Quasar Clustering in Cosmological Hydrodynamic Simulations: Evidence for mergers

We examine the clustering properties of a population of quasars drawn from fully hydrodynamic cosmological simulations that directly follow black hole growth. We find that the black hole correlation function is best described by two distinct components: contributions from BH pairs occupying the same dark matter halo ('1-halo term') which dominate at scales below 300 kpc/h, and contributions from BHs occupying separate halos ('2-halo term') which dominate at larger scales. From the 2-halo BH term we find a typical host halo mass for faint-end quasars (those probed in our simulation volumes) ranging from 10^11 to a few 10^12 solar masses from z=5 to z=1 respectively (consistent with the mean halo host mass). The BH correlation function shows a luminosity dependence as a function of redshift, though weak enough to be consistent with observational constraints. At small scales, the high resolution of our simulations allows us to probe the 1-halo clustering in detail, finding that the 1-halo term follows an approximate power law, lacking the characteristic decrease in slope at small scales found in 1-halo terms for galaxies and dark matter. We show that this difference is a direct result of a boost in the small-scale quasar bias caused by galaxies hosting multiple quasars (1-subhalo term) following a merger event, typically between a large central subgroup and a smaller, satellite subgroup hosting a relatively small black hole. We show that our predicted small-scale excess caused by such mergers is in good agreement with both the slope and amplitude indicated by recent small-scale measurements. Finally, we note the excess to be a strong function of halo mass, such that the observed excess is well matched by the multiple black holes of intermediate mass (10^7-10^8 solar masses) found in hosts of 4-8*10^11 solar masses, a range well probed by our simulations.Comment: 12 pages, 10 figures. Submitted to MNRA

Navigating Musical Periodicities: Modes of Perception and Types of Temporal Knowledge

This dissertation explores multi-modal, symbolic, and embodied strategies for navigating musical periodicity, or “meter.” In the first half, I argue that these resources and techniques are often marginalized or sidelined in music theory and psychology on the basis of definition or context, regardless of usefulness. In the second half, I explore how expanded notions of metric experience can enrich musical analysis. I then relate them to existing approaches in music pedagogy. Music theory and music psychology commonly assume experience to be perceptual, music to be a sound object, and perception of music to mean listening. In addition, observable actions of a metaphorical “body” (and, similarly, performers’ perspectives) are often subordinate to internal processes of a metaphorical “mind” (and listeners’ experiences). These general preferences, priorities, and contextual norms have culminated in a model of “attentional entrainment” for meter perception, emerging through work by Mari Riess Jones, Robert Gjerdingen, and Justin London, and drawing upon laboratory experiments in which listeners interact with a novel sound stimulus. I hold that this starting point reflects a desire to focus upon essential and universal aspects of experience, at the expense of other useful resources and strategies (e.g. extensive practice with a particular piece, abstract ideas of what will occur, symbolic cues) Opening discussion of musical periodicity without these restrictions acknowledges experiences beyond attending, beyond listening, and perhaps beyond perceiving. I construct two categories for various resources and strategies: those which involve dynamic symbolic encoding (such as conducting patterns and tala gestures) and those which utilize static theoretical information (such as score-based knowledge and calculation of abstract relationships). My primary means of revealing and exploring these additional resources involves instances of “metric multi-tasking,” in which musicians keep track of multiple non-nested periodicities occurring simultaneously. One of the reasons these situations work so well at revealing additional resources is that attentional entrainment offers no explanation for how one might be able to do such a thing (only that attention is insufficient for the task). I do not make these moves in an attempt to significantly alter the theory of attentional entrainment. Rather, I frame that model as but one mode of temporal perception among many. I also leave room for types of temporal knowledge which may not be perceptual at all, but are nonetheless useful in situations involving musical periodicity. Pedagogical systems already make use of dynamic symbols and theoretical knowledge to help with temporally difficult tasks, and generally not virtuosic feats of metric multi-tasking. With these ideas in mind, I return to more straightforward “mono-metric” contexts and reconsider what to do with the concepts of “meter” and “perception.

The Halo Occupation Distribution of Active Galactic Nuclei

Using a fully cosmological hydrodynamic simulation that self-consistently incorporates the growth and feedback of supermassive black holes and the physics of galaxy formation, we examine the effects of environmental factors (e.g., local gas density, black hole feedback) on the halo occupation distribution of low luminosity active galactic nuclei (AGN). We decompose the mean occupation function into central and satellite contribution and compute the conditional luminosity functions (CLF). The CLF of the central AGN follows a log-normal distribution with the mean increasing and scatter decreasing with increasing redshifts. We analyze the light curves of individual AGN and show that the peak luminosity of the AGN has a tighter correlation with halo mass compared to instantaneous luminosity. We also compute the CLF of satellite AGN at a given central AGN luminosity. We do not see any significant correlation between the number of satellites with the luminosity of the central AGN at a fixed halo mass. We also show that for a sample of AGN with luminosity above 10^42 ergs/s the mean occupation function can be modeled as a softened step function for central AGN and a power law for the satellite population. The radial distribution of AGN inside halos follows a power law at all redshifts with a mean index of -2.33 +/- 0.08. Incorporating the environmental dependence of supermassive black hole accretion and feedback, our formalism provides a theoretical tool for interpreting current and future measurements of AGN clustering.Comment: 14 pages, 11 figures, 2 Tables (Matches the MNRAS accepted version

Black hole clustering and duty cycles in the Illustris simulation

We use the high-resolution cosmological simulation Illustris to investigate the clustering of supermassive black holes across cosmic time, the link between black hole clustering and host halo masses, and the implications for black hole duty cycles. Our predicted black hole correlation length and bias match the observational data very well across the full redshift range probed. Black hole clustering is strongly luminosity dependent on small, 1-halo scales, with some moderate dependence on larger scales of a few Mpc at intermediate redshifts. We find black hole clustering to evolve only weakly with redshift, initially following the behaviour of their hosts. However, below z ~ 2 black hole clustering increases faster than that of their hosts, which leads to a significant overestimate of the clustering-predicted host halo mass. The full distribution of host halo masses is very wide, including a low-mass tail extending up to an order of magnitude below the naive prediction for minimum host mass. Our black hole duty cycles, $\textit{f}$duty, follow a power-law dependence on black hole mass and decrease with redshift, and we provide accurate analytic fits to these. The increase in clustering amplitude at late times, however, means that duty cycle estimates based on black hole clustering can overestimate $\textit{f}$duty substantially, by more than two orders of magnitude. We find the best agreement when the minimum host mass is assumed to be 10$^{11.2}$M⊙, which provides an accurate measure across all redshifts and luminosity ranges probed by our simulation.CD and DS acknowledge support by the ERC starting grant 638707 ‘Black holes and their host galaxies: co-evolution across cosmic time’. DS further acknowledges support from the STFC. Simulations were run on the Harvard Odyssey and CfA/ITC clusters, the Ranger and Stampede supercomputers at the Texas Advanced Computing Center as part of XSEDE, the Kraken supercomputer at Oak Ridge National Laboratory as part of XSEDE, the CURIE supercomputer at CEA/France as part of PRACE project RA0844 and the SuperMUC computer at the Leibniz Computing Center, as part of project pr85je

O princípio da publicidade na administração pública

A presente monografia concentra-se no princípio constitucional da publicidade na administração pública. Busca delimitar e esclarecer o conteúdo jurídico do princípio da publicidade, estabelecido no artigo 37, caput, da Constituição Federal, com o apoio bibliográfico e doutrinário de autores que valorizaram os aspectos principiológicos do direito administrativo. O trabalho também faz um estudo sucinto da força normativa dos princípios constitucionais, além de descrever a repercussão do princípio da publicidade no regime jurídico administrativo. Analisa-se o direito do cidadão à informação pública e o correlato dever de transparência da administração pública - binómio que resume o conteúdo jurídico do princípio da publicidade. O trabalho também discorre sobre a identidade entre o princípio e a noção de transparência administrativa. Traça-se um breve panorama internacional das principais leis de transparência, e da discussão no Brasil sobre a adoção de lei semelhante. Por fim, descreve os principais mecanismos jurisdicionais oferecidos ao cidadão para a garantia da publicidade administrativa

Mecanismos de HARQ usando códigos LDPC com retransmissão parcial e combinação por diversidade

Modern standards of communication systems are including in their standards retransmission mechanisms. This work presents mechanisms for retransmission of packets by simpler and more efficient than the classical mechanisms of packet retransmissions. The proposed schemes are presented that use packet retransmission with partial retransmission and diversity combining. In addition, theoretical analysis will be presented to validate the results of the simulations. These theoretical analysis are obtained through the analysis EXIT charts and mutual information. The results and analysis were performed on channels such as AWGN and Block-Fading. The computational complexity, ease implementation and low average energy consumption for transmission of the proposed methods are some of the reasons they become interesting both for academia and for industry.Os recentes padrões de sistemas de comunicação estão incluindo em suas normas mecanismos de retransmissão de pacotes. Este trabalho apresenta mecanismos de retransmissão de pacotes de formas simples e mais eficientes do que os mecanismos clássicos de retransmissão de pacotes. São apresentados esquemas de retransmissão de pacotes que utilizam retransmissões parciais e combinação por diversidade. Além disso, serão apresentadas análises teóricas para validar os resultados obtidos das simulações. Estas análises teóricas são obtidas através das análises de EXIT charts e da informação mútua. Os resultados e análises foram realizados em canais do tipo AWGN e com desvanecimento por blocos (Block-Fading). A complexidade computacional, facilidade de implementação e baixo consumo médio de energia por transmissão dos métodos propostos são alguns dos motivos pelos quais, tornam-se interessantes tanto para a área acadêmica quanto para a indústria

Análise da relação entre sensação térmica e qualidade de vida no trabalho

The aim of this study was to evaluate the relationship between thermal sensation and Quality of Work Life (QWL) in industries with different environmental characteristics. Data collection was done in three industries in the city of Ponta Grossa, Paraná State, each with different environmental characteristics of temperatures, namely a meat packing industry at low temperatures, a textile industry with neutral temperatures and metal industry with higher temperatures. To obtain data on environmental features such as air temperature, globe temperature, air velocity and relative humidity, used the station obtaining environmental data in 31 service stations by industry, the Predicted Mean Vote (PMV) calculated with data from environmental characteristics along with the dress and activities of workers. Questionnaires QVT Walton, adapted by Timossi (2009) were distributed. Of which 211 were completed, these 83 or 39.34% of the meatpacking industry, 73 or 34.60% of the textile, and 55 or 26.06% of the metal. Questionnaire was used only the criterion 'working conditions', to make the correlation between workers leased at their posts and the environmental characteristics of each post. It was observed that industries with extreme temperatures exhibited lower levels of QWL. In the textile industry, with neutral temperatures, QVT has averaged 72.60 (± 10.67), but to apply the correlation was found very low coefficient of determination, 0.029. The resulting mathematical equation, does not allow to find a variable from another. It is concluded that the relationship between thermal sensation through Predicted percentage dissatisfied (PPD) with QVT within the discretion of 'working conditions' has negligible values and establishes a correlation between the variables.O objetivo geral deste estudo foi analisar a relação entre sensação térmica e Qualidade de Vida no Trabalho (QVT) em indústrias com diferentes características ambientais. A coleta de dados foi feita em três indústrias da cidade de Ponta Grossa, no Estado do Paraná, cada uma delas com características ambientais de temperaturas diferenciadas, a saber: uma indústria frigorífica com temperaturas baixas, uma indústria têxtil com temperaturas neutras e uma indústria metalúrgica com temperaturas mais elevadas. Para obtenção dos dados das características ambientais, como temperatura do ar, temperatura de globo, velocidade do ar e umidade relativa, utilizou-se a estação de obtenção de dados ambientais, em 31 postos de serviço por indústria, calculado o Voto Médio Estimado – Predicted mean vote (PMV), com dados das características ambientais juntamente com as vestimentas e as atividades dos trabalhadores. Foram distribuídos questionários de QVT de Walton, adaptado por Timossi (2009). Dos quais 211 foram respondidos, destes 83 (49,34%) da indústria frigorífica, 73 (34,60%) da têxtil, e 55 (26,06%) da metalúrgica. Do questionário foi utilizado apenas o critério ‘condições de trabalho’, para fazer a correlação entre os trabalhadores locados em seus postos e as características ambientais de cada posto. Pôde-se observar que as indústrias com temperaturas extremas apresentaram menores índices de QVT. Na indústria têxtil, com temperaturas neutras, a QVT teve média de 72,60 (±10,67), mas ao aplicar-se a correlação foi encontrado coeficiente de determinação muito baixo, 0,029. A equação matemática resultante, não permite encontrar uma variável a partir da outra. Conclui-se então que a relação entre sensação térmica, através da Porcentagem de pessoas insatisfeitas – Predicted percentage dissatisfied (PPD), com a QVT dentro do critério ‘condições de trabalho’ apresenta valores pouco significativos e não estabelece correlação entre as variáveis