Título:

Descrição:Nas últimas duas décadas a astronomia optica e infravermelha do Brasil teve um grande crescimento, tanto em número de pessoas quanto em publicações e isto relfete no reconhecimento internacional de nossa comunidade. Este crescimento foi alavancado em boa parte pelo maior acesso a novos telescópios e instrumentação, seja no país seja por acordos internacionais. Em 2020 e 2021 vencem os atuais acordos do SOAR e do Gemini e fazem 10 anos do workshop promovido pelo LNA para avaliar a questão da infraestrutura observacional. Quais são os desafios científicos para a nova década e o que nossa comunidade precisa em termos de instrumentação para poder participar ativamente das respostas a estes desafios? Neste seminário não trazemos as respostas prontas a estas questões, mas sim levantamos a discussão e os pontos a serem discutidos para que toda a comunidade possa participar.

Palestrante:Dr. Bruno Castilho

Instituto:LNA

Data:2018-12-06

Hora:15:30

Local:Auditório do prédio Emmanuel Liais

Título:

Descrição:The attempt to unify all fundamental interactions resulted in the development of multidimensional theories like string derived field theories and related brane-world theories . Among these theories, there are some in which the gauge coupling constants may vary over cosmological timescales. On the other hand, a theoretical phenomenological framework based on first principles, was developed by Bekenstein and later improved by Barrow, Sandvik and Magueijo. Different versions of the theories mentioned above predict different time behaviours of the gauge coupling constants. On the other hand, many observational and experimental efforts have been made to establish constraints on such variations. The experimental research can be grouped into astronomical and local methods. The latter ones include geophysical methods such as the natural nuclear reactor that operated about 1.8e9 years ago in Oklo, and laboratory measurements with atomic clocks. The astronomical methods are based mainly on the analysis of high-redshift quasar absorption systems. In this talk, we will review the most relevant observational and experimental bounds on the variation of fundamental constants. Besides, we will show the predictions of some of the theories mentioned above and compare them with the observational bounds.

Palestrante:Susana Landau

Instituto:Universidad de Buenos Aires

Data:2018-11-29

Hora:15:30

Local:Auditório do prédio Emmanuel Liais

Título:The PAU Survey: Early demonstration of photometric redshift performance in the COSMOS field

Descrição:The PAU Survey (PAUS) is an innovative photometric survey with 40 narrow bands at the William Herschel Telescope (WHT). The narrow bands are spaced at 100 ansgstron intervals covering the range 4500to 8500 angstron and, in combination with standard broad bands, enable excellent redshift precision. This talk discuss the technique, galaxy templates and additional photometric calibration used to determine early photometric redshifts from PAUS. Using BCNZ2, a new photometric redshift code developed for this purpose, we characterise the photometric redshift performance using PAUS data on the COSMOS field. Comparison to secure spectra from zCOSMOS DR3 shows that PAUS achieves ?68/(1+z) = 0.0037 to iAB < 22.5 when selecting the best 50% of the sources based on a photometric redshift quality cut. Furthermore, a higher photo-z precision (?68 /(1+z) ~ 0.001) is obtained for a bright and high quality selection, which is driven by the identification of emission lines. We conclude that PAUS meets its design goals, opening up a hitherto uncharted regime of deep, wide, and dense galaxy survey with precise redshifts that will provide unique insights into the formation, evolution and clustering of galaxies, as well as their intrinsic alignments.

Palestrante:Martin Eriksen

Instituto:IFAE-PIC

Data:2018-11-22

Hora:12:00

Local:Seminários - http://www.linea.gov.br/seminarios/

Título:A new universe of online data

Descrição:SciServer (www.sciserver.org) is an online system for scientific research and education with big data. The system offers access to several Petabyte-scale scientific datasets in fields ranging from astronomy to turbulence to genomics, along with a set of simple but powerful browser-based tools to visualize and analyze those datasets. The power of SciServer lies in its close connection to datasets like the Sloan Digital Sky Survey (SDSS), allowing for simple, fast analysis with minimal setup. The SciServer Dashboard offers quick access to all SciServer tools and datasets, and to all prior work within the system. All users up to 10 GB of file and database storage space – and through the Dashboard, users can manage uploaded data files, and can create collaborative groups to share datasets and scripts publicly or with selected colleagues. SciServer makes it easy to share exactly the right data with exactly the right people. SciServer’s Compute tool enables online computational analysis of big data through Jupyter notebooks. With only a few clicks, a user can create a customized environment on fast, high-memory virtual machines hosted by IDIES, where they can write or upload Python, R, or Matlab scripts to perform all sorts of data-intensive tasks. Importantly, SciServer allows these scripts to be run in either interactive or batch mode, meaning that even the most demanding data-intensive analyses can be completed with ease. To help scale up research quickly, SciServer Compute features a wealth of “getting started” data files and example notebooks that can be adapted to meet researchers’ needs.
In addition to SciServer’s obvious potential for data-intensive science and engineering research, the system has been used effectively in many educational settings, particularly as data-intensive lab activities for undergraduate science courses. Learners get immediate access to high-performance computing resources without the need to install and configure software. A new set o

Palestrante:Jordan Raddick

Instituto:The Johns Hopkins University

Data:2018-11-08

Hora:14:00

Local:Página do LIneA - http://www.linea.gov.br/
Seminários - http://www.linea.gov.br/seminarios/