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Piero GaleottiUniversità di Torino and INFN
GianVittorio PallottinoUniversità di Roma and INFN
Guido PizzellaUniversità di Roma Tor VergataINFN- Frascati
SN1987A revisited
Results from LSD and KAMIOKANDE
Hours of 23 February 1987
Mont Blanc ~ 45 pulses/hour > 5 MeVKamiokande ~ 85 pulses/hour > 7.5 MeV (7.5 MeV corresponds to Nhit=20)
0 8
LSD
Kamioka
2h56m
7h35m
Mont Blanc neutrino telescope 1987
Kamiokande neutrino telescope 1987
Hirata et al.PR D 448 (1988)
May the Supernova Bang more than once ?
A.DeRujula Phys.Lett. B193:514 (1987) V.S. Berezinsky, C. Castagnoli, V.I .Dokuchaev, P.Galeotti On the possibility of a two-bang supernova collapse N. Cimento 11, 3, 287 (1988) V.S.Imshennik Space Science Rev., 74, 325 (1995) V.S.Imshennik and O.G.Ryashskaya Astronomy Letters, 30,14-31 (2004)
Kamiokande neutrino telescope 1987
The data have been supplied to us by the Kamiokande collaboration in 1987. We have acknowledged the
collaboration in several papers
New analysis
relative Kamiokande time
IMB
noIMB
11 in 12 sNh>20
11 in 12 sNh>20
7 in 6 sNh > 217 in 6 sNh > 21
relative Kamiokande time
IMBE>15 MeV
noIMB
E<15 MeV
Correlation of the Kamiokande and LSD neutrino detectors with
the Rome and Maryland gravitational wave detectors
We have searched for possible correlations between the signals
of the neutrino detectors and those of the g.w. detectors
C() =
1/Ni{ER(ti+ ) + EM(ti+ )}
N number of pulses (in the neutrino detector)
in a given period (say, one hour)
ti time of a pulse
common time shift for a possible delay
The algorithm The algorithm
Cb(1, 2) =
1/N{ER(1) + EM(2)}
N number of pulses (in the neutrino detector)
in a given period (say, one hour)
1, 2 random time shifts for the background
The background
We perform N random extractions of 1, 2 for the background and count the number n of times when
Cb(1, 2) > C()
Cb(1, 2) with random 1, 2
C()=72.6 K
N= one million random data for the background
Mont Blanc 1:45 - 3:45 ( 5-neutrinos at 2:56 U.T.)
+1.2 (second)
n
C(-1.1)
What about Kamiokande ?
(absolute time uncertainty ±1 min)
best c=7.8 s
c is the time correction in s
IMB
K
Kamiokande has a time error ± 1 minute
Kamiokande time correction + 7.8 s
Schramm and Truran (1990)
New analysis of the original data
hours of 23 February
with time correction of 7.8 s
Periods of one hour moved in steps of 6 min
n (N=105)
n(N=104)
CONCLUSIONS
This new analysis reinforces the idea of a long duration activity of
SN1987A in the neutrino emission.
…noi non doviamo desiderare che la natura si accomodi a quello che parrebbe meglio disposto et ordinato a noi, ma conviene che noiaccomodiamo l’intelleto nostro a quello che ella ha fatto, sicuri tale essere l’ottimo et non altro.
Galileo in 1612 to Federico Cesi.
THE ENDTHE END