The mid-infrared spectrum of the transiting exoplanet HD 209458b

We report the spectroscopic detection of mid-infrared emission from the transiting exoplanet HD 209458b. Using archive data taken with the Spitzer/IRS instrument, we have determined the spectrum of HD 209458b between 7.46 and 15.25 microns. We have used two independent methods to determine the planet spectrum, one differential in wavelength and one absolute, and find the results are in good agreement. Over much of this spectral range, the planet spectrum is consistent with featureless thermal emission. Between 7.5 and 8.5 microns, we find evidence for an unidentified spectral feature. If this spectral modulation is due to absorption, it implies that the dayside vertical temperature profile of the planetary atmosphere is not entirely isothermal. Using the IRS data, we have determined the broad-band eclipse depth to be 0.00315 +/- 0.000315, implying significant redistribution of heat from the dayside to the nightside. This work required development of improved methods for Spitzer/IRS data calibration that increase the achievable absolute calibration precision and dynamic range for observations of bright point sources.Comment: 35 pages, 12 figures, revised version accepted by the Astrophysical Journa

Spherical solid-propellant rocket motor Patent

Spherical solid propellant rocket engine desig

Habitat associations and natural history of the Tasmanian "snow skinks" (Niveoscincus spp.)

Niveoscincus "snow skink" is the largest genus of lizards in Tasmania, but little literature is available on the ecology of the seven species discussed here. They were examined by studying the vegetation associations and natural history of all Niveoscincus species except N palfreymani. Most were found to be primarily either ground-dwelling, saxicolous or arboreal, although a few species, such as N microlepidotus, showed a combination of these habits. Saxicolous and heath/rock-dwelling species were restricted to more open habitats. Ground-dwelling species, on the other hand, were widespread and found in many different habitats but not in open rocky areas. Arboreal species were found in a wide range of forest habitats from sea-level to the tree line. The species studied were found to have significantly different, although partially overlapping habitat preferences

Variable Dynamic Force Vector Rocket Test Apparatus

Design and performance characteristics of variable dynamic force vector rocket test apparatu

Implementation of ILLIAC 4 algorithms for multispectral image interpretation

Research has focused on the design and partial implementation of a comprehensive ILLIAC software system for computer-assisted interpretation of multispectral earth resources data such as that now collected by the Earth Resources Technology Satellite. Research suggests generally that the ILLIAC 4 should be as much as two orders of magnitude more cost effective than serial processing computers for digital interpretation of ERTS imagery via multivariate statistical classification techniques. The potential of the ARPA Network as a mechanism for interfacing geographically-dispersed users to an ILLIAC 4 image processing facility is discussed

Optimal squeezing, pure states, and amplification of squeezing in resonance fluorescence

It is shown that 100% squeezed output can be produced in the resonance fluorescence from a coherently driven two-level atom interacting with a squeezed vacuum. This is only possible for $N=1/8$ squeezed input, and is associated with a pure atomic state, i.e., a completely polarized state. The quadrature for which optimal squeezing occurs depends on the squeezing phase $\Phi ,$ the Rabi frequency $\Omega ,$ and the atomic detuning $\Delta$. Pure states are described for arbitrary $\Phi ,$ not just $\Phi =0$ or $\pi$ as in previous work. For small values of $N,$ there may be a greater degree of squeezing in the output field than the input - i.e., we have squeezing amplification.Comment: 6 pages & 7 figures, Submitted to Phys. Rev.

A Multiple Scattering Polarized Radiative Transfer Model: Application to HD 189733b

We present a multiple scattering vector radiative transfer model which produces disk integrated, full phase polarized light curves for reflected light from an exoplanetary atmosphere. We validate our model against results from published analytical and computational models and discuss a small number of cases relevant to the existing and possible near-future observations of the exoplanet HD 189733b. HD 189733b is arguably the most well observed exoplanet to date and the only exoplanet to be observed in polarized light, yet it is debated if the planet's atmosphere is cloudy or clear. We model reflected light from clear atmospheres with Rayleigh scattering, and cloudy or hazy atmospheres with Mie and fractal aggregate particles. We show that clear and cloudy atmospheres have large differences in polarized light as compared to simple flux measurements, though existing observations are insufficient to make this distinction. Futhermore, we show that atmospheres that are spatially inhomogeneous, such as being partially covered by clouds or hazes, exhibit larger contrasts in polarized light when compared to clear atmospheres. This effect can potentially be used to identify patchy clouds in exoplanets. Given a set of full phase polarimetric measurements, this model can constrain the geometric albedo, properties of scattering particles in the atmosphere and the longitude of the ascending node of the orbit. The model is used to interpret new polarimetric observations of HD 189733b in a companion paper.Comment: 13 pages, 13 figures. Accepted for publication in Ap

“It's about sharing a moment”: Parents' views and experiences of home reading with their autistic children with moderate-to-severe intellectual disabilities

BACKGROUND: The home literacy environment plays a critical role in the development of children’s literacy and language development. Little is known, however, about the home literacy environment of autistic children, especially those with moderate-to-severe intellectual disabilities. AIMS: The current study used a sequential mixed-methods design to understand how parents attempt to engage their autistic children in reading activities and support them in learning to read. METHODS AND PROCEDURE: First, 63 parents (53 mothers) whose autistic children attended an autism-specific special school completed a bespoke questionnaire about the home literacy environments for their children (n = 69, age range = 3–11 years, 61 boys, 8 girls). Second, a subsample of parents (n = 19, 15 mothers) participated in focus groups to understand in-depth their views and experiences of home reading with their children (n = 20, age range = 3–11 years, 19 boys, 1 girl). We used reflexive thematic analysis to analyse the focus group data. OUTCOMES AND RESULTS: Across questionnaire and focus group methods, parents were united in considering reading to be an important life skill, a sentiment that was reflected both by their often literacy-rich homes and the ingenuity in their efforts to engage their children in shared home-reading activities – even when such engagement could be challenging. They also emphasised, however, the importance of valuing these activities as an opportunity to “catch a moment” with their child. CONCLUSIONS AND IMPLICATIONS: Parents and teachers should work together to identify ways to enhance autistic children’s engagement in shared home-reading activities, listening to and learning from each other’s experiences and expertise, and to show what is possible within each learning context

Molecular Signatures in the Near Infrared Dayside Spectrum of HD 189733b

We have measured the dayside spectrum of HD 189733b between 1.5 and 2.5 microns using the NICMOS instrument on the Hubble Space Telescope. The emergent spectrum contains significant modulation, which we attribute to the presence of molecular bands seen in absorption. We find that water (H2O), carbon monoxide (CO), and carbon dioxide (CO2) are needed to explain the observations, and we are able to estimate the mixing ratios for these molecules. We also find temperature decreases with altitude in the ~0.01 < P < ~1 bar region of the dayside near-infrared photosphere and set an upper limit to the dayside abundance of methane (CH4) at these pressures.Comment: 13 pages, 3 figures. accepted in Astrophysical Journal Letter