Título:Cosmic Shear in the Year-3 DES data: 2-point and 3-point correlations

Descrição:The cosmology analyzes of the Year-3 (Y3) data from the Dark Energy Survey (DES) is at full speed ahead. Our preliminary weak lensing sample contains 120 million objects over 4200 square degrees of sky and is the largest shape catalog to date. This statistical power comes at a price: the cosmic shear measurements are more sensitive not only to the signal but also to potential systematics. In this talk, I will present our prospects for the 2-point cosmic shear cosmology analysis and some of the leading systematics that must be under control, in particular the Intrinsic Alignment of galaxies. Additionally, I will talk about a preliminary detection of a shear 3-point correlation in the DES-Y3 simulations and data which is unprecedented in weak lensing surveys.

Palestrante:Luccas Secco

Instituto:UPenn

Data:2019-11-21

Hora:11:00

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

Título:Decrypting the Large Scale Structure of the Universe with spectroscopic surveys: BOSS, eBOSS and DESI

Descrição:Spectroscopic surveys provided a unique opportunity to explore the large-scale structure in the Universe, in particular they have been conceived to study one of the most important questions of modern cosmology: the nature of dark energy. During this seminar I will review three spectroscopic surveys: BOSS, eBOSS and DESI.In the first part I will explain the observables that we can use to learn dark energy: the Baryons Acoustic Oscillations(BAO) and the Redshift Space Distortions (RSD). In the second part, I will focus to present the latest eBOSS results from the full shape analysis that includes de Redshift Space Distortions as well as the Alcock Paczinsky parameters with the Luminous Red Galaxy sample Data Release 14. In the third part I will present how we can use galaxy redshift surveys to explore other physics than dark energy, in particular to constrain properties of neutrinos. Neutrinos were a dominant component of the energy density in the early universe and, therefore, played an important role in the evolution of cosmological perturbations. In particular neutrinos imprint a temporal phase of sound waves in the primordial plasma. I will present the first constraint on this neutrino-induced phase shift in the spectrum of baryon acoustic oscillations of the BOSS DR12 data.

Palestrante:Mariana Vargas-Magana

Instituto:UNAM

Data:2019-11-14

Hora:11:00

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

Título:Teen Astronomy Cafés

Descrição:The National Optical-Infrared Astronomy Research Laboratory (formerly NOAO) started the Teen Astronomy Cafés program to excite the interest of talented youth in STEM. One Saturday a month during the academic year, high school students interact with expert astronomers who work with big data. Students learn about killer asteroids, exoplanets, lives and deaths of stars, variable stars, black holes, the structure of the universe, gravitational lensing, dark matter, colliding galaxies, and more. The format for the cafés is a short presentation by an astronomer, a computer-based lab activity and a discussion during lunch. Presently, 50% of the students are from schools with failing grades (by the Arizona Department of Education). Over 50% are girls. Our science cafés demonstrate that scientists play a key role in increasing student interest and curiosity about science research and in helping students get a sense of scientists as people. The cafés also demonstrate that scientists can help students see how research connects with issues important to society and with students’ daily lives.

Palestrante:Connie Walker

Instituto:NOAO

Data:2019-11-07

Hora:15:00

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

Título:Microssísmica e Geofísica Terrestre aplicada a Barragem de Mineração

Descrição:A mineração vem enfrentando o desafio operacional de garantir a continuidade de suas atividades envolvidas na extração dos depósitos minerários sem causar danos físicos às estruturas geotécnicas que circundam as áreas de lavra como: cavas, pilhas de estéril e barragens de rejeito. Diante da necessidade do maior entendimento do comportamento geotécnico de suas estruturas, a mineração tem buscado programas de monitoramento eficazes e eficientes. Nesse contexto, a geofísica fornece um conjunto de metodologias investigativas que indicam, por meio da detecção de contrastes físicos, como a estrutura está no momento de aquisição. Por outro lado, o monitoramento microssísmico é capaz de detectar a ocorrência de sismos com magnitude superiores a -2, além de utilizar o ruído ambiente para monitorar continuamente as mudanças de velocidade de propagação de ondas sísmicas no meio, associadas a mudanças em sua rigidez.

Palestrante:Camilla Tavares Rodrigues

Instituto:Tetratech - Belo Horizonte/MG

Data:0000-00-00

Hora:13h

Local:Auditório Emmanuel Liais