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Mapping solar irradiance within Schrödinger Basin for future robotic sample return missions
The US National Research Council (NRC) identified eight scientific concepts and thirty-five prioritized investigations to be addressed with continued lunar exploration. These objectives are broadly consistent with those identified throughout the international community. the majority of these objectives require sample return from the Moon. Schrödinger basin has been highlighted as a particularly attractive location to find suitable samples
Revisiting rho 1 Cancri e: A New Mass Determination Of The Transiting super-Earth
We present a mass determination for the transiting super-Earth rho 1 Cancri e
based on nearly 700 precise radial velocity (RV) measurements. This extensive
RV data set consists of data collected by the McDonald Observatory planet
search and published data from Lick and Keck observatories (Fischer et al.
2008). We obtained 212 RV measurements with the Tull Coude Spectrograph at the
Harlan J. Smith 2.7 m Telescope and combined them with a new Doppler reduction
of the 131 spectra that we have taken in 2003-2004 with the
High-Resolution-Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) for the
original discovery of rho 1 Cancri e. Using this large data set we obtain a
5-planet Keplerian orbital solution for the system and measure an RV
semi-amplitude of K = 6.29 +/- 0.21 m/s for rho 1 Cnc e and determine a mass of
8.37 +/- 0.38 M_Earth. The uncertainty in mass is thus less than 5%. This
planet was previously found to transit its parent star (Winn et al. 2011,
Demory et al. 2011), which allowed them to estimate its radius. Combined with
the latest radius estimate from Gillon et al. (2012), we obtain a mean density
of rho = 4.50 +/- 0.20 g/cm^3. The location of rho 1 Cnc e in the mass-radius
diagram suggests that the planet contains a significant amount of volitales,
possibly a water-rich envelope surrounding a rocky core.Comment: 16 pages, 5 figures, accepted for publication in the Astrophysical
Journal (the 300+ RV measurements will be published as online tables or can
be obtained from the author
Tri-material multilayer coatings with high reflectivity and wide bandwidth for 25 to 50 nm extreme ultraviolet light
Optical constants of magnetron-sputtered magnesium films in the 25-1300 eV energy range
The transmittance of dc magnetron-sputtered Mg thin films was measured in the 25-1300 eV spectral range. Freestanding Mg films protected with Al layers were characterized ex situ. Transmittance measurements were used to obtain the extinction coefficient k of Mg films. The obtained k values along with the data available in the literature, and with interpolations and extrapolations for the rest of the spectrum, were used to obtain the real part of the index of refraction n by the Kramers-Krönig analysis. Sum-rule tests indicated a good consistency of the data. © 2010 American Institute of Physics.Peer Reviewe
Habitat Selection of White-tailed Deer Fawns and their Dams in the Northern Great Plains
Habitat availability can affect important life-history traits such as survival; however, little information exists on how microhabitat characteristics found at parturition sites selected by dams and bed sites selected by their offspring differ fromthe surrounding area and from each other. Therefore, we assessed how vegetation affected maternal parturition and offspring bed site selection for white-tailed deer (Odocoileus virginianus) in the Northern Great Plains. Dams selected for sites with decreased vegetation height, potentially improving their visibility, which may increase their ability to escape approaching predators. Conversely, there was no variation between vegetative characteristics at neonate bed sites and their associated random sites, indicating grasslands provide adequate concealment for neonates. Dams possess the ability to flee from approaching predators, thus increasing the importance of visibility while giving birth. Conversely, neonates depend on fear bradycardia as their main antipredator defense, so concealment is more important. Our results suggest that vegetation structure is an important characteristic to white-tailed deer as habitat needs vary between adults and neonates
Momentum-resolved resonant inelastic soft X-ray scattering (qRIXS) endstation at the ALS
A momentum resolved resonant inelastic X-ray scattering (qRIXS) experimental station with continuously rotatable spectrometers and parallel detection is designed to operate at different beamlines at synchrotron and free electron laser (FEL) facilities. This endstation, currently located at the Advanced Light Source (ALS), has five emission ports on the experimental chamber for mounting the high-throughput modular soft X-ray spectrometers (MXS) [24]. Coupled to the rotation from the supporting hexapod, the scattered X-rays from 27.5° (forward scattering) to 152.5° (backward scattering) relative to the incident photon beam can be recorded, enabling the momentum-resolved RIXS spectroscopy. The components of this endstation are described in details, and the preliminary RIXS measurements on highly oriented pyrolytic graphite (HOPG) reveal the low energy vibronic excitations from the strong electron-phonon coupling at C K edge around σ* band. The grating upgrade option to enhance the performance at low photon energies is presented and the potential of this spectroscopy is discussed in summary
Soft-x-ray resonant scattering from V/Fe (001) magnetic superlattices
The magnetic properties of Fe and V in (n ML V / 5 ML Fe) (001) superlattices (n = 1, 2, and 5 ML) have been investigated by measuring the magnetization dependent scattering of elliptically polarized soft x rays at various scattering angles and for photon energies across the 2p x-ray-absorption edges of both Fe and V. A quantitative estimate of the magnetic moment induced on vanadium is obtained from the analysis of the resonant scattering data. [S0163-1829(99)50842-4]
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