Radio Astronomy Activities at RRI

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Radio Astronomy Activities at RRI. N. Udaya Shankar RRI. Indo-SA Astronomy Workshop 7 August 2012. The economically important Silk Road (red) and spice trade routes (blue). Pepper: MWA Precursor SKA EOI in SKA Low Science Case for SKA MID Evolution of HI in the universe. SALT. - PowerPoint PPT Presentation

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<ul><li><p>Radio Astronomy Activities at RRIN. Udaya ShankarRRIIndo-SA Astronomy Workshop7 August 2012</p></li><li><p>The economically important Silk Road (red) and spice trade routes (blue) </p></li><li><p>SALTPepper:MWA Precursor SKAEOI in SKA LowScience Case for SKA MIDEvolution of HI in the universe.</p></li><li><p>A&amp;A groupTheoretical astrophysics (5)Observational astronomy to (7) Builders: specialized instruments . Collaborations: Many body interactions Lead to joint pursuit of problems inTheory, Observations, Specialized instrumentsworld-wide collaborations.</p></li><li><p>Present Focus:</p><p>Low Frequency Radio Astronomy.</p><p>Frequencies Below: 1.4 GHz.</p><p>Developing interest in the freq range: 2 to 4 GHz.</p></li><li><p>Evolution of HI atom in the universea. HI mass fluctuations using ORT; 327 MHz, z=3.3b. EoR :I. Statistical DetectionOur participation in MWA80-300 MHz, z=4-16 ii. Global Signal DetectionIn-house Projects87.5 175 MHz, z= 4-8c. ERA : Epoch of Recombination array2 4 GHz, z=1000</p><p>2.Transients and Pulsars, MWA and ORT</p></li><li><p>2.Transients and Pulsars, MWA and ORT</p><p>3. Halos and Relics in Galaxy Clusters GMRT and MWA 50 MHz system for GMRT</p><p>4. Multi-frequency observations of Compact objects , X-ray polarimeter.</p></li><li><p>2. Murchison Wide Field Array (MWA)</p><p>MWA is a low-frequency imaging radio interferometer facility being built in the radio-quiet area of Western Australia</p></li><li><p>MWA-LFD Kick-Off June 2006This is one exciting project Scientifically richEOR, Solar, Transients, Pulsars, RRLs, etc.</p><p>Technologically innovativeLeading the way in multiple simultaneous areasTrailblazing!</p><p>Excellent partnershipCommon goals + motivationsAbundance of talent and energy</p><p>Enormous growth potentialInexpensive hardware, Moores lawLFD/xNTD synergy, path to SKAOpportunities abound, for Australian, Indian, US, and Global community</p></li><li><p>MurchisonMWA</p></li><li><p>Antenna tile with 16 dipoles placed on a ground screen of 5 x 5 m</p></li><li><p>Physical Layout</p></li><li><p>A digital receiver for MWA has been developed and built in the Radio Astronomy laboratory at RRI.</p><p>RRI digital receivers operate between 80 and 300 MHz and are based on state-of-the-art Virtex-5 FPGA chips</p><p>The receivers operate at 655 MHz sampling, include poly-phase digital filters and fiber optic links.</p></li><li><p>MWA Digital ReceiverEach receiver receives outputs from 8 tiles , digitize them, do 512 CH PFB and send them through fiber links after serializing.</p></li><li><p>RRI contributionDevelopment of i) A/D and Filter Bank (ADFB) Architecture ii) Firmware for ADFB boardDevelopment of i) Backplane and ii) Clock for 32 T digital receiverDevelopment of i) Hardware and firmware architecture for AGFO ii) Design of Board and firmware developmentDevelopment of Imaging Algorithms: Nithyas Talk</p></li><li><p>Current statusActively involving in system testing under integrated environmentPlanning to mass produce 16 digital receivers for 128 tiles by mid 2012Development of hardware and firmware to combine in the digital receiver the outputs of all 8 tiles to form one beam and use the entire bandwidth available</p></li><li><p>Challenges for MWA, LOFAR, GMRT, Global Signal Detection Experiments are same</p></li><li><p>Receiver is a 2 element interferometer with a space beam splitter Freq. range : 87.5 175 MHzThe screen is made resistive to ensure required phase diff. between transmitted and reflected signals exists and has equal transmission and reflected signals</p></li><li><p>Receiver system for EoR detectionFrequency Independent Antennas installed over absorber tilesWell matched receivers with low noise figure a digital receiver consisting of a high speed digitizers and a spectro-correlator</p></li><li><p>Current StatusThe Zero space interferometer has been completely characterized for all its properties and data acquired are being analyzed.Next Phase:</p><p>Take it to a radio quite zone </p><p>Australia</p><p>South Africa</p></li><li><p>5. X-Ray PolarimeterX-ray polarimeter based on the principle of Thomson scattering is being developed at the Raman Research Institute (RRI)The experiment has been proposed to the Indian Space Research Organization for a small satellite mission.</p></li><li><p>Scientific ObjectivePolarisation measurement gives insight aboutThe strength and the distribution of magnetic field in X-ray sourcesGeometric anisotropies in the source The nature of the accelerator responsible for energizing the electrons taking part in radiation and scattering.The instrument is suitable for X-ray polarisation measurement of hard X-ray sources like accretion powered pulsars,black hole candidates in low-hard states etc.</p></li><li><p>Instrument SpecificationsEnergy band covered 5-30keVDetectors Proportional countersPhoton collection area ~ 1018 cm2Field of view - 33 degree with 0.5 degree flat response</p></li><li><p>Current StatusThe development of a Thomson polarimeter including proportional counter detectors, associated front-end electronics, event processing logic, data acquisition system, and test and calibration system have been completed successfully.</p><p>Engineering Model is being developed</p><p>For more details contact : bpaul@rri.res.in</p></li><li><p>Sub-mm telescopeNew Optics design has been developed for constructing large sub-millimeter radio telescope economically.</p><p>Balasubramanyam, R, 2004, MNRAS, 354, 1189</p></li><li><p>Current StatusAt present a 3m Submillimeter-wave telescope prototype (3mSTeP) is being builtThe mechanical structure, design and optimization are completedWork on 8 GHz wide band spectrometer is under progress.For more details: contact : ramesh@rri.res.in</p></li><li><p>Possible Future Collaborations</p></li><li><p>Studies of galaxy populations in merging galaxy clusters using SALT and GMRT.</p><p>Radio monitoring of transient X-ray sources, disk-jet connection. </p><p>3. Optical reprocessing of X-rays, simultaneous observations with ASTROSAT and SALT.</p><p>4. NIR-studies (in continuum and shocked molecular hydrogen @ 2.1/2.2 um) of chosen southern massive star forming regions.</p><p>5. Observing for Global EoR signal detection in SKA site in SA.</p></li><li><p>Gauribidanur T Array</p></li><li><p>GBD_image</p></li><li><p>MRT Aerial View</p></li><li><p>Hierarchical Interference mitigation.Imaging with a non-coplanar array.Imaging two steradinas of the sky.</p><p>Human Resource Development:</p><p>8 Ph.D. students1 MS studentSeveral student projects</p></li><li><p> Major projects undertaken by RRIAperture Array for Low Frequency Radio astronomyDevelopment of Digital receivers for The Murchison Wide Field Array (MWA)Multiband receiver system at Green Bank TelescopeZero Spacing Interferometer to detect Cosmological Re-ionization Signatures Development of an X-ray polarimeter for small satellite missionUpgradation of Ooty Radio Telescope Development of a 3m Submillimeterwave telescope Prototype(3mSTeP)</p><p>******</p></li></ul>

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