Calendar

Sep
5
Thu
“Decoding the stars”: una recente biografia di Padre Secchi – Ileana Chinnici (INAF – OAPa)
Sep 5 @ 15:00 – 16:00

Come una tela di Penelope, il lavoro di tessitura che ha portato alla stesura di questo libro è stato lungo e lento, con un continuo fare e disfare, dovuto anche al continuo emergere di elementi inediti, che hanno molto arricchito il libro, ma ne hanno rallentato il completamento. Il risultato è una biografia a tutto tondo del celebre gesuita scienziato, che offre numerosi spunti di approfondimento agli studiosi di varie discipline scientifiche. Il talk illustrerà gli elementi di complessità incontrati nella stesura del lavoro, le novità emerse sugli aspetti biografici, la struttura del libro e le fonti, in parte ancora inesplorate, da cui ha attinto la ricerca.

Oct
10
Thu
Ripetizione tesi
Oct 10 @ 15:00 – 17:15
Oct
17
Thu
Ripetizione Tesi di Dottorato Salvatore Colombo, 17 Ottobre, Aula, ore 15
Oct 17 @ 15:00 – 16:30

Speaker: Salvatore Colombo

Titolo: “Radiation hydrodynamic and magnetohydrodynamic models of plasma flows accreting onto Classical T Tauri Stars”

Abstract: “Secondo lo scenario più accettato, le stelle T Tauri sono stelle giovani che accrescono massa dal loro disco circumstellare.
L’obiettivo del mio dottorato è stato quello di studiare il fenomeno di accrescimento di massa in questi sistemi. Durante il mio seminario presenterò i risultati ottenuti durante i miei 3 anni di dottorato.
Mii focalizzerò sui risultati ottenuti da modelli di interazione tra l’attività stellare e il disco circumstellare e mostrerò come l’attività coronale possa dare origine a fenomeni di accrescimento.
Illustrerò i risultati ottenuti dallo studio della regione di impatto di una colonna di accrescimento sulla superficie stellare tenendo conto, per la prima volta in letteratura, del ruolo della radiazione in regime di non equilibrio termodinamico locale (non-LTE).  Per fare questo modello è stato necessario sviluppare un modulo non-LTE per il codice magnetoidrodinamico PLUTO. Presenterò il modulo e i test di validazione fatti.
Inoltre proverò che considerare il regime non-LTE ha importanti conseguenze sulla struttura e dinamica di una regione di shock.
Usando questo modulo ho dimostrato la presenza di un precursore radiativo nella colonna di accrescimento, formatosi per il riscaldamento del materiale che assorbe la radiazione proveniente dalla regione post-shock.
Durante la presentazione illustrerò le conseguenze del considerare il precursore nell’interpretazione delle osservazioni in banda UV e X. “

Oct
25
Fri
Seminario: ripetizione Tesi di Dottorato di A. Garrido, Aula ore 11.30
Oct 25 @ 11:30 – 13:00

Speaker: A. Garrido (UNIPA)

Titolo: Analysis of exoplanetary atmospheres.

Abstract:

The seminar summarizes the work of my last PhD year.
During the talk I will explain how to obtain an atmospheric transmission spectrum of a transit exoplanet: Kelt-9b. The analyzes carried out will be explained and finally I will show the Balmer lines of the exoplanet’s atmosphere. The seminar concludes with the derivation of the exoplanet’s temperature by means of direct measurements made thanks to the development of tomography images.
Oct
29
Tue
Seminario: D. Modirrousta Galian (INAF), Aula ore 15:00
Oct 29 @ 15:00 – 16:30

Speaker:  Darius Modirrousta Galian

Titolo: Theoretical exoplanetology

Seminario: Why does 55 Cancri e have a H/H 2 -rich atmosphere? Why is there a bimodal distribution of exoplanet radii with one peak at ~ 1.3R ⨁ , the other and ~ 2.4R ⨁ , and the minima at ~ 1.8R ⨁ .
Why do some airless magma ocean super-Earths have albedos close to ~ 50% when earth-based magmas have measured albedos of ~ 10%? Conversely, why are some hot Jupiters so dark with albedos of ~ 1% or below? New data from astronomical measurements shows that
the universe is far more complex and interesting than what traditional literature predicted. Understanding these bodies and phenomena is not a trivial task, but by coupling different scientific fields with observational data it may be possible to shed some light on these systems.

Nov
6
Wed
Seminario: Ruggero Biondo (UNIPA) ore 11.30
Nov 6 @ 11:30 – 13:00

Speaker:  Ruggero Biondo

Titolo: Data-driven Numerical Reconstruction of the Interplanetary Parker Spiral

Abstract: Over the last decade the science community, governments and private partners have shown a growing interest in the topic of Space Weather: a broad discipline aimed to the forecasting of potential threats to space and ground-based systems and operations. The ability of the state-of-art codes to reconstruct the stationary conditions of the interplanetary plasma is still limited, as shown by the comparisons between model predictions and in-situ measurements acquired by various spacecrafts. Therefore, it is necessary to develop leaner codes and to improve the agreement between forecasts and observed data on the other. The aim of this work is to lighten the procedures involved in determining the inner heliospheric boundary and to bind the numerical simulations to direct measurements of the parameters of the interplanetary plasma. To do this, the ambient plasma parameters of the inner heliosphere are reconstructed, using the 1 AU data provided by the Solar Physics Group in INAF-Turin Astrophysical Observatory from different spacecrafts located in the lagrangian point L1 such as DSCOVR and GGS Wind, by going backwards to 0.1 AU following the spiraling arms of the Interplanetary Parker Spiral. The back-reconstructed plasma parameter at 0.1 AU are thus employed as inner boundary conditions for the solar wind expansion up to 1 AU based on a MHD simulation. This innovative approach provides a new method to reconstruct the conditions of the interplanetary plasma from the Sun to 1 AU and beyond

Nov
13
Wed
Seminario: Giuseppe Morello (INAF) Aula ore 15.00
Nov 13 @ 15:00 – 16:30

Speaker: Giuseppe Morello

Titolo: Towards high-precision modeling of star+exoplanet multiwavelength light-curves

Abstract: I will present new tools and methodologies purposely developed for modeling observations of transiting exoplanets and eclipsing binaries with precision down to <10 parts per million (ppm).

ExoTETHyS is a python package that aims to collect the functions needed to model the high-precision spectrophotometric observations obtained with JWST and ARIEL (not only). The current version includes a user-friendly stellar limb-darkening calculator that outperforms existing codes by one order of magnitude in terms of light-curve model accuracy. I will introduce to the current use of ExoTETHyS and discuss the planned developments.

I will also show the results from the consistent reanalyses of Spitzer and Hubble data with bayesian approaches and improved data detrending techniques.

Nov
27
Wed
Seminario: F. Reale (UNIPA) ore 11.30
Nov 27 @ 11:30 – 13:00

Speaker: Fabio Reale (UNIPA)

Authors: F. Reale(1,2), P. Testa(3), A. Petralia(2), D. Graham(4), D. Kolotkov(5)
(1) Dipartimento di Fisica & Chimica, Università di Palermo;
(2) INAF-Osservatorio Astronomico di Palermo;
(3) Center for Astrophysics | Harvard & Smithsonian, Cambridge, USA;
(4) Bay Area Environmental Research Institute, NASA Research Park, Moffett Field, USA;
(5) Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry, UK

Titolo: Impulsive heating in the solar corona: large scale magnetic rearrangements

Abstract:

Abstract: Multiband observations show clear evidence for large-scale magnetic interaction of coronal loops in solar active regions. These loops are transiently (~20 min) bright in hot EUV channels (Atmospheric Imaging Assembly on-board Solar Dynamics Observatory, SDO/AIA), with temperatures up to about 10 MK, intersect in the plane of the sky, and their footpoints are hot spots for a short time in transition region UV lines (Interface Region Imaging Spectrograph, IRIS). The UV spectral features can be explained as produced by non-thermal electron beams hitting the transition region and generating a heat pulse of less than 1 minute. This is consistent with periodic pulsations detected in EUV light curves along the interacting loops, produced by sloshing wave fronts driven by short heat pulses. These loop systems represent excellent laboratories for studying impulsive heating mechanisms and allow us to focus physical models for diagnostics. We show preliminary MHD modeling of interacting loops.
Dec
19
Thu
Seminario: Massimo Brescia (INAF)
Dec 19 @ 15:00 – 16:30

Speaker: Massimo Brescia (INAF-Osservatorio Asstronomico di Capodimonte).

Titolo: Leverage data science in modern astrophysics
Abstract:
The exploration of the Universe is one of main topics within the research in Physics Sciences. All incoming and on going astrophysical surveys are characterized by a huge amount of heterogeneous multi-wavelength data, which will require efficient automatic methods to be exploited in an optimal and competitive way by the italian scientific community.
Astrophysics data are then characterized by large volume, velocity and
variety, the three conditions at thebase of the Big Data paradigm. Therefore, an approach based on data mining, statistics,
machine and deep learning, in one word Astroinformatics, is required. We
will discuss a variety of such methodologies, already available and validated in several astrophysical contexts, with  the aim at proposing a pragmatic
way to approach the scientific topics of the incoming multi-messenger
Astrophysics.

Jan
21
Tue
Seminario: Elisa Guerriero (UNIPA), aula Osservatorio ore 15:00
Jan 21 @ 15:00 – 16:30

Speaker: Elisa Guerriero (UNIPA)

Titolo: Development polishing process for bare aluminum mirrors to ARIEL space mission

Abstract: ARIEL is the 4th medium-class mission of ESA’s Cosmic Vision Programme to see and to study the exoplanets’ atmospheres in VIS/IR. The technical innovation of the project is the use of bare aluminum for the mirrors. This material is light, cheap, and available in large quantities, but difficult to polish because it is not very dense. In this seminar, I will talk about my work at Media Lario S.r.l. for the development of the aluminum polishing process, the critical issues and the results obtained.