Understanding the shape of the galaxy two-point correlation function at z ≃ 1 in the COSMOS field

We investigate how the shape of the galaxy two-point correlation function as measured in the zCOSMOS survey depends on local environment, quantified in terms of the density contrast on scales of 5 h^(−1) Mpc. We show that the flat shape previously observed at redshifts between z= 0.6 and 1 can be explained by this volume being simply 10 per cent overabundant in high-density environments, with respect to a universal density probability distribution function. When galaxies corresponding to the top 10 per cent tail of the distribution are excluded, the measured w_(p)(r_(p)) steepens and becomes indistinguishable from Lambda cold dark matter (ΛCDM) predictions on all scales. This is the same effect recognized by Abbas & Sheth in the Sloan Digital Sky Survey (SDSS) data at z ≃ 0 and explained as a natural consequence of halo–environment correlations in a hierarchical scenario. Galaxies living in high-density regions trace dark matter haloes with typically higher masses, which are more correlated. If the density probability distribution function of the sample is particularly rich in high-density regions because of the variance introduced by its finite size, this produces a distorted two-point correlation function. We argue that this is the dominant effect responsible for the observed ‘peculiar’ clustering in the COSMOS field

The Arp 220 merger on kpc scales

For the first time we study the Eastern nucleus in greater detail and search for the more extended emission in the molecular gas in different CO line transitions of the famous ULIRG Arp 220. Furthermore we present a model of the merger in Arp 220 on large scales with the help of the CO data and an optical and near-infrared composite HST image of the prototypical ULIRG. Using the Plateau de Bure Interferometer (PdBI) we obtained CO(2-1) and (1-0) data at wavelengths of 1 and 3 mm in 1994, 1996, 1997 and 2006 at different beam sizes and spatial resolutions. The simulations of the merger in Arp 220 were performed with the Identikit modeling tool. The model parameters that describe the galaxy merger best give a mass ratio of 1:2 and result in a merger of ~6x10^8 yrs. The low resolution CO(1-0) PdBI observations suggest that there are indications for emission ~10" towards the south, as well as to the north and to the west of the two nuclei.Comment: accepted for publication in ApJ, 14 pages 10 figure

Mapping the Recent Star Formation History of the Disk of M51

Using data acquired as part of a unique Hubble Heritage imaging program of broadband colors of the interacting spiral system M51/NGC 5195, we have conducted a photometric study of the stellar associations across the entire disk of the galaxy in order to assess trends in size, luminosity, and local environment associated with recent star formation activity in the system. Starting with a sample of over 900 potential associations, we have produced color-magnitude and color-color diagrams for the 120 associations that were deemed to be single-aged. It has been found that main sequence turnoffs are not evident for the vast majority of the stellar associations in our set, potentially due to the overlap of isochronal tracks at the high mass end of the main sequence, and the limited depth of our images at the distance of M51. In order to obtain ages for more of our sample, we produced model spectral energy distributions (SEDs) to fit to the data from the GALEXEV simple stellar population (SSP) models of Bruzual and Charlot (2003). These SEDs can be used to determine age, size, mass, metallicity, and dust content of each association via a simple chi-squared minimization to each association's B, V, and I-band fluxes. The derived association properties are mapped as a function of location, and recent trends in star formation history of the galaxy are explored in light of these results. This work is the first phase in a program that will compare these stellar systems with their environments using ultraviolet data from GALEX and infrared data from Spitzer, and ultimately we plan to apply the same stellar population mapping methodology to other nearby face-on spiral galaxies.Comment: 13 pages, 3 figures, 1 table. Accepted to The Astronomical Journa

Millimeter-Wave Spectroscopy and Mapping of Quasar Hosts, and the Status of ULIRGs as Quasar 2s

It is becoming possible to detect high redshift quasars in various molecular lines, and to show by mapping lensed objects that the strong dust and molecular emission arises in warm dense ~100 pc-scale "tori." The properties of ULIRGs, at least those with AGN-like narrow line regions, are very similar, as expected in the hidden quasar hypothesis. Several of the latter are in fact confirmed as "Quasar 2s" by spectropolarimetry.Comment: 7 page

AzTEC Millimetre Survey of the COSMOS Field - II. Source Count Overdensity and Correlations with Large-Scale Structure

We report an over-density of bright sub-millimetre galaxies (SMGs) in the 0.15 sq. deg. AzTEC/COSMOS survey and a spatial correlation between the SMGs and the optical-IR galaxy density at z <~ 1.1. This portion of the COSMOS field shows a ~ 3-sigma over-density of robust SMG detections when compared to a background, or "blankfield", population model that is consistent with SMG surveys of fields with no extragalactic bias. The SMG over-density is most significant in the number of very bright detections (14 sources with measured fluxes S(1.1mm) > 6 mJy), which is entirely incompatible with sample variance within our adopted blank-field number densities and infers an over-density significance of >> 4. We find that the over-density and spatial correlation to optical-IR galaxy density are most consistent with lensing of a background SMG population by foreground mass structures along the line of sight, rather than physical association of the SMGs with the z <~ 1.1 galaxies/clusters. The SMG positions are only weakly correlated with weak-lensing maps, suggesting that the dominant sources of correlation are individual galaxies and the more tenuous structures in the region and not the massive and compact clusters. These results highlight the important roles cosmic variance and large-scale structure can play in the study of SMGs.Comment: 12 pages, 11 figures, 2 tables, accepted for publication in MNRA

Literatura das secas : ficção e história

Orientador: Prof. Dr. Paulo A. SoetheAutor não autorizou a divulgação do arquivo digitalTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Letras e Artes, Programa de Pós-Graduação em Letras. Defesa: Curitiba, 30/06/2011Inclui referênciasResumo: Neste estudo sobre a literatura das secas, é proposto um diálogo entre discursos ficcionais e não ficcionais, em especial entre a Literatura e a História, a partir da percepção de que a seca é um fenômeno climático e social. O trabalho abrange uma revisão conceitual sobre a literatura das secas, bem como sobre os termos &quot;Nordeste" e &quot;sertão" que a ela estão diretamente associados. Com base nos resultados obtidos, é realizado levantamento e análise de um conjunto de obras literárias em que se figuram as secas nordestinas. Nessa análise, são também confrontadas as perspectivas literárias sobre as secas com aquelas encontradas em textos técnicos e históricos. Sob a tentativa de se balizar a variedade de perspectivas sobre a seca, são abordados alguns temas e elementos recorrentes na literatura das secas, com ênfase nos personagens retirantes e nas migrações cujo ponto de origem é o sertão nordestino.Abstract: In this work on the literature of the drought, a dialogue among fictional and nonfictional discourses, especially among Literature and History, is proposed, based on a conception that drought is a climatic and social phenomenon. The work includes a conceptual review on literature of the drought, as well as on terms directly linked to it as &quot;Northeast" and &quot;hinterland". Based on obtained results, it is presented a survey and analysis of literary works on which northeastern droughts are figured. In this analysis, also the literary perspectives on the drought are compared with those found in technical and historical writings. Attempting to point out the variety of perspectives on droughts, some recurrent themes and aspects in the literature of the drought are approached focusing on migrants characters and migrations whose points of origin are at the northeastern hinterland

As cartas vão dizer: as relações interterritoriais na era de Amarna

Por meio de uma pesquisa interdisciplinar, que une a História à Egiptologia, à Assiriologia e às Humanidades Digitais, este estudo propõe reflexões acerca do Sistema Diplomático de Amarna. Para tanto, realizo uma discussão sobre a documentação das Cartas de Amarna (EA1-44) por meio de uma análise de redes sociais (a Social Network Analysis) em contraste com o contexto e com o conteúdo das correspondências. A pesquisa foi guiada pela perspectiva de compreender até que ponto essa comunicação interterritorial se caracteriza como sendo o primeiro sistema diplomático do qual temos notícia, como ele funcionava e se ele era eficaz. Assim, ponderei os costumes e regras que serviram de baliza para os contatos e as atitudes práticas dos reis, tentando entender seus anseios e preocupações. Por meio dessa pesquisa, foi possível perceber que, apesar de existirem diferentes compreensões em nível individual e coletivo, o Sistema de Amarna foi capaz de manter um equilíbrio de poderes no Antigo Oriente Próximo. Os contatos se sistematizaram por meio de dois conceitos essenciais: a reciprocidade e a fraternidade, que permitiam interpretações variadas, mesmo sendo tão importantes.Through interdisciplinary research, which merges History, Egyptology, Assyriology and the Digital Humanities, this study discuss the Diplomatic System of Amarna. To this end, I conduct research on the Amarna Letters (EA1-44) through Social Network Analysis, in contrast to the context and content of the correspondence. The thesis is guided by the perspective of understanding to what extent this interterritorial communication is characterized as being the first diplomatic system of which we know, how it worked and if it was effective. Thus, I pondered the customs and norms that served as a beacon for the contacts and practical attitudes of the kings, and aimed to understand their anxieties and concerns. Through this research, it was possible to perceive that, despite the existence of different understandings at the individual and collective level, the Amarna System was able to maintain a balance of powers in the Ancient Near East. The contacts were systematized through two essential concepts: reciprocity and fraternity (or brotherhood) - interpreted in multiple ways, despite being so important.A través de una investigación interdisciplinar, que une la Historia con la Egiptología, la Asiriología y las Humanidades Digitales, este estudio propone reflexiones sobre el sistema diplomático de Amarna. Para ello, realizo una discusión sobre la documentación de las Cartas de Amarna (EA1-44) mediante un análisis de redes sociales (el Social Network Analysis) en contraste con el contexto y el contenido de las correspondencias. La investigación se guió por la perspectiva de comprender hasta qué punto esta comunicación interterritorial se caracteriza por ser el primer sistema diplomático del que conocemos, cómo funcionaba y si era eficaz. Así, reflexioné sobre las costumbres y las normas que servían de faro para los contactos y las actitudes prácticas de los reyes, tratando de comprender sus deseos y preocupaciones. A través de esta investigación, fue posible percibir que, a pesar de las diferentes concepciones a nivel individual y colectivo, el sistema de Amarna fue capaz de mantener un equilibrio de poder en el Cercano Oriente Antiguo. Los contactos se sistematizaron mediante dos conceptos esenciales: la reciprocidad y la fraternidad, que permitían interpretaciones variadas, a pesar de ser tan importantes

Molecular Gas in the Powerful Radio Nucleus of the Ultraluminous Infrared Galaxy PKS 1345+12

Millimeter CO(1-0) interferometry and high resolution, Hubble Space Telescope (HST) 1.1, 1.6, and 2.2 micron imaging of the radio compact galaxy PKS 1345+12 are presented. With an infrared luminosity of 2x10^{12} L_sun, PKS 1345+12 is a prime candidate for studying the link between the ultraluminous infrared galaxy phenomenon and radio galaxies. These new observations probe the molecular gas distribution and obscured nuclear regions of PKS 1345+12 and provide morphological support for the idea that the radio activity in powerful radio galaxies is triggered by the merger of gas rich galaxies. Two nuclei separated by 2" (4.0 kpc) are observed in the near-infrared; the extended southeastern nucleus has colors consistent with reddened starlight, and the compact northwestern nucleus has extremely red colors indicative of an optical quasar with a warm dust component. Further, the molecular gas, 3mm continuum, and radio emission are coincident with the redder nucleus, confirming that the northwestern nucleus is the site of the AGN and that the molecular gas is the likely fuel source.Comment: LaTex, 5 pages with 1 postscript and 1 jpg figure, ApJ Letters, in press (August 20, 1999

Tablet definitions have been updated: The Ancient Near East and the Digital Humanities

A ascensão das pesquisas voltadas às Humanidades Digitais permitiu um novo olhar para o passado, até mesmo no mais remoto dos tempos. Neste artigo, busco trazer uma possibilidade de atualização das nossas visões sobre a Antiguidade Próximo-oriental, a partir de metodologias da informática. Para tanto, parto da ideia de ligações de rede (pela Social Network Analysis), criando um mapa visual sobre a interação de diferentes reinos em um sistema diplomático. Localizo essa pesquisa no século XIV AEC, quando o Sistema de Amarna estruturou regras e costumes para estabelecer contatos e manter o poder dos reinos de maior destaque. Com isso, espera-se revisitar o antigo oriente, desmistificando e recontextualizando aqueles povos em uma realidade mais integrada e interconectada.The increasing number of researches on Digital Humanities enables a new view of the past, even to the most ancient times. In this paper, I aim to facilitate a renovation of our notions about the Ancient Near East, through methodologies of the informatics. For that, I use the Social Network Analysis’ resources to create a visual map of the interaction between kingdoms in a diplomatic system. This inquiry is focused in the XIV century BCE when the structures and rules of the Amarna System permitted contacts and maintained the power of some well-established kingdoms. With that, I hope to revisit the Near East and rethink those peoples in a more integrated and interconnected reality