All future seminars

Number of entries: 5

21
February 2020

Intelligent Arxiv: Sort daily papers by learning users topic preferences


Start: 12:15h
Speaker: Manuel Szewc (ICAS, ARG)
Place: Alberto Lobo Room

We present and discuss some novel applications of the Linear Discriminant Analysis (LDA) technique of Machine Learning (ML). First in the field of New Physics (NP) searches at the LHC, where we are currently applying this unsupervised ML technique to find NP as emerging topics. Motivated by this powerful…
Start: 12:15h
Speaker: Manuel Szewc (ICAS, ARG)
Place: Alberto Lobo Room

We present and discuss some novel applications of the Linear Discriminant Analysis (LDA) technique of Machine Learning (ML). First in the field of New Physics (NP) searches at the LHC, where we are currently applying this unsupervised ML technique to find NP as emerging topics. Motivated by this powerful tool  we pursued the goal of sorting daily Arxiv papers in given field(s) according to individual user preference.  We model a scientific paper to be built as a combination of different scientific knowledge from diverse topics into a new problem. We apply then the (unsupervised) Machine Learning technique LDA to construct and extract topics from the corpus of papers. We obtain the topic weights of the available and new papers in the Arxiv,  and determine each user preference in topics according to each user preference in papers. This allows to determine the personal preference on new papers according to their topics weight distribution.  We have created the web interface IArxiv.org where users can read personally-sorted daily Arxiv releases (and more) while the algorithm learns his/her preferences.  Yielding therefore a more accurate sorting every day. Current IArxiv.org version runs on categories astro-ph, gr-qc, hep-ph and hep-th.
28
February 2020

Magneto-luminescence: from neutron stars to planets


Start: 12:15h
Speaker: Daniele Viganò
Place: Alberto Lobo

Magnetic fields play an important but often little understood role in many astrophysical scenarios. In astrophysical bodies, magnetism often drives their observable behaviour, making them outshine the rest of the sources. Typical and spectacular examples are neutron stars, but in our vicinity also the…
Start: 12:15h
Speaker: Daniele Viganò
Place: Alberto Lobo

Magnetic fields play an important but often little understood role in many astrophysical scenarios. In astrophysical bodies, magnetism often drives their observable behaviour, making them outshine the rest of the sources. Typical and spectacular examples are neutron stars, but in our vicinity also the Sun and Jupiter represent fascinating magnets, not to speak about the Earth itself.
More than a talk, this seminar is supposed to be a multidisciplinary brainstorming session, regarding magnetic field dynamics and observable imprints on different kind of astrophysical objects.
11
March 2020

The cosmic origin of the rapid neutron capture elements


Start: 12:00h
Speaker: Darach Watson (Cosmic Dawn Center/ Niels Bohr Institute )
Place: Alberto Lobo Conference Room

The processes that create the elements that make up the periodic table were laid down theoretically in the late 1950s, but the cosmic forges that actually carry out these processes have been more difficult to identify. The rapid (r) neutron capture process creates half of all the elements heavier than…
Start: 12:00h
Speaker: Darach Watson (Cosmic Dawn Center/ Niels Bohr Institute )
Place: Alberto Lobo Conference Room

The processes that create the elements that make up the periodic table were laid down theoretically in the late 1950s, but the cosmic forges that actually carry out these processes have been more difficult to identify. The rapid (r) neutron capture process creates half of all the elements heavier than iron and the bulk of the heaviest elements, including almost all gold, platinum, and uranium. Its site is currently a major source of debate. I present recently uncovered direct spectroscopic evidence for the creation of r-process elements in the merger of two neutron stars, proving that such mergers do create large quantities of heavy elements and that neutron stars are composed of neutron-rich matter, a fact not spectroscopically proven until now. However, the element we find is a light r-process element, not a heavy one, and other lines of evidence suggest there may be a second source of r-process elements in the Universe.
31
March 2020

HORuS: higher resolution for GTC


Start: 12:00h
Speaker: Carlos Allende Prieto (IAC)
Place: Alberto Lobo room

The High Optical Resolution Spectrograph (HORus) has been available on the 10-m GTC telescope since early 2019. Based largely on optical elements reused from UES, in operation on the 4-m WHT in the 90s, HORuS provides a resolving power of 25,000 with nearly complete coverage in the range 380-700 nm. …
Start: 12:00h
Speaker: Carlos Allende Prieto (IAC)
Place: Alberto Lobo room

The High Optical Resolution Spectrograph (HORus) has been available on the 10-m GTC telescope since early 2019. Based largely on optical elements reused from UES, in operation on the 4-m WHT in the 90s, HORuS provides a resolving power of 25,000 with nearly complete coverage in the range 380-700 nm.  This instrument gives a signal-to-noise ratio at 550 nm of 75 for a V=15 solar-like star in 1 hour, and its particularly well-suited for stellar spectroscopy and exoplanet transits. This seminar will offer useful tips and guidelines to prepare observations with HORuS and use its automated pipeline for data reduction.
22
April 2020

Spacecraft-to-Spacecraft Radio Occultations for the Study of Planetary Atmospheres: New Mission Concepts for Mars and Venus


Start: 12:00h
Speaker: Dr. Chi On Ao (Jet Propulsion Laboratory, California Institute of Technology, USA)
Place: Alberto Lobo, ICE

Radio occultation (RO) is a technique which was first used in 1965 during the Mariner 4 flyby of Mars, providing valuable information on the vertical structure of the Mars atmosphere.  Since then, it has been an important part of most planetary missions including the New Horizons’ recent flyby of…
Start: 12:00h
Speaker: Dr. Chi On Ao (Jet Propulsion Laboratory, California Institute of Technology, USA)
Place: Alberto Lobo, ICE

Radio occultation (RO) is a technique which was first used in 1965 during the Mariner 4 flyby of Mars, providing valuable information on the vertical structure of the Mars atmosphere.  Since then, it has been an important part of most planetary missions including the New Horizons’ recent flyby of Pluto.  By precise tracking of the radio signals from the spacecraft to an Earth tracking station (or vice versa) as they pass through the planetary atmosphere, it is possible to derive a profile of refractivity index (and hence density, temperature, pressure, etc.) with very good vertical resolution.
 
In the late 1980s, it was recognized that the same technique can be applied on radio links between a Global Positioning System (GPS) satellite and a receiver on low Earth orbit to sound the Earth’s atmosphere and ionosphere.  This concept was later proved with the GPS/MET mission, and subsequent analysis from various missions (CHAMP, COSMIC, MetOp, etc.) showed that such GPS-RO observations provide unique values in weather forecasting and climate applications with instrumentations that are cost effective.  An advantage of GPS-RO over traditional planetary RO is that, aside from the large number of transmitters, the spacecraft-spacecraft crosslink geometry from GPS-RO provides much more uniform distribution of occultation soundings geographically and across local times.  With the rapid advancement of smallsat technologies that are enabling deep space missions (e.g., the twin MarCO cubesats), it becomes increasingly feasible to deploy multiple smallsats in future Mars and Venus missions so that spacecraft-to-spacecraft RO can be realized for these planets.
 
In this talk, I will review the basic concept of RO and its historical developments.  I will discuss an opportunistic crosslink RO experiment performed by the JPL team between two Mars orbiters: the first spacecraft-to-spacecraft RO measurements ever recorded outside of Earth.  This demonstration opens the exciting possibility of obtaining dense RO measurements for sensing the atmospheres of Mars and Venus using multiple smallsats.  I will discuss some of the mission concepts that have been proposed, their benefits, and implementation challenges.
Institute of Space Sciences (IEEC-CSIC)

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08193 Barcelona.
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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