Constraining the evolution of the CMB temperature with SZ measurements from Planck data

The CMB temperature-redshift relation, T_CMB(z)=T_0(1+z), is a key prediction of the standard cosmology, but is violated in many non standard models. Constraining possible deviations to this law is an effective way to test the LambdaCDM paradigm and to search for hints of new physics. We have determined T_CMB(z), with a precision up to 3%, for a subsample (104 clusters) of the Planck SZ cluster catalog, at redshift in the range 0.01-- 0.94, using measurements of the spectrum of the Sunyaev Zel'dovich effect obtained from Planck temperature maps at frequencies from 70 to 353 GHz. The method adopted to provide individual determinations of T_CMB(z) at cluster redshift relies on the use of SZ intensity change, Delta I_SZ(nu), at different frequencies, and on a Monte-Carlo Markov Chain approach. By applying this method to the sample of 104 clusters, we limit possible deviations of the form T_CMB(z)=T_0(1+z)^(1-beta) to be beta= 0.022 +/- 0.018, at 1 sigma uncertainty, consistent with the prediction of the standard model. Combining these measurements with previously published results we get beta=0.016+/-0.012.Comment: submitted to JCAP, 21 pages, 8 figure

Constraining the redshift evolution of the Cosmic Microwave Background black-body temperature with PLANCK data

We constrain the deviation of adiabatic evolution of the Universe using the data on the Cosmic Microwave Background (CMB) temperature anisotropies measured by the {\it Planck} satellite and a sample of 481 X-ray selected clusters with spectroscopically measured redshifts. To avoid antenna beam effects, we bring all the maps to the same resolution. We use a CMB template to subtract the cosmological signal while preserving the Thermal Sunyaev-Zeldovich (TSZ) anisotropies; next, we remove galactic foreground emissions around each cluster and we mask out all known point sources. If the CMB black-body temperature scales with redshift as $T(z)=T_0(1+z)^{1-\alpha}$, we constrain deviations of adiabatic evolution to be $\alpha=-0.007\pm 0.013$, consistent with the temperature-redshift relation of the standard cosmological model. This result could suffer from a potential bias $\delta\alpha$ associated with the CMB template, that we quantify it to be $|\delta\alpha|\le 0.02$ and with the same sign than the measured value of $\alpha$, but is free from those biases associated with using TSZ selected clusters; it represents the best constraint to date of the temperature-redshift relation of the Big-Bang model using only CMB data, confirming previous results.Comment: ApJ, in press. Manuscript matches the accepted version: 10 pages, 7 figures, 3 table

Recorridos de los criterios de evaluación de los alumnos del Departamento de Ingeniería Agrícola y Forestal, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata

La evaluación es una preocupación didáctica en todos los niveles educativos, sobre todo desde mediados del siglo XX. En este trabajo se investigó sobre los criterios que utilizan los docentes para evaluar a los alumnos del Departamento de Ingeniería Agrícola y Forestal, con los objetivos de identificar los criterios de evaluación y analizarlos didácticamente. Fueron recopiladas y analizadas pruebas escritas parciales y fichas de evaluación de exámenes finales administradas durante 1998 y 2011 y entrevistados profesores y jefes de trabajos prácticos. La construcción de doce criterios evaluativos permitió concluir lo siguiente: a) Se identificaron criterios referidos a estrategias de corte asociativo, criterios instrumentales de base asociativa y criterios de actividades complejas identificadas con procesos cognitivos de elaboración o reconstrucción; b) Los criterios de recuerdo de información y de cálculo, resultaron los más utilizados; c) Existe en la mayoría de los cursos una significativa presencia de los criterios de aplicación; d) Los criterios referidos a la diferenciación cognitiva, tales como resolución de problemas y transferencia de aprendizaje, son utilizados por las asignaturas de aplicación y e) Se reconoce la escasez de criterios asociados a diferentes procesos cognitivos tales como hipotetizar, criticar, justificar, como así también los ítems de pruebas de ensayoEje temático 3: Los procesos de evaluación y acreditación a - La evaluación de los aprendizajes: problemas, experiencias y estrategiasFacultad de Ciencias Agrarias y Forestale

QUIJOTE Scientific Results. II. Polarisation Measurements of the Microwave Emission in the Galactic molecular complexes W43 and W47 and supernova remnant W44

We present Q-U-I JOint TEnerife (QUIJOTE) intensity and polarisation maps at 10-20 GHz covering a region along the Galactic plane 24<l<45 deg, |b|<8 deg. These maps result from 210 h of data, have a sensitivity in polarisation of ~40 muK/beam and an angular resolution of ~1 deg. Our intensity data are crucial to confirm the presence of anomalous microwave emission (AME) towards the two molecular complexes W43 (22 sigma) and W47 (8 sigma). We also detect at high significance (6 sigma) AME associated with W44, the first clear detection of this emission towards a SNR. The new QUIJOTE polarisation data, in combination with WMAP, are essential to: i) Determine the spectral index of the synchrotron emission in W44, beta_sync =-0.62 +/-0.03, in good agreement with the value inferred from the intensity spectrum once a free-free component is included in the fit. ii) Trace the change in the polarisation angle associated with Faraday rotation in the direction of W44 with rotation measure -404 +/- 49 rad/m2. And iii) set upper limits on the polarisation of W43 of Pi_AME <0.39 per cent (95 per cent C.L.) from QUIJOTE 17~GHz, and <0.22 per cent from WMAP 41 GHz data, which are the most stringent constraints ever obtained on the polarisation fraction of the AME. For typical physical conditions (grain temperature and magnetic field strengths), and in the case of perfect alignment between the grains and the magnetic field, the models of electric or magnetic dipole emissions predict higher polarisation fractions.Comment: Accepted for publication in MNRA

Kinematic Sunyaev-Zeldovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

If the gas in filaments and halos shares the same velocity field than the luminous matter, it will generate measurable temperature anisotropies due to the Kinematic Sunyaev-Zeldovich effect. We compute the distribution function of the KSZ signal produced by a typical filament and show it is highly non-gaussian. The combined contribution of the Thermal and Kinematic SZ effects of a filament of size $L\simeq 5$Mpc and electron density $n_e\simeq 10^3m^{-3}$ could explain the cold spots of $\delta\sim -200\mu$K on scales of 30' found in the Corona Borealis Supercluster by the VSA experiment. PLANCK, with its large resolution and frequency coverage, could provide the first evidence of the existence of filaments in this region. The KSZ contribution of the network of filaments and halo structures to the radiation power spectrum peaks around $l\sim 400$, a scale very different from that of clusters of galaxies, with a maximum amplitude $l(l+1)C_l/2\pi\sim 10-25 (\mu K)^2$, depending on model parameters, i.e., $\sigma_8$ and the Jeans length. About 80% of the signal comes from filaments with redshift $z\le 0.1$. Adding this component to the intrinsic Cosmic Microwave Background temperature anisotropies of the concordance model improves the fit to WMAP 3yr data by $\Delta\chi^2\simeq 1$. The improvement is not statistically significant but a more systematic study could demonstrate that gas could significantly contribute to the anisotropies measured by WMAP.Comment: ApJ Lett, to be publishe

Flood Hazard Management in Public Mountain Recreation Areas vs. Ungauged Fluvial Basins. Case Study of the Caldera de Taburiente National Park, Canary Islands (Spain)

Las Angustias River is an ungauged stream in the Caldera de Taburiente National Park (Spain), where frequent intense flash-flood events occur. The aim of this research is to analyze the flood hazard at the Playa de Taburiente. Based on the limited information available (short time-series of daily precipitation), a statistical frequency analysis of 24 h rainfall was completed and the precipitation results were transformed into surface runoff. To determine if the model underestimates the flows that are generated in the basin, the dendro-geomorphological information available was used to calibrate results. The results of the HMS model were significantly lower. At this point, both the rainfall data and the rainfall-runoff model were re-analyzed to maximize the rainfall intensity values and the runoff generated (increasing the CN value for the basin). For the 1997 flood event, a 1250 m3·s−1 flood minimizes the RMSE for the disturbed tree sample; this flow value also clearly exceeds any peak flow derived from the rainfall-runoff analysis. It is only when rainfall intensity and surface runoff are maximized that the peak flows obtained approximate those associated with dendro-geomorphological data. The results highlight the difficulties of flood hazard management in ungauged torrential basins in mountain recreational areas (such as National Parks). Thus, in the absence of flow records, when considering the maximum rainfall intensity scenario may be a useful and effective tool for flood risk management

Dendrogeomorphological evidence of flood frequency changes and human activities (Portainé basin, spanish Pyrenees)

The Portainé mountain catchment, containing the Port Ainé ski resort (Lleida, Spanish Pyrenees), displays active erosional and depositional phenomena caused by periodic torrential floods. These events present a potential risk and incur significant economic losses. In ungauged remote catchments (like Portainé), trees might be the only paleohydrological source of information regarding past floods. Thus, we estimated the temporal and spatial distribution of torrential floods by dendrogeomorphological techniques to assess whether human impact (land-use changes and infrastructure works) affected their frequency and magnitude. One-hundred and sixty-six samples from 67 trees belonging to 10 different species were analyzed; past flood events of the last 50 years were identified by dating and relating evidence between them. Moreover, a detailed geomorphological study was performed and the available historical data compiled. Our multi-evidence analysis provides new insight into the occurrence of paleofloods. Changes in flood frequency since 2006, especially from 2008, suggest that the geomorphological equilibrium has been disturbed, coinciding with both major earthworks within the ski resort and intense but not extraordinary rainfall. This conclusion has important implications for land planning and the design of future projects in the mountain watersheds

Sub-percent constraints on cosmological temperature evolution

The redshift dependence of the cosmic microwave background temperature is one of the key cosmological observables. In the standard cosmological model one has T (z) = T0(1 + z), where T0 is the present-day temperature. Deviations from this behavior would imply the presence of new physics. Here we discuss how the combination of all currently available direct and indirect measurements of T (z) constrains the common phenomenological parametrization T (z) = T0(1 + z)^(1−β) , and obtain the first sub-percent constraint on the temperature growth index 1 − β. Specifically, we find β = (7.6 ± 8.0) × 10^(−3) at the 68.3% confidence level

(Mis)Understandings in History-teaching University Education. A Curricular Case Analysis in UNMDP

Este artículo es el resultado de una serie de experiencias que compartimos tres profesores en Historia, en la intención de revisitar algunas características de nuestras prácticas docentes y de nuestras propias formaciones de grado. En ese sentido coincidimos el haber transitado carreras cuya formación profesional se planteó de manera disociada y colmada de desencuentros en lo que, a grandes rasgos, podemos escindir entre la Historia y la Pedagogía. Es por ello que en el transcurso de nuestros aprendizajes como profesores de esta disciplina de las Ciencias Sociales, comenzamos a acercarnos al campo de las Ciencias de la Educación, indagando allí saberes y herramientas que posibiliten potenciar los caminos de búsqueda que despierta nuestro desarrollo profesional. En estas páginas nos proponemos realizar un análisis crítico del Plan de Estudios del profesorado en Historia que se dicta en la Facultad de Humanidades de la UNMdP, con la intención de indagar las articulaciones y los desencuentros en la formación universitaria que se brinda a los Profesores en Historia. Al tomar como objeto esta carrera, intentamos caracterizar los perfiles profesionales y la formación que se les propone a partir de los aspectos curriculares.This article intends to delve into the current teaching practices and past education of three History professors. In such scenarios, the efforts to merge History and Pedagogy have resulted in discordances, divergence and misunderstandings. This has fostered our desire to further research in the Educational Sciences and make some of these issues comprehensible. Specifically, this paper focuses on the History- Teaching Program’s Curriculum at the School of Humanities, UNMDP, and its interplay with the intended professional profile and concrete educating practices.Facultad de Humanidades y Ciencias de la EducaciónUniversidad Nacional de Mar del Plat