CAMERA C ompact A utomated ME MS R ayleigh A daptive Optics System

1. CAMERA Compact Automated MEMS Rayleigh Adaptive Optics System C. Baranec, S. Kulkarni, R. Dekany, N. Law, E. Ofek, M. Kasliwal, V. Velur, & A. Ramaprakash (IUCAA) Overview Lab Testbed a) • Rapidly develop and deploy low cost adaptive optics (AO) system for 1-3 meter telescopes: • Use low-risk technologies • Ease of use, fully robotic • Emphasis on high observing efficiency • New astronomical science capability: • Allocate large amounts of time to diffraction-limited astronomy, previously not possible • Integrated visible and near IR science instruments The gravitational lens HE 1113-0641 [2]. In V: HST image. In g': Seeing-limited discovery image, taken in exceptional seeing. High angular resolution observations were required to confirm the lens properties, search for the lens galaxy and photometrically separate the images. Observations taken in standard seeing would have failed to resolve this lens. AO Performance New Science Capability • Extensive surveys (1000++ objects) • Stellar, sub-stellar companion searches • Lensed quasars (300-700 new over a 9 month period of intermittent observing) • Asteroid binarity • Rapid transient characterization • Respond to transients identified by other systems (e.g. PTF, Catalina Sky Survey, PanSTARRs) • Rapid near-IR photometry • Time-domain astronomy • Long term, high-resolution monitoring • Solar system objects, repeating transients, orbits • Astrometry • Dedicated system to optimize stability • High H-Strehl improves precision Testbed closed loop at 120 Hz: Fully remote operation, including simulated queue scheduled observations Swift J1955+2614, one of the strangest transients of recent years [3-5]. This galactic transient was discovered in the galactic plane by the Swift Gamma-Ray-Burst detector satellite. Follow-up observations revealed an extremely complex (and still poorly understood) light curve, followed by rapid fading. Since stellar crowding was significant, LGS-AO observations were required to separate the transient light from surrounding stars. (Left): The transient during emission. (Right): the transient location after emission ceased. Note the 1” scale bar; clearly, accurate photometry of this very interesting source required high-angular-resolution observations. CAMERA could easily perform similar observations within minutes of initial detection. Example error budget for CAMERA under different seeing conditions (r0) and for different zenith angles (z) assuming an on-axis mV=17 star for tip-tilt sensing and on-axis science target. Design • Compact - WFS and science cameras fit on 0.5 x 0.5 m breadboard • 120” field of view • 12X12 Boston Micromachines MEMS DM • Shack-Hartmann WFS (CCD39) • 355nm Rayleigh LGS (similar systems FAA approved), packaged in secondary hub • IR and visible tip/tilt sensors • IR and science detectors • Automated operation FWHM at H < 0.26” in even the 75% worst seeing conditions 5” CAMERA at the 200”!?! • The CAMERA adaptive optics system can be replicated and potentially deployed at the 200” with a focus on improving energy concentration for existing instrumentation such as DoubleSpec and TripleSpec. • COO is currently investigating this new type of AO for increasing the SNR and resolution of spectroscopic astronomy. Calculated H-band Strehl ratios for CAMERA under the various observing conditions presented above for different visual magnitudes of on-axis tip-tilt star. Provides a 1.5 m telescope the H sensitivity of a 4 m telescope References Supernova 2006GY [1], the second-most luminous supernova ever recorded. Lick AO observations were required to separate the supernova from its host galaxy and ascertain if it was simply AGN variability. The AO observations rapidly confirmed the nature of the transient and gave vital information: position in the host galaxy and a light curve resolved from the bright galaxy nucleus. The ability to quickly and inexpensively perform such observations is growing ever more important as surveys begin to find many potentially interesting transients every night. [1] N. Smith, et al., “SN 2006gy: Discovery of the Most Luminous Supernova Ever Recorded, Powered by the Death of an Extremely Massive Star like nu Carinae,” Astrophysical Journal, 666, 1116–1128, 2007. [2] J. A. Blackburne, L. Wisotzki, and P. L. Schechter, “HE 1113-0641: The Smallest Separation Gravitational Lens Identified by a Ground-based Optical Telescope,” ArXiv e-prints, 710, October 2007. [3] A. Stefanescu, et al., “Very fast optical flaring from a possible new Galactic magnetar,” Nature, 455, 503-505, 2008. [4] A. J. Castro-Tirado, et al., “Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars,” Nature, 455, 506-509, 2008. [5] M. M. Kasliwal, et al., “GRB 070610: A Curious Galactic Transient,” Astrophysical Journal, 678, 1127–1135, 2008. Ratio of CAMERA enhanced integration time for the same SNR ratio vs. seeing limited telescopes Palomar Science Meeting, Pasadena, CA, Apr. 30 – May 1, 2009.