The Canada-France High-z Quasar Survey: 1.2mm Observations

We report 250 GHz (1.2 mm) observations of a sample of 20 QSOs at redshifts 5.8<z<6.5 from the the Canada-France High-z Quasar Survey (CFHQS), using the Max-Planck Millimeter Bolometer (MAMBO) array at the IRAM 30-metre telescope. A rms sensitivity <~ 0.6 mJy was achieved for 65% of the sample, and <~ 1.0 mJy for 90%. Only one QSO, CFHQS J142952+544717, was robustly detected with S_250GHz = 3.46 +/-0.52 mJy. This indicates that one of the most powerful known starbursts at z~6 is associated with this radio loud QSO. On average, the other CFHQS QSOs, which have a mean optical magnitude fainter than previously studied SDSS samples of z~6 QSOs, have a mean 1.2 mm flux density = 0.41 +/-0.14 mJy; such a 2.9-sigma average detection is hardly meaningful. It would correspond to ~ 0.94+/-0.32 10^12 Lo, and an average star formation rate of a few 100's Mo/yr, depending on the IMF and a possible AGN contribution to . This is consistent with previous findings of Wang et al. (2011) on the far-infrared emission of z~6 QSOs and extends them toward optically fainter sources.Comment: 6 pages, 1 figure, A&A in pres

The dust emission of high-redshift quasars

The detection of powerful near-infrared emission in high redshift (z>5) quasars demonstrates that very hot dust is present close to the active nucleus also in the very early universe. A number of high-redshift objects even show significant excess emission in the rest frame NIR over more local AGN spectral energy distribution (SED) templates. In order to test if this is a result of the very high luminosities and redshifts, we construct mean SEDs from the latest SDSS quasar catalogue in combination with MIR data from the WISE preliminary data release for several redshift and luminosity bins. Comparing these mean SEDs with a large sample of z>5 quasars we could not identify any significant trends of the NIR spectral slope with luminosity or redshift in the regime 2.5 < z < 6 and 10^45 < nuL_nu(1350AA) < 10^47 erg/s. In addition to the NIR regime, our combined Herschel and Spitzer photometry provides full infrared SED coverage of the same sample of z>5 quasars. These observations reveal strong FIR emission (L_FIR > 10^13 L_sun) in seven objects, possibly indicating star-formation rates of several thousand solar masses per year. The FIR excess emission has unusally high temperatures (T ~ 65 K) which is in contrast to the temperature typically expected from studies at lower redshift (T ~ 45 K). These objects are currently being investigated in more detail.Comment: 6 pages, 3 figures, to appear in the proceedings to "The Central Kiloparsec in Galactic Nuclei (AHAR2011)", Journal of Physics: Conference Series (JPCS), IOP Publishin

Compact polymer components for an integrated add-drop multiplexer

A phasar and a digital thermo optic switch have been designed and processed in a high index contrast polymer technology. Both devices are small enough to fabricate two integrated add-drop multiplexers on one 4 inch wafe

Tanino condensando das espécies jurema preta (Mimosa hostilis), sabiá (Mimosa caesalpinifolia) e mororó (Bauhinia cheilantha), em três fases do ciclo fenológico.

Resumo: O objetivo do presente trabalho foi caracterizar os taninos condensados das espécies Jurema Preta (Mimosa hostilis), Sabiá (Mimosa caesalpinifolia) e Mororó (Bauhinia cheilantha) nas fases de vegetação(Mimosa hostilis), Sabiá (Mimosa caesalpinifolia) e Mororó (Bauhinia cheilantha) nas fases de vegetação plena, floração plena e frutificação. A concentração em tanino solúvel, tanino ligado ao resíduo e tanino total (TT) foi determinada pelo método butanol-HCL e a adstringência pelo método de difusão radial. Foram observadas diferenças entre as espécies quanto a concentração (P<0,05) e adstringência (P<0,05) dos taninos. A Jurema Preta apresentou os maiores valores (30,98% TT e 22% de adstringência na vegetação plena) e Mororó as menores (10,38% TT e 14% de adstringência na frutificação). A concentração e adstringência dos taninos condensados, assim como a adstringência variaram entre as espécies e, em alguns casos, entre as fases do ciclo fenológico. Os valores observados foram sempre superiores aos considerados benéficos (5%) para a digestão ruminal e aproveitamento geral da dieta. Abstract: This study was conducted aiming at characterizing the condensed tannins present in the legumes species Jurema Preta (Mimosa hostilis), Sabiá (Mimosa caesalpinifolia) and Mororó (Bauhinia cheilantha) at three stages of their phenological cycle. The concentration of soluble tannin, bound tannin and total tannin (TT) was determined using the butanol-HCL method and astringency was determined using the radial diffusion method. Jurema Preta presented the highest values (30.98% TT and 22 % astringency at full growth stage), and Mororó the lowest (10.38% TT and 14 % astringency during fructification). Concentration and astringency of condensed tannins, as well as their monomeric composition varied between species, and in some cases among phenological cycles. The values observed were always above the limits considered beneficial for ruminal digestion (i.e. 5%)

Neural Language Models for Nineteenth-Century English

We present four types of neural language models trained on a large historical dataset of books in English, published between 1760 and 1900, and comprised of ≈5.1 billion tokens. The language model architectures include word type embeddings (word2vec and fastText) and contextualized models (BERT and Flair). For each architecture, we trained a model instance using the whole dataset. Additionally, we trained separate instances on text published before 1850 for the type embeddings, and four instances considering different time slices for BERT. Our models have already been used in various downstream tasks where they consistently improved performance. In this paper, we describe how the models have been created and outline their reuse potential

Structure formation in a colliding flow: The Herschel view of the Draco nebula

The Draco nebula is a high Galactic latitude interstellar cloud likely to have been formed by the collision of a Galactic halo cloud entering the disk of the Milky Way. Such conditions are ideal to study the formation of cold and dense gas in colliding flows of warm gas. We present Herschel-SPIRE observations that reveal the fragmented structure of the interface between the infalling cloud and the Galactic layer. This front is characterized by a Rayleigh-Taylor instability structure. From the determination of the typical length of the periodic structure (2.2 pc) we estimated the gas kinematic viscosity and the turbulence dissipation scale (0.1 pc) that is compatible with that expected if ambipolar diffusion is the main mechanism of energy dissipation in the WNM. The small-scale structures of the nebula are typical of that seen in some molecular clouds. The gas density has a log-normal distribution with an average value of $10^3$ cm$^{-3}$. The size of the structures is 0.1-0.2 pc but this estimate is limited by the resolution of the observations. The mass ranges from 0.2 to 20 M$_{\odot}$ and the distribution of the more massive clumps follows a power law $dN/d\log(M) \sim M^{-1.4}$. We identify a mass-size relation with the same exponent as that found in GMCs ($M\sim L^{2.3}$) but only 15% of the mass of the cloud is in gravitationally bound structures. We conclude that the increase of pressure in the collision is strong enough to trigger the WNM-CNM transition caused by the interplay between turbulence and thermal instability as self-gravity is not dominating the dynamics.Comment: 16 pages, A&A, in pres