2,874 research outputs found
EXPLANATION OF THE BASIC FORMULA PRICE PROVISIONS OF THE PROPOSED RULE
An important segment of milk marketing order reform involves replacing the current BFP. This working paper explains the background of the BFP issue, the options considered and the provisions of the proposed rule as related to the BFP issue.Marketing,
EVALUATION OF THE PROPOSED RULE FOR SETTING CLASS III AND CLASS IV MILK PRICES UNDER FEDERAL MILK MARKETING ORDERS
Marketing,
Discovery of dumbbell-shaped Cs*He_n exciplexes in solid He 4
We have observed several new spectral features in the fluorescence of cesium
atoms implanted in the hcp phase of solid helium following laser excitation to
the 6P states. Based on calculations of the emission spectra using
semiempirical Cs-He pair potentials the newly discovered lines can be assigned
to the decay of specific Cs*He exciplexes: an apple-shaped CsHe and a dumbbell-shaped CsHe exciplex with
a well defined number of bound helium atoms. While the former has been
observed in other enviroments, it was commonly believed that exciplexes with
might not exist. The calculations suggest CsHe to be
the most probable candidate for that exciplex, in which the helium atoms are
arranged on a ring around the waist of the dumbbell shaped electronic density
distribution of the cesium atom.Comment: 4 pages, 4 figure
Four New BL Lac Surveys: Sampling New Populations
The advent of large area deep radio and X-ray surveys is leading to the
creation of many new BL Lac samples. In particular, the ROSAT All-Sky, Green
Bank and FIRST surveys are proving to be rich sources of new BL Lacs. We will
discuss the methods used in four independent BL Lac searches based on these
surveys. Comparison of the broadband spectral energy distributions of these BL
Lacs with those of previously known objects clearly points to the existence of
a large previously unrecognized population of objects with characteristics
intermediate between those exhibited by Low and High energy peaked BL Lacs.Comment: 4 pages, 3 postscript figures, To be published in the Proceedings of
the conference "BL Lac Phenomenon" held in Turku, Finland, June 22-26, 199
Radio Loud AGN in the Context of the Eigenvector 1 Parameter Space
We consider the properties of radio-loud (RL) AGN in the context of the
Eigenvector 1 (E1) parameter space. RL sources show a restricted E1 parameter
space occupation relative to the radio-quiet (RQ) majority. The Fanaroff-Riley
II ``parent population'' of relatively un-boosted RL sources (median
radio/optical flux ratio ~490) shows the most restricted occupation. RL sources
have different broad line properties (and inferred black hole masses and
Eddington ratios). FWHM H_beta for the broad line component in RL sources are
at least twice as large as the RQ majority. The average broad FeII emission
line strength is also about half that for RQ sources. Our sample suggests that
the RL cutoff occurs near R_k=70 or logP(6cm)=32.0 ergs/s/Hz. Sources below
this cutoff are RQ although we cannot rule out the existence of a distinct
intermediate population. We show that the Doppler boosted core-dominated RL
sources (median flux ratio ~1000) lie towards smaller FWHM(H_beta_bc) and
stronger FeII in E1 as expected if the lines arise in an accretion disk. Our
subsample of superluminal sources, with orientation inferred from the
synchrotron self Compton model, reinforce this general E1 trend and allow us to
estimate the role of source orientation in driving E1 domain occupation.Comment: 9 pages, 3 figures, accepted for publication in ApJ
The Jet of 3C 17 and the Use of Jet Curvature as a Diagnostic of the X-ray Emission Process
We report on the X-ray emission from the radio jet of 3C 17 from Chandra
observations and compare the X-ray emission with radio maps from the VLA
archive and with the optical-IR archival images from the Hubble Space
Telescope. X-ray detections of two knots in the 3C 17 jet are found and both of
these features have optical counterparts. We derive the spectral energy
distribution for the knots in the jet and give source parameters required for
the various X-ray emission models, finding that both IC/CMB and synchrotron are
viable to explain the high energy emission. A curious optical feature (with no
radio or X-ray counterparts) possibly associated with the 3C 17 jet is
described. We also discuss the use of curved jets for the problem of
identifying inverse Compton X-ray emission via scattering on CMB photons.Comment: 6 pages, 6 figure (3 in color), 4 tables, ApJ accepte
Water footprints of cities indicators for sustainable consumption and production
Water footprints have been proposed as sustainabilityindicators, relating the consumption of goods likefood to the amount of water necessary for their productionand the impacts of that water use in the source regions. Wefurther developed the existing water footprint methodology,by globally resolving virtual water flows from production toconsumption regions for major food crops at 5 arcmin spatialresolution. We distinguished domestic and internationalflows, and assessed local impacts of export production. Applyingthis method to three exemplary cities, Berlin, Delhiand Lagos, we find major differences in amounts, composition,and origin of green and blue virtual water imports,due to differences in diets, trade integration and crop waterproductivities in the source regions. While almost all ofDelhi’s and Lagos’ virtual water imports are of domestic origin,Berlin on average imports from more than 4000 km distance,in particular soy (livestock feed), coffee and cocoa.While 42% of Delhi’s virtual water imports are blue waterbased, the fractions for Berlin and Lagos are 2 and 0.5 %, respectively,roughly equal to the water volumes abstracted inthese two cities for domestic water use. Some of the externalsource regions of Berlin’s virtual water imports appear tobe critically water scarce and/or food insecure. However, forderiving recommendations on sustainable consumption andtrade, further analysis of context-specific costs and benefitsassociated with export production will be required
Is B1422+231 a Golden Lens?
B1422+231 is a quadruply-imaged QSO with an exceptionally large lensing
contribution from group galaxies other than the main lensing galaxy. We detect
diffuse X-rays from the galaxy group in archival Chandra observations; the
inferred temperature is consistent with the published velocity dispersion. We
then explore the range of possible mass maps that would be consistent with the
observed image positions, radio fluxes, and ellipticities. Under plausible but
not very restrictive assumptions about the lensing galaxy, predicted time
delays involving the faint fourth image are fairly well constrained around 7/h
days.Comment: 17 pages, 9 figures, to appear in the June/03 issue of A
A Very Radio-Loud Narrow-Line Seyfert 1: PKS 2004-447
We have discovered a very radio-loud Narrow-Line Seyfert 1 candidate: PKS
2004-447. This Seyfert is consistent with the formal definition for NLS1s,
although it does not have quite the same spectral features as some typical
members of this subclass. Only ROSAT survey data is available at X-ray
wavelengths, so it has not been possible to compare this source with other
NLS1s at these wavelengths. A full comparison of this source with other members
of the subclass will improve our physical understanding of NLS1s. In addition,
using standard calculations, we estimate the central black hole to have a mass
of . This does not agree with predictions in the
literature, that radio-loud AGN host very massive black holes.Comment: 15 pages, 4 figures, accepted for publication in ApJ, minor typos
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