PERSPECTIVES OF THE RADIO ASTRONOMICAL DETECTION OF EXTREMELY HIGH ENERGY NEUTRINOS BOMBARDING THE MOONR.D. Dagkesamanskii1) , I.M. Zheleznykh2) and V.A. Matveev 3)1) – Pushchino Radio Astronomy Observatory of the Lebedev Physical Institute, Russian Academy of Sciences 2) – Institute for Nuclear Research, Russian Academy of SciencesVLVνT-09
- Earth’s atmosphere,
- Lake and sea waters,
- Ice massifs,
- Moon regolith – the subject of this talk/
1. R.D.Dagkesamanskii and I.M.Zheleznykh (1989).
2. G.A.Gusev and I.M.Zheleznykh (1983)
3-4. G.A.Askaryan (1961, 1965).
5. P.Gorham, D.Saltzberg et al. (2000).
The antenna beamwidths are ~11' at 1.4 GHz and ~7' at 2.3 GHz. The expected events should be near the limb of the Moon, so the pointing was at 14' apart from the center of the MoonPosition of the antenna beams on the Moon
Our main results- Today the total “live-time on the Moon” is slightly more than 150 hrs with threshold level of 3500 Jy. - With this “exposition” we also had not found any reliable radio pulse similar to Cherenkov emission pulse. - So, our sensitivity and exposition are close to GLUE one. However, combined estimate of the upper limit to the SHE neutrino flux is more conservative than GLUE’s one. Certainly, it is mainly due to our less optimistic estimate of the effective target volume . Another (additional) cause: it could be due to different slopes adopted for neutrino spectrum above 1020eV or differences in some other model parameters.
How to improve our estimates ? Here is some of the obvious ways:1. Increasing the “live-time on the Moon” (i.e. make more and more observations). 2. Increasing the sensitivity (use wider receiver bandwidths and coincidence schemes). 3. Reduce the thresholds and use some kind statistic analysis of the suspicious events. All these ways are rather hard.
SOME OTHER PERSPECTIVES 1. To optimize observational frequency range. NuMoon experiment. Possibilities of Indian GMRT and Ooty radio telescopes. 2. To observe more time during the AGNs occultations by the Moon. (Some correlation was found between the direction to nearby AGNs and SHE cosmic ray’s arrival directions. (Australian team). 3. Lunar Orbital Radio Detector proposed by LPI team (V.Tsarev et al., 2005). 3. International cooperation similar to that proposed by I.Zheleznykh in 1988.
International cooperationThe possible scheme of international cooperative observaions proposed by I.Zheleznykh in 1988. Such observations will be very useful: they improve sensitivity, increase the reliability of results, and even could help us to determine the direction to the UHE neutrino source.