Past Pizza Lunches

Number of entries: 155

19
February 2016

The Sun as a laboratory for particle physics


Start: 12:30h
Speaker: Núria Vinyoles Vergés
Place: Sala Alberto Lobo - ICE (Campus UAB - Can Magrans S/N)

Stars have been widely used as laboratories for particle physics due to their extreme conditions not reproducible anywhere else. The presence of non-standard particles would change their structure and evolution through different channels (extra energy-loss, changes on the energy transport, ...) depending…
Start: 12:30h
Speaker: Núria Vinyoles Vergés
Place: Sala Alberto Lobo - ICE (Campus UAB - Can Magrans S/N)

Stars have been widely used as laboratories for particle physics due to their extreme conditions not reproducible anywhere else. The presence of non-standard particles would change their structure and evolution through different channels (extra energy-loss, changes on the energy transport, ...) depending on the nature of the particles considered. Those changes on the stars can be used to limit the parameter space of the particle properties.
The Sun is by far the best-known star. The solar structure, revealed by helioseismology and solar neutrinos, is well determined, and accurate solar models give us information about its past, present and future. For this reason, many studies have focused on using the Sun to test non-standard physics.
In this talk, I will introduce the Standard Solar Models, the main solar observations and how they can be used to give constrains on the properties of non-standard weakly interacting particles. In particular, I will present a new statistical analysis that combines the results of SSMs, helioseismology and solar neutrino observations to place upper limits on exotic particles. Some applications and results will be presented.
05
February 2016

The AAVSO as a Resource for Variable Star Research


Start: 12:30h
Speaker: Stella Kafka (American Association of Variable Star Observers; AAVSO)
Place: Sala de Conferencies Alberto Lobo

The AAVSO was formed in 1911 as a group of US-based amateur observers obtaining data in support of professional astronomy projects. Now, it has evolved into an International Organization with members and observers from both the professional and non-professional astronomical community, contributing photometry…
Start: 12:30h
Speaker: Stella Kafka (American Association of Variable Star Observers; AAVSO)
Place: Sala de Conferencies Alberto Lobo

The AAVSO was formed in 1911 as a group of US-based amateur observers obtaining data in support of professional astronomy projects. Now, it has evolved into an International Organization with members and observers from both the professional and non-professional astronomical community, contributing photometry to a public photometric database of about 22,000 variable objects, and using it for research projects. As such, the AAVSO’s main claim to fame is that it successfully engages backyard Astronomers, educators, students and professional astronomers in astronomical research. I will present the main aspects of the association and how it has evolved with time to become a premium resource for variable star researchers. I will also discuss the various means that the AAVSO is using to support cutting-edge variable star science, and how it engages its members in projects building a stronger international astronomical community.  
29
January 2016

The Dark Energy Spectroscopic Instrument


Start: 12:30h
Speaker: Francisco Javier Castander Serentill (Institut de Ciències de l'Espai (CSIC-IEEC))
Place: Alberto Lobo Conference Room (Campus UAB, Institut de Ciències de l'Espai, C/ de Can Magrans s/n)

The Dark Energy Spectroscopic Instrument (DESI) is a project to build a multifiber spectrograph, with the goal to obtain tens of millions of spectra to map the structure of the universe and study dark energy. The DESI instrument is a robotically-actuated, fiber-fed spectrograph capable of taking up…
Start: 12:30h
Speaker: Francisco Javier Castander Serentill (Institut de Ciències de l'Espai (CSIC-IEEC))
Place: Alberto Lobo Conference Room (Campus UAB, Institut de Ciències de l'Espai, C/ de Can Magrans s/n)

The Dark Energy Spectroscopic Instrument (DESI) is a project to build a multifiber spectrograph, with the goal to obtain tens of millions of spectra to map the structure of the universe and study dark energy. The DESI instrument is a robotically-actuated, fiber-fed spectrograph capable of taking up to 5,000 simultaneous spectra over a wavelength range from 360 nm to 980 nm. The fibers feed ten three-arm spectrographs with resolution R = λ/∆λ between 2000 and 5500, depending on wavelength. This powerful instrument will be installed at prime focus on the 4-m Mayall telescope in Kitt Peak, Arizona, along with a new optical corrector, which will provide a three-degree diameter field of view. The DESI collaboration will also deliver a spectroscopic pipeline and data management system to reduce and archive all data for eventual public use. Here, we will describe the contribution of our group that will provide the guiding and alignment sub-systems and the guiding software of the instrument.
15
January 2016

Chondritic asteroids: Scientific and technological opportunity from their meteorites


Start: 12:30h
Speaker: Marina Martínez Jiménez
Place: Sala de Conferencies Alberto Lobo (Edifici nou)

Meteorites are peaces broken from asteroids or even comets, but also from the Mars and the Moon. They are classified as iron (metal), stony (silicates), or stony-iron (equal proportions of metal and silicates). Chondrites (stony meteorites) are the most primitive and by far the most numerous, having…
Start: 12:30h
Speaker: Marina Martínez Jiménez
Place: Sala de Conferencies Alberto Lobo (Edifici nou)

Meteorites are peaces broken from asteroids or even comets, but
also from the Mars and the Moon. They are classified as iron (metal),
stony (silicates), or stony-iron (equal proportions of metal and
silicates). Chondrites (stony meteorites) are the most primitive and by
far the most numerous, having a quasi-solar composition and being
little-fractionated primordial materials. In the recent years, asteroids have grab the attention of scientific
community since they contain high amounts of valuable resources including
gold, platinum group metals, iron, nickel, rare earth elements, and water.
Hence, may not be surprising that some private companies start considering
mining them. We have analyzed whether undifferentiated asteroids are worth
mining in a not far future from the analyses of 56 chondrites by
inductively coupled plasma mass spectrometry technique. To develop proper
space missions for mining asteroids, other studies should be done as well
as a fully comprehension of the near-Earth asteroids population, taking
advantage of them when approaching to the Earth's orbit.
11
December 2015

Testing the Standard cosmological model with model-independent parametrizations: some issues


Start: 12:30h
Speaker: Diego Saez Gomez (Facultad de Ciencias, Universidad de Lisboa)
Place: Sala Alberto Lobo (ICE - Campus UAB)

Over the last years, several model-independent methods in cosmology have been proposed as a tool for reconstructing theoretical models departing from observational data. This may be used to test the Standard cosmological model and its comparison with other theories. One of such model-independent method…
Start: 12:30h
Speaker: Diego Saez Gomez (Facultad de Ciencias, Universidad de Lisboa)
Place: Sala Alberto Lobo (ICE - Campus UAB)

Over the last years, several model-independent methods in cosmology have been proposed as a tool for reconstructing theoretical models departing from observational data. This may be used to test the Standard cosmological model and its comparison with other theories. One of such model-independent method is the so-called cosmographic approach, which relies only in the homogeneity and isotropy of the Universe on large scales. In this talk, I will review some parametrizations of the dark energy equation of state, but particularly I will focus on the many shortcomings within the cosmographic approach, since it provides biased results depending on the auxiliary variable used in the series expansion and is unable to rule out models or adequately reconstruct theories with higher-order derivatives in either the gravitational or matter sector.
04
December 2015

Chasing Dark Energy with the Dark Energy Survey : Status and Early Science Results


Start: 12:30h
Speaker: Martin Crocce
Place: ICE seminar room

The Dark Energy Survey (DES) is a next-generation large galaxy survey designed to unravel the nature of the dark energy that powers the current accelerated expansion of the Universe. The DES collaboration built a 570 mega-pixel optical and near-infrared camera, DECam, with a large 3 deg$^2$ field of…
Start: 12:30h
Speaker: Martin Crocce
Place: ICE seminar room

The Dark Energy Survey (DES) is a next-generation large galaxy survey designed to unravel the nature of the dark energy that powers the current accelerated expansion of the Universe. The DES collaboration built a 570 mega-pixel optical and near-infrared camera, DECam, with a large 3 deg$^2$ field of view. DECam is set at the prime focus of the Víctor M. Blanco 4-meter telescope in at the Cerro Tololo Inter-American Observatory in Chile. Using DECam, DES will map 5000 deg$^2$ to a depth $I_{AB}\sim24$ and observe designated supernova survey fields at high cadence. These data will allow DES to measure positions, approximate redshifts, and shapes for 300 million galaxies, the light-curves of several thousand supernovae, and the masses of tens of thousands of galaxy clusters. DES will then use four main probes to study the properties of dark energy: galaxy clustering on large scales, weak gravitational lensing, galaxy-cluster abundance, and supernova distances. I will describe the early progress of the survey with brief highlights of the science analyses that have been completed so far. These include: large-scale galaxy clustering measurements (that will be discussed in more depth); significant detection of a cross-correlation with SPT CMB lensing maps; wide mass maps from weak gravitational lensing; galaxy-shear and shear-shear correlation function measurements; the characterization of DES galaxy clusters and SNe1a light-curves, among other results. I will finish by presenting the current status and the plans for the upcoming years.
27
November 2015

A new family of compact objects? Dark Compact Planets


Start: 12:30h
Speaker: Laura Tolos
Place: Sala de Conferencies Alberto Lobo (Edifici nou)

A new family of compact objects formed by dark matter admixed with neutron star matter and white dwarf material is investigated. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi gas. We obtain new stable solutions, dark compact planets. For weakly…
Start: 12:30h
Speaker: Laura Tolos
Place: Sala de Conferencies Alberto Lobo (Edifici nou)

A new family of compact objects formed by dark matter admixed with neutron star matter
and white dwarf material is investigated. We consider non-self annihilating dark
matter with an equation-of-state given by an interacting Fermi gas. We obtain new stable
solutions, dark compact planets. For weakly interacting dark matter, the dark compact
planets have Earth-like masses and radii from few Km to few hundred Km, whereas they
have Jupiter-like masses and radii of few hundred Km for the strongly interacting dark
matter case. The dark compact planets could be formed primordially and accrete white
dwarf material afterwards. They could be observed as exoplanets with unusually small
radii. Furthermore, we find that the recently observed 2 Msun pulsars set limits on the
amount of dark matter inside neutron stars which is, at most, 10^−6Msun.  
20
November 2015

On the Possibility of Quark Matter inside Compact Stars


Start: 12:30h
Speaker: Stiele, Rainer (University of Frankfurt)
Place: Sala de Conferencies Alberto Lobo (ICE)

Compact stars, generally known as ordinary neutron stars, are a unique laboratory for testing matter under extreme densities. The aim is to understand the interior of compact stars through their observables, such as the mass and typical radii. In this talk I will review different scenarios for…
Start: 12:30h
Speaker: Stiele, Rainer (University of Frankfurt)
Place: Sala de Conferencies Alberto Lobo (ICE)

Compact stars, generally known as ordinary neutron stars, are a unique
laboratory for testing matter under extreme densities. The aim is to
understand the interior of compact stars through their observables, such
as the mass and typical radii. In this talk I will review different scenarios for the composition of
compact stars, focussing in particular on the possibility of absolutely
stable strange quark matter. The relation of the equation of state that
specifies the matter properties and interactions and the corresponding
mass-radius relationship will be delineated. Theoretical and observational
constraints in the mass-radius diagram of compact stars will serve as
probe for the existence of quark stars.  
13
November 2015

Modelling of galaxy emission with 3D dust radiative transfer


Start: 12:30h
Speaker: Giovanni Natale (Post-doctoral Research Associate, University of Central Lancashire Jeremiah Horrocks Institute, Preston, UK)
Place: Sala de Conferencies Alberto Lobo (ICE)

Interstellar dust strongly affects the appearance of galaxies within a wide range of wavelengths. In fact, dust both absorbs and scatters stellar light, which dominates the emission in the UV to near-IR range, and it re-emits the absorbed stellar luminosity in the infrared-submm regime. The complex propagation…
Start: 12:30h
Speaker: Giovanni Natale (Post-doctoral Research Associate, University of Central Lancashire Jeremiah Horrocks Institute, Preston, UK)
Place: Sala de Conferencies Alberto Lobo (ICE)

Interstellar dust strongly affects the appearance of galaxies within a wide range of wavelengths. In fact, dust both absorbs and scatters stellar light, which dominates the emission in the UV to near-IR range, and it re-emits the absorbed stellar luminosity in the infrared-submm regime. The complex propagation of stellar light within a galaxy can be modelled by performing 3D dust radiative transfer (RT) calculations. In this talk I will introduce the basic dust radiative transfer problem in galaxies and I will show some applications of our ray-tracing 3D dust RT code "DART-Ray" for the prediction of galaxy emission maps. In particular, I will discuss our results for the fraction of dust heating powered by young and old stellar populations in the context of star formation studies on galactic scales. 
06
November 2015

Imaging geospace and the heliosphere by charge exchange


Start: 12:30h
Speaker: Justin Elfritz (University of Amsterdam)
Place: Sala Alberto Lobo (ICE)

Charge exchange production of energetic neutral atoms (ENAs) gives us a novel, powerful diagnostic for imaging the ion populations of astrophysical and fusion-grade plasmas. I will discuss the historical challenges ENA scientists have faced, and how the systematic mis-interpretation of ENA telescope…
Start: 12:30h
Speaker: Justin Elfritz (University of Amsterdam)
Place: Sala Alberto Lobo (ICE)

Charge exchange production of energetic neutral atoms (ENAs) gives us a novel, powerful diagnostic for imaging the ion populations of astrophysical and fusion-grade plasmas. I will discuss the historical challenges ENA scientists have faced, and how the systematic mis-interpretation of ENA telescope data became an unlikely savior. After an introduction to the concept and scope of charge exchange imaging, I will discuss some high-impact results from TWINS which have revolutionized our understanding of Earth's magnetosphere, and discuss the controversial, unexpected truths shown by IBEX regarding the structure of the heliosphere.
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