The First Detections of the Extragalactic Background Light at 3000, 5500, and 8000A (II): Measurement of Foreground Zodiacal Light

We present a measurement of the absolute surface brightness of the zodiacal light (3900-5100A) toward a fixed extragalactic target at high ecliptic latitude based on moderate resolution (~1.3A per pixel) spectrophotometry obtained with the du Pont 2.5m telescope at Las Campanas Observatory in Chile. This measurement and contemporaneous Hubble Space Telescope data from WFPC2 and FOS comprise a coordinated program to measure the mean flux of the diffuse extragalactic background light (EBL). The zodiacal light at optical wavelengths results from scattering by interplanetary dust, so that the zodiacal light flux toward any extragalactic target varies seasonally with the position of the Earth. This measurement of zodiacal light is therefore relevant to the specific observations (date and target field) under discussion. To obtain this result, we have developed a technique that uses the strength of the zodiacal Fraunhofer lines to identify the absolute flux of the zodiacal light in the multiple-component night sky spectrum. Statistical uncertainties in the result are 0.6% (1 sigma). However, the dominant source of uncertainty is systematic errors, which we estimate to be 1.1% (1 sigma). We discuss the contributions included in this estimate explicitly. The systematic errors in this result contribute 25% in quadrature to the final error in our coordinated EBL measurement, which is presented in the first paper of this series.Comment: Accepted for publication in ApJ, 22 pages using emulateapj.sty, version with higher resolution figures available at http://www.astro.lsa.umich.edu/~rab/publications.html or at http://nedwww.ipac.caltech.edu/level5/Sep01/Bernstein2/frames.htm

Upper atmospheres and ionospheres of planets and satellites

The upper atmospheres of the planets and their satellites are more directly exposed to sunlight and solar wind particles than the surface or the deeper atmospheric layers. At the altitudes where the associated energy is deposited, the atmospheres may become ionized and are referred to as ionospheres. The details of the photon and particle interactions with the upper atmosphere depend strongly on whether the object has anintrinsic magnetic field that may channel the precipitating particles into the atmosphere or drive the atmospheric gas out to space. Important implications of these interactions include atmospheric loss over diverse timescales, photochemistry and the formation of aerosols, which affect the evolution, composition and remote sensing of the planets (satellites). The upper atmosphere connects the planet (satellite) bulk composition to the near-planet (-satellite) environment. Understanding the relevant physics and chemistry provides insight to the past and future conditions of these objects, which is critical for understanding their evolution. This chapter introduces the basic concepts of upper atmospheres and ionospheres in our solar system, and discusses aspects of their neutral and ion composition, wind dynamics and energy budget. This knowledge is key to putting in context the observations of upper atmospheres and haze on exoplanets, and to devise a theory that explains exoplanet demographics.Comment: Invited Revie

OPTICAL PUMPING OF THE b4Σ−XIIb^{4}\Sigma^{-}XII TRANSITION IN NO∗NO^{\ast}

$^{1}$. C. Amiot and J. Verges, J. Mol. Spectrosc. 81, 424 (1980). 2. K. P. Huber and M. Vervloet, J. Mol. Spectrosc. 129, 1 (1988).Author Institution: Molecular Physics Laboratory., SRI InternationalThe $NO(b^{4}\Sigma^{-})$ state, in $v = 2-5$, has been excited from the $X^{2}II$ ground state by optical pumping from 187 to 205 nm, and detected by $b^{4}-a^{4}II$ Ogawa band emission. This represents the first optical connection between the doublet and quartet systems and provides a foundation for investigations of the kinetics of the quartet states based on selective optical preparation. Simulation, using published spectroscopic $constants^{1,2}$, shows good agreement for the positions of low J transitions. Comparison of the simulated and observed intensities of the 24 rotational branches suggests that the b-X transition moment involves contributions from perturbers of all potential symmetries: $^{2}\Sigma, {^{2}}II,{^{2}}\Delta,{^{4}}\Sigma$, and $^{4}II$. The b-X Einstein coefficient is estimated to be about $103 s^{-1}$ based on comparison with $B^{2}-X^{2}II$ bands in the same spectral region. We have also investigated predissociation of $b^{4}\Sigma^{-} (v=6)$ and high-J levels of $b (v=5)$, and collisional production of $b^{4}\Sigma^{-}$ following optical excitation of the $A^{2}\Sigma^{+}\, B^{2}\Pi$, and $D^{2}\Sigma^{+}$ states. As most of the NO(b) radiates to the $NO(a^{4}II)$ state, this study also provides a means of preparing the low-v levels, principally $v = 1,2$, of the NO(a) state, whose kinetic importance has frequently been inferred, but for which no direct production scheme has been available

The Establishment of Ovine Progressive Pneumonia (Lungers) Free Sheep From Infected Herds

Volume is misnumbered as 37:3Progressive pneumonia is a chronic disease of adult sheep which may cause serious financial losses in infected flocks of sheep. Symptoms include slow progressive weight loss, physical weakness, a lack of fever, increasing severe respiratory distress with a chronic cough and labored breathing leading to death ultimately. It's first reference was in 1923 in Montana. the North Dakota Agricultural Experiment Station imported 26 Border Leicester ewes from Canada in 1970-71. Also, they purchased a few Columbia ewes from Colorado in 1971. Due to the high incidence of Ovine Progressive Pneumonia in these sheep and that semi-confined enterprises mightexperience likewise, an experiment was initiated in 1974 to attempt the establishment of sheep flocks which were free of this disease. The authors give us the procedures used this this experiment. The immediate isolation and rearing of newborn lambs away from infected parental stock may be a means of reserving valuable bloodlines in pure breeds