Past Pizza Lunches

Number of entries: 153

27
October 2017

GNSS Transpolar Earth Reflectometry exploriNg system (G-TERN): a proposal for ESA EE9 co-led by ICE-CSIC/IEEC


Start: 12:15h
Speaker: Estel Cardellach Galí
Place: Sala Alberto Lobo

The GNSS Transpolar Earth Reflectometry exploriNg system (G-TERN) was proposed in response to ESA’s Earth Explorer 9 Revised Call by a team of 33 multi-disciplinary scientists and co-led by E. Cardellach (ICE-CSIC/IEEC) and J. Wickert (GFZ/Germany). The primary objective of the mission is to quantify…
Start: 12:15h
Speaker: Estel Cardellach Galí
Place: Sala Alberto Lobo

The GNSS Transpolar Earth Reflectometry exploriNg system (G-TERN) was proposed in response to ESA’s Earth
Explorer 9 Revised Call by a team of 33 multi-disciplinary scientists and co-led by E. Cardellach (ICE-CSIC/IEEC) and J. Wickert (GFZ/Germany). The primary objective of the mission is to quantify crucial characteristics, processes and interactions between the sea ice and other Earth system components in order to advance the understanding and prediction of climate change and its impacts on the environment and society.  To contribute answering these questions G-TERN will measure key parameters of the sea ice, the oceans and the atmosphere with frequent and dense coverage over polar areas, becoming a ’dynamic mapper’ of the ice conditions, ice production and loss in multiple time and space scales, and surrounding environment. Over polar areas, G-TERN will measure sea ice surface elevation (<10 cm precision), roughness and
polarimetry aspects at 30 km resolution and 3 days full coverage. G-TERN will implement the interferometric GNSS reflectometry concept (pioneered at ICE-CSIC/IEEC).  The lifetime would be 2025-2030 or optimally 2025-2035, covering key stages of the transition towards a Summer Arctic sea ice free. ESA will take a decision by the end of 2017 and proceed with Phase-A studies of two selected proposals. This seminar will provide an overview of G-TERN mission goals, techniques and suggested implementation.
20
October 2017

The flux of chondritic meteorites reaching the Earth over time and its astro-biological implications


Start: 12:30h
Speaker: Josep M. Trigo-Rodríguez (ICE)
Place: Sala L3 / 01 (workshop room third floor)

A recent study led by ICE has revealed the unique catalytic properties of the minerals forming chondritic meteorites, authentic primordial aggregates of the materials forming the protoplanetary disk. These minerals are able to catalyze tens of organics compounds that are considered essential in prebiotic…
Start: 12:30h
Speaker: Josep M. Trigo-Rodríguez (ICE)
Place: Sala L3 / 01 (workshop room third floor)

A recent study led by ICE has revealed the unique catalytic properties of the minerals forming chondritic meteorites, authentic
primordial aggregates of the materials forming the protoplanetary disk. These minerals are able to catalyze tens of organics compounds that are
considered essential in prebiotic chemistry. These meteorites come from highly porous transitional asteroids that retained significant amounts of
water,  organics  and volatile compounds in their interiors. Our scenario suggests that these bodies caused an intense meteoritic flux that
delivered about 5 to 6 orders of magnitude the current one (estimated to be 10^5 metric tons).
It traduces in huge amounts of chondritic materials reaching  the Earth’s surface at an annual rate of thousands of billions of metric tons, and
exposed to the action of water, nitrogen species and igneous heat. Under these unique properties of chondrites, and such primordial circumstances
we envision that they probably played a key role in fertilizing the Earth’s surface towards the appearance of life in Earth about 4 Gyrs ago.
23
June 2017

Magnetars: recent discoveries and a catalogue of their outbursts


Start: 12:00h
Speaker: Francesco Coti Zelati (ICE)
Place: Sala Alberto Lobo

I will present recent X-ray observational results on two peculiar strongly magnetized isolated neutron stars: SGR 1745-2900, the closest pulsar to a black hole ever observed; 1E 161348–505, the slowest magnetar known at the centre of a supernova remnant. I will also show the results of a systematic…
Start: 12:00h
Speaker: Francesco Coti Zelati (ICE)
Place: Sala Alberto Lobo

I will present recent X-ray observational results on two peculiar strongly magnetized isolated neutron stars: SGR 1745-2900, the
closest pulsar to a black hole ever observed; 1E 161348–505, the slowest magnetar known at the centre of a supernova remnant. I will also show the results of a systematic study of all magnetar outbursts detected in the past 2 decades.
16
June 2017

Anatomy of the archetypal protostellar shock L1157-B1


Start: 12:00h
Speaker: Gemma Busquet (Institut de Ciències de l'Espai (IEEC-CSIC))
Place: 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…
Start: 12:00h
Speaker: Gemma Busquet (Institut de Ciències de l'Espai (IEEC-CSIC))
Place: 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. 
09
June 2017

Obtaining precipitation information from Polarimetric GNSS radio occultation observables


Start: 12:00h
Speaker: Ramon Padullés Rulló (Institute of Space Sciences)
Place: 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…
Start: 12:00h
Speaker: Ramon Padullés Rulló (Institute of Space Sciences)
Place: 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.  
02
June 2017

Challenges in Gravitational Wave Astronomy


Start: 12:00h
Speaker: Carlos Sopuerta (ICE (CSIC-IEEC))
Place: Sala Alberto Lobo (ICE)

In this talk I will summarize the efforts to detect gravitational waves in the different frequency bands, describing what are the main challenges, not only from the point of view of instrumentation, but also from the point of view of data analysis and science exploitation.  This talk will be complementary…
Start: 12:00h
Speaker: Carlos Sopuerta (ICE (CSIC-IEEC))
Place: Sala Alberto Lobo (ICE)

In this talk I will summarize the efforts to detect gravitational waves in the different frequency bands, describing what are the main challenges, not only from the point of view of instrumentation, but also from the point of view of data analysis and science exploitation.  This talk will be complementary to the one given recently about LISA in a recent pizza seminar, and in this sense, only material not introduced there will appear.
26
May 2017

Supernova or impostor?


Start: 12:00h
Speaker: Nancy Elias-Rosa
Place: Sala Alberto Lobo

A fully consistent picture of the SNe progenitor evolution can't be found yet. Such scenario increases in complexity as deep and wide surveys, using latest generation instruments, discover new types of transients with unprecedented observational characteristics, for example, the wide heterogeneity…
Start: 12:00h
Speaker: Nancy Elias-Rosa
Place: Sala Alberto Lobo

A fully consistent picture of the SNe progenitor evolution can't be found yet. Such scenario increases in complexity as deep and wide surveys, using latest generation instruments, discover new types of transients with unprecedented observational characteristics, for example, the wide heterogeneity observed in interacting transients in the recent years. Still, the nature of these transients is largerly debated: Some are without doubt genuine core-collapse SNe, while others may be giant non-terminal outburst from luminous blue variables. The talk includes my contribution to this topic with data of the recent objects of study and the conclusions extracted from their analysis.
19
May 2017

Clustering of halos in Lagrangian Space


Start: 12:00h
Speaker: Kwan Chuen Chan
Place: Sala Alberto Lobo

To extract cosmological information from galaxy surveys, the galaxy bias must be understood. As galaxies are hosted within halos, we often take the more tractable step by first studying halo formation and its bias. The most popular theoretical approach to model halo formation and its bias starts in Lagrangian…
Start: 12:00h
Speaker: Kwan Chuen Chan
Place: Sala Alberto Lobo

To extract cosmological information from galaxy surveys, the galaxy bias must be understood. As galaxies are hosted within halos, we often take the more tractable step by first studying halo formation and its bias. The most popular theoretical approach to model halo formation and its bias starts in Lagrangian space, i.e. the initial condition. In this talk I will first review the modelling of the Lagrangian halos in a pedagogical manner. I then present some of the progress on the smoothing window for the Lagrangian halos and the Lagrangian bias consistency relations, which enable us to extract the halo formation physics from the clustering properties.
12
May 2017

Singularities in cosmology: theory and observations


Start: 12:00h
Speaker: Diego Sáez-Chillón Gómez
Place: 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.…
Start: 12:00h
Speaker: Diego Sáez-Chillón Gómez
Place: 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.
05
May 2017

The gravitational capture of compact objects with supermassive black holes


Start: 12:00h
Speaker: (Institut de Ciències de l'Espai (CSIC-IEEC))
Place: Sala Alberto Lobo (ICE building, Campus UAB)

One of the most interesting sources of gravitational waves for space-borne missions is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an "extreme-mass ratio inspiral". The small object, typically a stellar black hole, emits significant amounts of GW along…
Start: 12:00h
Speaker: (Institut de Ciències de l'Espai (CSIC-IEEC))
Place: Sala Alberto Lobo (ICE building, Campus UAB)

One of the most interesting sources of gravitational waves for space-borne missions is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an "extreme-mass ratio inspiral". The small object, typically a stellar black hole, emits significant amounts of GW along each orbit in the detector bandwidth. In my talk I will review the most significant advances in our understanding of the astrophysics of this process. In particular, I will present new rates and the confirmation that EMRIs formed via two-body relaxation dominate them. I will also show that, contrary to those formed below a hundreth of a parsec via resonant relaxation, two-body relaxation EMRIs are not blocked.
Institute of Space Sciences (IEEC-CSIC)

Campus UAB, Carrer de Can Magrans, s/n
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