A Measurement of Secondary Cosmic Microwave Background Anisotropies with Two Years of South Pole Telescope Observations

We present the first three-frequency South Pole Telescope (SPT) cosmic microwave background (CMB) power spectra. The band powers presented here cover angular scales 2000 < ℓ < 9400 in frequency bands centered at 95, 150, and 220 GHz. At these frequencies and angular scales, a combination of the primary CMB anisotropy, thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, radio galaxies, and cosmic infrared background (CIB) contributes to the signal. We combine Planck/HFI and SPT data at 220 GHz to constrain the amplitude and shape of the CIB power spectrum and find strong evidence for nonlinear clustering. We explore the SZ results using a variety of cosmological models for the CMB and CIB anisotropies and find them to be robust with one exception: allowing for spatial correlations between the thermal SZ effect and CIB significantly degrades the SZ constraints. Neglecting this potential correlation, we find the thermal SZ power at 150 GHz and ℓ = 3000 to be 3.65 ± 0.69 μK^2, and set an upper limit on the kinetic SZ power to be less than 2.8 μK^2 at 95% confidence. When a correlation between the thermal SZ and CIB is allowed, we constrain a linear combination of thermal and kinetic SZ power: D^(tSZ)_(3000) + 0.5D^(kSZ)_(3000) = 4.60 ± 0.63 μK^2, consistent with earlier measurements. We use the measured thermal SZ power and an analytic, thermal SZ model calibrated with simulations to determine σ_8 = 0.807 ± 0.016. Modeling uncertainties involving the astrophysics of the intracluster medium rather than the statistical uncertainty in the measured band powers are the dominant source of uncertainty on σ_8. We also place an upper limit on the kinetic SZ power produced by patchy reionization; a companion paper uses these limits to constrain the reionization history of the universe

Assessing soil erosion after fire and rehabilitation treatments in NW Spain: performance of rusle and revised Morgan-Morgan-Finney models

Although the Revised Universal Soil Loss Equation (RUSLE) and the revised Morgan–Morgan–Finney (MMF) are well‐known models, not much information is available as regards their suitability in predicting post‐fire soil erosion in forest soils. The lack of information is even more pronounced as regards post‐fire rehabilitation treatments. This study compared the soil erosion predicted by the RUSLE and the revised MMF model with the observed values of soil losses, for the first year following fire, in two burned areas in NW of Spain with different levels of fire severity. The applicability of both models to estimate soil losses after three rehabilitation treatments applied in a severely burned area was also tested. The MMF model presented reasonable accuracy in the predictions while the RUSLE clearly overestimated the observed erosion rates. When the R and C factors obtained by the RUSLE formulation were multiplied by 0·7 and 0.865, respectively, the efficiency of the equation improved. Both models showed their capability to be used as operational tools to help managers to determine action priorities in areas of high risk of degradation by erosion after fire.publishe

Experimental observation of two-dimensional fluctuation magnetization in the vicinity of T_c for low values of the magnetic field in deoxygenated YBa_2Cu_3O_{7-x}

We measured isofield magnetization curves as a function of temperature in two single crystal of deoxygenated YBaCuO with T_c = 52 and 41.5 K. Isofield MvsT were obtained for fields running from 0.05 to 4 kOe. The reversible region of the magnetization curves was analyzed in terms of a scaling proposed by Prange, but searching for the best exponent $\upsilon$. The scaling analysis carried out for each data sample set with $\upsilon$=0.669, which corresponds to the 3D-xy exponent, did not produced a collapsing of curves when applied to MvsT curves data obtained for the lowest fields. The resulting analysis for the Y123 crystal with T_c = 41.5 K, shows that lower field curves collapse over the entire reversible region following the Prange's scaling with $\upsilon$=1, suggesting a two-dimensional behavior. It is shown that the same data obeying the Prange's scaling with $\upsilon$=1 for crystal with T_c = 41.5 K, as well low field data for crystal with $T_c$ = 52 K, obey the known two-dimensional scaling law obtained in the lowest-Landau-level approximation.Comment: 4 pages, 3 figure

Redshift Determination and CO Line Excitation Modeling for the Multiply Lensed Galaxy HLSW-01

We report on the redshift measurement and CO line excitation of HERMES J105751.1+573027 (HLSW-01), a strongly lensed submillimeter galaxy discovered in Herschel/SPIRE observations as part of the Herschel Multi-tiered Extragalactic Survey (HerMES). HLSW-01 is an ultra-luminous galaxy with an intrinsic far-infrared luminosity of L _(FIR) = 1.4 × 10^(13) L _⊙, and is lensed by a massive group of galaxies into at least four images with a total magnification of μ = 10.9 ± 0.7. With the 100 GHz instantaneous bandwidth of the Z-Spec instrument on the Caltech Submillimeter Observatory, we robustly identify a redshift of z = 2.958 ± 0.007 for this source, using the simultaneous detection of four CO emission lines (J = 7 → 6, J = 8 → 7, J = 9 → 8, and J = 10 → 9). Combining the measured line fluxes for these high-J transitions with the J = 1 → 0, J = 3 → 2, and J = 5 → 4 line fluxes measured with the Green Bank Telescope, the Combined Array for Research in Millimeter Astronomy, and the Plateau de Bure Interferometer, respectively, we model the physical properties of the molecular gas in this galaxy. We find that the full CO spectral line energy distribution is described well by warm, moderate-density gas with T _(kin) = 86-235 K and n_H_2 = (1.1-3.5)x10^3 cm^(–3). However, it is possible that the highest-J transitions are tracing a small fraction of very dense gas in molecular cloud cores, and two-component models that include a warm/dense molecular gas phase with T _(kin) ~ 200 K, n_H_2 ~ 10^5 cm^(–3) are also consistent with these data. Higher signal-to-noise measurements of the J _(up) ≥ 7 transitions with high spectral resolution, combined with high spatial resolution CO maps, are needed to improve our understanding of the gas excitation, morphology, and dynamics of this interesting high-redshift galaxy

Key factors controlling the post-fire hydrological and erosive response at micro-plot scale in a recently burned Mediterranean forest

The impacts of wildfires on the hydrological and erosive response of forest ecosystems have been extensively studied worldwide. Nevertheless, few studies have measured post-fire runoff and erosion over large time scales in Mediterranean-climate type environments and even fewer studies considered the effects of pre-fire land management practices on post-fire hydrological and erosive processes. In a previous study in the Colmeal study area, Vieira et al. (2016) revealed that post-fire runoff and erosion may not follow the classic window of disturbance model, since the peak of post-fire response occurred in the second and third years after fire. This previous study also showed that pre-fire land management can substantially influence the post-fire response, since annual runoff and erosion were lower in pre-fire unplowed than plowed sites. In this follow-up work, a multiple regression model (MRM) analysis was performed to understand how several key factors influence the hydrological and erosive response of a burned Mediterranean forest, taking into account the wildfire; pre-fire land management practices (unplowed, downslope plowed, and contour plowed) and soil moisture conditions. Based on the results of the present study, post-fire runoff was largely explained by rainfall amounts and soil water repellency (SWR)-related variables, whereas erosion processes were better explained by rainfall intensity and ground cover variables. Fewer factors were found to control the hydrological response of plowed sites when compared to the unplowed site. Aside from rainfall intensity, which was the major factor controlling sediment losses, bare soil cover also seems to have been important for erosion processes at the unplowed site, whereas at the plowed sites stone cover was the second most relevant factor. Rainfall-related variables (rainfall and maximum 30-min rainfall intensity) were more important for explaining runoff and erosion under dry conditions than under wet conditions. The results of the MRM analysis are an important contribution to understand the dynamics of burned forest areas and should be considered when adapting hydrological and erosion models to post-fire environments.publishe

Herschel-SPIRE, far-infrared properties of millimetre-bright and -faint radio galaxies

We present the first study of the far-infrared (FIR) properties of high-redshift, radio-selected ultraluminous infrared galaxies (ULIRGs) using deep observations obtained with the Spectral and Photometric Imaging Receiver (SPIRE) from the Herschel Multi-tiered Extragalactic Survey (HerMES). These galaxies span a large range of 850-μm fluxes from submillimetre-luminous ∼10 mJy sources (SCUBA galaxies) to ∼1.5 mJy from stacked SCUBA non-detections, thus likely representing a complete distribution of ULIRG spectral energy distributions (SEDs). From Keck spectroscopic surveys in the Lockman-North field we identified a sample of 31 submillimetre galaxies (SMGs) and 37 submillimetre-faint, optically faint radio galaxies (OFRGs), all with radio-inferred IR luminosities >10^(12) L_⊙. These galaxies were cross-identified with SPIRE 250-, 350- and 500-μm catalogues based on fluxes extracted at 24-μm positions in the SWIRE survey, yielding a sample of more than half of the galaxies well detected in at least two of the SPIRE bandpasses. By fitting greybody dust models to the SPIRE photometry together with SCUBA 850-μm measurements (for OFRGs, only 850-inline image upper limits), we infer dust temperatures and FIR luminosities. The OFRGs detected by SPIRE have median 〈T_d〉= 41 ± 5 K and the SMGs have 〈T_d〉= 34 ± 5 K, both in reasonable agreement with previous (pre-Herschel) estimates, reaffirming that the local FIR/radio correlation holds (at least for this subset of high-z ULIRGs) at high redshift (we measure 〈q_(IR)〉= 2.43 ± 0.21 using S_(IR) derived from greybody fit coupled with a power-law extrapolation to the 24 μm). Our observations first confirm that a substantial fraction of OFRGs exhibits large infrared luminosities corresponding to SFRs of ∼400 M_⊙ yr^−1. The SPIRE observations secondly confirm the higher dust temperatures for these OFRGs than similarly selected SMGs, consistent with early predictions of the submillimetre-faint radio populations. Our observations also clearly confirm the large infrared luminosities of most SMGs selected with S_(850 μm) > 5 mJy and radio and strong 24-μm detections, corresponding to SFRs of ∼700 M_⊙ yr^(−1)

Estudos de desbaste em Eucalyptus saligna Sm. para rotação longa.

bitstream/item/101259/1/PA-1983-Pereira-EstudoDesbaste.pd

Estudo de desbaste em Eucalyptus grandis Hill ex Maiden para rotação longa.

bitstream/item/101256/1/PA-1983-Pereira-EstudoDesbaste.pd

Multitechnique testing of the viscous decretion disk model I. The stable and tenuous disk of the late-type Be star β\beta CMi

The viscous decretion disk (VDD) model is able to explain most of the currently observable properties of the circumstellar disks of Be stars. However, more stringent tests, focusing on reproducing multitechnique observations of individual targets via physical modeling, are needed to study the predictions of the VDD model under specific circumstances. In the case of nearby, bright Be star $\beta$ CMi, these circumstances are a very stable low-density disk and a late-type (B8Ve) central star. The aim is to test the VDD model thoroughly, exploiting the full diagnostic potential of individual types of observations, in particular, to constrain the poorly known structure of the outer disk if possible, and to test truncation effects caused by a possible binary companion using radio observations. We use the Monte Carlo radiative transfer code HDUST to produce model observables, which we compare with a very large set of multitechnique and multiwavelength observations that include ultraviolet and optical spectra, photometry covering the interval between optical and radio wavelengths, optical polarimetry, and optical and near-IR (spectro)interferometry. Due to the absence of large scale variability, data from different epochs can be combined into a single dataset. A parametric VDD model with radial density exponent of $n$ = 3.5, which is the canonical value for isothermal flaring disks, is found to explain observables typically formed in the inner disk, while observables originating in the more extended parts favor a shallower, $n$ = 3.0, density falloff. Modeling of radio observations allowed for the first determination of the physical extent of a Be disk (35$^{+10}_{-5}$ stellar radii), which might be caused by a binary companion. Finally, polarization data allowed for an indirect measurement of the rotation rate of the star, which was found to be $W \gtrsim 0.98$, i.e., very close to critical.Comment: 19 pages (35 including online material), 17 figures, 2 online figures, 2 online tables with dat