C a l i b r e r u n e c a m r a g r a n d c h - - PowerPoint PPT Presentation

SLIDE 1

C a l i b r e r u n e c a m é r a g r a n d c h a m p : l ' e x p é r i e n c e d e S N L S

N . R e g n a u l t e t a l ( L P N H E , P a r i s )

SLIDE 2

S N L S / C F H T L S

• D

E E P Me g a C a m : 1 d e g 2 1 5 h

• u

r s

• n

C F H T 1 5 h

• u

r s

• n

8

• m

t e l e s c

• p

e s ~ 5 S N e I a w i t h s p e c

• i

d

SLIDE 3

SLIDE 4

S e e a l s

• :
• (

A s t i e r e t a l , 2 1 4 ) p r e c i s i

• n

p h

• t
• m

e t r y

• (

B

• h

l i n e t a l , 2 1 4 ) H S T s t a n d a r d s S e e a l s

• :
• (

A s t i e r e t a l , 2 1 4 ) p r e c i s i

• n

p h

• t
• m

e t r y

• (

B

• h

l i n e t a l , 2 1 4 ) H S T s t a n d a r d s

SLIDE 5

? ?

S e e a l s

• :
• (

A s t i e r e t a l , 2 1 4 ) p r e c i s i

• n

p h

• t
• m

e t r y

• (

B

• h

l i n e t a l , 2 1 4 ) H S T s t a n d a r d s S e e a l s

• :
• (

A s t i e r e t a l , 2 1 4 ) p r e c i s i

• n

p h

• t
• m

e t r y

• (

B

• h

l i n e t a l , 2 1 4 ) H S T s t a n d a r d s

SLIDE 6

O u t l i n e

• I

m a g e r U n i f

• r

m i t y

– R

e s p

• n

s e m a p s / “ g r i d s ” / s t a r f l a t s

• F

l u x m e t r

• l
• g

y c h a i n

– F

u n d a m e n t a l f l u x s t a n d a r d s

– B

u i l d i n g r

• b

u s t m e t r

• l
• g

y c h a i n s

• I

n s t r u m e n t a l c a l i b r a t i

• n

SLIDE 7

I n s t r u m e n t r e s p

• n

s e

• F

l a t f i e l d s

– A

f f e c t e d b y p l a t e s c a l e v a r i a t i

• n

s ( w e l l m e a s u r e d ↔ a s t r

• m

e t r y )

– c

• n

t a m i n a t e d b y g h

• s

t s ( r e f l e c t i

• n

s i n t h e WF C )

• F

i l t e r u n i f

• r

m i t y

– Me

g a C a m f i l t e r s v a r y b y ~ 5

• n

m c e n t e r

• t
• c
• r

n e r .

( Ma g n i e r e t a l , ' 4 ) ( R e g n a u l t e t a l , ' 9 ) ( B e t

• u

l e e t a l , ' 1 3 )

SLIDE 8

G h

• s

t s

N G C 3 4 8 9 ( MA T L A S )

http://irfu.cea.fr/Projets/matlas/atlas3D/NGC3489.html

SLIDE 9

SLIDE 10

5

SLIDE 11

SLIDE 12

Ma p p i n g t h e i n s t r u m e n t r e s p

• n

s e

• D

i t h e r e d

• b

s e r v a t i

• n

s

• f

d e n s e s t e l l a r f i e l d s

– L

• g

a r i t h m i c a l l y I n c r e a s i n g s t e p s ( 1 . 5 ' → . 5 d e g )

– O

b s e r v e d e v e r y ~ 6 m

• n

t h s

• Mo

d e l

m(x) = m(x0) + δzp(x) + δk(x) x col Maps (~ 100 pars) Star mags @ center (~ 100,000 pars)

(Magnier & Cuillandre, 2004; Regnault et al, 2009)

SLIDE 13

P l a t e s c a l e + g h

• s

t s

SLIDE 14

F i l t e r v a r i a t i

• n

s ( i n λ )

P r e f e r a b l e t

• m

e a s u r e t h e f i l t e r s

• n

a b e n c h . . . )

SLIDE 15

V a r i a b i l i t y

• f

t h e i m a g e r r e s p

• n

s e

SLIDE 16

U n i f

• r

m i t y

• Ma

p p i n g t e c h n i q u e s r e l y

• n

s e t s

• f

d i t h e r e d

• b

s e r v a t i

• n

s w h i c h a r e

– C

• s

t l y i n t e r m s

• f
• b

s e r v i n g t i m e → t a k e n e v e r y ~ 6 m

• n

t h s / 1 y e a r

• B

U T

– ~

1 % v a r i a t i

• n

s

• b

s e r v e d ,

• v

e r ~ 6 m

• n

t h s t i m e s c a l e s

• B

e s t s

• l

u t i

• n

w

• u

l d b e a m i x

• f

– d

i t h e r e d

• b

s e r v a t i

• n

s

– i

n s t r u m e n t a l m

• n

i t

• r

i n g

• f

t h e u n i f

• r

m i t y ( e v e r y w e e k )

• Wh

y n

• t

i n s t r u m e n t a l m

• n

i t

• r

i n g

• n

l y ?

– b

e c a u s e u n i f

• r

m i t y m a p s d e p e n d

• n

f l u x e s t i m a t

• r

u s e d . . .

SLIDE 17

O u t l i n e

• I

m a g e r U n i f

• r

m i t y

– R

e s p

• n

s e m a p s / “ g r i d s ” / s t a r f l a t s

• F

l u x m e t r

• l
• g

y c h a i n

– F

u n d a m e n t a l f l u x s t a n d a r d s

– B

u i l d i n g r

• b

u s t m e t r

• l
• g

y c h a i n s

• I

n s t r u m e n t a l c a l i b r a t i

• n

SLIDE 18

F l u x m e t r

• l
• g

y c h a i n

• I

n s t r u m e n t r e s p

• n

s e

– Me

a s u r e f l u x r a t i

• s

i n a s i n g l e i m a g e

SLIDE 19

F l u x m e t r

• l
• g

y c h a i n

• I

n s t r u m e n t r e s p

• n

s e

– Me

a s u r e f l u x r a t i

• s

i n a s i n g l e i m a g e

• C

a l i b r a t i

• n

t r a n s f e r

– H

S T s t a n d a r d s a s p r i m a r y f l u x c a l i b r a t

• r

s

SLIDE 20

F i e l d s t a r s S t a n d a r d s S t a n d a r d s F l u x S t d

G

• a

l < . 3 % T y p i c a l r e p e a t a b i l i t i e s ~ 2 % I f c a r e f u l < 1 % p e r e p

• c

h

F i e l d s t a r s → S N ~ a f e w . 1 % S T I S r e p e a t a b i l i y ~ 1 % \

Mo d e l u n c e r t a i n t i e s ~ ? %

S N

SLIDE 21

S N L S / S D S S ( J L A ) c a l i b r a t i

• n

p a t h s

• D

i r e c t

• b

s e r v a t i

• n

s

• f

S D S S & H S T s t a r s

• S

e v e r a l c a l i b r a t i

• n

p a t h s

. 3 % a c c u r a c y i n g r i

(Betoule et al, 2013)

SLIDE 22

O u t l i n e

• I

m a g e r U n i f

• r

m i t y

– R

e s p

• n

s e m a p s / “ g r i d s ” / s t a r f l a t s

• F

l u x m e t r

• l
• g

y c h a i n

– F

u n d a m e n t a l f l u x s t a n d a r d s

– B

u i l d i n g r

• b

u s t m e t r

• l
• g

y c h a i n s

• I

n s t r u m e n t a l c a l i b r a t i

• n

SLIDE 23

I n s t r u m e n t a l c a l i b r a t i

• n
• S

t e l l a r f l u x s t a n d a r d s v s L a b

• r

a t

• r

y s t a n d a r d s

• P

r e c i s i

• n

m

• n

i t

• r

i n g

• f

l a r g e f

• c

a l p l a n e s

. 1 % c a l i b r a t i

• n

a c c u r a c y

Hamamatsu S2281

SLIDE 24

S w i t c h i n g t

• a

L a b S t a n d a r d

H a m a m a t s u S 2 2 8 1 C a l i b r a t e d @ N I S T

SLIDE 25

A n e w m e t r

• l
• g

y c h a i n

B a c k t

• t

h e s t a r s . . .

SLIDE 26

A n e w m e t r

• l
• g

y c h a i n

B a c k t

• t

h e s t a r s . . .

( R e g n a u l t e t a l , A & A ) ( S . B

• n

g a r d ' s t a l k ) Current efforts concentrate here

SLIDE 27

C a l i b r a t i

• n

P r

• j

e c t s

• H

a r v a r d ( S t u b b s e t a l )

–

E S S E N C E

–

P a n S T A R R S

• T

e x a s A & M ( D e P

• y

e t a l )

–

D E S ( D a r k E n e r g y S u r v e y )

• N

I S T ( C r a m e r e t a l )

–

A r t i f i c i a l s t a r → r e c a l i b r a t i

• n
• f

V e g a

• A

C C E S S ( K a i s e r e t a l )

–

S m a l l r

• c

k e t

• b
• r

n e t e l e s c

• p

e ( I R s p e c t r

• p

h

• t
• m

e t r y )

• L

P N H E

–

S n D I C E ( Me g a C a m )

–

S k y D I C E ( S k y Ma p p e r )

SLIDE 28

D I C E : a s t a b l e L E D s

• u

r c e

SLIDE 29

O p t i c a l s e t u p

Point source @ finite distance

Quasi-parallel beam

Mirror

• C

a l i b r a t i

• n

b e a m ≠ s c i e n c e b e a m ! → ~ 3 %

• f

m i r r

• r

s u r f a c e → b e a m a n g l e w . r . t . f i l t e r

~ flat field (direct light) Ghosts

SLIDE 30

T y p i c a l L E D c

• v

e r a g e

SLIDE 31

T h e ” C

• l

e r

• b

r i g h t e r e f f e c t ”

0.1%

About 0.5% / oC for all LEDs

( R e g n a u l t e t a l , s u b m i t t e d t

• A

& A )

SLIDE 32

L

• n

g t e r m s t a b i l i t y s t u d i e s

3 w e e k s

r m s ~ 5 1

• 4

(Regnault et al, submitted to A&A)

SLIDE 33

A S p e c t r

• p

h

• t
• m

e t r i c m

• d

e l f

• r

t h e L E D s

• u

r c e

P r e d i c t s t h e L E D s p e c t r a l i n t e n s i t y ( w a t t s / s r / n m ) i n a r a n g e

• f

t e m p e r a t u r e (

• C

< T < 2 5

• C

)

S n D I C E L E D s → ~ m i c r

• Wa

t t s / s r / n m → ~ O ( 1 e

• /

s / p i x e l )

(Regnault et al, submitted to A&A)

SLIDE 34

G h

• s

t s

Two different filter models 105 7201 67 221 727

SLIDE 35

C

• n

c l u s i

• n
• S

t e a d y p r

• g

r e s s

• v

e r t h e l a s t d e c a d e

~ 1 y e a r s t

• i

n c r e a s e a c c u r a c y b y a f a c t

• r

~ 1

• E

a c h s t e p r e q u i r e s

– N

e w t e c h n i q u e s

– m

• r

e d a t a

• We

a r e ~

• n
• p

a r w i t h t h e p r e c i s i

• n
• f

t h e f u n d a m e n t a l ( H S T ) f l u x c a l i b r a t

• r

s

→ A r t i f i c i a l s

• u

r c e s u n d e r d e v e l

• p

m e n t

SLIDE 36