59 research outputs found
Observing the Earth as an exoplanet with LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth
The detections of small, rocky exoplanets have surged in recent years and
will likely continue to do so. To know whether a rocky exoplanet is habitable,
we have to characterise its atmosphere and surface. A promising
characterisation method for rocky exoplanets is direct detection using
spectropolarimetry. This method will be based on single pixel signals, because
spatially resolving exoplanets is impossible with current and near-future
instruments. Well-tested retrieval algorithms are essential to interpret these
single pixel signals in terms of atmospheric composition, cloud and surface
coverage. Observations of Earth itself provide the obvious benchmark data for
testing such algorithms. The observations should provide signals that are
integrated over the Earth's disk, that capture day and night variations, and
all phase angles. The Moon is a unique platform from where the Earth can be
observed as an exoplanet, undisturbed, all of the time. Here, we present LOUPE,
the Lunar Observatory for Unresolved Polarimetry of Earth, a small and robust
spectropolarimeter to observe our Earth as an exoplanet.Comment: 14 pages, 3 figures, submitted in special Issue of Planetary and
Space Science on Scientific Preparations for Lunar Exploratio
The Environment of z > 1 3CR Radio Galaxies and QSOs: From Proto-clusters to Clusters of Galaxies?
Galaxie
P-wave excited baryons from pion- and photo-induced hyperon production
We report evidence for , , ,
, , and , and find
indications that might have a companion state at 1970\,MeV. The
controversial is not seen. The evidence is derived from a
study of data on pion- and photo-induced hyperon production, but other data are
included as well. Most of the resonances reported here were found in the
Karlsruhe-Helsinki (KH84) and the Carnegie-Mellon (CM) analyses but were
challenged recently by the Data Analysis Center at GWU. Our analysis is
constrained by the energy independent scattering amplitudes from either
KH84 or GWU. The two amplitudes from KH84 or GWU, respectively, lead to
slightly different branching ratios of contributing resonances but the
debated resonances are required in both series of fits.Comment: 22 pages, 28 figures. Some additional sets of data are adde
Cold Gas in Cluster Cores
I review the literature's census of the cold gas in clusters of galaxies.
Cold gas here is defined as the gas that is cooler than X-ray emitting
temperatures (~10^7 K) and is not in stars. I present new Spitzer IRAC and MIPS
observations of Abell 2597 (PI: Sparks) that reveal significant amounts of warm
dust and star formation at the level of 5 solar masses per year. This rate is
inconsistent with the mass cooling rate of 20 +/- 5 solar masses per year
inferred from a FUSE [OVI] detection.Comment: 10 pages, conference proceeding
Raining in MKW 3 s: a Chandra-MUSE analysis of X-Ray cold filaments around 3CR 318.1
High Energy Astrophysic
Optical Light Curves of Supernovae
Photometry is the most easily acquired information about supernovae. The
light curves constructed from regular imaging provide signatures not only for
the energy input, the radiation escape, the local environment and the
progenitor stars, but also for the intervening dust. They are the main tool for
the use of supernovae as distance indicators through the determination of the
luminosity. The light curve of SN 1987A still is the richest and longest
observed example for a core-collapse supernova. Despite the peculiar nature of
this object, as explosion of a blue supergiant, it displayed all the
characteristics of Type II supernovae. The light curves of Type Ib/c supernovae
are more homogeneous, but still display the signatures of explosions in massive
stars, among them early interaction with their circumstellar material. Wrinkles
in the near-uniform appearance of thermonuclear (Type Ia) supernovae have
emerged during the past decade. Subtle differences have been observed
especially at near-infrared wavelengths. Interestingly, the light curve shapes
appear to correlate with a variety of other characteristics of these
supernovae. The construction of bolometric light curves provides the most
direct link to theoretical predictions and can yield sorely needed constraints
for the models. First steps in this direction have been already made.Comment: To be published in:"Supernovae and Gamma Ray Bursters", Lecture Notes
in Physics (http://link.springer.de/series/lnpp
Properties of baryon resonances from a multichannel partial wave analysis
Properties of nucleon and resonances are derived from a multichannel
partial wave analysis. The statistical significance of pion and photo-induced
inelastic reactions off protons are studied in a multichannel partial-wave
analysis.Comment: 12 pages, 8 Table
RECENT RESEARCH ADVANCES ON THE EUROPEAN CORN BORER IN NORTH AMERICA 1,2,3
BIOLOGY AND ECOLOGY
Distribution
The recorded distribution of the European corn borer, Osttinia nubilalis, has not changed significantly since Brindley & Dicke\u27s review in 1963 (15), except along the southernmost portion of its range. Annual articles presenting the status of the European corn borer (3) indicate that each year the borer spreads into a few previously uninfested counties within known infested states. Sparks & Young (116) made a survey and found 34 of 35 counties infested in southern Georgia and concluded that the borer probably was present in all areas of extensive com production in Georgia. Light-trap records from Tifton, Georgia, indicate that the borer\u27s seasonal life history is very similar to its life history in South Carolina (31) and in Alabama (32). There are three complete generations each year and a fourth-generation completes development in most years. Although official records do not show the presence of the borer in Florida, records from the southern tier of counties in Alabama (H. F. McQueen, personal communication) and in Georgia (116) indicate that com-growing areas of the Florida panhandle probably are infested. Showers, Reed & Brindley (109) conducted laboratory studies and concluded that the Georgia borer had adapted to the photoperiod-temperature interaction of the region and was capable of producing large numbers of moths for the summer and autumn generaÂtions.
Chiang (20) studied the dispersion of the borer in Minnesota and in South Dakota from 1945 to 1970 and suggested that after the initial invasion in 1943, two distinctly different populations could have invaded Minnesota, one in 1952 and one in 1966. Chiang & Hodson (21) concluded that populations in the Waseca, Minnesota, area were kept at relatively low levels by environmental factors, but that with favorable temperatures, the borer populations could return to an economically significant level
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