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Present and future e-VLBI / EVN2015 science Zsolt Paragi, JIVE.

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Presentation on theme: "Present and future e-VLBI / EVN2015 science Zsolt Paragi, JIVE."— Presentation transcript:

1 Present and future e-VLBI / EVN2015 science Zsolt Paragi, JIVE

2 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #2 The European VLBI Network What are we doing not so good at the moment: No real frequency agility Limited observing time Little support for ToOs Slow science turnaround time (from proposal to paper) Although most of these problems are not directly related to e-VLBI, all of these are addressed today in the framework of e-VLBI developments. The EVN2015 has to be a real-time array with great frequency coverage and sensitivity, and should operate throughout the whole year. And these tapes below will be gone long time before that!

3 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #3 The end of the tape era Tape recording had limited performance (parity errors), and limited data rate (256 Mbps; 512 Mbps with two write heads). Tapes were expensive Tape playback units were not easy to maintain Disk based recording systems were developed at Haystack (Mark5A) and Metsahovi Radio Observatory (PC EVN) And it worked! The EVN is fully disk operational (Mark5A) since early 2004 Cheaper, off the shelf technology, perfect recording; data rate up to 1 Gbps

4 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #4 Disks+ftp VLBI: reliability! Disk recording is better quality, but it also provides a way to quickly check telescope performance: ftp tests 2-4s data at 256 Mbps MB files, may be transferred through the Internet! Data processed by a software correlator developed in NICT, Japan Since late 2004 there are regular ftp tests during EVN sessions. The software correlator runs on a PC cluster Feedback to telescopes used to take at least a week, now it is a matter of minutes OK, let us see what else can we improve…

5 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #5 Select your source Write an observing proposal EVN PC makes a decision Publishing results EVN scheduler provides a date 1-2 weeks 2-3 months 2-3 months Observe with VLBI Data correlation Data processing … another 2-3 months well, why would you hurry? VLBI observations timeline THIS MUST CHANGE!

6 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #6 Target of Opportunity projects An example: the huge flare of SGR SGR is a soft gamma-ray repeater a neutron star with very strong magnetic fields, a magnetar Produced the greatest explosion witnessed by humans in our Galaxy, on 27 December 2004 Observations with various instruments, also VLBI (with the VLBA array) Could not image reliably because of lack of known calibrator in the vicinity of the target! Is there a way to do these projects more efficiently? Is there a way to get the data and analyze them quickly??? Fender et al. (2005), MNRAS 367, L6

7 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #7 What is EXPReS? EXPReS = Express Production Real-time e-VLBI Service Three year project, started March 2006, funded by the European Commission (DG-INFSO), Sixth Framework Programme, Contract # Objective: to create a distributed, large-scale astronomical instrument of continental and inter-continental dimensions Means: high-speed communication networks operating in real- time and connecting some of the largest and most sensitive radio telescopes on the planet

8 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #8 Jodrell Bank UK Onsala Sweden Medicina Italy Torun Poland Westerbork Netherlands Telescopes connections (early 2007) JIVE 10Gb/s 1Gb/s 155Mb/s Cambridge UK 2.5Gb/s 1Gb/s e-MERLIN ? ? ? ? ? Soon available: Effelsberg, Yebes 40m, Shanghai …

9 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #9 e-VLBI activities in 2006/2007 There are regular e-VLBI test observations in every six week (on average) Normal operations at 256 Mbps (Cm, Jb2, Mc, On, Tr, Wb) Fringes to several telescopes at 512 Mbps, most recently to Mc 24h time is pre-allocated for science observation during each e-VLBI test Observing proposals may be submitted two weeks before the advertised date Science projects observed in 2006/ early 2007: Cyg X-3, 20 Apr/18 May, 128 Mbps, Tudose et al. GRS1915, 20 Apr, 128 Mbps, Rushton et al. LSI , 256 Mbps, 26 Oct, Perez-Torres et al. Algol, 26 Oct/14 Dec, 256 Mbps, Paragi et al. Calibrators near M81, 14 Dec, 256 Mbps, Brunthaler et al. INTEGRAL microquasar candidates, 14 Dec, Pandey et al. 16 XRBs adaptive run, 29/30 Jan, Spencer et al. Calibrators, 21 Feb, Fender et al.

10 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #10 First refereed journal papers: Rushton et al. (2007), MNRAS 374, L47 Tudose et al. (2007), MNRAS… very soon Cyg X-3

11 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #11 LSI preliminary results: Perez-Torres et al. (in prep.) Gamma-detected XRB candidate; Recent VLBA observations (Mioduszewski et al.) suggest interacting pulsar wind… e-EVN, MERLIN, CHANDRA Observations on 26 October 2006

12 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #12 Algol preliminary results: Csizmadia et al. (in prep.) 26 October 2006

13 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide # Mbps e-VLBI run 1/2 February 2007 (Cm),Jb2,On,Mc,Wb And Ef, Sh, Yb … coming: We are almost there!!!

14 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #14 e-VLBI challenges We are already very good in quick science turnaround: on the fly data processing/pipelining is possible! At 512 Mbs and with Effelsberg, Shanghai and other new telescopes, we will also be very good in sensitivity and resolution (in 2007/2008) BUT We are poor with immediate good calibration The current system is not suitable for real ToOs We have to be able to produce high dynamic range maps of sources varying on timescales of hours (=>EVN2015) We must be able to change schedule on the fly to be able to observe e.g. new transients with poor coordinates (=>EVN2015)

15 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #15 Example: the Algol miniflare (14 Dec 2006) Csizmadia et al. (in prep.) Variable flux, position and structure within hours!

16 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #16 Westerbork e-EVN as a unique instrument Westerbork Synthesis Array data may help in calibration (amplitude, linear and circular polarization) May help to confirm detection/non-detection of weak targets Could be used as a built-in alert instrument for the e-EVN Wb can help improving coordinates of new transients… …with adaptive scheduling, this could be immediately used for the VLBI array Not to mention the additional information on the very large-scale structure (which we normally waste when we do not reduce Wb data along with the EVN) Will Westerbork be still around in 2015???

17 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #17 The e-EVN as an alert instrument? Because we are not good in responding ToOs, but good in providing quick results, can we turn around the logic? Initially could monitor known transient sources (e.g. microquasars like GRS ) in a snapshot mode during the e-VLBI tests, regularly. In case of a flare, report to the community, providing 0-epoch maps! (not possible when a ToO VLBI run follows a single dish trigger) Easily accessible for the whole astronomical community, ready maps from the EVN archive (all public!) With more sensitivity and dynamic scheduling, may continue this with new X-ray transients or gamma bursts How shall we select these key science targets? Can we contribute to X-ray and gamma ray missions like GLAST? Have invested a lot of money in e-VLBI, now let us invest a great deal of observing time!

18 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #18 EVN2015 science I. Microquasars Besides the present known radio-jet XRBs, a much larger fraction of the X-ray binaries will be detected by EVN2015. Initial phases of flare evolution / jet proper motion in the first 100AU scales is not known. Observation of mas-scale jet structural changes just before and during the early stages of a flare is necessary to understand better disk-jet coupling. A change in Lorentz factor is predicted – how could we observe that? Can we detect circular polarization at sub-mJy levels? Jet composition? Is there an outflow or jet/ISM interaction region roughly perpendicular to the jet in all microquasars (like in SS433)? What is the difference between the NS and the BH microquasar outflows? Is there an underlying high Lorentz-factor jet in all microquasars?

19 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #19 EVN2015 science I. Microquasars So, what is happening to the core-jets during an outburst? Paragi et al New A.R. 43, 553

20 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #20 EVN2015 science II. Other radio active binaries Late-type stars show magnetic activity, a great stellar population to be studied by EVN2015. At VLBI resolution one could resolve the magnetosphere of nearby spotted stars, and image the stellar spots in the radio directly! Radio flaring Algol and RS CVn sources could be easily observed (on the fly selection of active targets) What is the relation of the flares to magnetic activity or mass-exchange in these binaries? For example in Algol, one could resolve the Roche-lobe and even the stellar disks with the EVN. Are these sources producing collimated outflows?

21 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #21 EVN2015 science III. Gamma bursts Is there prompt radio emission? LOFAR will do it at low frequencies. Can we constrain cm-wavelength emission (models do not predict, but…)? Will the EVN2015 (or earlier) be able to observe the prompt burst? Theories/observations predict a jet break up days after the burst, with sudden drop of the Lorentz-factor; needs high frequency (22 GHz) very sensitive VLBI observations to study proper motion. These are far too faint for cm wavelength studies with space-VLBI. What is the relation between SNIb/c and gamma bursts? Can we observe off-axis GRBs in the radio?

22 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #22 An old story: the first e-VLBI science result (continuum) SN2001em was discovered on 15 September 2001 in UGC11794 galaxy (Pepenkova 2001). Filippenko and Chornok (2001) classified it as type Ib/c, most likely Ic. Exceptional radio and X-ray luminosities (off axis GRB, developing late radio emission due to jet break?), Not quite a 1 mJy radio source EVN observations: Cm, Jb2, On, Tr, Wb (128Mbps), +Arecibo 300m (64 Mbps) at 18cm, on 2005 Mar 11 Tentative detection (4.5 ) of the first real faint target with e-VLBI Paragi et al. (2005), MSAIt 76, 570 Needs better resolution and sensitivity! => EVN2015

23 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #23 EVN2015 science IV. Extragalactic XRBs, ULXs, IMBHs EVN2015 will have the sensitivity to study microquasars in nearby galaxies Ultra-luminous X-ray sources: all super-Eddington accreting XRBs with geometric beaming of X-rays, or are there intermediate mass black holes as well? The superior sensitivity of EVN2015 will be able to constrain black hole masses in ULXs, and will provide resolution to image their (sub-) pc-scale structure. More resolution together with VSOP-2! Again, the e-EVN could monitor ULXs and alert community in case of a radio detection. With wide field of view imaging, could monitor whole (or part of) nearby galaxies, looking for radio transients; note that e-MERLIN and e-VLA could do this as well, but we would be late with follow up VLBI observations!

24 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #24 EVN2015 science IV., ULXs… The minimum detectable black hole mass

25 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #25 EVN2015 science IV., ULXs… The minimum detectable black hole mass

26 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #26 EVN2015 science IV., ULXs… Predicted ULX radio flux densities

27 2007 March 1-2, DwingelooPresent and future e-VLBI... EVN2015 scienceSlide #27 EVN2015 science IV., ULXs… Predicted ULX radio flux densities


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