robo-ao first science workshop may 20, 2010. the demo period robo-ao science workshop agenda
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Robo-AO
First Science Workshop
May 20, 2010
The Demo PeriodR
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Robo-AO: Demo Period
Nicholas Law
The Demo Period
• 4 weeks on the Palomar 60”
• Q2 2011
• Mission: do lots of great science
What’s unique to Robo-AO?
• Large surveys
• High efficiency
• Continual availability
• Great sky coverage
• Visible-light & high speed imaging
Demo Period Goals
• Variety of science programs
• Extragalactic
• Transients
• Stars
• Planets
• ...
• Cover all Robo-AO unique capabilities
• Large surveys
• High efficiency
• Visible-light AO
• High NIR Strehl
• Resulting in great science... and a large group of papers
Survey Programs
Binarity survey
•all spectral types, companions down to brown dwarfs for most
•cover range of stellar parameter space with one instrument and one coherent survey
Monitoring
Trent Dupuy 2008, 2009
High availability programs
• The Palomar Transient Factory finds 1 transient candidate every ~10 minutes
• Many found near galactic nuclei - how do we separate them?
New Old Subtraction
5/17/2010 2Astronomy Tea Talk
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High-speed, high-resolution imaging
How much time is one month?
• Overheads
• 35-40 secs: telescope pointing & settling
• 20 secs: Centering on target & verification
• 10 secs: WFS calibration, wait for loop to close
• Assume:
• no science in first week
• 50% uptime
• 30% weather losses
• Conservatively ~60 hours, or 1800 targets at 2 mins per target
• However, we need about 5000 targets for contingency!
Types of demo programs
• Large, 1000 targets
• Need to be very exciting papers -- only 2-3 possible
• High-risk if incomplete
• Medium, 100-300 targets
• 10+ projects
• Lower risk
• Others
• eg. transient followup (equiv. to 4m in sensitivity...)
Demo period capabilities
• General AO imaging
• NIR & Visible [specific NIR camera TBD]
• Dithering, standard observation sequences, etc.
• Visible-light high-speed imaging
• Efficiency will improve throughout run
• Likely semi-robotic system
• Probably manual target lists to start with
• Maybe some simple scheduling by end of demo
Decision process
• Projects defined by September
• Robo-AO team will collaborate, provide data, and support for data reduction, in exchange for paper authorship
• Mini-TAC process within Robo-AO team
• Current science team:
• C. Baranec, R. Dekany, J. Johnson, M. Kasliwal, M. van Kerkwijk, S. Kulkarni, N. Law, T. Morton, E. Ofek, A. Ramaprakash, R. Riddle, S. Tendulkar
Robo-AO Robo-AO Astrometry (1)Astrometry (1)
Nicholas LawNicholas Law
Astrometric Performance Astrometric Performance LimitsLimits
Signal, noise, and image size (photon statistics):Signal, noise, and image size (photon statistics):
SystematicsSystematics
Focal plane distortionFocal plane distortion
Atmospheric refraction (inc. chromatic Atmospheric refraction (inc. chromatic effects)effects)
Changes in instrument / telescopeChanges in instrument / telescope
Atmospheric turbulenceAtmospheric turbulence
Astrometric Performance Astrometric Performance LimitsLimits
Focal plane distortionFocal plane distortion
Atmospheric refraction (inc. chromatic Atmospheric refraction (inc. chromatic effects)effects)
Changes in instrument / telescopeChanges in instrument / telescope
Atmospheric turbulenceAtmospheric turbulence
Detailed calibration using crowded fieldsDetailed calibration using crowded fields
Work in narrow bands in the near-IR: Work in narrow bands in the near-IR:
in a 30nm bandpass at 2.0in a 30nm bandpass at 2.0μμm refraction effects are < m refraction effects are < 5050μμasas
• Don’t do that! Robo-AO won’tDon’t do that! Robo-AO won’t
Complicated... but that’s what Robo-AO is forComplicated... but that’s what Robo-AO is for
Band SNR Compared to 1.5 m
SNR Compared to 4 m
FWHM (1” is typical)
Strehl
J 2.9X 0.4X 0.2” 50%
H 7.1X 0.98X 0.26” 70%
Robo-AO AstrometryRobo-AO Astrometry
Astrometric precision gains in FWHM & SNRAstrometric precision gains in FWHM & SNR
With careful experimental design, performance With careful experimental design, performance limited by atmospheric tip/tilt jitter (see Cameron limited by atmospheric tip/tilt jitter (see Cameron et al. 2009)et al. 2009)
Prediction of performance:Prediction of performance:
100-200uas precision in 10-30 minutes100-200uas precision in 10-30 minutes(depending on details of target & field)(depending on details of target & field)
Integration time / secondsIntegration time / seconds
2 milliarcsec2 milliarcsec
M-dwarf Planetary M-dwarf Planetary PopulationsPopulations
Only 16 planetary systems detected around M-dwarfs (<~0.6 solar Only 16 planetary systems detected around M-dwarfs (<~0.6 solar masses)masses)
Several hundred detected around solar-type starsSeveral hundred detected around solar-type stars
M-dwarfs are very M-dwarfs are very FAINT and red FAINT and red for RV searchesfor RV searches
Only the highest-mass M-dwarfs (<M3) have been probed with Only the highest-mass M-dwarfs (<M3) have been probed with radial velocity searchesradial velocity searches
Even so, some of the most interesting systems have been found Even so, some of the most interesting systems have been found around M-dwarfsaround M-dwarfs
Gl 581Gl 581
2 M2 MEarthEarth
16 M16 MEarthEarth
5 M5 MEarthEarth
7 M7 MEarthEarth
Mayor et al 2009 arXiv:0906.2780
MM-dwarf -dwarf AAstrometric strometric AOAO PPlanet lanet SSurveyurvey
Target M-dwarfs in galactic planeTarget M-dwarfs in galactic plane
Few hundred microarcsec precision per epochFew hundred microarcsec precision per epoch
Sensitive to Jupiter-mass planets in few-month Sensitive to Jupiter-mass planets in few-month orbitsorbits
Competitive with (future) ~10 m/s radial velocity Competitive with (future) ~10 m/s radial velocity surveys around mid M-dwarfs for few month orbitssurveys around mid M-dwarfs for few month orbits
Robo-AO: Binarity Survey
Nicholas Law
Multiplicity in solar neighborhood
5/17/2010 2Astronomy Tea Talk
• Various surveys
• Solar type stars:
• Duquennoy & Mayor (1991)
• More recent RV surveys
• Some AO BD surveys (eg. Gelino et al.)
• All 100-200 targets
• M-dwarfs
• Lots of ~50-target AO surveys
• RV surveys starting up for planet searches
• Other types have a similar patchwork of surveys
Robo-AO’s contribution
5/17/2010 2Astronomy Tea Talk
• 8 Target groups
• A, F, G, K, M0-3, M3-6, M6-9, L0+
• Sensitivity
• High-mass BD companions in ~120 secs (at large radii)
• Main sequence companions at most separations
• In visible, white dwarf companions reachable
• CPM confirmation in 1 month is conceivable
• Target numbers
• 150 targets per night
• Useful contribution in 5-8 nights @ 150 targets per target group
• Large, coherent, well-understood-bias survey