52 research outputs found
The Growth of Black Holes and Bulges at the Cores of Cooling Flows
Central cluster galaxies (cDs) in cooling flows are growing rapidly through
gas accretion and star formation. At the same time, AGN outbursts fueled by
accretion onto supermassive black holes are generating X-ray cavity systems and
driving outflows that exceed those in powerful quasars. We show that the
resulting bulge and black hole growth follows a trend that is roughly
consistent with the slope of the local (Magorrian) relation between bulge and
black hole mass for nearby quiescent ellipticals. However, a large scatter
suggests that cD bulges and black holes do not always grow in lock-step. New
measurements made with XMM, Chandra, and FUSE of the condensation rates in
cooling flows are now approaching or are comparable to the star formation
rates, alleviating the need for an invisible sink of cold matter. We show that
the remaining radiation losses can be offset by AGN outbursts in more than half
of the systems in our sample, indicating that the level of cooling and star
formation is regulated by AGN feedback.Comment: 3 pages, 4 figures, to appear in the proceedings of "Heating vs.
Cooling in Galaxies and Clusters of Galaxies," edited by H. Boehringer, P.
Schuecker, G. W. Pratt, and A. Finogueno
AGN effect on cooling flow dynamics
We analyzed the feedback of AGN jets on cooling flow clusters using
three-dimensional AMR hydrodynamic simulations. We studied the interaction of
the jet with the intracluster medium and creation of low X-ray emission
cavities (Bubbles) in cluster plasma. The distribution of energy input by the
jet into the system was quantified in its different forms, i.e. internal,
kinetic and potential. We find that the energy associated with the bubbles, (pV
+ gamma pV/(gamma-1)), accounts for less than 10 percent of the jet energy.Comment: "Accepted for publication in Astrophysics & Space Science
Hot gas flows on global and nuclear galactic scales
Since its discovery as an X-ray source with the Einstein Observatory, the hot
X-ray emitting interstellar medium of early-type galaxies has been studied
intensively, with observations of improving quality, and with extensive
modeling by means of numerical simulations. The main features of the hot gas
evolution are outlined here, focussing on the mass and energy input rates, the
relationship between the hot gas flow and the main properties characterizing
its host galaxy, the flow behavior on the nuclear and global galactic scales,
and the sensitivity of the flow to the shape of the stellar mass distribution
and the mean rotation velocity of the stars.Comment: 22 pages. Abbreviated version of chapter 2 of the book "Hot
Interstellar Matter in Elliptical Galaxies", Springer 201
Racism as a determinant of health: a systematic review and meta-analysis
Despite a growing body of epidemiological evidence in recent years documenting the health impacts of racism, the cumulative evidence base has yet to be synthesized in a comprehensive meta-analysis focused specifically on racism as a determinant of health. This meta-analysis reviewed the literature focusing on the relationship between reported racism and mental and physical health outcomes. Data from 293 studies reported in 333 articles published between 1983 and 2013, and conducted predominately in the U.S., were analysed using random effects models and mean weighted effect sizes. Racism was associated with poorer mental health (negative mental health: r = -.23, 95% CI [-.24,-.21], k = 227; positive mental health: r = -.13, 95% CI [-.16,-.10], k = 113), including depression, anxiety, psychological stress and various other outcomes. Racism was also associated with poorer general health (r = -.13 (95% CI [-.18,-.09], k = 30), and poorer physical health (r = -.09, 95% CI [-.12,-.06], k = 50). Moderation effects were found for some outcomes with regard to study and exposure characteristics. Effect sizes of racism on mental health were stronger in cross-sectional compared with longitudinal data and in non-representative samples compared with representative samples. Age, sex, birthplace and education level did not moderate the effects of racism on health. Ethnicity significantly moderated the effect of racism on negative mental health and physical health: the association between racism and negative mental health was significantly stronger for Asian American and Latino(a) American participants compared with African American participants, and the association between racism and physical health was significantly stronger for Latino(a) American participants compared with African American participants.<br /
The health of young Swedish Sami with special reference to mental health
Objectives. To investigate the health of young Sami in Sweden and the relationship between health and experience of negative societal treatment due to ethnicity, as well as socio-demographic background factors. Study design. Cross-sectional population-based questionnaire study. Methods. A total of 876 persons aged 18–28 and involved in Sami associated activities were addressed, and 516 (59%) responded to a questionnaire investigating physical health, mental health, and stress. Data were analyzed with regard to gender, family situation, occupation, education, enculturation factors and experience of being badly treated because of ethnicity. Results. A majority of the young Sami reported feeling healthy, but close to half of the group reported often having worries, often forgetting things and often experiencing lack of time for doing needed things. Women and those living alone reported a more negative health. Furthermore, half of the group had perceived bad treatment because of Sami ethnicity, and this was negatively associated with some aspects of mental health. Conclusion. The young Sami had a rather good and possibly slightly better health than other young Swedes, except regarding worries and stress. A high degree of bad treatment due to Sami ethnicity and its negative association with health, may partly explain the high degree of some health problems
The relationship between nailfold capillaroscopic assessment and telangiectasia score with severity of peripheral vascular involvement in systemic sclerosis
Objective. To determine the association of nailfold video-capillaroscopy (NVC) findings and telangiectasia score with digital ulcer (DU) history and severity of peripheral vascular involvement (PVI) in systemic sclerosis (SSc)
Favourable pregnancy outcome in Takayasu arteritis: a single-centre experience.
Introduction. Takayasu arteritis is a chronic large-vessel vasculitis in young women of reproductive age. We aimed to obtain information on pregnancy in TA retrospectively
Metabolic syndrome is not only a risk factor for cardiovascular diseases in systemic lupus erythematosus but is also associated with cumulative organ damage: a cross-sectional analysis of 311 patients.
Background/Purpose Patients with systemic lupus erythematosus (SLE) have increased rates of cardiovascular disease (CVD) that are one of the major causes of mortality. The aim of this study was to determine the frequencies of metabolic syndrome (MetS) and CVD in SLE patients and investigate the link between these and clinical features of SLE
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