Início » Ciência » Webinars » Apresentações » 2016
15/12 - 04:00 pm
Frossie Economou
Abstract ⓘ
Abstract
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Frossie Economou
Title
It’s 10pm - do you know where your data are? (LSST)
Abstract
Data management in astronomy has undergone a series of radical transformations in living memory. While much of that has been because of the evolution of computing itself, the demands of astronomical processing have sometimes led ahead and sometimes lagged behind the capabilities of commodity IT. This talk is a personal view on how current developments in cloud computing are affecting the landscape of data processing and data publication, and what we can learn about past experiences to best take advantage of new trends in platforms and software engineering. I’m also going to share some practical lessons learned drawn from engaging with the commodity computing landscape within LSST’s Science Quality and Reliability Engineering (SQuaRE) team.
Slides not available
08/12 - 12:00 pm
William Nielsen Brandt
Abstract ⓘ
Abstract
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William Nielsen Brandt
Title
Supermassive Black Hole Studies with the LSST (Penn State University)
Abstract
Data from the Large Synoptic Survey Telescope (LSST) will enable multiple breakthrough investigations of active galactic nuclei (AGNs) as well as typically dormant supermassive black holes (SMBHs). I will describe how the decade-long LSST main survey will discover at least 20 million AGNs across 18,000 deg^2, obtaining 60-180 visits per source for each of the ugrizy filters. Several extragalactic LSST Deep-Drilling Fields will provide even deeper coverage and denser temporal sampling for about a hundred thousand AGNs. Efficient AGN identification from z = 0-7.5 will be possible via a combination of techniques: color selection, variability selection, lack of proper motion, differential chromatic refraction patterns, and multiwavelength matching. I will also describe a few of the prime SMBH science investigations that LSST will enable including (1) massive investigations of AGN variability, (2) studies of transient SMBH fueling events, and (3) the identification of large AGN samples at high redshifts.
07/12 - 03:00 pm
Mario Juric
Abstract ⓘ
Abstract
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Mario Juric
Title
LSST Data Spaces: Access, Visualization, and Analysis of LSST Datasets (University of Washington/LSST)
Abstract
The LSST will deliver two primary classes of data products: the near-real time stream of alerts to changes in the sky (so called \\\\\\\"Level 1” products), and the annual, systematics limited, reprocessing of the entire data sets (so called “Level 2” products, the \\\\\\\"Data Releases”). The scale of both of these products, but especially Level 2 (~few petabytes), will stress the ability of the users to download and analyze on their laptop. The LSST is therefore building a system to make it possible to perform some of the visualization and data analysis remotely. This environment, currently envisioned to be based on well known tools such as JupyterHub, will enable users to engage in interactive analysis (or run their analysis codes) at the LSST data center. Through it, the users will have access to fast database space, file storage, as well as a medium-scale computing cluster. In this talk, I will discuss our plans for such an environment -- a “data space” in which research with LSST data could be performed, and added value (“Level 3”) data products created.
01/12 - 02:00 pm
Jeff Newman
Abstract ⓘ
Abstract
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Jeff Newman
Title
The Future of Ground-Based Astronomy in the US (University of Pittsburgh)
Abstract
In this talk, I will summarize the results of two different efforts to determine how the US can best leverage the large upcoming surveys from DESI and LSST: the National Science Foundation-requested Kavli/NOAO/LSST report and the US Department of Energy-requested Cosmic Visions report. I will attempt to lay out the landscape of what observational resources may be available in the next decade and beyond. I will particularly focus on a project at the intersection of these two reports, a Southern Spectroscopic Survey Instrument (SSSI).
24/11 - 11:00 am
Luiz Nicolaci da Costa
Abstract ⓘ
Abstract
×Speaker
Luiz Nicolaci da Costa
Title
BPG-LSST: motivação, filosofia, organização e objetivos (LIneA)
Abstract
Nesta apresentação a motivação, filosofia, organização e objetivos para a formação do BPG-LSST serão discutidos. Alguns aspectos sobre o projeto LSST e o acordo que permitiu a participação deste grupo no LSST também serão apresentados. Finalmente, a importância de que o trabalho do BPG seja coordenado será enfatizada. Ao final da apresentação perguntas e comentários são bem vindos.
Slides not available
17/11 - 04:00 pm
Ashish Mahabal
Abstract ⓘ
Abstract
×Speaker
Ashish Mahabal
Title
The LSST Informatics and Statistics Science Collaboration: Activity at the SAMSI ASTRO Program (Caltech)
Abstract
We will describe activity taking place as part of the year-long Program on Statistical, Mathematical and Computational Methods for Astronomy (ASTRO) at the Statistical and Applied Mathematical Sciences Institute (SAMSI). ASTRO hosts five working groups covering several topics in astrostatistics relevant to LSST science. We will provide an overview of activity in WG2 (Synoptic Time Domain Surveys), WG3 (Multivariate and Irregularly Sampled Time Series), and WG4 (Astrophysical Populations). WG2 has a number of subgroups covering setting up a data challenge, light-curve decomposition, incorporating ancillary information, outlier detection etc.. WG3 is covering time series topics arising in gravitational wave, exoplanet, and synoptic survey astronomy. WG4 is so far focusing on population studies for exoplanets, but is also covering science and methods relevant to LSST. An interesting area of overlap between WG3 and WG4 is the statistical area of functional data analysis (FDA): how to do statistics with populations of functions, rather than of scalars or small, fixed-length vectors (as in luminosity function estimation). Working Groups mostly meet remotely; some subgroups will become active only after the New Year, providing opportunities for new participants to join in some areas. Ashish Mahabal (Caltech) and Tom Loredo (Cornell University)
17/11 - 04:00 pm
Tom Loredo
Abstract ⓘ
Abstract
×Speaker
Tom Loredo
Title
The LSST Informatics and Statistics Science Collaboration: Activity at the SAMSI ASTRO Program (Cornell University)
Abstract
We will describe activity taking place as part of the year-long Program on Statistical, Mathematical and Computational Methods for Astronomy (ASTRO) at the Statistical and Applied Mathematical Sciences Institute (SAMSI). ASTRO hosts five working groups covering several topics in astrostatistics relevant to LSST science. We will provide an overview of activity in WG2 (Synoptic Time Domain Surveys), WG3 (Multivariate and Irregularly Sampled Time Series), and WG4 (Astrophysical Populations). WG2 has a number of subgroups covering setting up a data challenge, light-curve decomposition, incorporating ancillary information, outlier detection etc.. WG3 is covering time series topics arising in gravitational wave, exoplanet, and synoptic survey astronomy. WG4 is so far focusing on population studies for exoplanets, but is also covering science and methods relevant to LSST. An interesting area of overlap between WG3 and WG4 is the statistical area of functional data analysis (FDA): how to do statistics with populations of functions, rather than of scalars or small, fixed-length vectors (as in luminosity function estimation). Working Groups mostly meet remotely; some subgroups will become active only after the New Year, providing opportunities for new participants to join in some areas. Ashish Mahabal (Caltech) and Tom Loredo (Cornell University)
03/11 - 05:00 pm
Masao Sako
Abstract ⓘ
Abstract
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Masao Sako
Title
Exploring the Transient Sky with the Dark Energy Survey (University of Pennsylvania)
Abstract
Slides not available
27/10 - 10:00 am
Koenraad Kuijken
Abstract ⓘ
Abstract
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Koenraad Kuijken
Title
Cosmology with the KiDS weak lensing survey (Leiden Observatory)
Abstract
The Kilo-Degree Survey (KiDS) is mapping 1500 square degrees of sky using the ESO VLT Survey Telescope, a wide-field imaging telescope on Paranal. I will discuss the recent results presented in Hildebrandt et al (2016, 1606.05338) from a tomographic analysis of the matter power spectrum using weak gravitational lensing, as well as the implications of the measurements for cosmology.
20/10 - 11:00 am
Federica Bianco
Abstract ⓘ
Abstract
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Federica Bianco
Title
The transient sky and LSST (NYU Center for Urban Science and Progress)
Abstract
I will review the many scientific topics on transient and variable sky in which members of our collaboration are world-leading experts, from geometric transits to nuclear explosions, and give a brief overview of the expected and wished for results LSST could provide, and of the work needed to do to assure LSST\\\\\\\'s potential to explore the transient sky is unleashed.
13/10 - 10:00 am
Ivan Minchev
Abstract ⓘ
Abstract
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Ivan Minchev
Title
New results from the APOGEE survey and their interpretation using a Milky Way chemo-dynamical model (Astrophysical Institute Potsdam (AIP))
Abstract
One of the central questions of Galactic astrophysics is how galaxies form and evolve. The galaxy we can study in detail like no other is our own Milky Way. To this end, a number of ground-based spectroscopic and photometric Galactic surveys have been planned or currently ongoing. The Gaia DR1 is already complementing some of these (RAVE, APOGEE) with accurate proper motions and parallaxes. I will present recent observational results from the near-infrared spectroscopic survey APOGEE, which I will interpret using a chemo-dynamical model tailored to the Milky Way. I will argue that to break degeneracy among different Galactic evolution scenarios we need accurate stellar ages, such as those obtained through asteroseismology by the CoRoT and Kepler missions.
Slides not available
06/10 - 01:00 pm
Lucianne Walkowicz
Abstract ⓘ
Abstract
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Lucianne Walkowicz
Title
An Overview of the LSST Science Collaborations (Adler Planetarium - LSST Science Collaboration Coordinator)
Abstract
The LSST Science Collaborations are topical working groups of international scientists, who work together to provide scientifically-motivated feedback to survey implementation, develop software and data products to enable LSST science, and organize follow-up and analysis resources in preparation for LSST\\\'s first light. In this talk, I will discuss the structure of the science collaborations, their current activities, and how new LSST members can join the thriving collaboration community.
29/09 - 10:00 am
Marc Huertas-Company
Abstract ⓘ
Abstract
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Marc Huertas-Company
Title
Mass assembly and morphological transformations since z~3 (Observatoire de Paris)
Abstract
The life of a galaxy is a balance between processes that trigger star formation by accelerating gas cooling and others which tend to prevent stars to form by expelling or heating gas. Over the past years, the picture is emerging that, during most of its life, a galaxy seems to live a rather quiet life, gradually growing in stellar mass through the formation of new stars which are formed at a rate remarkably proportional to its stellar mass, This is interpreted as an indirect evidence that fuel in the form of cold gas is somehow continuously being fed into the galaxies to sustain star formation. Two major events, eventually related, can break this apparent equilibrium. An episode of high star formation activity (e.g starburst) can be triggered. Or, suddenly something might happen that prevents the galaxy to continue forming new stars. Quenching is probably the most important event that a galaxy experiences during its life and a fundamental mechanism that helps understanding most of the properties of our surrounding Universe. There are a variety of different mechanisms entertained for the quenching process, e.g. feedback, interactions, halo driven shock heating, morphological quenching etc. Which one is dominantly driving galaxy evolution (if there is) or under which circumstances one or another process is triggered is still a mystery. In my talk I will focus on the relation between structure and quenching in massive galaxies. By using advanced machine intelligence techniques, I will analyze the relation between quenching and bulge growth in massive galaxies from z~3. I will in fact show evidences of two distinct channels for the growth of bulges in the massive end of the present day Hubble sequence (Huertas-Company+15ab).
22/09 - 02:00 pm
Alexander Mead
Abstract ⓘ
Abstract
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Alexander Mead
Title
The halo model and cosmological power spectra (University of British Columbia)
Abstract
Cosmological weak gravitational lensings surveys use the correlated distortions of galaxy shapes to infer properties of the matter distribution in the Universe. In principle, these measurements may then be used to constrain theories of the accelerated expansion, to infer the neutrino mass, and to learn about baryonic feedback processes. However, the interpretation of weak lensing data is complicated by the fact that non-linear structure along the line-of-sight contributes to the lensing signal. In this talk I will discuss how to model the non-linear matter distribution using N-body simulations and analytical techniques.
25/08 - 11:00 am
Yuanyuan Zhang
Abstract ⓘ
Abstract
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Yuanyuan Zhang
Title
Understanding Cluster Central Galaxies with the Dark Energy Survey (Fermilab)
Abstract
Galaxy clusters are important subjects of study for both cosmology and astrophysics research. Ongoing optical surveys like the Dark Energy Survey (DES) are observing tens of thousands of clusters to redshift 1.0 and beyond. The evolution of cluster central galaxies is one topic that will benefit from the statistical power of DES data. The LambdaCDM model provides the big picture explanation for the formation of cluster galaxies. However, astrophysical processes like in situ star formation, stripping and disruption are critical in shaping the galaxies’ properties. In this webinar, I will present studies about cluster central galaxies with DES data. I will also discuss the high redshift prospect of the topic, utilizing the discovery power of DES on z > 1.0 clusters.
23/08 - 02:00 pm
Angelo Fausti
Abstract ⓘ
Abstract
×Speaker
Angelo Fausti
Title
O Portal Científico: Uma ferramenta para analisar dados de grandes levantamentos astronômicos (LIneA/LSST)
Abstract
Nesta apresentação o atual status do portal científico sendo desenvolvido nos últimos oito anos pelo LIneA é revisto. O objetivo do portal é permitir ao pesquisador explorar de uma forma eficiente o grande volume de dados sendo gerados pelos grandes levantamentos astronômicos. Ele foi concebido para atender as necessidades do DES, mas pode ser facilmente estendido para atender as necessidades de pesquisadores envolvidos na análise de simulações numéricas e de dados na era do LSST
18/08 - 12:00 pm
Alex Drlica-Wagner
Abstract ⓘ
Abstract
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Alex Drlica-Wagner
Title
Fundamental Physics with the Smallest Galaxies (Fermilab)
Abstract
The population of Milky Way satellite galaxies includes the least luminous, least chemically evolved, and most dark matter dominated galaxies in the known universe. Due to their proximity, high dark matter content, and low astrophysical backgrounds, dwarf spheroidal galaxies are unique probes of cosmology and promising targets for indirect searches for dark matter. Prior to 2015, roughly two dozen dwarf spheroidal galaxies were known to surround the Milky Way. Since the beginning of last year, new optical imaging surveys have discovered over twenty new dwarf galaxy candidates, potentially doubling the population of Milky Way satellite galaxies in a single year. I will discuss recent optical searches for dwarf galaxies, focusing specifically on results from the Dark Energy Survey (DES) and the implications for gamma-ray searches for dark matter annihilation with the Fermi Large Area Telescope.
11/08 - 12:00 pm
Eric Baxter
Abstract ⓘ
Abstract
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Eric Baxter
Title
New Methods for Measuring the Masses of Galaxy Clusters (UPenn)
Abstract
Clusters of galaxies are the most massive gravitationally bound structures in the Universe. The abundance of these rare objects is very sensitive to cosmological parameters such as the equation of state of dark energy. However, exploiting the full power of galaxy clusters as cosmological probes requires accurate constraints on their masses. In this talk, I will describe two relatively new but potentially powerful approaches to constraining the masses of galaxy clusters: gravitational lensing of the Comic Microwave Background and cluster clustering.
Slides not available
04/08 - 12:00 pm
Edmond Cheung
Abstract ⓘ
Abstract
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Edmond Cheung
Title
Suppressing star formation in quiescent galaxies with supermassive black hole winds (Kavli IPMU)
Abstract
Quiescent galaxies with little or no ongoing star formation dominate the population of galaxies with masses above 2 × 10^10 M_sun; the number of quiescent galaxies has increased by a factor of about 25 over the past ten billion years. Once star formation has been shut down, perhaps during the quasar phase of rapid accretion onto a supermassive black hole, an unknown mechanism must remove or heat the gas that is subsequently accreted from either stellar mass loss or mergers and that would otherwise cool to form stars. Energy output from a black hole accreting at a low rate has been proposed, but observational evidence for this in the form of expanding hot gas shells is indirect and limited to radio galaxies at the centres of clusters, which are too rare to explain the vast majority of the quiescent population. In this talk, we report bisymmetric emission features co-aligned with strong ionized-gas velocity gradients from which we infer the presence of centrally driven winds in typical quiescent galaxies that host low-luminosity active nuclei. These galaxies are surprisingly common, accounting for as much as ten per cent of the quiescent population with masses around 2 × 10^10 times that of the Sun. In a prototypical example, we calculate that the energy input from the galaxy’s low-level active supermassive black hole is capable of driving the observed wind, which contains sufficient mechanical energy to heat ambient, cooler gas (also detected) and thereby suppress star formation.
Slides not available
28/07 - 02:00 pm
Lindsay Bleem
Abstract ⓘ
Abstract
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Lindsay Bleem
Title
Constraining Cosmology using Galaxy Clusters in the SPT-SZ Survey (Argonne National Laboratory)
Abstract
Galaxy clusters are powerful tools with which to constrain cosmological models as their abundance depends upon both the expansion history of the universe and the growth of density fluctuations. In this talk, I will describe the ongoing program by the South Pole Telescope collaboration to test such models using a sample of massive clusters identified in the SPT-SZ survey. One of the primary objectives of this 2500-square-degree mm-wavelength survey was the construction of a mass-limited sample of galaxy clusters identified via the thermal Sunyaev- Zel’dovich (SZ) effect (through which clusters imprint small temperature distortions on the cosmic microwave background). I will describe the galaxy cluster sample, efforts to improve understanding of the mass-calibration of cluster observables, as well as our newly-published cosmological constraints. Finally, there is a wealth of information that can be extracted from analyses of clusters using multi-wavelength data such as from the SPT and the optical-wavelength Dark Energy Survey. I will highlight several such ongoing projects.
Slides not available
21/07 - 12:00 pm
Adriano Pieres
Abstract ⓘ
Abstract
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Adriano Pieres
Title
The Magellanic Clouds outer regions (UFRGS)
Abstract
The Magellanic Clouds (composed by the Large and the Small Magellanic Cloud) are the most luminous and largest dwarf galaxies satellites of the Milky Way. In its first infall towards the Galaxy, they are a rich laboratory to study the star formation, the galactic evolution and its geometry. The Magellanic Clouds present a strong interaction between LMC-SMC in the last Gyrs, forming the Magellanic Bridge (a bridge of gas, stars and clusters linking SMC and LMC) and the Magellanic Stream (a gas strip spanning at least 200 degrees on the sky). In this talk, beyond a brief review of Magellanic System I will present our main results about the outer LMC star clusters covered by Dark Energy Survey: the discovery of 28 new clusters, the age distribution and the age-metallicity relationship for a sample of 117 clusters.
Slides not available
14/07 - 10:00 am
Juan Garcia-Bellido
Abstract ⓘ
Abstract
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Juan Garcia-Bellido
Title
Gravitational Waves from Primordial Black Holes as Dark Matter (Universidad Autónoma de Madrid)
Abstract
Twenty years ago, we predicted that primordial black holes would form via the gravitational collapse of matter associated with peaks in the spectrum of fluctuations, and that they could constitute all of the dark matter today. More recently, we predicted the mass distribution of PBH, which peaks at 50 Msun and whose tails could be responsible for the seeds of galaxies. LIGO has recently detected gravitational waves from the inspiraling of two 30 Msun black holes. In arXiv:1603.05234, we propose that LIGO has actually detected dark matter in the form of PBH, and predict that within 10 years, an array of GW detectors (i.e. LIGO, VIRGO, KAGRA, INDIGO, etc.) could be used to determine the mass distribution of PBH dark matter with 10% accuracy.
Slides not available
23/06 - 02:00 pm
Joel Primack
Abstract ⓘ
Abstract
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Joel Primack
Title
New Insights on Galaxy Formation from Observations and Simulations (University of California, Santa Cruz)
Abstract
Large-scale simulations track the evolution of structure in the ΛCDM universe of dark energy and cold dark matter on scales of billions of light years, and cosmological zoom-in simulations model how individual galaxies evolve through the interaction of baryonic matter and dark matter. New large-scale simulations based on the latest cosmological parameters are being used in novel ways to predict the rate of star formation and the distribution of galaxies with various properties across cosmic time. Astronomers used to think (1) that galaxies are a combination of stellar disks and spheroids, like nearby galaxies; (2) that galaxies are mostly smooth (the largest lumps in the Milky Way are globular clusters and giant molecular clouds, each with a maximum mass about a million times the mass of the sun); and (3) that galaxies mostly grow in radius as they grow in mass. New discoveries from CANDELS, the biggest-ever Hubble Space Telescope program, have shown that all three are wrong! Instead, by comparing zoom-in galaxy simulations with CANDELS observations, we have found that (1) most galaxies start elongated (zucchini-shaped) and only later become rounder as their centers become dominated by baryonic matter; (2) most star-forming galaxies in the early universe have giant clumps of stars with masses of a hundred million solar masses or more; and (3) forming galaxies sometimes undergo a period of rapid shrinkage in the radius that encloses half their light as they grow in mass, a process that we call “compaction”. New telescopes including James Webb Space Telescope will no doubt lead to further insights on structure formation in the universe.
Slides not available
16/06 - 10:00 am
Francisco “Fubica” Vilar Brasileiro
Abstract ⓘ
Abstract
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Francisco “Fubica” Vilar Brasileiro
Title
Executando Aplicações Científicas em uma Federação de Nuvens Computacionais Privadas (Universidade Federal de Campina Grande)
Abstract
O paradigma de computação na nuvem vem revolucionando a forma como as pessoas passaram a atender as suas demandas computacionais. Ao invés de implantar suas próprias instalações, os usuários podem recorrer a provedores de computação na nuvem de acesso público, como Amazon Web Services, Microsoft Azure e Google App Engine para implantar, sob demanda, infraestruturas computacionais customizadas para seus propósitos específicos, que podem ser rapidamente comissionadas e depois desmanteladas, pagando apenas pelo custo da infraestrutura durante o período de tempo em que a mesma foi utilizada. Esse modelo não só agiliza a implantação de infraestruturas, mas pode também significar enormes economias para o usuário. Em uma escala menor, organizações que já têm uma infraestrutura computacional própria podem usar tecnologias similares às usadas pelos provedores de computação na nuvem de acesso público para prover um serviço equivalente voltando para seus usuários internos, ou seja, transformando-se em provedores de computação na nuvem de acesso privado. Nesse caso, por um lado as vantagens de rápido provisionamento continuam sendo oferecidas aos usuários internos, enquanto por outro lado a infraestrutura compartilhada entre os vários usuários da organização pode ser melhor aproveitada, reduzindo o custo de implantação e operação da mesma. Nesse webminar eu irei falar sobre as tecnologias que podem ser usadas para implantação de provedores de computação na nuvem de acesso privado, como essas infraestruturas podem ser usadas para dar suporte à execução de aplicações científicas e como nuvens computacionais de várias organizações podem ser federadas para oferecer ainda mais recursos e de forma mais eficiente. O webminar apresentará exemplos de uso de nuvem privada baseada no Openstack, enquanto que a Nuvem Acadêmica Federada, um serviço experimental operado pela UFCG com apoio da RNP, será usada para exemplificar o uso de uma federação de nuvens computacionais acadêmicas.
Slides not available
09/06 - 10:00 am
Jonathan Loveday
Abstract ⓘ
Abstract
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Jonathan Loveday
Title
Galaxy and Mass Assembly (GAMA): Small scale anisotropic galaxy clustering and the pairwise velocity dispersion of galaxies (University of Sussex)
Abstract
The Galaxy and Mass Assembly (GAMA) survey provides an unprecedented database for detailed study of galaxies in the nearby (z < 0.5) Universe by combining imaging data from UV to radio and highly-complete spectroscopy to r = 19.8 mag. I will briefly summarise the current status of the GAMA survey and present some key results. I will then describe some work in progress to characterise the galaxy pairwise velocity dispersion to smaller scales than has hitherto been possible, and how such measurements may in future place stringent constraints on modified gravity models.
Slides not available
02/06 - 10:00 am
Fabricio Ferrari
Abstract ⓘ
Abstract
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Fabricio Ferrari
Title
Morfometryka — A New Way of Establishing Morphological Classification of Galaxies (FURG)
Abstract
We present an extended morphometric system to automatically classify galaxies from astronomical images. The new system includes the original and modified versions of the CASGM coefficients (Concentration $C1$ , Asymmetry $A_3$ , and Smoothness $S_3$ ), and the new parameters entropy, $H$, and spirality $\\\\sigma\\\\psi$. The new parameters $A_3$ , $S_3$ , and $H$ are better to discriminate galaxy classes than $A_1$ , $S_1$ , and $G$, respectively. The new parameter $\\\\sigma_psi$ captures the amount of non-radial pattern on the image and is almost linearly dependent on T-type. Using a sample of spiral and elliptical galaxies from the Galaxy Zoo project as a training set, we employed the Linear Discriminant Analysis (LDA) technique to classify EFIGI (Baillard et al. 4458 galaxies), Nair & Abraham (14,123 galaxies), and SDSS Legacy (779,235 galaxies) samples. The cross-validation test shows that we can achieve an accuracy of more than 90\\\\% with our classification scheme. Therefore, we are able to define a plane in the morphometric parameter space that separates the elliptical and spiral classes with a mismatch between classes smaller than 10\\\\%. We use the distance to this plane as a morphometric index ($M_i$) and we show that it follows the human based T-type index very closely. We calculate morphometric index M i for ∼780k galaxies from SDSS Legacy Survey–DR7. We discuss how M i correlates with stellar population parameters obtained using the spectra available from SDSS–DR7. We discuss two science cases. We apply the morphometric system together with photometric analysis to discriminate classical from pseudo bulges in a sample of $\\\\sim$1000 SDSS galaxies from Gadotti (2009). Also, we compare morphometry and kinemtics for CALIFA survey galaxies.
Slides not available
19/05 - 02:00 pm
Roberto Souto
Abstract ⓘ
Abstract
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Roberto Souto
Title
Supercomputador Santos Dumont: ambiente computacional petaflópico para pesquisa científica no Brasil (LNCC)
Abstract
O supercomputador Santos Dumont (SDumont) possui capacidade instalada de processamento na ordem de 1,1 Petaflop/s, apresentando uma configuração híbrida de nós computacionais, no que se refere à arquitetura de processamento paralelo disponível. A chegada de uma máquina deste porte, possibilita aos pesquisadores do país realizarem experimentos e simulações, em uma escala de grandeza que não seria factível com os recursos computacionais para pesquisa disponíveis no Brasil até então. Nesta palestra iremos abordar aspectos tais como a configuração dos nós computacionais, as políticas de alocação de recursos implementadas, e alguns detalhes sobre a operação da máquina até o momento.
Slides not available
05/05 - 10:00 am
William Hartley
Abstract ⓘ
Abstract
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William Hartley
Title
Modelling photo-z in current and future imaging dark energy experiments (University College London)
Abstract
There are a number of ambitious ongoing and forthcoming cosmological experiments utilizing information contained within multiple broadband images of galaxies. Among the most important measurable quantities in these surveys are the distances to the galaxies used for a weak lensing or BAO analysis via their photometric redshift. Two approaches are typically taken to the problem of deriving photo-z: modelling the galaxy population and using machine learning techniques to directly map from the photometry to the likely redshift. Machine learning methods are proving to be the more powerful presently, but face fundamental difficulties in the future due to the lack of spectroscopic information. It is vital, then, that modelling methods become competitive. In this webinar I will outline some of the major challenges and necessary developments in pursuit of this goal.
28/04 - 02:00 pm
Filipe Abdalla
Abstract ⓘ
Abstract
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Filipe Abdalla
Title
Using cross correlations for calibrating cosmology in with photometric redsfhit surveys (University College London)
Abstract
Using photometric redsfhits can be a very statistically useful comsological probe for large scale structure. I will show how we shoudl be able to make great advances in this area by in order to measure the neutrino mass. However calibration of the order of 10^-3 has to be achieved otherwise there will be a large cosmological bias. I will show how to perform a joint analysis in order to calibrate fully the photometric redsfhit sfor the next geenration of data including the Dark nenergy survey and Euclid.
Slides not available
14/04 - 10:00 am
Francisco Castander
Abstract ⓘ
Abstract
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Francisco Castander
Title
The PAUCamera and Survey (Institut de Ciències de l’Espai)
Abstract
PAUCam is new wide field imaging instrument that has been recently commissioned at the WHT telescope. PAUCam is equipped with 40 narrow band filters and 6 broad band filters. It has the capabilty of delivering accurate photometric redshifts. I will talk about the capabilities of the instrument and the PAU Survey that we are starting. The science case of PAUS is based on the combination of clustering and lensing observables.
Slides not available
07/04 - 10:00 am
Bhuvnesh Jain
Abstract ⓘ
Abstract
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Bhuvnesh Jain
Title
Lensing measurements of galaxies, voids and the CMB: tests of the standard cosmological model (University of Pennsylvania)
Abstract
I will show weak lensing results from the Sloan Digital Sky Survey and the Dark Energy Survey. We use new methods to measure the mass distribution and clustering of cosmic voids and the shapes of galaxy halos. With the Dark Energy Survey, we have made wide field mass maps and related the galaxy distribution to the lensing mass, including CMB lensing. Ideas that provide alternatives to the standard cosmological model include the possibility that gravity on large scales deviates from general relativity or that dark matter has new interactions. I will describe how a variety of measurements are used to pursue such new physics.
Slides not available
31/03 - 01:00 pm
Rita Tojeiro
Abstract ⓘ
Abstract
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Rita Tojeiro
Title
Unlocking the full potential of galaxy spectroscopic surveys (St. Andrews)
Abstract
The great era of massive galaxy spectroscopic surveys has opened many doors across galaxy evolution and observational cosmology studies. Accurate three-dimensional positions of millions of galaxies allow us to map the large-scale structure and expansion history of the Universe. In parallel, galaxy spectra allow us to infer many physical properties of galaxies, including their time-resolved star-formation histories. In this webinar I will show how combining these two probes – the large-scale structure and time-resolved star-formation histories – offers a unique perspective in helping us answer a variety of questions, from the growth rate of structure to halo assembly bias.
10/03 - 02:00 pm
Friedrich Anders
Abstract ⓘ
Abstract
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Friedrich Anders
Title
APOGEE, Archaeology and Asteroseismology (Potsdam)
Abstract
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) was designed to discover new terrain – by taking high-resolution infra-red spectra of red giants throughout the heavily obscured Galactic midplane. I will present some recent APOGEE results in terms of Galactic Archaeology and its synergies with asteroseismology. Finally, I will discuss science that will be possible with APOGEE-2 and by combining APOGEE with Gaia and K2 data, with a focus on projects with Brazilian involvement.
03/03 - 10:00 am
Roy Maartens
Abstract ⓘ
Abstract
×Speaker
Roy Maartens
Title
Cosmology with the SKA (Portsmouth and University of Western Cape)
Abstract
The Square Kilometre Array will be the world’s largest astronomy experiment in the next decades. It will open up a new era of cosmology, mapping the Universe on the largest scales in the radio. I will describe the different surveys planned with the SKA, and what we can expect to learn from these surveys.