Summary of the Multi-Messenger Astronomy Workshop Garmt de Vries Les Houches, 2002 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Multi-Messenger Astronomy Workshop • Organisers: D. Smith & A. Barrau • 2 sessions planned • 2 sessions added Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Goal of the workshop: To dive into the wonderful world of astrophysical catalogues! Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
We play a little game: • Imagine a 0.1 km 2 detector with 3 years of data resolution ~ 1 o • After subtracting the atmospheric background there is one bin with 7 events: RA = 12 h 34’ δ = - 56.78 o • What can this be? Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Possible explanations • Statistical fluctuations • Gamma Ray Burst (GRB) • SuperNova (SN) • Pulsar, SuperNova Remnant (SNR) • Active Galactic Nucleus (AGN) • SuperSymmetry (SUSY) • Microquasar • ............... Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
How to play the game? • Look in catalogues at this place • Look for coincidence with VIRGO, HETE, AUGER, ... • Look at various models ⇒ Which model(s) can be excluded? ⇒ Which model(s) explain(s) the data best? We split up into subgroups and investigate the various hypotheses Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Let the game begin! Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Statistical fluctuations (S. Cartwright et al.) It is known from previous experience that: 30 bins give a background of 3 events/year ⇒ expect ~ 0.3 event/bin in 3 years ⇒ Probability of finding 7 events in this bin: 3.2 10 -8 ⇒ Probability of finding 7 events in at least one of the 40,000 bins: 1.3 10 -3 ⇒ Probably not a statistical fluctuation Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
GRB (S. Ferry et al.) There are 3 GRBs close to RA = 188.5 o δ = - 56.78 o in the BATSE catalogue: 4B950628 RA = 180 o δ = -55.88 o Error box radius: l = 295.72 o b = 6.27 o 4.93 o GRB961224 RA = 182.84 o δ = -64.64 o Error box radius: l = 298.66 o b = -2.11 o 5.4 o GRB971210 RA = 176.91 o δ = -51.95 o Error box radius: l = 293.04 o b = 9.69 o 1.11 o Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
GRB (continued) Possible actions: • Send alert to SN people (GRB ↔ SN?) • Try to get timing information • Look for γ -rays • If both γ and ν observed ⇒ GRB not leptonic • If no γ observed ⇒ choked GRB? (look for afterglow!) ⇒ Multi-messenger interplay is certainly possible Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
AGN (N. Girard et al.) There is no quasar near RA = 188.5 o δ = - 56.78 o Other types of AGN have not been looked for Anyway, hadronic models predict ~ 100 times fewer ν events ⇒ This hypothesis can be excluded Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Microquasar (S. Karkar et al.) No microquasar was seen near RA = 188.5 o δ = - 56.78 o ⇒ This hypothesis can be excluded Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
SUSY (S. Cartwright et al.) One could expect a SUSY signal from: • Galactic centre • Sun • Centre of the earth None of these are close to RA = 188.5 o δ = - 56.78 o ⇒ Perhaps a galactic halo clump? One would also expect to see ~ 10 GeV γ -rays ⇒ Further investigation needed Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Diffuse background (A. Romeyer et al.) Yellow area: 4 σ detection possible ⇒ It seems to be difficult to get a good signal Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Conclusions Our cluster of 7 events is not due to statistical fluctuations To say more, we need further information: Time Energy Other messengers Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrino Astronomy with MACRO This paper describes exactly the game we played Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrino Astronomy with MACRO Search for pointlike sources with clustering algorithm: Look in 1.5 o , 3 o , 5 o around each of the 1100 muon events ⇒ 60 clusters of ≥ 4 events found in 3 o cone RA δ # events 222.5 o -72.7 o 7 188.1 o -48.1 o 6 342.5 o -74.4 o 6 Compatible with atmospheric ν background Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrino Astronomy with MACRO Search among known point sources: Make a list of 42 sources that look interesting Look in 1.5 o , 3 o , 5 o around each of these sources Everything is compatible with atmospheric ν background Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrino Astronomy with MACRO MACRO observed neutrinos from the direction of microquasar GX 339 – 4: “We notice that there are six events from GX 339 – 4 in a 3 o search cone with chance probability P = 6 × 10 -3 . Considering that we have looked at 42 sources, the probability of finding such an excess from at least one of these sources is 8.6%.” Still, this source was interesting enough for our working group to investigate it Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Microquasars (courtesy F. Mirabel) Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
GX 339 – 4 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
GX 339 – 4 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
GX 339 – 4 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrinos from GX 339 – 4 -46,5 -47 2000 -47,5 -48 -48,5 -49 -49,5 -50 -50,5 -51 250 252 254 256 258 260 262 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrinos from GX 339 – 4 GX339-4 30 25 20 15 10 5 0 10/10/95 21/02/97 06/07/98 18/11/99 01/04/01 50000 50500 51000 51500 52000 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
The big question: How surprising is it to see 7 neutrinos from GX339 – 4 during and after its active period? Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrinos from microquasars Presentation by D. Guetta: Predictions of neutrino fluxes from microquasars ⇒ GX339 – 4 is one of the most powerful neutrino sources among microquasars: ~ 200 upward going muon events per year in 1 km 3 However: This prediction is based on the assumption that GX339 – 4 is persistent. The active state has not been taken into account. Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrinos from microquasars There is no a priori connection between soft X-ray activity and neutrino emission Correlation between dip in ~ 50 keV photons and neutrino emission could be understood: Source optically thick for these γ ⇒ more γ present that can serve as a target for ν production But the connection is not very clear... Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Statistics What is the probability of seeing these 7 neutrinos from the direction of GX339 – 4 ? 3 × 10 -3 Seeing 7 neutrinos during 7 years Seeing 3 neutrinos during the 450 days 4 × 10 -3 active period Seeing 3 neutrinos clustered in a 30 day 1 × 10 -4 period during 7 years ⇒ Chance probability ~ few × 10 -3 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Statistics We need the probability of finding 7 events from at least one of the sources considered: Looking at all 42 sources on the MACRO list: Looking only at the microquasars on the list: Looking only at GX339 – 4 and SS433, for which a high neutrino flux is predicted: P ≈ 8.6 × 10 -2 P ≈ 1 × 10 -2 P ≈ 6 × 10 -3 But how valid is all this? Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Other signals? Super-K sees nothing AMANDA GX339 – 4 is above AMANDA’s horizon ?? BATSE terrestrial gamma flashes? ?? ANTARES GX339 – 4 is visible for 19.6 hrs/day Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Neutrinos from other microquasars? A high flux is also predicted for microquasar SS433 (835 events year -1 km 3 ) MACRO sees no neutrinos from this sources SS433 15 10 No active 5 periods! 0 -5 -10 50000 50500 51000 51500 52000 52500 Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
☺ Neutrinos from other microquasars? ☺ ☺ ☺ A very bold assumption: ☺ ☺ ☺ Microquasars emit neutrinos Microquasars emit neutrinos ☺ ☺ ☺ ☺ during their active state during their active state ☺ ☺ ☺ One would have to look at all the microquasars in MACRO’s ☺ ☺ field of view, and search for a correlation. ☺ ☺ Two things may happen... Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
Further ideas: • .................................... • .................................... • .................................... • .................................... • .................................... • .................................... • .................................... • .................................... Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
To be continued... Multi-Messenger Astronomy - Garmt de Vries - Les Houches 2002
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