Past Pizza Lunches

Número de entradas: 152

23
Octubre 2020

Physics Nobel Prize 2020: Black Hole Formation and the Supermassive Black Hole at the Milky Way Galactic Center


Inicio: 12:15h
Ponente: Carlos Sopuerta (ICE, CSIC and IEEC)
Lugar: Zoom Meeting: https://us02web.zoom.us/j/85044910172?pwd=bXRmeWx3cTdDSzkrMFFJUXI5eE9hQT09 Meeting ID: 850 4491 0172 Passcode: 996691

The Black Hole idea is a purely relativistic concept: Contrary to stars, which humans see with their own eyes and are in the process of understanding what are they made of and where they come from, the Black Hole concept emerges from the General Theory of Relativity that Albert Einstein completed in…
Inicio: 12:15h
Ponente: Carlos Sopuerta (ICE, CSIC and IEEC)
Lugar: Zoom Meeting: https://us02web.zoom.us/j/85044910172?pwd=bXRmeWx3cTdDSzkrMFFJUXI5eE9hQT09 Meeting ID: 850 4491 0172 Passcode: 996691

The Black Hole idea is a purely relativistic concept: Contrary to stars, which humans see with their own eyes and are in the process of understanding what are they made of and where they come from, the Black Hole concept emerges from the General Theory of Relativity that Albert Einstein completed in 1915. The Black Hole concept is also a geometrical concept in the sense that their composition is irrelevant. Moreover, the Black Hole concept is revolutionary: Despite Karl Schwarzschild found the first Black Hole model in 1916 it was not until the late 1950s that we understood their nature. 

Roger Penrose pioneered in the 1970s a new way of studying General Relativity, with new methods and techniques, that clarified the fact that Black Holes are not just weird solutions of the theory but the unavoidable consequence of gravitational collapse and therefore they must be ubiquitous objects in our Universe. On the other hand, the most convincing observational evidence of the existence of Black Holes (left alone the recent observations by the LIGO gravitational wave detector that already got the Nobel Prize) comes from the observations of the Galactic Center made since the early 1990s by the research groups led by Reinhard Genzel and Andrea Ghez. By monitoring stars orbiting the region of Sagittarius A* they concluded that there must be a supermassive black hole pulling those stars into such orbits. And this is the most conservative explanation that we have for this system.
26
Junio 2020

Rectifying Problematic Modified Gravity Theories in View of GW170817


Inicio: 12:15h
Ponente: V.K.Oikonomou (Thessaloniki Univ., Greece )
Lugar: Remote Pizza Seminar

The striking event GW170817 indicated that gravitons are nearly massless, since the gravitational waves and the gamma rays emitted from the two neutron stars merging arrived almost simultaneously. Since there is no fundamental reason for the graviton to change its mass during the inflationary and…
Inicio: 12:15h
Ponente: V.K.Oikonomou (Thessaloniki Univ., Greece )
Lugar: Remote Pizza Seminar

The striking event GW170817 indicated that gravitons are nearly massless, since the gravitational waves and the gamma rays emitted from the two neutron stars merging arrived almost simultaneously. Since there is no fundamental reason for the graviton to change its mass during the inflationary and post-inflationary era, several modified gravities predicting a primordial gravity wave speed not equal to that of light, became non-viable. In this talk we shall demonstrate how Einstein-Gauss-Bonnet theories and some classes of Hondeski theories may be revived in view of the GW170817, thus predicting a nearly zero mass for the primordial graviton.
19
Junio 2020

ETG properties as revealed by MaNGA


Inicio: 12:15h
Ponente: Helena Domínguez Sánchez (Institut de Ciències de l'Espai (CSIC-IEEC))
Lugar: Remote Pizza Seminar

In this talk I will (try to!) summarise the findings presented in a series of four papers dedicated to the study of early type galaxies (ETGs) with integral field spectroscopy (IFU) from the MaNGA survey. The formation channels and mass assembly of ETGs is still a matter of debate in current galaxy evolution…
Inicio: 12:15h
Ponente: Helena Domínguez Sánchez (Institut de Ciències de l'Espai (CSIC-IEEC))
Lugar: Remote Pizza Seminar

In this talk I will (try to!) summarise the findings presented in a series of four papers dedicated to the study of early type galaxies (ETGs) with integral field spectroscopy (IFU) from the MaNGA survey. The formation channels and mass assembly of ETGs is still a matter of debate in current galaxy evolution models. The combined analysis of galaxy kinematics and stellar population gradients (age, metallicity, alpha-enhancement, initial mass function -IMF-) is a powerful tool to disentangle  between in situ star formation or merger events. We divide our sample into elliptical fast rotators (E-FR), elliptical slow rotators (E-SR) and lenticular (S0). To achieve enough signal to noise to reliably measure IMF variations we need to stack the galaxies in bins of luminosity and central velocity dispersion. We observe significant differences between the three sub-samples — e.g., E-FR are much younger and metal rich than E-SR — , suggesting that kinematics and morphology have a strong impact on galaxy content. In addition, I will show that there are three mass-scales where scaling relations change slope and for which there is also a dramatic change in the number counts and stellar population gradients of ETGs. I will also discuss the implications of IMF variations within galaxies and how this helps reconciling stellar mass with dynamical mass estimates. Finally, I will show that the thickness of the Fundamental Plane depends strongly on morphology. If the sample only includes E-SRs, then the observed scatter is significantly reduced.
05
Junio 2020

The Driving Mechanisms Of Protostellar Evolution


Inicio: 12:15h
Ponente: Felipe Alves (Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik)
Lugar: Remote Pizza Seminar

Gravity and magnetic fields are competing entities in the formation process of stars like our Sun. While dense cores of molecular clouds collapse under their own gravity, magnetic fields represent a resisting force since charged dust and gas are tied to the field lines. Polarization observations have…
Inicio: 12:15h
Ponente: Felipe Alves (Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik)
Lugar: Remote Pizza Seminar

Gravity and magnetic fields are competing entities in the formation process of stars like our Sun. While dense cores of molecular clouds collapse under their own gravity, magnetic fields represent a resisting force since charged dust and gas are tied to the field lines. Polarization observations have shown that magnetic fields are unambiguously present in the universe and theory predicts their severe impact on the core dynamics. Because the new generation of instruments such as ALMA and SOFIA has been revealing the magnetic field morphology, dust and gas distribution in cores and protostellar cocoons in great detail, we have expanded our understanding of the interplay between magnetic fields and gravity. In this talk, I will review some of the classical and modern aspects of protostellar evolution, and present my contribution to the topic. Specifically, I will focus on our ALMA observations toward one of the nearest regions of low-mass star-forming regions, Barnard 59. 
24
Abril 2020

The Atacama Large Aperture Submm Telescope (AtLAST): Cosmological and Sunyaev-Zeldovich Effect Applications


Inicio: 12:15h
Ponente: Tony Mroczkowski (European Southern Observatory )
Lugar: Remote Pizza Seminar

The thermal and kinematic SZ effects provide a strong and independent complement to X-ray observations of the warm and hot ionised intracluster medium, particularly at high redshift where X-ray counts are limited. Being observable from the ground, new instruments for studying the SZ effects can be developed…
Inicio: 12:15h
Ponente: Tony Mroczkowski (European Southern Observatory )
Lugar: Remote Pizza Seminar

The thermal and kinematic SZ effects provide a strong and independent complement to X-ray observations of the warm and hot ionised intracluster medium, particularly at high redshift where X-ray counts are limited. Being observable from the ground, new instruments for studying the SZ effects can be developed more rapidly and can be upgraded more readily than their space-borne counterparts. I will discuss recent results from ALMA and MUSTANG2, as well as a newly-proposed research infrastructure (recently approved by the European Commission as a Design Study) for a 50-meter-class widefield submm/mm telescope called AtLAST. AtLAST will be capable of observing the multifaceted SZ effects and disentangling them from contaminating radio and dusty submm sources. This will provide 10′′ resolution at 150 GHz (near the peak of the thermal SZ decrement) and a 2 degree instantaneous field of view. AtLAST is beginning to garner broad international support, with many US Astro2020 decadal and Canadian Long Range Plan 2020 submissions.
24
Abril 2020

Online: The Atacama Large Aperture Submm Telescope (AtLAST): Cosmological and Sunyaev-Zeldovich Effect Applications


Inicio: 12:15h
Ponente: Dr. Tony Mroczkowski (ESO)
Lugar: Online: Join Zoom Meeting https://zoom.us/j/346578843

The thermal and kinematic SZ effects provide a strong and independent complement to X-ray observations of the warm and hot ionised intracluster medium, particularly at high redshift where X-ray counts are limited. Being observable from the ground, new instruments for studying the SZ effects can be developed…
Inicio: 12:15h
Ponente: Dr. Tony Mroczkowski (ESO)
Lugar: Online: Join Zoom Meeting https://zoom.us/j/346578843

The thermal and kinematic SZ effects provide a strong and independent complement to X-ray observations of the warm and hot ionised intracluster medium, particularly at high redshift where X-ray counts are limited. Being observable from the ground, new instruments for studying the SZ effects can be developed more rapidly and can be upgraded more readily than their space-borne counterparts. I will discuss recent results from ALMA and MUSTANG2, as well as a newly-proposed research infrastructure (recently approved by the European Commission as a Design Study) for a 50-meter-class widefield submm/mm telescope called AtLAST. AtLAST will be capable of observing the multifaceted SZ effects and disentangling them from contaminating radio and dusty submm sources. This will provide 10′′ resolution at 150 GHz (near the peak of the thermal SZ decrement) and a 2 degree instantaneous field of view. AtLAST is beginning to garner broad international support, with many US Astro2020 decadal and Canadian Long Range Plan 2020 submissions.
20
Abril 2020

Due to the Covid-19 restrictions our pizza seminars will be online.


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17
Abril 2020

Due to the Covid-19 restrictions our pizza seminars will be online


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17
Abril 2020

A new approach for modelling pulsar wind nebulae


Inicio: 12:15h
Ponente: Diego F. Torres (Institut de Ciències de l'Espai (CSIC-IEEC))
Lugar: Remote Seminar

In this talk I will introduce a new approach for theoretical modelling of pulsar wind nebulae: a hybrid hydrodynamic-radiative model able to reproduce morphological features and spectra of PWN sources, with relatively limited numerical cost.
Inicio: 12:15h
Ponente: Diego F. Torres (Institut de Ciències de l'Espai (CSIC-IEEC))
Lugar: Remote Seminar

In this talk I will introduce a new approach for theoretical modelling of pulsar wind nebulae: a hybrid hydrodynamic-radiative model able to reproduce morphological features and spectra of PWN sources, with relatively limited numerical cost.
10
Abril 2020

Due to the Covid-19 restrictions our pizza seminars will be online


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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