All future seminars

Número de entradas: 5

28
Abril 2017

CosmoHub on Hadoop: a web portal to analyze and distribute massive cosmological data


Inicio: 12:00h
Ponente: Jorge Carretero (PIC )
Lugar: Sala Alberto Lobo (ICE building, Campus UAB)

We present CosmoHub, a web platform to perform interactive analysis of massive cosmological data without any SQL knowledge. CosmoHub is built on top of Apache Hive, which is an Apache Hadoop ecosystem component, which facilitates reading, writing, and managing large datasets.   CosmoHub is…
Inicio: 12:00h
Ponente: Jorge Carretero (PIC )
Lugar: Sala Alberto Lobo (ICE building, Campus UAB)

We present CosmoHub, a web platform to perform interactive analysis of massive cosmological data without any SQL knowledge. CosmoHub is built on top of Apache Hive, which is an Apache Hadoop ecosystem component, which facilitates reading, writing, and managing large datasets.   CosmoHub is hosted at the Port de Informació Científica (PIC) and currently provides support to several international cosmology projects such as the Euclid space ESA mission, the Dark Energy Survey (DES), the Physics of the Accelerated Universe (PAU) and the Marenostrum Institut de Ciències de l'Espai Simulations (MICE). More than two billion objects, from public and private data, as well as observed and simulated data, are available among all projects. In the last three an a half years more than 400 users have produced about 1500 custom catalogs occupying 2TB in compressed format.

CosmoHub allows users to access value-added data, to load and explore pre-built datasets and to create their own custom datasets through a guided process. All those datasets can be interactively explored using an integrated visualization tool which includes 1D histogram and 2D heatmap plots. In our current implementation, online analysis of datasets of a billion objects can be done in less than 25 seconds. Finally, all those datasets can be downloaded in three different formats: CSV.BZ2, FITS and ASDF.
12
Mayo 2017

Singularities in cosmology: theory and observations


Inicio: 12:00h
Ponente: Diego Sáez Gómez
Lugar: Sala de Conferencias Alberto Lobo

As pointed by the observations, the Universe expansion is increasing its speed. Nevertheless, how this acceleration works is still a mystery that has been called dark energy. On the other hand, General Relativity contains inherently singularities, which refer to singular points of the spacetime, i.e.…
Inicio: 12:00h
Ponente: Diego Sáez Gómez
Lugar: Sala de Conferencias Alberto Lobo

As pointed by the observations, the Universe expansion is increasing its speed. Nevertheless, how this acceleration works is still a mystery that has been called dark energy. On the other hand, General Relativity contains inherently singularities, which refer to singular points of the spacetime, i.e. geodesically incomplete spacetimes according to the usual definitions by Hawking and Ellis. Over the last years, some proposed dark energy models drive the universe towards one of these future "singularities", near which the laws of physics lose their validity. In this talk, I will review and show the physical features of these singularities and present a new one that encompasses all the future singularities. Then, I will present several phenomenological parameterizations of the Hubble expansion rate to model different types of singularities and use SN Ia, BAO and H(z) data to constrain how far in the future the singularity may be, and how good the models are in comparison with the concordance model in cosmology.
31
Mayo 2017

Cherenkov Telescope Arrays for Optical Astronomy: Intensity interferometry and imaging of stellar surfaces


Inicio: 12:00h
Ponente: Dainis Dravins (Lund Observatory)
Lugar: Sala Alberto Lobo

Optical imaging with microarcsecond resolution will reveal details on and around stellar surfaces but requires kilometer-scale interferometers.  Intensity interferometry, electronically connecting independent telescopes, has an error budget that relates to electronic time resolutions of nanoseconds…
Inicio: 12:00h
Ponente: Dainis Dravins (Lund Observatory)
Lugar: Sala Alberto Lobo

Optical imaging with microarcsecond resolution will reveal details on and around stellar surfaces but requires kilometer-scale interferometers.  Intensity interferometry, electronically connecting independent telescopes, has an error budget that relates to electronic time resolutions of nanoseconds and light-travel distances of centimeters or meters (rather than scales of an optical wavelength), circumventing issues of atmospheric turbulence.  Once pioneered by Hanbury Brown and Twiss, digital versions of this quantum-optical technique have now been demonstrated in the laboratory, reconstructing diffraction-limited images from measurements over hundreds of optical baselines.  Baselines up to a few km will soon become available with the Cherenkov Telescope Array (primarily built for gamma-ray studies), thus realizing an optical interferometer in software, somewhat analogous to that of ALMA at radio wavelengths.
09
Junio 2017

Obtaining precipitation information from Polarimetric GNSS radio occultation observables


Inicio: 12:00h
Ponente: Ramon Padullés Rulló (Institute of Space Sciences)
Lugar: Sala de Conferencias Alberto Lobo

The Earth observation satellite PAZ will be finally launched by the end of this year, thanks to the agreement signed between Hisdesat (the owner of the satellite) and SpaceX. PAZ will test the new Polarimetric Radio Occultation observation concept. During the last years, the theoretical framework of…
Inicio: 12:00h
Ponente: Ramon Padullés Rulló (Institute of Space Sciences)
Lugar: Sala de Conferencias Alberto Lobo

The Earth observation satellite PAZ will be finally launched by the end of this year, thanks to the agreement signed between Hisdesat (the owner of the satellite) and SpaceX. PAZ will test the new Polarimetric Radio Occultation observation concept. During the last years, the theoretical framework of the concept has been set, the feasibility of the technique has been proven and some applications have been investigated. In this talk I will briefly review the most relevant aspects of the technique, and I will focus on the characterization of the signal, describing the effects that electromagnetic waves emitted from the GPS undergo in their way to the receiver. A detailed set of simulations has been performed in order to test the performance of the retrieval algorithms, that allow us to obtain precipitation information from the differential phase measurements.  
16
Junio 2017

Anatomy of the archetypal protostellar shock L1157-B1


Inicio: 12:00h
Ponente: Gemma Busquet (Institut de Ciències de l'Espai (IEEC-CSIC))
Lugar: Sala Alberto Lobo, ICE

During the earliest protostellar stages of their formation, young stars generate fast collimated winds (or jets) which impact the parent molecular cloud through shock fronts.  Protostellar shocks play a crucial role in the chemical evolution of star-forming clouds because they induce in the surrounding…
Inicio: 12:00h
Ponente: Gemma Busquet (Institut de Ciències de l'Espai (IEEC-CSIC))
Lugar: Sala Alberto Lobo, ICE

During the earliest protostellar stages of their formation, young stars generate fast collimated winds (or jets) which impact the parent molecular cloud through shock fronts. 
Protostellar shocks play a crucial role in the chemical evolution of star-forming clouds because they induce in the surrounding medium large variation of temperature and density, which can locally activate endothermic gas-phase reactions, ionization processes, and evaporation/erosion of dust grains and their icy mantles. The nature and properties of these shocks and jets are a source of major debate. The launching mechanism of the jet, the role of the magnetic field, or the shock properties (i.e. ionization fraction) are some of the key questions that remain to be answered
Associated with a low-mass Class 0 protostar, L1157-B1 is a protostellar chemically rich bow-shock that has been extensively studied from the infrared to millimeter wavelengths.
In this talk I’ll review the most relevant aspects of protostellar shocks and for the particular case of the shock laboratory L1157-B1. I’ll also present the recent work we are conducting with several telescopes to obtain a comprehensive view of the bow-shock structure and shock chemistry. 
Institute of Space Sciences (IEEC-CSIC)

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08193 Barcelona.
Phone: +34 93 737 9788
Email: ice@ice.csic.es
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An institute of the Consejo Superior de Investigaciones Científicas

An institute of the Consejo Superior de Investigaciones Científicas
Affiliated with the Institut d'Estudis Espacials de Catalunya

Affiliated with the Institut d'Estudis Espacials de Catalunya