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We describe a new instrument that forms the core of a long-term high contrast imaging program at the 200 inch (5 m) Hale Telescope at Palomar Observatory. The primary scientific thrust is to obtain images and low-resolution spectroscopy of brown dwarfs and young exoplanets of several Jupiter masses in the vicinity of stars within 50 pc of the Sun. The instrument is a microlens-based integral field spectrograph integrated with a diffraction-limited, apodized-pupil Lyot coronagraph. The entire combination is mounted behind the Palomar adaptive optics (AO) system. The spectrograph obtains imaging in 23 channels across the J J and H H bands (1.06–1.78 μm). The image plane of our spectrograph is subdivided by a200 × 200 200 × 200 element microlens array with a plate scale of 19.2 mas per microlens, critically sampling the diffraction-limited point-spread function at 1.06 μm. In addition to obtaining spectra, this wavelength resolution allows suppression of the chromatically dependent speckle noise, which we describe. In addition, we have recently installed a novel internal wave front calibration system that will provide continuous updates to the AO system every 0.5–1.0 minutes by sensing the wave front within the coronagraph. The Palomar AO system is undergoing an upgrade to a much higher order AO system (PALM-3000): a 3388-actuator tweeter deformable mirror working together with the existing 241-actuator mirror. This system, the highest-resolution AO corrector of its kind, will allow correction with subapertures as small as 8.1 cm at the telescope pupil using natural guide stars. The coronagraph alone has achieved an initial dynamic range in the H H band of2 × 10-4 2 × 10 - 4 at 1″, without speckle noise suppression. We demonstrate that spectral speckle suppression provides a factor of 10–20 improvement over this, bringing our current contrast at 1″ to∼2 × 10-5 ∼ 2 × 10 - 5 . This system is the first of a new generation of apodized-pupil coronagraphs combined with high-order adaptive optics and integral field spectrographs (e.g., GPI, SPHERE, HiCIAO), and we anticipate that this instrument will make a lasting contribution to high-contrast imaging in the Northern Hemisphere for years.

We have investigated the temporal variability and statistics of the 'instantaneous' Strehl ratio. The observations were carried out with the 3.63-m AEOS telescope equipped with a high-order adaptive-optics system. In this paper Strehl ratio is defined as the peak intensity of a single short exposure. We have also studied the behavior of the phase variance computed on the reconstructed wavefronts. We tested the Marechal approximation and used it to explain the observed negative skewness of the Strehl ratio distribution. The estimate of the phase variance is shown to fit a three- parameter Gamma distribution model. We show that simple scaling of the reconstructed wavefronts has a large impact on the shape of the Strehl ratio distribution.

We present a new and computationally efficient method for characterizing very low-mass companions using low-resolution (R ∼ 30), near-infrared (YJH) spectra from high-contrast imaging campaigns with integral field spectrograph (IFS) units. We conduct a detailed quantitative comparison of the efficacy of this method through tests on simulated data comparable in spectral coverage and resolution to the currently operating direct-imaging systems around the world. In particular, we simulate Project 1640 data as an example of the use, accuracy, and precision of this technique. We present results from comparing simulated spectra of M, L, and T dwarfs with a large and finely sampled grid of synthetic spectra using Markov-chain Monte Carlo techniques. We determine the precision and accuracy of effective temperature and surface gravity inferred from fits to PHOENIX dusty and cond, which we find reproduce the low-resolution spectra of all objects within the adopted flux uncertainties. Uncertainties in effective temperature decrease from ± 100-500 K for M dwarfs to as small as ± 30 K for some L and T spectral types. Surface gravity is constrained to within 0.2-0.4 dex for mid-L through T dwarfs, but uncertainties are as large as 1.0 dex or more for M dwarfs. Results for effective temperature from low-resolution YJH spectra generally match predictions from published spectral type-temperature relationships except for L-T transition objects and young objects. Single-band spectra (i.e., narrower wavelength coverage) result in larger uncertainties and often discrepant results, suggesting that high-contrast IFS observing campaigns can compensate for low spectral resolution by expanding the wavelength coverage for reliable characterization of detected companions. We find that S/N ∼ 10 is sufficient to characterize temperature and gravity as well as possible given the model grid. Most relevant for direct-imaging campaigns targeting young primary stars is our finding that low-resolution near-infrared spectra of known young objects, compared to field objects of the same spectral type, result in similar best-fit surface gravities but lower effective temperatures, highlighting the need for better observational and theoretical understanding of the entangled effects of temperature, gravity, and dust on near-infrared spectra in cool low-gravity atmospheres.

Anne Perry's Victorian detective novels link women's domestic power, criminal investigations, and social reform. Although she argues that women exercised social control through their domestic gaze, Perry finally can offer only the companionable marriage of Thomas and Charlotte Pitt as an answer to the violence of both the Victorian period and our own. [PUBLICATION ABSTRACT]

The purpose of this study was to identify the psychosocial characteristics of incarcerated girls with a substance use disorder. Profile analysis, the repeated measures extension of multivariate analysis of variance, was conducted to compare a state-based sample of incarcerated girls with ( n  = 140) and without ( n  = 63) a substance use disorder across multiple subscales of the Multidimensional Adolescent Assessment Scale. Girls with a substance use disorder had higher levels of problem severity. They were more likely to have problems related to alcohol use, drug use, aggression, and cognition. Incarcerated girls with a substance use disorder may benefit from intense interventions that focus on cognitive restructuring or cognitive recovery, and interventions that promote coping and stress management skills.