GMRT Observing Application CYCLE 15 DEADLINE: Monday, July 07, 2008 Proposal Code: INSTRUCTIONS: Each numbered item must have an entry or N/A or NA SEND TO: GMRT Time Allocation Committee, NCRA–TIFR, Post Bag 3, Ganeshkhind, Pune 411 007, INDIA Received: Email: [email protected] (1) Date of preparing this application: July 6, 2008 (2) Title of Proposal: The first low radio frequencies study of the intriguing SNR G347.3−0.5 (RX J1713.7−3946) (3) AUTHORS† INSTITUT ION Will come Email (needed for PI & Co-PIs) Nationality * to GMRT? FABIO ACERO CEA Saclay, France Yes [email protected] French Mamta Pandey-Pommier Univeristy of Leiden No [email protected] Indian Martin Ortega IAFE, Argentina No [email protected] Argentine Gloria Dubner IAFE, Argentina No [email protected] Argentine Gabriela Castelletti IAFE, Argentina No [email protected] Argentine Elsa Giacani IAFE, Argentina No [email protected] Argentine Alexandre Marcowith Universit´eMontpellier II No [email protected] French Yves Gallant Universit´eMontpellier II No [email protected] Canadian Armand Fiasson Universit´eMontpellier II No armand.fi[email protected] French Jean Ballet CEA Saclay, France No [email protected] French Anne Decourchelle CEA Saclay, France No [email protected] French † Please write the PI’s name in CAPITAL LETTERS. * Nationality is mandatory to obtain official clearance, only for non-Indian nationals coming for observations. (4) Related previous GMRT proposal number(s): None (5) Contact author Address: M. Pandey-Pommier, Leiden Observatory, Leiden University, Oort Gebouw, P.O. Box 9513, 2300 RA Leiden, The Netherlands Telephone:(31)71-5275596, secr.:(31)71-5275833, Fax:(31)71-5275743 (6) If this proposal is intended to support a Ph.D. project, please mention the name of the student, the anticipated year of completion of the Ph.D. and also include a brief outline of the project in the Scientific Justification. (7) Scientific Category: astrometry, geodesy & techniques, solar, propagation, planetary, stellar, pulsar N ISM, galactic center, galactic structure & dynamics (HI), normal galaxies, active galaxies, cosmology (8) Wavebands 21 cm 50 cm 90 cm 128 cm 200 cm dual (50/128) cm Total (9) Time requested (hrs) 14 14 28 (10) Type of Observation: N imaging, point source, N continuum, solar, spectroscopy, pulsar, (check all that apply) phased array, Other (11) ABSTRACT (Please type within this space only.) G347.3-0.5 is one of the brightest shell-type supernova remnant found at very high energies. The X-ray emission from the source is dominated by a synchrotron continuum where no emission lines (sign of thermal X-ray emission) have been observed so far. This synchrotron emission is an evidence that electrons are accelerated at the shock wave of the remnant to energies of at least 1 GeV for radio and ∼ 20 TeV for X-rays. The radio flux together with the X-ray synchrotron spectrum as well as morphological comparison between radio and X-rays allow to study the population of accelerated electrons and the acceleration mechanism. Though the morphologies at Gamma-ray and X-ray wavelengths have been well resolved for G347.3-0.5, the flux, and the morphology in the radio domain are not well known. With superb couple of arc sec resolution and good imaging capability of GMRT at low frequencies we will be able to provide a well resolved morphology of the radio counterpart. The team is very experienced in observing with the GMRT and VLA interferometers at low radio frequencies, and have carried out different research works complementing radio observations with high-energy data. In this proposal, we plan to observe the source at 150 and 325 MHz simultaneously with the GMRT for 28 hours, in 4 slots of 7 hours each (two slots at each frequency spread over March, 2009). (12) Will PI/ Co-PI be present for observations? N Yes No Data reduction at? N Home Other xxxxxx (13) Help required: None Consultation Friend (extensive help) (14) Spectroscopy Only: line 1 line 2 line 3 line 4 Transition (HI, OH, etc) ——— ——— ——— ——— Rest Frequency (MHz) ——— ——— ——— ——— Velocity (km/s) ——— ——— ——— ——— Observing frequency (MHz) ——— ——— ——— ——— Frequency Resolution (kHz/channel) ——— ——— ——— ——— Rms noise (mJy/bm, nat. weight., 1 hr) ——— ——— ——— ——— Rms noise (K, nat. weight., 1 hr) ——— ——— ——— ——— (15) Number of sources 1 (If more than 10 please attach a list together with LST range(s). If more than 30 sources give only selection criteria and LST range(s).) (16) Name Epoch: 1950 gmrt Freq. Band- Flux Density Max. Requ- Timeβ LST* 2000 N array† (MHz) width line cont. ang. ired requ- range RA Dec (MHz) (mJy‡) (mJy) size rms ested hh mm ± xx.x◦ (0) (mJy/ beam) (hrs) (hrs) G347.3-0.5 17h13m33s -39d45’32” F 325 16+16 70 0.5 7 × 2 14.15-20.15 17h13m23s -39d23’00” F 150 6+6 70 1.5 7 × 2 14.15-20.15 † Please indicate your preference for the GMRT Array configuration as per the following possibilities: F : All antennas available. Nxx: Only xx antennas required (eg. VLBI, pulsar test/ monitoring) A00: Arm antennas only A01: Arm antennas only with upto 4 antennas from the Central Square C00: Central square only C01: Central square + 1st antenna in each arm (for Phased Array) ‡ Peak flux density. ß including overheads. * Please take help from www.gmrt.ncra.tifr.res.in/gmrt hpage/Users/Help/sys/time.html Notes to the table (if any): (17) Dates preferably avoided: Between begining of October, 08 and end of February, 09 (18) Special requirements of hardware, software, or operating procedures, etc: • 1 side band (16 MHz) or, 2 side bands (32 MHz) N • Is integration time less than 8 seconds required for extended periods? • Specify expected disk space requirement for the project (if more than 10 GBytes): • Non-standard Frequency • Short spacing critical • Frequency switching * • Correlator - Full Polar * • Correlator - High resolution (256 channels) • Phased array required • If pulsar, specify pulsar backend required: —————————————– * on experimental basis (19) IMPORTANT: Please mark in one of the two boxes below: [This is a mandatory field ]. The proposers have not been allotted time in GMRT before. A brief status report (not exceeding 150 words) on each previous proposal, and any preprint/ reprint. based on these GMRT observations is attached. Yes, we have been alloted time in GMRT before and a status report is attached on the last page. (20) Please attach a self-contained Scientific Justification not exceeding 1000 words. (Preprints or reprints will be ignored, unless reporting previous GMRT observations). When your proposal is scheduled, the contents of the cover sheets become public information (Any supporting pages are for refereeing purpose only). The first low radio frequencies study of the intriguing SNR G347.3−0.5 (RX J1713.7−3946) Scientific Justification Shell-type SNRs have long been considered to be the primary candidates for accelerating particles up to energy close to the “knee” (∼1015 eV) in the energy spectrum of cosmic rays. The majority of the Galactic supernova remnants (SNRs) known today were discovered through their radio synchrotron emission, demonstrating that electrons are accelerated at the shock wave of the remnant to energies of at least 1 GeV. In three cases the synchrotron radiation was also detected in the X-rays domain, namely SN 1006 (Koyama et al. 1995), G266.2−1.2 (Slane et al. 2001), and in our target, G347.3−0.5 (RXJ 1713.7−3946) (Koyama et al. 1997), evidencing that electrons can be accelerated up to ∼20 TeV. A more direct proof of particles’s acceleration at very high energies in SNRs has been provided by the detection of TeV gamma-ray emission from a number of Galactic SNRs, including our target G347.3-0.5, that was detected at TeV energies with CANGAROO (Muraishi et al. 2000, Enomoto et al. 2002) and with H.E.S.S Cherenkov instrument (Aharonian et al. 2004). From a theoretical point of view, several models explain how particles can be accelerated in supernova shocks to these high energies (see for example Malkov & Drury 2001; Hillas 2005). Observational evidence, however, is still scarce, and high-quality multispectral observations are essential to advance in the understanding of the complex processes involved. G347−0.5 is a shell-type SNR first discovered in X-rays in the ROSAT All-Sky Survey (Pfeffermann & Aschenbach 1996). Further studies of this SNR in the X-rays domain were carried out based on ASCA data by Koyama et al. (1997) and later by Slane et al. (1999) revealing that the X-ray emission is enterely non-thermal. This interesting property was later confirmed through XMM-Newton observations (Cassam-Chenai et al. 2004). In the radio regime this SNR, about 700 in size, was observed by Lazendic et al. (2004) at 1.4 and 2.5 GHz using ATCA radiotelescope. G347.3−0.5 appears as a faint incomplete shell with two bright arcs to the North-West (indicated in Fig.1 as “arc 1” and “arc 2” following Slane et al.’s nomenclature). Near the center it can be seen a weak inner ring of emission with a diameter of ∼300 whose emission decreases to the east. The rest of the SNR appears, at these two relatively high radio frequencies, as a collection of short weak filaments embedded in diffuse emission. The two bright arcs mentioned above are roughly coincident with the edges of the brightest structure observed in X-rays, and were assumed to be part of the SNR. However, studies of the interstellar gas in the direction of G347.3-0.5 (Fukui et al. 2003, Cassam-Chena¨ıet al.