A wide dispersion in star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6

ALMA [CII] line and continuum observations of five redshift z>6 quasars are presented. This sample was selected to probe lower black hole mass quasars than most previous studies. We find a wide dispersion in properties with CFHQS J0216-0455, a low-luminosity quasar with absolute magnitude M_1450=-22.2, remaining undetected implying a limit on the star formation rate in the host galaxy of <10 solar masses per year, whereas other host galaxies have star formation rates up to hundreds of solar masses per year. Two other quasars have particularly interesting properties. VIMOS2911 is one of the least luminous z>6 quasars known with M_1450=-23.1, yet its host galaxy is experiencing a very powerful starburst. PSO J167-13 has a broad and luminous [CII] line and a neighbouring galaxy a projected distance of 5kpc away that is also detected in the [CII] line and continuum. Combining with similar observations from the literature, we study the ratio of [CII] line to far-infrared luminosity finding this ratio increases at high-redshift at a fixed far-infrared luminosity, likely due to lower dust content, lower metallicity and/or higher gas masses. We compile a sample of 21 high-redshift quasars with dynamical masses and investigate the relationship between black hole mass and dynamical mass. The new observations presented here reveal dynamical masses consistent with the relationship defined by local galaxies. However, the full sample shows a very wide scatter across the black hole mass - dynamical mass plane, whereas both the local relationship and simulations of high-redshift quasars show a much lower dispersion in dynamical mass.Comment: 10 pages, 11 figures, ApJ in pres

Star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6

We present ALMA observations of two moderate luminosity quasars at redshift 6. These quasars from the Canada-France High-z Quasar Survey (CFHQS) have black hole masses of ~10^8 M_solar. Both quasars are detected in the [CII] line and dust continuum. Combining these data with our previous study of two similar CFHQS quasars we investigate the population properties. We show that z>6 quasars have a significantly lower far-infrared luminosity than bolometric-luminosity-matched samples at lower redshift, inferring a lower star formation rate, possibly correlated with the lower black hole masses at z=6. The ratios of [CII] to far-infrared luminosities in the CFHQS quasars are comparable with those of starbursts of similar star formation rate in the local universe. We determine values of velocity dispersion and dynamical mass for the quasar host galaxies based on the [CII] data. We find that there is no significant offset from the relations defined by nearby galaxies with similar black hole masses. There is however a marked increase in the scatter at z=6, beyond the large observational uncertainties.Comment: 10 pages, 7 figures, accepted for publication in Ap

Redshift 6.4 host galaxies of 10^8 solar mass black holes: low star formation rate and dynamical mass

We present ALMA observations of rest-frame far-infrared continuum and [CII] line emission in two z=6.4 quasars with black hole masses of ~10^8 M_sun. CFHQS J0210-0456 is detected in the continuum with a 1.2 mm flux of 120+/-35 microJy, whereas CFHQS J2329-0301 is undetected at a similar noise level. J2329-0301 has a star formation rate limit of <40 M_sun/yr, considerably below the typical value at all redshifts for this bolometric luminosity. By comparison with hydro simulations, we speculate that this quasar is observed at a relatively rare phase where quasar feedback has effectively shut down star formation in the host galaxy. [CII] emission is also detected only in J0210-0456. The ratio of [CII] to far-infrared luminosity is similar to that of low redshift galaxies of comparable luminosity, suggesting the previous finding of an offset in the relationships between this ratio and far-infrared luminosity at low- and high-redshift may be partially due to a selection effect from the limited sensitivity of previous observations. The [CII] line of J0210-0456 is relatively narrow (FWHM=189+/-18 km/s), indicating a dynamical mass substantially lower than expected from the local black hole - velocity dispersion correlation. The [CII] line is marginally resolved at 0.7" resolution with the blue and red wings spatially offset by 0.5" (3 kpc) and a smooth velocity gradient of 100 km/s across a scale of 6 kpc, possibly due to rotation of a galaxy-wide disk. These observations are consistent with the idea that stellar mass growth lags black hole accretion for quasars at this epoch with respect to more recent times.Comment: 8 pages, 7 figures, ApJ in press, replaced with final versio

L’Étoile Bleue : responsabiliser et revaloriser les jeunes psychiatrisés vivant dans la communauté

L'expérience du Café l'Étoile Bleue (Laval) vise à créer un lieu de passage alternatif où des jeunes psychiatrisé(e)s pourront développer les habiletés nécessaires pour briser Ie cadre d'interprétation négative qu'ils ont d'eux-mêmes, et réussir à se trouver une identité positive propre de même qu'une place dans la communauté. Pour ce faire, un milieu de travail à stress dosé, où les relations sont déprofessionnalisées et décloisonnées, parvient à susciter la participation des jeunes et leur désir de se prendre en charge.The experience of the Café l'Étoile Bleue (Laval) illustrates an attempt to create an alternative gateway where young psychiatric patients can develop the necessary skills to break through the negative view they have of themselves, thus achieving a positive identity as well as a position in the community. To do this, a working environment of controlled stress is provided where the interactions are not compartmentalised and limited to professionals. This succeeds in gaining the participation of the young people and prompts their desire to become responsible for their own lives

Conifer Recruitment in Trembling Aspen (Populus Tremuloides Michx.) Stands along an East-West Gradient in the Boreal Mixedwoods of Canada

Ongoing climate change is likely to result in shifts in successional dynamics in boreal mixedwood stands. Using data from provincial forest inventory databases, we examined the occurrence and abundance of the regeneration of various coniferous species (white spruce, black spruce and balsam fir) along an east-west Canadian gradient in aspen-dominated stands. The interpretation of the results was based on environmental conditions, including climate, natural fire regime and human impacts. We found that conifer regeneration was present in aspen stands along the entire gradient, despite differences in climatic conditions and fire regimes between the west (warmer and drier, with large recurrent fires) and east (more humid with relatively long fire cycles). However, abundance and distribution varied from one conifer species to the next. The abundance of white spruce decreased towards the eastern end of the longitudinal gradient, while balsam fir and black spruce abundance decreased towards the west. Although abundance decreased, balsam fir and black spruce regeneration was still present in western Canada. This study shows that it is difficult to interpret the effects of climate change on conifer recruitment without accounting for the superimposed effects of human activities

Climate and disturbance regime effects on aspen (Populus tremuloidesMichx.) stand structure and composition along an east–west transect in Canada's boreal forest

Stand structure and composition play a key role in maintaining the ecological integrity of the boreal forest. However, future changes in climate and disturbance regime could affect these forest attributes. Using provincial forest inventory datasets, we analysed stands dominated by aspen (=75% of the plot total basal area) distributed along a wide longitudinal gradient of environmental conditions across Canada. Stands were classified into three diameter structure types (inverted J, intermediate and advanced). There was no major difference in the distribution pattern of structural types of aspen-dominated stands between the western and eastern Canadian boreal mixedwood forests, despite a marked contrast in climatic conditions and fire regime. These results suggest that the predominance of juvenile structures in the western aspen forests is mainly related to the frequent recurrence of fires, while within eastern aspen forests, the longer fire cycle was not the controlling factor of stand structure. Anthropogenic activities would have strongly shaped the structure of aspen forests in eastern Canada. White spruce in the west and balsam fir in the east are among the main shade-tolerant conifer companion species associated with these stands. Although stand structure and composition were highly related to stand age and site productivity, regional climate and human activities, through their influence on disturbance regime, might have impacted these forest attributes

Can Retention Harvest Maintain Natural Structural Complexity? A Comparison of Post-Harvest and Post-Fire Residual Patches in Boreal Forest

Variable retention harvest promotes biodiversity conservation in managed boreal forests by ensuring forest continuity and structural complexity. However, do post-harvest and post-fire patches maintain the same structural complexity? This study compares post-harvest and post-fire residual patches and proposes retention modalities that can maintain the same structural complexity as in natural forests, here considering both continuous forest stands and post-fire residual patches. In boreal black spruce forests, 41 post-fire residual patches, and 45 post-harvest retention patches of varying size and ages (exposure time to disturbed matrix) and 37 continuous forest stands were classified into six diameter structure types. Types 1 (inverted-J) and 2 (trunked-unimodal) characterized stands dominated by small trees. The abundance of small trees decreased and the abundance of large trees increased from Type 1 to Type 6. Type 6 had the most irregular structure with a wide range of diameters. This study indicates that: (1) old post-harvest residual retentions maintained the range of structural complexity found in natural stands; (2) Types 1 and 2 were generally associated with young post-fire patches and post-harvest retention clumps; (3) the structure of residual patches containing only small trees was usually younger (in terms of the age of the original forest from which residual patches were formed) than those with larger trees. To avoid the risk of simplifying the structure, retention patches should be intentionally oriented towards Types 3–6, dominated by intermediate and large trees

Les agressions en milieu psychiatrique. Vécu et perceptions des intervenants du Pavillon Roland-Saucier du Complexe hospitalier de la Sagamie

Cet article présente les résultats d'une étude effectuée au Pavillon Roland-Saucier, aile psychiatrique du Complexe hospitalier de la Sagamie. Le but poursuivi était d'explorer, par une approche phénoménologique, la problématique des agressions dont les intervenants étaient victimes de la part de bénéficiaires, et particulièrement l'impact de ces agressions sur leur vie professionnelle. Trente intervenants de différentes catégories professionnelles, sélectionnés par une procédure aléatoire stratifiée, ont accepté d'accorder des entrevues. L'analyse de ces entrevues a permis de dégager des éléments importants sur la base desquels diverses recommandations ont été formulées en vue d'améliorer la situation.This article presents results of a study conducted at the Pavillon Roland-Saucier, the psychiatric ward of the Complexe hospitalier de la Sagamie. The objective was to explore with a phenomenological approach the issue of assaults by patients of mental health workers and in particular the impact of theses assaults on their professional life. Thirty workers of various professional categories, selected by a stratified random procedure, have accepted to be interviewed. The analysis of theses interviews has allowed to draw important elements on the basis which various recommendations have been suggested in order to improve the situation.Este articulo presenta los resultados de un estudio efectuado en el ala psiquiátrica del Pabellón Roland-Saucier del complejo hospitalario de la Sagamie. El objetivo era el de explorar por medio de un enfoque fenomenologico, el problema de las agresiones de las que los trabajadores eran víctimas de parte de los beneficiarios, y particularmente del impacto de esas agresiones en sus vidas profesionales. Treinta trabajadores de diferentes categorías profesionales, seleccionados por un procedimiento aleatorio estratificado, aceptaron acordar entrevistas. El análisis de estas entrevistas permitió despejar los elementos importantes y diversas recomendaciones fueron emitidas sobre esta base, con el fin de mejorar la situación