Bubbles as tracers of heat input to cooling flows

We examine the distribution of injected energy in three-dimensional, adaptive-grid simulations of the heating of cooling flows. We show that less than 10 percent of the injected energy goes into bubbles. Consequently, the energy input from the nucleus is underestimated by a factor of order 6 when it is taken to be given by PVgamma/(gamma-1), where P and V are the pressure and volume of the bubble, and gamma the ratio of principal specific heats.Comment: Accepted for publication in MNRAS; 5 page

Structural stability of cooling flows

Three-dimensional hydrodynamical simulations are used to investigate the structural stability of cooling flows that are episodically heated by jets from a central AGN. The radial profile of energy deposition is controlled by (a) the power of the jets, and (b) the pre-outburst density profile. A delay in the ignition of the jets causes more powerful jets to impact on a more centrally concentrated medium. The net effect is a sufficient increase in the central concentration of energy deposition to cause the post-outburst density profile to be less centrally concentrated than that of an identical cluster in which the outburst happened earlier and was weaker. These results suggest that the density profiles of cooling flows oscillate around an attracting profile, thus explaining why cooling flows are observed to have similar density profiles. The possibility is raised that powerful FR II systems are ones in which this feedback mechanism has broken down and a runaway growth of the source parameters has occurred.Comment: 4 pages, 2 figure

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

Fanatisme Pada Penikmat Musik Metal

Fanaticism is a belief in fanatical objects that are often associated with something excessive on an object, where the fanatic attitude is shown with extreme enthusiasm, emotional attachment and excessive love and interest that lasts for a long time, and often considers what they believe is the most correct thing. The purpose of this research is to understand and describe fanaticism in metal music lovers. This study uses qualitative methods, and the techniques that researchers use are interactive data analysis techniques. The informants in this study were selected by purposive sampling with the characteristics of the subject criteria of a connoisseur of metal music with more than one year enjoying metal music, amounting to eight informants. The results of this study indicate that 1) Fanaticism that is generally encountered in metal music lovers is listening to metal music almost every day both outside the house and inside the house, moving his limbs such as feet, hands and head when listening to metal music. 2) When listening to metal at a metal music event, all informants showed fanaticism, ie doing moshing, headbang, and the wall of death. 3) Individuals basically like music with a fast tempo. 4) Informants who work more often listen to metal music outside working hours, and student informants listen to metal music all the time. 5) Individuals are supported by families by buying t-shirts, entertaining guests from out of town, and visiting the event venue.

Can the mean platelet volume be a predictor of disease activity in primary Sjogren syndrome?

Background: Disease activity in primary Sjogren syndrome (PSS) is measured by the EULAR Sjogren’s syndrome disease activity index (ESSDAI) and patient reported index (ESSPRI). Studies investigating the association between ESSDAI and ESSPRI and previously reported indicators of systemic inflammation are few in the literature. The aim of this study was to determine the clinical utility of the mean platelet volume (MPV) in predicting disease activity in PSS patients.Methods: A total of 190 subjects including ninety-five PSS patients and ninety-five healthy controls were enrolled. Associations between MPV and other known indicators of systemic inflammation (red cell distribution width (RDW), neutrophil to lymphocyte ratio (NLR) and patient clinical characteristic, ESSDAI and ESSPRI were investigated by using spearman correlation and linear regression analysis.Results: MPV levels were found to be significantly higher in the PSS group than the control group (10.5±1.2 versus 9.0±1; P<0.001 respectively). Correlation and regression analysis showed a positive correlation between MPV levels and ESSDAI scores (r=0.24, p=0.01). There was a negative correlation between ESSPRI and MPV levels (r=-0.32, p=0.001). NLR and RDW did not show any significant correlation with either ESSDAI or ESSPRI scores.Conclusions: MPV levels are significantly elevated in PSS patients compared to their control peers, positively correlate with ESSDAI but negatively with ESSPRI scores. MPV might be a useful inflammatory marker to measure disease activity in PSS.

Correlation of Black Hole and Bulge Masses: Driven by Energy but Correlated with Momentum

We use a recent sample of 49 galaxies to show that there is a proportionality relation between the black hole mass M_BH and the quantity \mu =M_G*\sigma /c, where M_G is mass of the spheroidal stellar component and \sigma is the stellar velocity dispersion. \mu is called the momentum parameter and the ratio is M_BH/\mu ~3.3. This result is applied to the penetrating-jet feedback model which argues that the correlation that holds is with a momentum-like parameter, although this feedback mechanism is based on energy balance.Comment: Accepted to MNRA

Sound Waves Excitation by Jet-Inflated Bubbles in Clusters of Galaxies

We show that repeated sound waves in the intracluster medium (ICM) can be excited by a single inflation episode of an opposite bubble pair. To reproduce this behavior in numerical simulations the bubbles should be inflated by jets, rather than being injected artificially. The multiple sound waves are excited by the motion of the bubble-ICM boundary that is caused by vortices inside the inflated bubbles and the backflow (`cocoon') of the ICM around the bubble. These sound waves form a structure that can account for the ripples observed in the Perseus cooling flow cluster. We inflate the bubbles using slow massive jets, with either a wide opening angle or that are precessing. The jets are slow in the sense that they are highly sub-relativistic, $v_j \sim 0.01c-0.1c$, and they are massive in the sense that the pair of bubbles carry back to the ICM a large fraction of the cooling mass, i.e., \sim 1-50 M_\odot \yr^{-1}. We use a two-dimensional axisymmetric (referred to as 2.5D) hydrodynamical numerical code (VH-1).Comment: submitted to MNRA

Mii *eai leat gal vuollánan -- Vi *ha neimen ikke gitt opp: En hybrid grammatikkontroll for å rette kongruensfeil

Machine learning is the dominating paradigm in natural language processing nowadays. It requires vast amounts of manually annotated or synthetically generated text data. In the GiellaLT infrastructure, on the other hand, we have worked with rule-based methods, where the linguistis have full control over the development the tools. In this article we uncover the myth of machine learning being cheaper than a rule-based approach by showing how much work there is behind data generation, either via corpus annotation or creating tools that automatically mark-up the corpus. Earlier we have shown that the correction of grammatical errors, in particular compound errors, benefit from hybrid methods. Agreement errors, on the other other hand, are to a higher degree dependent on the larger grammatical context. Our experiments show that machine learning methods for this error type, even when supplemented by rule-based methods generating massive data, can not compete with the state-of-the-art rule-based approach.Maskinlæringsteknikker der lingvistisk ekspertise ikke brukes dominerer språkteknologi nå til dags. Dette krever at man merker opp en stor datamengde manuelt på forhånd. I GiellaLT-infrastrukturen har man der- imot jobbet med regelbaserte metoder der lingvisten har kontroll over hvordan verktøyene fungerer. Det er ikke bare tekniske årsaker for metodevalget. Kunnskapsøkning om samisk grammatikk, kvalitetssikring og kontrollerbarhet (verktøyene gjør det de skal gjøre også ifølge menneskelige standard) ligger bak preferansen om å jobbe regelbasert. I denne artikkelen vil vi forsøke å avdekke myten om at maskinlæring blir billigere enn regelbaserte metoder. Likevel tror vi at maskinlæringsmetoder kan være nyttige der vi ønsker større dekning av feilretting. Vi viser at maskinlæringsmodeller som har tilgang til små datameng- der (i dette tilfelle for små språk) er avhengig av gode regelbaserte verktøy som erstatning for manuell oppmerking

Bayesian modelling of the cool core galaxy group NGC 4325

We present an X-ray analysis of the radio-quiet cool-core galaxy group NGC 4325 (z=0.026) based on Chandra and ROSAT observations. The Chandra data were analysed using XSPEC deprojection, 2D spectral mapping and forward-fitting with parametric models. Additionally, a Markov chain Monte Carlo method was used to perform a joint Bayesian analysis of the Chandra and ROSAT data. The results of the various analysis methods are compared, particularly those obtained by forward-fitting and deprojection. The spectral mapping reveals the presence of cool gas displaced up to 10 kpc from the group centre. The Chandra X-ray surface brightness shows the group core to be highly disturbed, and indicates the presence of two small X-ray cavities within 15 kpc of the group core. The XSPEC deprojection analysis shows that the group has a particularly steep entropy profile, suggesting that an AGN outburst may be about to occur. With the evidence of prior AGN activity, but with no radio emission currently observed, we suggest that the group in in a pre-outburst state, with the cavities and displaced gas providing evidence of a previous, weak AGN outburst.Comment: 12 pages, 10 figures; accepted for publication in MNRA