28,702 research outputs found

    Incidental Captures of Plains Spotted Skunks (Spilogale putorius interrupta) By Arkansas Trappers, 2012-2017

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    Arkansas trappers were surveyed following the 2012 and four subsequent trapping seasons regarding accidental captures of spotted skunks while attempting to trap other species. A total of 132 trappers reported capturing spotted skunks although further investigation confirmed the validity of only 42 reports from trappers that caught a total of 60 spotted skunks. Incidental captures were rare; only 0.35-1.29% of trappers each year caught spotted skunks and came primarily from the Ozark and Ouachita regions of the state

    Primeness in Early Season Arkansas Raccoon Pelts

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    Trapping seasons in the United States are generally set around the time of the year when pelts are in “prime” condition and are in their most valuable state. In order to assess whether the start of the Arkansas trapping season is at an appropriate date 122 raccoons were captured during the month of November in 2014 and 2015. Based on the evaluation of experienced fur dealers, the percentage of pelts in prime condition was then assessed on weekly and half-monthly basis. This study indicates that starting the trapping season in the last half of the month may maximize the percentage of pelts that are in prime condition early in the season, especially in the southern region of the state

    The Shift of the Baryon Acoustic Oscillation Scale: A Simple Physical Picture

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    A shift of the baryon acoustic oscillation (BAO) scale to smaller values than predicted by linear theory was observed in simulations. In this paper, we try to provide an intuitive physical understanding of why this shift occurs, explaining in more pedagogical detail earlier perturbation theory calculations. We find that the shift is mainly due to the following physical effect. A measurement of the BAO scale is more sensitive to regions with long wavelength overdensities than underdensities, because (due to non-linear growth and bias) these overdense regions contain larger fluctuations and more tracers and hence contribute more to the total correlation function. In overdense regions the BAO scale shrinks because such regions locally behave as positively curved closed universes, and hence a smaller scale than predicted by linear theory is measured in the total correlation function. Other effects which also contribute to the shift are briefly discussed. We provide approximate analytic expressions for the non-linear shift including a brief discussion of biased tracers and explain why reconstruction should entirely reverse the shift. Our expressions and findings are in agreement with simulation results, and confirm that non-linear shifts should not be problematic for next-generation BAO measurements.Comment: 10 pages, replaced with version accepted by Phys. Rev.

    Herschel/HIFI spectroscopy of the intermediate mass protostar NGC7129 FIRS 2

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    Herschel/HIFI observations of water from the intermediate mass protostar NGC 7129 FIRS 2 provide a powerful diagnostic of the physical conditions in this star formation environment. Six spectral settings, covering four H_2^(16)O and two H_2^(18)O lines, were observed and all but one H_2^(18)O line were detected. The four H_2 ^(16)O lines discussed here share a similar morphology: a narrower, ≈6km s^(−1), component centered slightly redward of the systemic velocity of NGC7129 FIRS 2 and a much broader, ≈25 km s^(−1) component centered blueward and likely associated with powerful outflows. The narrower components are consistent with emission from water arising in the envelope around the intermediate mass protostar, and the abundance of H_2O is constrained to ≈10^(−7) for the outer envelope. Additionally, the presence of a narrow self-absorption component for the lowest energy lines is likely due to self-absorption from colder water in the outer envelope. The broader component, where the H_2O/CO relative abundance is found to be ≈0.2, appears to be tracing the same energetic region that produces strong CO emission at high J

    The Impact of Wrong Assumptions in BAO Reconstruction

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    The process of density field reconstruction enhances the statistical power of distance scale measurements using baryon acoustic oscillations (BAO). During this process a fiducial cosmology is assumed in order to convert sky coordinates and redshifts into distances; fiducial bias and redshift-space-distortion parameters are also assumed in this procedure. We analytically assess the impact of incorrect cosmology and bias assumptions on the post-reconstruction power spectra using low-order Lagrangian perturbation theory, deriving general expressions for the incorrectly reconstructed spectra. We find that the BAO peak location appears to shift only by a negligible amount due to wrong assumptions made during reconstruction. However, the shape of the BAO peak and the quadrupole amplitude can be affected by such errors (at the percent- and five-percent-level respectively), which potentially could cause small biases in parameter inference for future surveys; we outline solutions to such complications.Comment: 18 pages, 3 figures; comments welcome. v2 matches JCAP accepted versio
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