Transcript Max_ScienceReplan.ppt

Keck NGAO Project Replan:
Science Cases and Requirements
Claire Max
NGAO Team Meeting 6
April 25, 2007
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Not on this list
• Orion Initial Mass Function
• Mira Variables
• T Tauri
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AO Roll-Up to date
Science Case
Observing
wavelengths
WFE
Enclosed
Energy
Contrast
Photometric
accuracy
Astrometric
accuracy
Asteroid shape
0.7 – 2.4 m
155 nm
na
na
?
na
Asteroid
companions
0.7 – 2.4 m
depends on
sensitivity
170 nm
na
=5.5 at 0.5 arc
sec sep'n
140 nm OK
Planets around 0.9 – 2.4 m plus 170 and 200 nm
low-mass stars possible L band
under
investigation
?
H=13 at 1 arc
sec sep'n
Radial velocity
AO Background
accuracy
Overheads
between
targets
Minimum sky
coverage
na
Equal to or lower
than current LGS At most 10 min
background
?
Astrometric
5% at 0.6 arc
accuracy better
sec with m=3 than 1.5 mas at I
band
na
Equal to or lower
than current LGS At most 10 min
background
?
0.05 mag
relative to
primary star
Astrometric
accuracy better
than 2 mas at J
and H bands
na
na
At most 10 min
> 30%
?
0.1 mas
10 km/sec
na (confusion
limited)
na
Must give
desired WFE at
GC
TBD
Galactic Center
K band + maybe
H band
170 nm at Gal.
Ctr. (low
elevation target)
?
High (not clear
yet how high)
Nearby AGNs
0.8 - 2.4 m
Good Strehl at
800 nm => 140
nm WFE or less
TBD
na
na
High z Galaxies
JHK bands
TBD
50% within 0.07
arc sec
na
na
na
Less than 30%
over sky plus
telescope
na (long
exposures)
> 30% with
encircled energy
of 0.07 arc sec
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Summary of rolled-up requirements
• Wavelength range 0.7 - 2.4 m
• Wavefront error: 140 nm
– Tip-tilt blurring has not been thoroughly explored yet
– 170 nm acceptable for some science cases
• Enclosed energy (high-z galaxies): 50% within
0.07 arc sec over >30% of sky
• Contrast:
– I=5.5 at 0.5 arc sec sep'n
– H=53 at 1 arc sec sep'n
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Rolled-up requirements, contd
• Photmetric accuracy: 5%
• Astrometric accuracy:
– Galactic Center 0.1 mas
– Other science cases 1.5 - 2 mas
• Added background due to AO system:
– Less than 30% above (sky + telescope)
• Radial velocity accuracy <10 km/s Galactic Ctr
• Time to switch between LGS targets < 10 min
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