We present on-sky performance results of a new technique, speckle stabilization, with the Stabilized sPeckle
Integral Field Spectrograph Proof-Of-Concept (SPIFS-POC) instrument. The SPIFS-POC is an optical-imaging
instrument capable of high spatial resolutions much finer than the seeing-limit. It achieves this aim by measuring
speckle patterns in real time (through the use of an L3CCD), finding the highest quality speckle, and stabilizing
it onto a traditional, low readout speed science camera through the use of a fast steering mirror. This process
is repeated at ≈100 Hz over the course of long exposures resulting in a high-resolution core surrounded by a
diffuse halo. We show that in the Sloan z' bands, SPIFS is able to acquire spatial resolutions much greater than
the seeing limit, even approaching 3λ/D. We also discuss improvements for the next phase of the SPIFS project
where we fully expect to be able to recover diffraction-limited spatial resolutions in the optical.
We present the results of performance simulations characterizing the Stabilized sPeckle Integral Field Spectrograph (SPIFS). Our simulations of images distorted by Kolmogorov atmospheric turbulence confirm that stabilization of the single brightest speckle via a fast steering mirror (FSM) produces near-diffraction-limited spatial resolution for the red part of the visible spectrum (0.6 μm-1.0 μm). On a 10-meter class telescope this corresponds to an angle of ~13 mas. We also demonstrate that the Strehl ratio of the stabilized speckle will be between 1 and 3% for r0 = 20cm on a 10-meter class telescopes. The guide star limiting magnitude, through the use of a shutter, will be I=16.5. Simulations also reveal that the guide star can be as far away as 20" from the source and still recover tip-tilt information to drive SPIFS.
We describe an instrument concept and basic feasibility study for a new observational technique which we call
Stabilized-sPeckle Integral Field Spectroscopy (SPIFS). SPIFS will enable, under certain observational conditions and
constraints, low-to-modest-Strehl diffraction-limited imaging spectroscopy from large ground-based telescopes in the
optical bandpass (i.e. V, R, and I bands). SPIFS is capable of exploring important scientific niches which are not
currently available using existing high angular resolution techniques such as adaptive optics or speckle imaging, using
existing, relatively-inexpensive technology. Based on our simulations presented in a companion paper (Keremedjiev,
Eikenberry & Carson, 2008), SPIFS can provide integral field spectroscopy at ~15-mas resolution and ~3% Strehl over
the I-band with sky coverage of ~20% to 100% in the Galactic Plane and ~5% at the Galactic poles. We present an
overview of the SPIFS technique and simulated performance in realistic observations of the microquasar SS 433 to
demonstrate one simple example of the power of SPIFS.