Calendar

Nov
6
mer
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
mer
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
mer
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.
Dic
19
gio
Seminario: Massimo Brescia (INAF)
Dic 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.

Gen
21
mar
Seminario: Elisa Guerriero (UNIPA), aula Osservatorio ore 15:00
Gen 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.

Feb
12
mer
Seminario: Darius Modirrousta Galian (UNIPA), 12 Febbraio 2020 ore 15:00 Aula OAPA
Feb 12@15:00–16:30

Speaker: Darius Modirrousta Galian (UNIPA)

Titolo: Exploring Super-Earth Surfaces: Albedo of Near-Airless Magma Ocean Planets and Topography

Abstract:

In this paper we propose an analytic function for the bond albedo of an airless or near-airless magma ocean planet (AMOP). We generated multiple 100 m wide 1D fractal surfaces unto which we individually bombarded 10,000 light rays. Using an approximate form of the Fresnel equations we measured how much of the incident light was reflected. Having repeated this algorithm on varying surface roughnesses we find the albedo as a function of the Hurst exponent, the geochemical composition of the magma, and the wavelength. As a proof of concept, we used our model on Kepler-10 b to demonstrate the applicability of our equations. We present the albedos of different lava compositions and multiple tests that can be applied to observational data in order to determine the characteristics of the lava. When applied to Kepler-10 b we show that the high albedo could be caused by a moderately wavy ocean composed of oxidised metallic species such as FeO, Fe2O3, Fe3O4, and some silicates. This would imply that Kepler-10 b is a coreless or near-coreless body. However, since the uncertainty in albedo measurements is large there is a strong degeneracy in the surface composition.
Feb
19
mer
Seminario: S. Sciortino (INAF), ore 14:30 Aula Osservatorio
Feb 19@14:30–16:00

Speaker: Salvatore Sciortino (INAF)

Titolo: A prototype Palermo- Wavelet Detection Code for the
ATHENA WFI: investigating the effect on detection of telescope (or lack of) baffle
and other new challenges posed by very deep exposures of a large area telescope

Abstract:

I will discuss the motivations for and the initial results of a prototype
version of the so-called Pwedetect code for the Athena WFI.  I will discuss the
use of this prototype for assessing the effect of stray-light in the detection
of weak sources with Athena and results from an on-going extensive set of
simulations that have already pinpoint some of the new challenges that the WFI
poses with respect to the past and current generation of X-ray imaging detectors.

Feb
20
gio
Visite al Museo – Esperienza Insegna
Feb 20@8:30–13:30
SEMINARIO: Ileana Chinnici (INAF – OAPa) – Aula Osservatorio ore 15
Feb 20@15:00–16:30

Titolo:

Dalla Società degli Spettroscopisti Italiani alla Società Astronomica Italiana: storia della SAIt

Abstract:

Cent’anni fa, nel 1920, nel corso di una riunione tenutasi all’Accademia dei Lincei, nasceva la Società Astronomica Italiana, come risultato della trasformazione della Società degli Spettroscopisti Italiani. In questo talk saranno ripercorsi i passaggi salienti che hanno portato alla nascita della SAIt, con un breve excursus sui suoi primi cinquant’anni di vita.

Feb
21
ven
Visite al Museo – Esperienza Insegna
Feb 21@8:30–13:30