A flux-ratio anomaly in the CO spectral line emission from gravitationally-lensed quasar MG J0414+0534

We present an analysis of archival observations with the Atacama Large (sub-)Millimetre Array (ALMA) of the gravitationally lensed quasar MG J0414+0534, which show four compact images of the quasar and an Einstein ring from the dust associated with the quasar host galaxy. We confirm that the flux-ratio anomalies observed in the mid-infrared and radio persists into the sub-mm for the continuum images of the quasar. We report the detection of CO (11-10) spectral line emission, which traces a region of compact gas around the quasar nucleus. This line emission also shows evidence of a flux-ratio anomaly between the merging lensed images that is consistent with those observed at other wavelengths, suggesting high-excitation CO can also provide a useful probe of substructures that is unaffected by microlensing or dust extinction. However, we do not detect the candidate dusty dwarf galaxy that was previously reported with this dataset, which we conclude is due to a noise artefact. Thus, the cause of the flux-ratio anomaly between the merging lensed images is still unknown. The composite compact and diffuse emission in this system suggest lensed quasar-starbursts will make excellent targets for detecting dark sub-haloes and testing models for dark matter.Comment: Accepted as MNRAS Lette

THE VALUE OF SPORT FISHING IN THE SNAKE RIVER BASIN OF CENTRAL IDAHO

The value of sportfishing in the Snake River Basin in Central Idaho was measured using a two-stage/disequilibrium travel model. The two-stage/disequilibrium model does not require monetization of recreationists? travel time as required of traditional equilibrium labor market travel cost models. The model was estimated using Poisson regression, appropriate for count data when over-dispersion is absent, and adjusted for endogenous stratification (self selection bias) . Contrary to expectations that anglers living close to the sites with low values would be over represented in the sample, the endogenous stratification adjustment caused estimated consumers surplus to decline from $42 per person per trip before adjustment for endogenous stratification to$35 after adjustment. The average number of sportfishing trips per year was 6.72, resulting in an average annual willingness-to-pay of $236 per year per angler.Resource /Energy Economics and Policy,

Measuring the Location Value of a Recreation Site

The demand for sport fishing on the Snake River reservoirs was estimated using the travel cost method. A short-run demand model was specified with location value for anglers who have the option to access a follow-on site if fishing conditions are poor. Willingness to pay for a fishing trip to the site was $18.52 for anglers who did not have a follow-on site and$43.48 for anglers who did. A location value of $24.96 accrued only to anglers with a follow-on site. Total annual site value was understated by as much as 40$0.78 million) if location value for anglers with a follow-on site was excluded from the benefit estimate.contingent behavior, count data, endogenous stratification, follow-on site, location value, multiple destination, option value, short-run demand, travel cost method, Resource /Energy Economics and Policy,

ISSUES IN NONMARKET VALUATION AND POLICY APPLICATION: A RETROSPECTIVE GLANCE

While issues in estimating nonmarket values continue to cause concern, resource economists have more reason now than ever before to be optimistic. More progress toward improved measurement has been made in the past six years than in the previous quarter century since development of the contingent valuation and travel cost methods. The new challenge is to learn how to adjust past studies to estimate nonmarket values for future policy analysis. The process involves developing an understanding of the important variables that explain the observed difference in estimates. This paper illustrates how the results thus far could be adjusted to develop some tentative estimates of the recreation-use value of Forest Service resources.Research Methods/ Statistical Methods, Resource /Energy Economics and Policy,

Mass along the Line of Sight to the Gravitational Lens B1608+656: Galaxy Groups and Implications for H_0

We report the discovery of four groups of galaxies along the line of sight to the B1608+656 gravitational lens system. One group is at the redshift of the primary lensing galaxy (z = 0.631) and appears to have a low mass, with eight spectroscopically confirmed members and an estimated velocity dispersion of 150 ± 60 km s^(-1). The three other groups are in the foreground of the lens. These groups contain ~10 confirmed members each and are located at redshifts of 0.265, 0.426, and 0.52. Two of the three additional groups are centered roughly on the lens system, while the third is centered ~1' south of the lens. We investigate the effect of each of the four groups on the gravitational lensing potential of the B1608+656 system, with a particular focus on the implications for the value of H_0 derived from this system. We find that each group provides an external convergence of ~0.005-0.060, depending on the assumptions made in the calculation. For the B1608+656 system, the stellar velocity dispersion of the lensing galaxy has been measured, thus breaking the mass sheet degeneracy due to the group that is physically associated with the lens. The effect of the other groups along the line of sight can be folded into the overall uncertainties due to large-scale structure (LSS) along the line of sight. Because B1608+656 appears to lie along an overdense line of sight, the LSS will cause the measurement of H_0 to be biased high for this system. This effect could be 5% or greater

Economy of Albany, Carbon, and Sweetwater counties, Wyoming, The: description and analysis

Submitted to U.S. Dept. of Interior, Bureau of Land Management, Colorado State Office, Denver, Colorado.Bibliography: pages 74-76.Contract no. YA-510-PH8-57

Economy of Albany, Carbon and Fremont counties, Wyoming, Rawlins BLM district, The

May 1983.Submitted to U.S. Dept. of Interior, Bureau of Land Management, Colorado State Office.Bibliography: pages 60-64.Contract no. YA-553-CT0-1077

Economy of Lincoln, Sublette, Sweetwater and Uinita counties, Wyoming: Rock Springs BLM district, The

Submitted to U.S. Dept. of Interior, Bureau of Land Management.May 1983.Contract Nos. YA-553-CT0-1077 and YA-553-CT1-1088

Direct and indirect economic effects of hunting and fishing in Colorado--1981

Includes bibliographical references