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ASTROPHYSICAL HIGH-ENERGY PHENOMENA DETECTED IN THE EARTH’S IONOSPHERE

ASTROPHYSICAL HIGH-ENERGY PHENOMENA DETECTED IN THE EARTH’S IONOSPHERE. Jean-Pierre Raulin. Centro de Radioastronomia e Astrofísica Mackenzie, Universidade Presbiteriana Mackenzie, Escola de Engenharia, São Paulo, SP, Brasil.

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ASTROPHYSICAL HIGH-ENERGY PHENOMENA DETECTED IN THE EARTH’S IONOSPHERE

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  1. ASTROPHYSICAL HIGH-ENERGY PHENOMENA DETECTED IN THE EARTH’S IONOSPHERE Jean-Pierre Raulin Centro de Radioastronomia e Astrofísica Mackenzie, Universidade Presbiteriana Mackenzie, Escola de Engenharia, São Paulo, SP, Brasil 4th SchoolonCosmicRaysandAstrophysics – UFABC – Sto André – 28/08/2010

  2. CARPET + EFM 100 ROI ROEN SAVNET COMTE. FERRAZ SST Scientific Research at CRAAM/EE/UPM SOLAR PHYSICS SOLAR-TERRESTRIAL RELATIONSHIP SST IONOSPHERIC PHYSICS GALACTIC AND EXTRAGALACTIC RADIO ASTROPHYSICS SPACE GEODESICS 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  3. Photosphere H = 500 km ; T ~ 6000 K Few Gauss < B < ~ 2500 G 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  4.  << 1 TRACE 171 Ang.  = Pgas/Pmag  >> 1 Few 104 km Solar Flares Eth few 10 MK Ek  few 10 MeV Emec  CMEs Solar Flares 1032 erg in few sec. to few min. 1041 e-/s > 20 keV 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  5. Solar Flares 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  6. Solar Flares • Fast releases of energy in the solar atmosphere. Up to 1032-33 ergs (1 J = 107 ergs) are dissipated in few seconds to few minutes. This energy is observed as : • thermal energy (few MK  tens of MK) • kinetic energy (acceleration of particles) • mechanical energy (mass motions - CMEs) Ne ~ 1010cm-3 ; Te ~ 5 MK ; R ~ 20” ~ 1026 J - B ~ 100 G ; R ~ 20” 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  7. Solar Flares Coronal Mass Ejection (CME) 1 AU = 150 106 km ~ 110 solar Ø Arrival time at 1 AU ~ 1.5 – 3 d 2003/10/28 11:10 UT 2003/11/02 17:15 UT 2003/11/04 19:40 UT CMEs are fundamental for Space Weather prediction 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  8. 4 November 2003 solar flare CSR P1 ISR P1 CSR P4 Laboratory accelerators ISR P4 ISR(?) pulses 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  9. TheEarthIonosphere The ionization of the neutral component of the Earth’s atmosphere is done through 2 processes Photo-ionization (Chapman) and collision 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  10. TheEarthIonosphere Height (km) 1000 400 100 70 Ionization due to solar radiation 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  11. TheEarthIonosphere Rate of e- - ion production (cm-3s-1) Sun s Intensity of radiation (energy flux in eV/m2/s) Line-of-sight path length h Zenith angle Photon absorption cross-section (m2) Density of neutral Ground 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  12. TheEarthIonosphere D and E regions Hot plasma heated during solar flares will emit a copious amount of X-rays Photo-ionization • X-rays (  < 10 Å) • O2 • N2 • Lyman- (  = 1216 Å) • NO • Low ionization potential component • Ultraviolet (  < 1750 Å) • Minor constituents Solar Minimum Solar Maximum 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  13. The Earth Ionosphere • Collisions • Solar Cosmic Rays • Galactic Cosmic Rays • Radiation belts particles • High latitudes (auroral and sub-auroral); • Regions of low magnetic field(AMAS) Computer anomaly locations experienced by STS and TOPEX 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  14. TheEarthIonosphere For VLF waves (f between 3 – 30 kHz) the ionospheric D region and the Earth’s surface are good electrical conductors and reflecting media. These layers forms the Earth-Ionosphere Waveguide (EIW). Electromagnetic energy can therefore be guided and propagate along the waveguide long axis. At 70 km  300 e-. cm-3  156 kHz For 20 kHz  4.9 e-.cm-3 At 200 km  800000 e-. cm-3  8 MHz 28 90 283 900 2846 9000 (kHz) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  15. TheEarthIonosphere Appleton-Hartree, (Quemada, 1967) B = 0 ;  << 2

  16. TheEarthIonosphere Conductivity parameter (Wait & Spies, 1964) Conductivity gradient  [km-1], Reference height H′ [km] • At 70 km (D region) we have  ~ 5 MHz >> VLF At 220 km (F region) we have  ~ 50 Hz << VLF

  17. TheEarthIonosphere Conductivity parameter (Wait & Spies, 1964) Conductivity Gradient (sharpness)  [km-1] Reference height H′ [km] Increases of incoming X-ray fluxes during flares and increasing particle precipitations during geomagnetic storms produce ionization excesses and change of the electrical properties of the lower ionosphere D region. Then changing: conductivity gradient  [km-1] and reference height H′ [km] Excesses of ionization can be monitored using the phase of long distance VLF propagating waves 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  18. TheEarthIonosphere Wait 1950s-60s; Budden, 1961; Wait,1962 Solar flare Ref. Height 70 km Δh Perturbed Ref. height 60 km 60 km The lowering of H produces a change  of the phase of the VLF wave. This change is measured by the VLF receiver, and can be expressed in terms of h. The change  is proportional to the VLF path. 90 km 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  19. TheEarthIonosphere • Solar Flares (Chilton et al. 1965; Kaufmann & Paes de Barros 1969; • Mitra 1974; Muraoka et al. 1978, McRae et al. 2004) • Geomagnetic Storms (Spjeldvik & Thorne 1975; Kikuchi & Evans 1983) • Supernova (Edwards 1987) • Magnetar • Nuclear explosions in the atmosphere(Jean & Wait, 1965; Carpenter et al. 1968; • Mikhailov et al. 1999) Solar Flare SPA (Sudden Phase Anomaly)  (h) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  20. TheEarthIonosphereSensitivity R > 0.95 For a given solar flare the lowering of the reference height is higher (by about 1 km) during solar minimum The low ionosphere is more sensitive during minimum of solar activity Ionospheric indice for monitoring of the long-term solar radiation McRae & Thomson 2000, 2004 showed that the quiescent (undisturbed) ionospheric D region reference height is higher during solar activity minimum periods by about ~ 1 km ~ 1 km Raulin et al. 2006; Pacini & Raulin 2006 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  21. SAVNETCRAAM/EE 8 VLF tracking receiver stations deployed in Brazil, Peru and Argentina. 3 years of operation since 2007 • Long-term and transient solar activity (Ly- ; solar flares) • mesospheric disturbances (T, NO, O3) • Physics of the lower ionospheric (C/D) regions • Atmos. Physics (TGFs) • Subionospheric radio propagation modeling • Search for seismic-EM effects • Detection of Remote astrophysical objects 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  22. SAVNET: The basics Characteristics of the sensors b ; A ; Ae 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  23. SAVNET: Installation Punta Lobos, 2007, April 1- 8 Piura, 2007, June 5-11 São Martinho da Serra, RS, 2007, May 1- 5 Palmas, TO, 2007, May 21-26 CASLEO, 2007, Julio 1- 07 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  24. SAVNET: Design Power supply Pre-amp to Audio to Audio to Ant. GPS to Antena Alimen. Alimen. Alimen. Computer to Antena 1 PPS to Audio Interface loop sensor Interface vertical sensor Interface GPS 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  25. SAVNET: Design Audio Card 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  26. SAVNET: Design Loops (magnetic) or vertical (Ez) antennae Phase anomalies to measure are very small (s)  cristal, atomic clocks Cristal  10-8 – 10-6 this OK for fast phenomena, but not for solar flares, or for long-term monitoring Atomic clocks  10-12 – 10-11 (for ex. GPS system) Drift of 1 s at each 108 s  Drift of 0.000036 s in 1 hour During 0.000036 s the phase of the wave at 24 kHz  24000 x 360 x 0.000036 > 300 grados 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  27. VLF REMOTE SENSING OF THE LOWER IONOSPHERE South America VLF NETwork (SAVNET; CRAAM/EE/UPM; Brasil) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  28. SENSITIVITY OF THE LOWER IONOSPHERE (Raulin et al. 2010) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  29. SENSITIVITY OF THE LOWER IONOSPHERE (Raulin et al. 2010) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  30. Baker et al. 2004: Period of strong geomagnetic disturbances (Out-Dez/2003): sucessive intense solar events with particles, shock waves and CMEs  Important changes of Van Allen radiation belts and intense precipitation of electrons from these regions. SENSITIVITY OF THE LOWER IONOSPHERE (Pacini, 2006) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  31. GRBs and SGRs FLARES • Soft Gamma-ray repeaters repeat sporadically from the same source (SNRs, AXPs), while Gamma-Ray Bursts have never been verified to come more than once from the same spot in the sky • GRB are numerous while we know about 6 SGRs sources • SGR are softer than GRB (less mean energy per photon) • photon flux is generally higher for SGR • SGR outbursts occur in group • duration ranges from < 1 s to few minutes in average • SGRs do produce some spectacular giant flares (3 known in 30 years) • SGRs more probably originate in Magnetars (rotating neutron stars with B ~ 1015 G) • Observing and instrumental limitations: • saturation during giant flares  (problems to recover photon spectra) • off-pointing  (problems to recover photon spectra) • Earth occultation  (no observations) 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  32. SENSITIVITY OF THE LOWER IONOSPHERE • The daytime sensitivity of the low ionospheric plasma has been estimated for daytime conditions, using solar flares as external forcing (Pacini & Raulin, 2006; Raulin et al. 2010) • - Minimum peak power detected at Earth orbit for [1.5 – 24 keV] photons : • 2.7 10-4 erg/cm2/s (solar min.) and 10-3 erg/cm2/s (solar max.) • - Fluence > 14 keV, for 10 min. accumulated times: • ~ 10-7 erg/cm2 (solar min.) and few 10-7 erg/cm2 (solar max.) • The nighttime sensitivity has been estimated to 10 times less than that during daytime (Tanaka, Raulin, Bertoni et al. 2010). •  Therefore we do expect the VLF technique to detect intermediate-to-low SGRs and GRBs outbursts. 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  33. GIANT SGRs FLARES • So far (30 years) , we know of 3 giant flares from SGRs. The most spectacular event occurred on 2004, December 27 at about 21:30 UT, from SGR 1806-20: • estimated distance 15 kpc • main peak (0.2 s) : rise < 1 ms, decay < 65 ms • periodic tail (400 s), P ~ 7.56 s • main peak satured all onboard -ray sensors • Emain peak ~ total energy released by the Sun in • 250 .103 years ~ 1010 times E (largest solar flares) • lowering of daytime ionosphere ~ 10 km • Magnetar, B ~ 1015 G RHESSI 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  34. IONOSPHERIC OBSERVATIONS OF AXP 1E 1547-5408 (also known as SGR J1550-5418 , PSR J1550-5418) (Tanaka, Raulin, Bertoni et al. 2010, ApJL) 22-Jan. 2009, 0648 UT, larger burst VLF propagation path from NPM transmitter (Hawaii) to ATI observing station (São Paulo, Brazil). Also shown are the locations of other four VLF transmitters (NLK, NDK, NAA, and NAU). Shaded hemisphere indicates the night side part of the Earth at 06:48 UT, when the largest burst occurred. The part of the Earth illuminated by -rays at 6:48 UT is also drawn by dashed area. Although not shown, bursts were also detected by other SAVNET bases at Palmas, TO (PAL), São Martinho da Serra, RS (SMS), and Piura, Peru (PIU). 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  35. IONOSPHERIC OBSERVATIONS OF AXP 1E 1547-5408 (also known as SGR J1550-5418 , PSR J1550-5418) (Tanaka, Raulin, Bertoni et al. 2010, ApJL) 22-Jan. 2009 bursts Over 100 -ray bursts were observed in the (South America) night of 22 January, 2009. Amplitude and phase variations of a VLF signal from NPM transmitter (21.4 kHz) are shown, which were observed at ATI from 04:00 UT to 10:00 UT. Lower figures are background-subtracted blown-ups at time ranges during which short repeated SGR bursts were detected. 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  36. IONOSPHERIC OBSERVATIONS OF AXP 1E 1547-5408 (also known as SGR J1550-5418 , PSR J1550-5418) (Tanaka, Raulin, Bertoni et al. 2010, ApJL) Detailed amplitude time profiles on NPM-ATI (a) and NPM-SMS (b) VLF propagation paths during the largest 06:48 UT -ray burst, are compared with the > 25 keV INTEGRAL/SPI-ACS signal. Dashed lines suggest common temporal fine structures. The spin period of the remote object (P ~ 2.07 s) can be seen in the INTEGRAL -ray time profile . Phase and amplitude variations are interpreted in terms of the lowering of the ionospheric reference (reflection) height, after -ray photons enter the Earth’s atmosphere and ionize the neutral component at and below ~ 85 km. INTEGRAL SPI-ACS 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  37. IONOSPHERIC OBSERVATIONS OF AXP 1E 1547-5408 (also known as SGR J1550-5418 , PSR J1550-5418) (Tanaka, Raulin, Bertoni et al. 2010, ApJL) Main result of this study: The amplitude and phase variations detected using NPM – ATI VLF propagation path, during 8 gamma-ray bursts on 22 January 2009, are well correlated with the photon (> 25 keV) fluences. 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  38. IONOSPHERIC OBSERVATIONS OF AXP 1E 1547-5408 (also known as SGR J1550-5418 , PSR J1550-5418) (Tanaka, Raulin, Bertoni et al. 2010, ApJL) Main result of this study: The amplitude and phase variations detected using NPM – ATI VLF propagation path, during 8 intermediate-to-low gamma-ray bursts on 22 January 2009, are well correlated with the photon (> 25 keV) fluence. 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

  39. SUMMARY The lower ionosphere plasma is a very sensitive medium to external forcing: radiation, energetic particle fluxes, atmospheric variability. It is therefore a unique laboratory to better track the Space Weather conditions and study the coupling with the upper and lower atmosphere. The timescales involved give new insights on the monitoring of the long-term and transient solar activities, the episodic geomagnetic disturbances, and upper propagating phenomena in the neutral atmosphere. We have detected, for the first time, ionospheric disturbances caused by intermediate-to-low short repeated gamma-ray bursts from a Magnetar. Amplitude and phase changes of Very Low Frequency propagating waves are well correlated with gamma-ray fluences. This can be understood in terms of the lowering of the ionospheric reflection height due to excesses of ionization at and below ~ 85 km. While satellites in space cannot continuously observe the whole sky due to Earth occultation, the Earth’s ionosphere can monitor it without interruption. Very Low Frequency observations provide us with a new method, cheap and easy to implement, to monitor high energy transient phenomena of astrophysical importance. Therefore, the Very Low Frequency diagnostic of high-energy astrophysical processes is, at least, a complementary information to space detections, and, sometimes, it may be the only way of recovering the incident photon spectrum at low energies. 4th School on Cosmic Rays and Astrophysics – UFABC – Sto André – 28/08/2010

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