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OSETI with MAGIC

OSETI with MAGIC. Introduction Radio SETI Optical SETI OSETI with MAGIC Summary. July 2004. ~ 110 Jupiter-like planets discovered so far. Earth-like planets still remains undetected due to the mass sensitivity limit of the experiments. Introduction.

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OSETI with MAGIC

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  1. OSETI with MAGIC Introduction Radio SETI Optical SETI OSETI with MAGIC Summary July 2004

  2. ~ 110 Jupiter-like planets discovered so far. Earth-like planets still remains undetected due to the mass sensitivity limit of the experiments. Introduction • Philosophically: since the time of ancient Greek civilization, some people think that Earth is not a special place: • “Principle of Mediocrity”. • Scientifically: • recent development on Astrometry and Planetary Search: • rocky habitable planets expected to be found (NEWTON/TPF). • different environments can also evolve life taking profit of some different energy sources → planets evolving life much more probable. • After that, to become an intelligent kind of extra-terrestrial life could be just a question of time. 14th ISCRA Course, Erice 2004

  3. Introduction Drake equation • The number N of intelligent communicative civilizations in our galaxy can be estimated by the known as Drake equation • where • R is the yearly rate at which stars form in the galaxy (1 yr-1) • fpis the fraction of stars that possesses planets (0.5) • n is the number of planets with environment suitable for life (2) • fl is the fraction of planets on which life actually develops (1) • fi is the fraction of these planets in which life develops intelligence (1) • fc is the fraction of intelligent life forms that developes a culture capable of interstellar communication (0.1) • L is the time that this culture will devote to communication (106 yr) • Supposing optimistic parameters → high N (e.g., those in brackets lead us to N = 105 communicative ETC) → Fermi Paradox: “where are they?” N = R · fp · n · fe · fi · fc · L 14th ISCRA Course, Erice 2004

  4. Natural diffuse background SETI Radio SETI (traditional) Cocconi & Morrison (1959) → proposition of MASERS operating at HI frequency (1.4GHz). Moderate RF/MW background & high development of radio communication Frank D. Drake (Project Ozma, 1961) → first scientific search based on the idea of C&M, searching for HI emissions SETI programs now are restricted by radio-telescopes observations. Present searches: try to enhance their signal detection→ interference & instrumental background reduction. At the moment, there are no significant signal for any of the observed targets. 14th ISCRA Course, Erice 2004

  5. Optical SETI (OSETI) • Based in optical LASER: • LASER devices have more power than MASER. • They operate in the optical range → higher bandwidth (faster transmission of information) & atmosphere transparency. • Pulsed emission ~ ns → less natural background (Cherenkov flashes). • →higher probability for success with more significant results. 14th ISCRA Course, Erice 2004

  6. OSETI with MAGIC MAGIC is the largest optical reflector ever built. • 234 m2 mirror surface → high concentration of light. • time resolution about 1 ns → expected pulses (O(1ns)) could be resolved. • PMT’s able to detect pulses with few photons → weak luminosity excess could be detected from a star. 14th ISCRA Course, Erice 2004

  7. PMT 1ns γ analogical pulse Single pixel threshold (discriminator level) Pulse rate Logical pulse COUNTER Energy/area|pulse ~ 8.1·10-20 J/m2 Telescope parameter (minimum value) OSETI with MAGIC Minimum pulse energy to get a Single Pixel Trigger • Single Pixel Threshold ~ 8 phe • Average QE ~ 20 % • Transmissions ~ 80 % • Mean λ for optical γ ~ 500 nm 14th ISCRA Course, Erice 2004

  8. Adiverged beam LASER dt D Minimum Energy Emitted per Pulse ~ 24 kJ OSETI with MAGIC But LASER traveling : • for reasonable parameters: • dt~ 1m • D ~ 10 pc Helios ~ 3.6 MJ per 3 ns pulse !!! 14th ISCRA Course, Erice 2004

  9. Nphe/ns detected~ 13.5 phe/ns ↓ P>8phe/ns~ 1.5·10-2 ↓ Δt ~ 1ns → OSETI with MAGIC What can MAGIC do just now? νLASER ≤ Rspt max to be detected, and also it must be above the Rspt accidental due to stars luminosity in a significant way. Rspt accidental can be estimated: for an F type star (like our Sun) with a magnitude 5.5, Nphe/ns NSB~ 0.13 phe/ns ҒEarth ≈ 2.52·10-8·10-0.4·m J·s-1·m-2 Rspt accidental~ 15 MHz Rspt Cherenkov~ 180 Hz Rspt max readable by MAGIC (expected) ~100 MHz 14th ISCRA Course, Erice 2004

  10. OSETI with MAGIC • Following Kardashev’s civilization criteria (based on the energy resources employed): • KI (employing their planet) • KII (employing their star) • KIII (employing their whole galaxy) ←Helios (at 100 MHz) MAGIC parameters Dt =1m KI→ ↑ closest star Galactic ↑ Center 14th ISCRA Course, Erice 2004

  11. Summary The MAGIC Telescope is working now, and Rspt data is taken. • After that, to find an intelligent kind of extra-terrestrial life could be just a question of time (spent in analysis)! 14th ISCRA Course, Erice 2004

  12. 14th ISCRA Course, Erice 2004

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