PALM-3000 Observers Information - 2011B

Overview

PALM-3000 and its back-end instruments are optimized for high-angular resolution science at visible and near-infrared wavelengths. As the world's highest order adaptive optics system, PALM-3000 will correct for atmospheric turbulence to an unprecedented degree using a new 3,388 actuator Xinetics deformable mirror in conjunction with the former 349 actuator DM and separate fast tip-tilt mirror. Wavefront sensing requires a bright natural guide star in proximity to the science target.

2011B Call for Proposals

PALM-3000 will be available for shared-risk science observations, per the Call for Proposals in 2011B.

Current Instruments Status

PALM-3000 is undergoing system integration at Palomar Observatory.
- We expect our first light engineering test of PALM-3000 in mid-May 2011, with several engineering runs before reaching peak performance, particularly for high contrast.
PHARO is currently operational at the summit and we expect to open the dewar for a single mask/filter exchange in late-April 2011.
P1640
- Coronagraph + CAL is undergoing integration and testing at JPL in Pasadena.
- IFS is enjoying an upgrade to a science-grade H2RG detector at AMNH in New York City.
SWIFT is currently undergoing refurbishment at Oxford University, UK and is expected to return to Palomar by June 2011.

Expected System Capabilities

For 2011B, PALM-3000 will support natural guide star wavefront sensing (only) in the following correction modes:

Number of subapertures per pupil diameter	WFS limiting mag	WFS best performance mag	Notes
62	V < 6.5	V < 5.5
32	V < 10	5.5 < V < 8
16	V < 13.5	---	Not offered in 2011B
8	V < 17	---	Not offered in 2011B

PALM-3000 correction will be best in the direction of the guide star, and fall off due to atmospheric anisoplanatism. The corrected field of view diameter will vary with conditions, but is generally expected to be between 1-2 arcmin diameter in K-band, decreasing to 10-20 arcsec in I-band.

Expected Performance on Bright Guide Stars

The bright star wavefront error budget for PALM-3000 is as follows:

* Assumptions

Mean turbulence weighted wind speed = 9.5 m/s
Zenith pointing
Guide star brightness V ~ 5
AO mode: N = 62 AO

Seeing	r_0(0.5um)	RMS residual wavefront error	Strehl Ratio
			r'	i'	Z	Y	J	H	K
			0.62um	0.75um	.88um	1.03um	1.25um	1.64um	2.2um
0.7"	0.14 m	83 nm	48%	61%	70%	78%	84%	90%	95%
1.1" (median)	0.092 m	95 nm	40%	54%	65%	73%	80%	88%	93%
1.6"	0.07 m	165 nm	26%	38%	47%	54%	61%	68%	73%

Expected Observing Overheads

Instrument requirement #0480 states that PALM-3000 shall be ready to begin a science exposure < 2 minutes after the end of a telescope slew (< 1 minute goal). During shared-risk science observing in 2011B, we expect observations performed in a single AO mode in a localized part of the sky to approach the final requirement. For now, changes in telescope pointing or AO mode may result in greater acquisition overheads.

Closed-loop AO image dithering on PHARO is expected to be functional at a level equal to or better than the prior PALMAO system (smallest step size ~ 5 mas), with improved non-common-path flexure during long exposures [check back for measurements from engineering nights].

Wide-field astrometry

During 2011B, we do not recommend wide-field PHARO astrometric programs, due to the unchacterized nature of our dual-DM correction architecture. Contact the PALM-3000 PI for further details.

Extended objects

PALM-3000 is designed to support NGS observations of Uranus and Neptune, but optimization on these targets will require additional calibration effort. Contact the PALM-3000 PI for further information.

Contact information

Technical inquiries for specific observing proposals not addressed here can be referred to Principal Investigator Dr. Richard Dekany at Caltech Optical Observatories.

Last updated - 04 Mar 2011

Topic revision: r3 - 2011-03-04 - RichardDekany

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