prototype

For 19 fibers

In USTC

LAMOST-LRS Optical System

R1000/2000R5000/10000

R5000/10000

R1000/2000

Blue (370~590nm)

Red (570~900nm)

VPHG (Volume Phase Holographic Grating)

E2V-CCD203

Image quality (R=1000)

blue red

Resolution of the spectrum

蓝区红区

南京

兴隆

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

Skylight in day

5 月 25 日 15 时

6 月 5 日 18时

Skylight spectra

Select the targets

Field No. 9 June 22, 02h

203 targets

3600

123 Spectrum

Component & Total Efficiency

0.00

0.20

0.40

0.60

0.80

1.00

370 450 550 650 750 850

Wavelength(A)

Effi

cieny

telescope

fiber

Spectrograph

CCD

total

Efficincy

R band Observe data ( Sky) ： 12.0% Theoretical value ： 16.5%

中值为 1

Current States

MB

37sub-mirrors of MB （ July 13,2008)

24 sub-mirrors of MA

Preliminary test on pointing error of telescope

24 sub-mirrors of MA （ Sept. 10, 2008)

Oct. 11, 2008image quality

I mage Qual i ty vs I terat i on

0

2

4

6

8

10

12

14

16

1 3 5 7 9 11 13 15 17 19 21 23I terat i ons

( 3. 5 )每次迭代约 分钟

EE80

(arc

sec)

I mage Qual i ty vs I terat i on

0

0. 2

0. 4

0. 6

0. 8

1

1. 2

1. 4

1. 6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21I terati ons

( 3. 5 )每次迭代约 分钟

EE80

(arc

sec)

Statistics

0

1

2

3

4

5

6

7

8

9

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4

EE80(arcsec)

Times

Oct. 11, 2008

Oct. 8, 2008

I mage Qual i ty vs I terat i on

0

1

2

3

4

5

6

7

8

9

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55I terat i ons

EE80

(arc

sec)

Mean=1.14″, Maintenance Mean=1.00″80%=1.21″, 80% Maintenance=1.14″

Statistics

0

1

2

3

4

5

6

7

8

9

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1

EE80(arcsec)

Times

I mage Qual i ty vs I terati on

0

0. 5

1

1. 5

2

2. 5

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52I terati ons

( 3. 5 )每次迭代时间 分钟

EE80

(arc

sec)

At 5.2 degrees FOV

4000 optical fibers

spectrographs

Test spectra （ 8 月 25 日 3 号光谱仪）

Blue Red

Relative efficiency （ No.6spectrograph-blue ）

Efficiency of spectrograph 370~900nm

Target ： 35% （ peak ） According to test on reach parts: 50% According to test on whole spectrograph: 43%

Image quality in spectrographs达到计算分辨率的 FWHM 值 : 9.2 pixels红区测试结果：

兰区点数少，像质暂时更好

Aug. 30 All hardwares installed

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

commission period

Sep.-Dec., 2008

Fiber positioning units To 4000 objects

Spectroscopic calibration

Operation software Pipelines for data processing

Softwares for automatic observation & data processing

catalogue processing

observation

OCS

SSS DPS

Operation software

OCS

SSS

TCS ICS DHS

InputCatalog

LAMOSTSpectr.Database

commission period 2009:

Stability Active optics Dome seeing

Efficiency Fibers Spectrographs CCDs

Scientific test observations Open clusters, nearby galaxies, selected area

survey, …

regular spectroscopic survey

2010-2015

Working groups for Extragalactic survey Galactic survey

input catalog for LAMOST (end of 2009)

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.

Thank You！