Gamma-Ray Burst observations by the Square Kilometre Array. New perspectives

354 Pages·2015·9.23 MB·English

by  Alan Cosimo Ruggeri

Universit`a degli Studi di Napoli Federico II
DOTTORATO DI RICERCA IN
FISICA FONDAMENTALE ED APPLICATA
Ciclo: XXVII
Coordinatore: Prof. Raffaele Velotta
Gamma-Ray Burst observations by
the Square Kilometre Array. New perspectives
Settore Scientifico Disciplinare FIS/05
Dottorando Tutore
Alan Cosimo Ruggeri Prof. Salvatore Capozziello
Anni 2012/2015

Non fidarti di coloro che in ogni momento ti riempiono di lodi e ti inondano di compli-
menti. I veri amici sono quelli che hanno il coraggio di dirti che sei un cretino, quando
ritengono che tu stia sbagliando.
Un cretino
Don’t trust people who compliment and praise you at anything. Good friends are brave
enough to call you an idiot, when you are wrong.
An idiot

Papers related to the Ph.D.
1. Capozziello S., De Laurentis M., Ruggeri A. C. Dark energy observational tests
and the SKA perspective. In Feretti L., Prandoni I., Brunetti G., Burigana C.,
Capetti A., Della Valle M., Ferrara A., Ghirlanda G., Govoni F., Molinari S., A.
P., Scaramella R., Testi L., Tozzi P., Umana G., Wolter A., editors, Italian SKA
White Book. INAF Press, 2014. ISBN ISBN 978-88-98985-00-5
2. Capozziello S., De Laurentis M., Luongo O., Ruggeri A.C. Cosmographic Con-
straintsandCosmicFluids. Galaxies,1:216260,December2013. doi: 10.3390/galax-
ies1030216
3. Amati L., Ruggeri A. C., Stratta G., Capozziello S., De Laurentis M., Della
Valle M., Luongo O. The SKA contribution to GRB cosmology. Science with the
Square Kilometre Array, Accepted.
4. Ruggeri A. C., Dainotti M. G., Capozziello S. Possible detection of Gamma Ray
Bursts in the radio band by the Square Kilometre Array. Mon. Not. R. Astron.
Soc., Submitted, 2015
Two internal reports for the SKA-dish consortium with the SAM/EIE Companies:
1. Parziale S., Ruggeri A.C., Aurigemma R., Formentin F., De Lorenzi S., “Feed
location maintenance concept analysis”
2. Parziale S., Ruggeri A.C., Aurigemma R., De Lorenzi S., “Feed Indexer and
PAF de-rotation”
v

Abstract
Doctor of Philosophy
Gamma-Ray Burst observations by
the Square Kilometre Array. New perspectives
by Alan Cosimo Ruggeri
Gamma-Ray Bursts (GRBs) are the most powerful astrophysical source in the universe
and have been studied since the ’70s. Nevertheless, these objects are still not completely
understood and many hypotheses have not been confirmed yet. Past and current obser-
vationshavebeenmademostlyatgamma,Xandopticalfrequencies. Thisthesisaimsto
promote radio GRB observations, in order to thin out a menagerie of different opinions
about these sources. In fact, GRBs have been prevalently studied as single cases, more
often highlighting their peculiar features than elucidating their common characteristics,
and thus leading to fragment the problem. Here the general properties are discussed, so
that the attention is moved from the exception to the general case. In other words, this
work suggests viewing GRBs in a broad ensemble instead of searching out single cases
to explain every peculiarity and as a result increasing the number of possible groups to
categorize them.
This work concerns astrophysics, Gamma-Ray Bursts (GRBs) sources, the Square Kilo-
metre Array (SKA) radio telescope, radio observations and cosmology. For this reason,
it has been divided into three parts, with six chapters in total. Each chapter is a step
thatleadstothenextonefollowingaprecisescheme. Intheend, allthisworkhighlights
both the importance of GRB radio observations and their real feasibility.
The first part concerns the high energies and consists of two chapters. The first chap-
ter contains an overview about GRB state of the art, showing how from the gamma
range the GRB afterglow emission reaches the lower frequency range up to the radio
band. The second chapter passes from the theory to the practice, where different GRB
satellite missions are listed with their gamma payloads, having thus an idea about GRB
detection.
The second part is dedicated solely to the radio observations. Chapter 3 regards ra-
dio instrumentations and so the SKA is introduced here. This chapter may need some
elucidation. My Ph.D. has been carried out between the University and the Societ`a
Aerospaziale Mediterranea S.c.r.l. company, hence on one hand I have been able to con-
duct a study about GRBs, on the other hand I have had the opportunity to collaborate
with a company in charge of designing the feed indexer of the SKA. This mechanical
component will be assembled with the telescope antenna to select the receivers during
the radio observations and details are contained in the chapter.
Since the SKA is a interferometer, chapter 4 regards the radio interferometry. This
brief introduction to interferometry helps for the reading of the next chapter, where
GRB radio observations are discussed. Chapter 5 concerns principally three works in
radio astronomy. Firstly, the first radio observations ever for a very large GRB sample
are presented. Secondly, the first considerations deduced from analyses of those first
results. Finally, a work of mine currently submitted to the Monthly Notices of the Royal
Astronomical Society where it is discussed the GRB detection rate for the SKA.
Afterdiscussionsofobservationaltechniques,detectionsandpossibleobservationalstud-
ies in the radio band about GRBs, the third part and its last chapter close the thesis
by explaining what advantages a precise and complete study of GRBs can provide for
cosmology. Indeed, thesesourceswillbeabletoshinealightonthevariouscosmological
models created to attempt to explain the expansion of the universe. This last point will
be possible only when GRBs are studied proceeding with the precise method suggested
here, considering GRBs as complex sources which must be observed and analyzed at all
available wavelengths.
Acknowledgements
I acknowledge my supervisor, Prof. Salvatore Capozziello, and the project “Dottorato
in Azienda” by Regione Campania.
Thanks to the Societ`a Aerospaziale Mediterranea S.c.r.l. (SAM) Company and its Pres.
ing Luigi Iavarone. Thanks to my company supervisor, ing. Renato Aurigemma. Ac-
knowledgements also to the European Industrial Engineering S.r.l. (EIE - Group) Com-
pany for their collaboration with the SAM.
An additional acknowledgement to Prof. Patrick Alan Woudt of the the University of
Cape Town (UCT), who allowed me time abroad in South Africa, at the Department of
Astronomy of the UCT. Many thanks for his help and our discussions concerning radio
astronomy.
Also acknowledgements to the “SKA guys”, in particular Thomas Kusel, Jean Kotze
and Niesa Burgher. Thanks to them I was able to go the MeerKAT situ, in the Karoo
Desert.
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