Status of LAMOST ZHAO Yongheng National Astronomical Observatories of China
Jan 04, 2016
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!