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STUDIES OF THE POYNTING-ROBERTSON EFFECT IN ACCRETION PHYSICS PHENOMENA

English title STUDIES OF THE POYNTING-ROBERTSON EFFECT IN ACCRETION PHYSICS PHENOMENA
Applicant Falanga Maurizio
Number 149865
Funding scheme Project funding
Research institution International Space Science Institute (ISSI)
Institution of higher education Other Research Institutes - FINST
Main discipline Astronomy, Astrophysics and Space Sciences
Start/End 01.02.2014 - 31.07.2017
Approved amount 202'463.00
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Keywords (3)

binary systems, disk accretion; black holes, neutron stars, AGN; General Relativity

Lay Summary (Italian)

Lead
Il progetto considera sistemi binari di raggi X dove la materia è cresciuta su una stella di neutroni o su un buco nero di massa stellare nonché nuclei galattici attivi, cioè galassie ospitanti un buco nero supermassivo al loro centro. Il moto della materia nella vicinanza dell’orizzonte degli eventi ci da la possibilità di studiare la distorsione dello spazio-tempo, permettendoci di inferire importanti caratteristiche come la massa ed lo spin. Questo è un’opportunità unica di studiare la gravità in un regime di campo forte e rappresenta un'evidenza sperimentale per testare la Relatività Generale sotto condizioni estreme. Dopo decenni di osservazione, ci sono ancora molti punti da chiarire come per esempio la materia (intorno ad un oggetto compatto) viene influenzata dal punto di vista relativistico e della radiazione.
Lay summary

Nel seguente progetto di ricerca noi proponiamo di chiarire queste questioni attraverso differenti tecniche complementari che coinvolgono sia modelli teorici che l’analisi dei dati osservativi. Noi proponiamo un nuovo approccio che include modelli teorici non esplorati precedentemente i quali contemplano gli effetti della radiazione sul moto delle particelle nel disco di accrescimento; si fa anche uso di avanzate analisi spettrali e di cronometraggio con le quali comparare il modello con i dati reali disponibili da passati, presenti e futuri satelliti spaziali. In particolare: - Gli effetti della presenza del campo di radiazione sulla dinamica del flusso di accrescimento sarà incluso nel modello proposto. Questo modello appoggia le sue fondamenta sul cosiddetto effetto Poynting-Robertson, un fenomeno che è stato per primo preso in considerazione nel contesto della planetologia e nello studio del moto delle comete e della polvere nel sistema solare. Noi svilupperemo un codice numerico per simulare il moto del plasma nei dischi di accrescimento e così la K-linea di Fe osservata e la variabilità delle curve di luce includenti l’effetto Poynting-Robertson nel pieno contesto relativistico. - Noi useremo il tempo risoluto tramite dati di raggi X e tecniche di analisi spettrale per confrontare I risultati del codice con le osservazioni nello scopo di adattare I parametri del codice e cercare  di dare nuove ed innovative spiegazioni ad alcune caratteristiche osservate riguardo sorgenti fortemente accresciute.

Sarà necessario assumere uno student PhD per sviluppare codici numerici per queste applicazioni astrofisiche riguardo l’effetto Poynting-Robertson in Relatività Generale.

 

Direct link to Lay Summary Last update: 07.02.2014

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Lagrangian formulation of the general relativistic Poynting-Robertson effect
De FalcoVittorio, BattistaEmmanuele, FalangaMaurizio (2018), Lagrangian formulation of the general relativistic Poynting-Robertson effect, in Physical Review D, 97(8), 1-11.
The transitional millisecond pulsar IGR J18245-2452 during its 2013 outburst at X-rays and soft gamma-rays
De Falco V., Kuiper L., Bozzo E., Ferrigno C., Poutanen J., Stella L., Falanga M. (2017), The transitional millisecond pulsar IGR J18245-2452 during its 2013 outburst at X-rays and soft gamma-rays, in Astronomy & Astrophysics, 603, A16-A16.
The 2015 outburst of the accretion-powered pulsar IGR J00291+5934: INTEGRAL and Swift observations
De Falco V., Kuiper L., Bozzo E., Galloway D. K., Poutanen J., Ferrigno C., Stella L., Falanga M. (2017), The 2015 outburst of the accretion-powered pulsar IGR J00291+5934: INTEGRAL and Swift observations, in Astronomy & Astrophysics, 599, A88-A88.
Approximate analytical calculations of photon geodesics in the Schwarzschild metric
De Falco Vittorio, Falanga Maurizio, Stella Luigi (2016), Approximate analytical calculations of photon geodesics in the Schwarzschild metric, in Astronomy & Astrophysics, 595, A38-A38.

Collaboration

Group / person Country
Types of collaboration
Astronomical Institute, Academy of Sciences of Czech Republic, Prague Czech Republic (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Univ. of Basel Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Osservatorio di Roma Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
ISDC, Obs. of Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
ICRA, University of Roma "La Sapienza" Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Seminar Physics Department Univ. of Hong Kong Individual talk Millisecond X-ray Pulsars: 15 Years of Progress 14.07.2017 Univ. of Hong Kong, Hongkong Falanga Maurizio;
Seminars for Astrophysics, University of Oxford Individual talk Approximate analytical calculations of photon geodesics in the Schwarzschild metric 05.07.2017 University of Oxford, Great Britain and Northern Ireland De Falco Vittorio;
Seminar at the NCU, astronomy Department Individual talk Millisecond X-ray pulsars: 15 years of  progress 05.06.2017 NCU, , Taiwan Falanga Maurizio;
Seminars in Astrophysics, ZARM, University of Bremen Talk given at a conference Approximate analytical calculations of photon geodesics in the Schwarzschild metric 28.02.2017 ZARM, University of Bremen, Germany, Germany De Falco Vittorio;
ISSI Bern Team led by S. Motta and T. Belloni on "There it Spins: the Hunt for Black Hole Spins" Talk given at a conference Approximate analytical calculations of photon geodesics in the Schwarzschild metric 06.02.2017 ISSI, Bern, Switzerland De Falco Vittorio;
ISSI team led by D. Galloway on Nuclear Reactions in Superdense Matter - From the Laboratory to the Stars Talk given at a conference The bursts of three different Accreting Millisecond X-ray Pulsars using the Integral data: IGR J00291+5934, IGR J18245-2452, and SAX J1748.9-2021 30.01.2017 ISSI, Bern, Switzerland De Falco Vittorio;
Seminars at the Silesian University in Opava (Czech Republic) Talk given at a conference Accretion disks in Kerr metric including the Poynting Robertson effect 20.04.2016 Silesian University in Opava, Czech Republic De Falco Vittorio;
28th Texas Symposium on Relativistic Astrophysics in Geneva Talk given at a conference Approximation of relevant elliptical equations in the Schwarzschild metric and some astrophysical applications 13.12.2015 Geneva, Switzerland, Switzerland De Falco Vittorio;
Italy National Congress on Compact Objects (CNOC IX) in Rome Talk given at a conference Approximation of relevant elliptical equations in the Schwarzschild metric and some astrophysical applications 22.09.2015 Rome, Italy, Italy De Falco Vittorio;
European Week of Astronomy and Space Science Talk given at a conference Chair of a session: Neutron stars at the crossroads: X-ray binaries and transitional millisecond pulsars 22.06.2015 La Laguna, Tenerife, Canary Islands, Spain, Spain Falanga Maurizio;
The 10th INTEGRAL Workshop "A Synergistic View of the High Energy Sky" Talk given at a conference Eclipsing High Mass X-ray Binaries: 10 years of INTEGRAL observations 15.09.2014 Annapolis, Md, USA, United States of America Falanga Maurizio;


Associated projects

Number Title Start Funding scheme
169044 Interdisciplinary Research at the International Space Science Institute (ISSI) 01.10.2016 Research Infrastructure

Abstract

The physics of accretion onto compact objects has been experiencing a golden age in terms of discoveries for many decades. Space satellites like XMM-Newton, INTEGRAL (ESA missions), RXTE and Chandra (NASA missions) have collected over the years a wealth of information, which have in turn provided astronomers with new insights into the physics of X-ray sources. The project considers X-ray binary systems where matter is accreted onto a neutron star (NS) or a stellar-mass black hole (BH). We are also interested in Active Galactic Nuclei (AGN), i.e., galaxies very likely hosting a supermassive black hole at their center, which is thought to accrete mass at a huge rate, allowing such sources to be very bright at different wavelengths.For all of these objects, the X-ray part of the emitted spectrum gives us clues about the processes occurring in the innermost regions of the accretion disk. In the case of black holes, the motion of matter in the vicinity of the event horizon lets us to investigate the space-time distortion generated by the central object, allowing us to infer important characteristics such as its mass and spin. This is also a unique opportunity to study gravity in the strong-field regime and represents a very powerful diagnostic to validate the predictions of General Relativity under extreme conditions.After decades of observations, there are still many points to be addressed and to be given an adequate explanation. Among these, are: is the profile and variability of the very broad Fe K-line that is observed in many AGNs due to matter orbiting the disk very close to the innermost stable circular orbit? What is the origin of the observed Quasi-Periodic-Oscillations (QPOs) in the power spectrum of neutron stars and black holes binaries light-curves? Do current models include all the relevant physical processes and are they adequate to fit and interpret the data?In the research project we propose a program to address this issues through different complementary techniques, which involve both theoretical modeling and observational data analysis. We put forward a new approach which includes unprecedentedly-explored theoretical models comprising the effects of radiation on the motion of particles in the accretion disks; we also make use of advanced spectral and timing analysis with which to compare the model with real data available from past, current and future space satellites. In particular:•The effects of the presence of a radiation field on the dynamics of the accretion flow will be included in the proposed model. This model lays its foundations on the the so-called Poynting-Robertson effect, a phenomenon which has been first taken into account in the context of planetology and in the study of the motion of comets and dust in the solar system. We will develop a numerical code for simulating the motion of the plasma in accretion disks an thus the observed Fe K-line and light-curves variability including the Poynting-Robertson effect in a fully-relativistic picture.•We will use time resolved X-ray data and spectral analysis techniques to compare the code results with observations in the aim of adjusting the code parameters and try to give new and innovative explanations to some observed features of accretion-powered sources.It will be necessary to hire a PhD student in order to develop numerical codes for these astrophysical applications of the GR Poynting-Robertson effect.
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