Update on Planets WG activities

Philippe Zarka
LOFAR Transients Key Project Meeting, Meudon, December 2011

Transcript

1. Update on Planets WG activities P. Zarka on behalf of the (e)PWG
2. (e)Planets WG members & associate members [*] activity in commissionning Members: Philippe Zarka (Group leader; Obs. Paris, Meudon) [***] Jean-Mathias Griessmeier (LPC2E) [***] Gregg Hallinan (National U. Ireland, Galway) Sébastien Hess (LATMOS/IPSL) [**] Walid Majid (JPL) [**] Imke de Pater (U. California, Berkeley) Hanno Spreeuw (?) [*] Daphne Stam (SRON) Graham Woan (U. Glasgow) [*] Associate members: Tim Bastian (NRAO) Julien Girard (LESIA, Meudon) [***] Artie Hatzes (Tautenburg) Jonathan Nichols (U. Leicester) [*] Elena Seran (IPSL, Paris) + support from C. Tasse (GEPI, Meudon ; Surveys) [**]
3. Scope: - Jupiter MS emission (DAM → LF) - Jupiter & other planets synchrotron em. from rad. belts (Saturn?, Mercury? → LF & HF) - SS planetary lightning (Saturn, Uranus, Venus?, Mars?… → LF) - Exoplanets MS emissions : predictions for hot Jupiters and normal Jupiters, modelling… (→ LF & HF)
4. Scope: - Jupiter MS emission (DAM → LF) - Jupiter & other planets synchrotron em. from rad. belts (Saturn?, Mercury? → LF & HF) - SS planetary lightning (Saturn, Uranus, Venus?, Mars?… → LF) - Exoplanets MS emissions : predictions for hot Jupiters and normal Jupiters, modelling… (→ LF & HF) λ=20 cm
5. Scope: - Jupiter MS emission (DAM → LF) - Jupiter & other planets synchrotron em. from rad. belts (Saturn?, Mercury? → LF & HF) - SS planetary lightning (Saturn, Uranus, Venus?, Mars?… → LF) - Exoplanets MS emissions : predictions for hot Jupiters and normal Jupiters, modelling… (→ LF & HF)
6. Scope: - Jupiter MS emission (DAM → LF) - Jupiter & other planets synchrotron em. from rad. belts (Saturn?, Mercury? → LF & HF) - SS planetary lightning (Saturn, Uranus, Venus?, Mars?… → LF) - Exoplanets MS emissions : predictions for hot Jupiters and normal Jupiters, modelling… (→ LF & HF) Tau Bootes Orbit inclination Revolution period Mag. moment Intensity Polarization Type of interaction Emitting hemisphere (RH-N, LH-S) North South
7. LEA048: Tied Array Beam observations of Jupiter, Saturn, and selected candidate exoplanets Jupiter DAM (~10-40 MHz) 2005/11/30: ~a few minutes, raw voltages from ITS // Nançay 2008-2009: a few hours raw voltages 2009/11/27: 2 hours, raw voltages from 5 stations incl. int’l, // Nançay (SETI searches done in //) 2010/04/02: 20 min, raw voltages from 4 stations CS 2010/05/26: 1 hour, raw voltages from 5 stations incl. int’l 2010/06/03: 1 hour, raw voltages from 5 stations incl. int’l + incoherent sum Existing commissionning data: A. Nigl et al.: Jupiter VLBI with LOFAR/ITS and NDA 1101 Fig. 1. Dynamic spectra of a simultaneous observation with the Nançay Decametric Array () [] and ’s Initial Test Station Fig. 2. Spectra of the two linear polarizations of ’s Initial Test Station (/) (red: E-W antennae dipole beam and blue: N-S an- tennae dipole beam). The best-fit sine function (in frequency, not inten- sity) of the computed Faraday angle is superimposed to both  spec- tra. For the East-West polarization direction the maxima of the Faraday fringes are indicated with dots. 48 antennae of  and the 72 antennae of  were beam- formed in the direction of Jupiter. The spectra were computed with 0.2 ms time resolution and consequently a spectral resolu- tion of 4.9 kHz. The Jupiter signal received was expected be- tween 20 MHz and 30 MHz, where only a few narrow band lines contaminate the spectra. Below 20 MHz strong  is dom-
8. Existing commissionning data: LEA048: Tied Array Beam observations of Jupiter, Saturn, and selected candidate exoplanets Saturn lightning 2010/04/08 (3h) incoherent sum of 10 stations, 30-90 MHz, On only 2010/12/17-18 (16h) incoherent sum of 22 stations, 15-75 MHz, 81 µsec x195/16 kHz, Off=PSR1133 (TBB taken in //) 2011/07/07-08 (12h) coherent sum of 5 superterp stations, 20-70 MHz, 1.3 msec x195/16 kHz
9. NDA Existing commissionning data: LEA050: Imaging observations of Jupiter and Saturn Jupiter Obs in coll. with Wucknitz for long baseline imaging (LEA066) of Jupiter 2011/07/08: 1 sec visibilities with 15 stations incl. long baselines ) 2011/11/24: raw voltages with long baselines ) Total ~4h? 2011/11/10 imaging (10h, 110-190 MHz, Cal=4C +15.05) Coll. with LEA122: Jupiter polarization (circular) : 4h on 2011/01/23 Io-Jupiter em. RH ellipt. Jupiter’s auroral em. RHC NDA LOFAR LOFAR
10. • Modest overall allocations (~50 h total) • Reports to LOFAR Status Meetings (to be written !) Commissionning work achieved: - General purpose IDL software (read, plot, process) → to be translated in Python - S-burst movie for LOFAR inauguration - Commissioning/test results: • Validation of occurrence prediction methods (Cassini, NDA...) • Station operation&pointing/test, LF, influence of ionosphere • Large data volumes to disk (up to 5 Tb/hour) • Structure of raw/incoherent sum/beamformed data • Observation strategy (incoherent sum unadapted to high sensitivity obs) • Comparisons of our RFI flagging (PS detected on 18/12/2010) with A. Offringa’s AOflagger (→ future «exoplanet» pipeline) • Imaging of a moving source
12. Potential Science results: - Detection/Characterization (spectrum, time (sub)structure, energy) of Saturn’s lightning ≥20 MHz (tbc, ongoing) - Fine structure of Jovian S-burst emission : flux density & polarization down to the finest time scales
13. Plans for further commissionning observations/analyses: - Analyse Jupiter imaging data (cont'd) - Analyse long baselines obs of Jupiter - Analyse Jupiter polarization measurements, compared to calibrated Nançay data - Further Saturn lightning observations in better conditions that previous ones ("Call B") + Participation to development of dynamic spectrum pipeline (if programmer found) Data center in Nançay
14. Plans for responses to calls: - Above 4 scientific topics : DAM, synchrotron, lightning, exoplanets - Exoplanets search/detection strategy: • Piggyback search for transients at known coordinates (in Transients Catalog) • Selected targets : hot Jupiters, normal Jupiters around high LXUV stars, Corot planets, Kepler field, all stars <10 pc, selected magnetic stars, UTR2 planets? … [ Possibility to plan joint obs. with UTR2, Cassini, Nançay, Espadons/ Narval, etc. ] - Planetary atmospheres (// survey, accurate absolute calibration, moving source) - Occultations by small SS bodies