Calendar

Set
1
gio
Visita Museo Jordie Sans Forcada
Set 1@9:30–11:00

Visita Museo Jordie Sans Forcada

7 pax

Set
6
mar
Visita museo 2 persone: Aiello
Set 6@9:00–10:00

Aiello ore 9

 

Seminario: R. Giuffrida (UNIPA)
Set 6@15:00–16:30

Seminario in forma ibrida

Indirizzo Google meet: https://meet.google.com/sxz-cctp-tsc

Speaker: R. Giuffrida (UNIPA)
Titolo: The supernova remnant SN 1006 as a Galactic particle accelerator
Abstract:
The origin of cosmic-rays is an open issue of high-energy astrophysics. Supernova remnants are expected to be the main source of Galactic cosmic rays up to energies of about 3 PeV, provided that they transfer a significant fraction of their kinetic energy to the particles (∼ 10%). In particular, the loss of such a large fraction of energy is predicted to alter the shock dynamics by enhancing the shock compression ratio above the canonical value of 4 (shock modification). The bilateral supernova remnant SN 1006 is an ideal target to study shock modification because of its evolution in a fairly uniform environment. SN 1006 shows bright synchrotron X-ray emission from ultrarelativistic electrons accelerated at the shock front in its northeastern and southwestern limbs. If efficient hadron acceleration occurs in these regions, we should observe shock modification therein. We performed a spatially resolved spectral analysis of Chandra and XMM-Newton observations of SN 1006 by selecting narrow regions between the shock front and the contact discontinuity and measuring the density of the X-ray emitting plasma. Our results show an increase of the compression ratio from the characteristic value of 4, in thermal limb, up to ∼ 7 in nonthermal limbs, i.e. in regions where the ambient magnetic field is almost parallel to the shock velocity. We conclude that an efficient particle acceleration causes shock modification in quasi-parallel shocks in SN 1006. By comparing our results with state-of-the-art models, we find that SN 1006 is transferring a significant fraction of its kinetic energy to hadrons. The inferred values of compression ratios and cosmic ray slopes are consistent with those expected for modified shocks when the effects of the postcursor are included.

Set
7
mer
Telecon Sara, Loredana, Jesus, Paolo (remoto)
Set 7@11:30–12:30
Set
8
gio
Incontro con tesista (Sara Bonito, Giovanni Peres, Alessandro Tramuto)
Set 8@10:00–11:00
visita museo ARS 4 pax
Set 8@10:00–11:15

visita museo ARS 4 pax

Tesista Giovanni Peres
Set 8@11:00–13:00
Set
9
ven
Restart e visite notturne al museo della Specola
Set 9@18:30–23:45

Totale 20 pax + 4 guide Amici dei Musei

Set
12
lun
Laboratorio di restauro fotografico
Set 12@9:00–Set 16@17:00
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Set
13
mar
Telecon Serena
Set 13@14:00–18:00