Piero Galeotti
Università di Torino and INFN
GianVittorio Pallottino
Università di Roma and INFN
Guido Pizzella
Università di Roma Tor Vergata
INFN- Frascati
SN1987A revisited
Results from LSD and
KAMIOKANDE
2h56m
7h35m
LSD
Kamioka
0
Hours of 23 February 1987
Mont Blanc ~ 45 pulses/hour > 5 MeV
Kamiokande ~ 85 pulses/hour > 7.5 MeV
(7.5 MeV corresponds to Nhit=20)
8
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. B19 3 :5 1 4 (1 9 87)
V. S. Berezinsky, C. Castagnoli,
V.I.Dokuchaev , P.Galeott i
On the po ssibilit y of a two -bang
supernova collapse
N. Ciment o 1 1, 3, 2 8 7 (1 9 88)
V. S.Imshennik
Space Science Rev., 7 4, 3 2 5 (19 9 5)
V. S.Imshennik and O.G.Ryashskaya
Ast ronomy Letters, 30 ,1 4 -31 (2 0 04)
New analysis
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
relative Kamiokande time
IMB
no
IMB
11  in 12 s
Nh>20
7  in 6 s
Nh > 21
relative Kamiokande time
IMB
E>15 MeV
no
IMB
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
The algorithm
C(f) =
1/N Si {ER(ti+f ) + EM(ti+f )}
N
number of pulses (in the neutrino detector)
in a given period (say, one hour)
ti
time of a pulse
f
common time shift for a possible delay
The background
Cb(f1, f2) =
1/N S {ER(f1) + EM(f2)}
N
f1, f2
number of pulses (in the neutrino detector)
in a given period (say, one hour)
random time shifts for the background
We perform N random
extractions of f1, f2 for the
background and count the
number n of times when
Cb(f1, f2) > C(f)
N= one million random data for the background
C(f1.1)=72.6 K
Cb(f1, f2) with random f1, f2
Mont Blanc 1:45 - 3:45 ( 5-neutrinos at 2:56 U.T.)
n
C(-1.1)
F +1.2 (second)
What about Kamiokande ?
(absolute time uncertainty ±1 min)
fc is the time correction in s
best fc=7.8 s
Kamiokande has a time error ± 1 minute
Kamiokande time correction
+ 7.8 s
Schramm and Truran (1990)
IMB
K
New analysis of the original data
Periods of one hour moved in steps of 6 min
n
(N=105)
hours of 23 February
n
(N=104)
with time correction of 7.8 s
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 noi
accomodiamo l’intelleto nostro a quello che ella
ha fatto, sicuri tale essere l’ottimo et non altro.
Galileo
in
1612
to
THE END
Federico
Cesi.