Subaru Telescope before and after the earthquake

Daigo Tomono and members of Telescope Engineering Division

2007-03-23

Agenda

TimelineSubsystems affected– Az axis– IR secondary mirror– Primary mirror support?

Optical adjustments– M2 position– Pointing

Timeline - first shakeTimeline - first shake

500500

10001000

15001500

20002000

25002500

30003000

07:08:0007:08:00 07:09:0007:09:002006-10-15 HST2006-10-15 HST

FX1FX1FX2FX2FX3FX3

Forc

e (N

)Fo

rce

(N)

2007-03-23

Timeline07:08:00 HST– Oil bearing active– M1 felt the shake– DG started

07:20– UPS for OCS

workstations drained10:00-11:00– Power to telescope

control system (TCS) stopped

2007-03-23

Timeline12:00– First staffs arrived– Power for TCS

supplied by diesel generator

14:30– HELCO power

recovered16:00– Recovered network

connection

Timeline - gathering records

2007-03-23 Subaru Telescope (Tomono) 7

Physical recoveryOct 15– Heat exhaust systems– Az & El oil bearings– M1 cover– CsOpt M2– Instrument rotator

Oct 16– El axis– AG/SH cameras– Calibration units

Oct 17– El axis– ADC– M3– AG/SH prove– Dome flat source– Balancer

Oct 22– Az axis drive

Oct 24– 1st observation

Nov 2– IRM2

2007-03-23

Subsystems affected

Az axisIR secondary mirror– Sitting in the dome

Primary mirror support?

Main shutterObservation floor doorNsIR instruments

2007-03-23

Damage on Az axis

Copyright 2003 META Corporation Japan #150102

www.auto-met.com

Damage on Az axis

Telescope moved 1.2mm towards EES (20 deg to S from E)

500t

2007-03-23

Damage on Az axis

Center hub shiftedBroken grout

Damage on Az axis

Moved encoder tape following the telescope

Primary mirrorDamage on IR secondary mirror

Damage on IR secondary mirror

Photo by Satoru Negishi

2007-03-23

Damage on IR secondary mirror

Replaced the mechanical fuse

2007-03-23

Primary mirror support?

While tilting the telescope ...BIG SOUND heard

Force to fixed points?Released displacements with extracting actuators

-40000

0

4000

-2

-1

x(mm, opt+)y(mm, rear+)

Forc

e ch

ange

(N) FX1

FX2

FX3

2007-03-23 Subaru Telescope (Tomono) 17

Optical adjustments

Many configurations– 12.5 of 28 ready as of

March 2007– 3-4 hours for each

Adjustment of M2 position– Mechanical shift of

5mm at somewhere between M1 and M2

Pointing analysis– By the earth quake

• Az zero point: 72"• El zero point: 14"

– Long term drift• El zero point• EW misalignment of Az

axis

Adjustment of M2 position

Gradient of PSF on wide field instrumentsOffset M2 shadow

2007-03-23 19

Adjustment of M2 positionOff-axis SH test– Measures defocus

around the telescope field of view

Mechanical field of view

Best focal sphere

2007-03-23

Adjustment of M2 position

-5

0

5

-10 -5 0 5 10

Front -y(mm) -Rear

IR - x(mm) - Opt

Cs(IR)Cs(CsOpt+ADC)

Cs(CsOpt)NsIR(IR+ImR)

NsOpt(Opt+ADC)NsOpt(Opt+ADC+ImR Red)

NsOpt(CsOpt)NsOpt(CsOpt+ADC)

NsOpt(NsOpt+ImR Blue)NsOpt(NsOpt)

Fron

t -y(

mm

) -R

ear

Off-axis SH test– Measures defocus

around the telescope field of view

Detected shifts of M2 in relation with M1

2007-03-23 Subaru Telescope (Tomono) 21

Pointing analysis

75

60

45

30

10"

N

E

S

W

Example:– Nov 17– Prime focus

2007-03-23 22

Az zero point

0.31

0.315

0.32

0.325

0.33

0.335

0.34

0.345

0.35

0.355

2000 2001 2002 2003 2004 2005 2006 2007Year

A0:

Az

zero

poi

nt o

n C

s (d

eg)

2007-03-23 23

El zero point

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

0.022

0.024

0.026

2000 2001 2002 2003 2004 2005 2006 2007Year

A1:

El z

ero

poin

t on

Cs(

IR) (

deg)

2007-03-23 24

NS misalignment of Az axis

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

-0.001

0

0.001

2000 2001 2002 2003 2004 2005 2006 2007Year

A2:

NS

mis

alig

nmen

t of A

z ax

is o

n C

s (d

eg)

2007-03-23 25

EW misalignment of Az axis

-0.003

-0.0028

-0.0026

-0.0024

-0.0022

-0.002

-0.0018

-0.0016

-0.0014

-0.0012

-0.001

2000 2001 2002 2003 2004 2005 2006 2007Year

A3:

EW

mis

alig

nmen

t of A

z ax

is o

n C

s (d

eg)

2007-03-23 26

Non-perpendicularity: Az & El

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

2000 2001 2002 2003 2004 2005 2006 2007Year

A4:

non

-per

pend

icul

arity

of A

z an

d E

l on

Cs

(deg

)

2007-03-23 27

Non-perpendicularity: El & optics

-0.01

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

2000 2001 2002 2003 2004 2005 2006 2007Year

A5

on C

s(IR

) (de

g)N

on-p

erpe

ndic

ular

ity o

f El &

poi

ntin

g ax

es

2007-03-23 28

Tube flexure

-0.005

-0.0045

-0.004

-0.0035

-0.003

-0.0025

2000 2001 2002 2003 2004 2005 2006 2007Year

A6:

Tub

e fle

xure

on

Cs(

IR) (

deg)

2007-03-23 Subaru Telescope (Tomono) 29

Concerns

Power supply– Unknown cause of power failure to telescope

control system– Power failure protection not well tested

M2 shift– Where is the mechanical shift?

Summary

Physical damages– Az axis– IR secondary mirror

Optical parameters– Az zero point: 72"– El zero point: 14"– M2 shift of: 5 mm

Physical damages– Az axis– IR secondary mirror

Optical parameters– Az zero point: 72"– El zero point: 14"– M2 shift of: 5 mm