Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 Eleventh Synthesis Imaging Workshop, June 10-17, 2008 The Promise of ‘Future’ Radio Telescope Facilities Tracy Clarke (NRL, II) The Radio Revolution Radio Galaxies in the Chandra Era Faster, Bigger, more Sensitive 2008 2009 2010 2011 2012 2013 EVLA WIDAR Controls Array EVLA CfP L band ALMA Shared Risk CfP ALMA Complete EVLA All Antennas Retrofitted EVLA Final Receivers Complete EVLA Shared Risk EVLA WIDAR 4 Station Tests EVLA WIDAR 10 Station Tests ALMA Early Science Starts ALMA Pipelines for Standard Modes LWA-1 Complete LWA 16 Complete LWA-3 Complete LOFAR Effelsberg Station LOFAR 20 Stations VSOP-2 Launch ASKAP Complete Expanded Very Large Array Magnetic Universe Obscured Universe Transient Universe Evolving Universe Measure the strength and topology of the cosmic magnetic field. Image young stars and massive black holes in dust enshrouded environments. Follow the rapid evolution of energetic phenomena. Study the formation and evolution of stars, galaxies and AGN. Science Themes Expanded Very Large Array Parameter VLA EVLA Factor Point Source Sensitivity (1-σ, 12 hours)‏ 10 μ Jy 1 μ Jy 10 Maximum BW in each polarization 0.1 GHz 8 GHz 80 # of frequency channels at max. bandwidth 16 16,384 1024 Maximum number of frequency channels 512 4,194,304 8192 Coarsest frequency resolution 50 MHz 2 MHz 25 Finest frequency resolution 381 Hz 0.12 Hz 3180 Parameter VLA EVLA Factor EVLA: Frequency Coverage Continuous frequency coverage from 1 to 50 GHz separated into 8 frequency bands two completely new bands S (2-4 GHz) and A (26.5-40.0 GHz) VLA had 6 bands covering 22% of the frequency window EVLA covers 100%, opens up enormous new ‘real estate’ Two simultaneous frequency tunings anywhere Low frequency bands at 74 and 330 MHz will remain unchanged Resolution is unchanged Blue: Existing bands Green: New bands Science drives the observations, not hardware! Chandra Resolution HST resolution Full band tuning available now Old correlator’s limitations remain: 50 MHz BW 16 to 512 channels The old correlator will likely be available until the WIDAR correlator achieves full 27-antenna capability – mid 2009. EVLA: Wideband Availability June 1 2008 deadline had special call for proposals: L band tuning 1000-1200 MHz Limitations of the VLA correlator remain until Q3 2009: 50 MHz maximum BW 16 to 512 channels WIDAR correlator: 8 GHz maximum BW (dual polz.) 16,384 to 4,194,304 channels 128 independently tunable sub-bands 2008 2010 2012 Widar EVLA: 8 GHz (z=1.4 to 1.9 for CO J=1-0; z=3.8 to 4.8 for 2-1)‏ 16384 spectral channels (1 MHz res’n= 5.0 km/s)‏spectral channels (1 MHz res’n= 5.0 km/s)‏ Example: 2:1 bandwidth ratios and MANY channels instantaneous velocity coverage (53,300 km/s vs. current 666 km/sec at 45 GHz) lines at arbitrary redshift and over large redshift range 128 independently tunable sub-bands zoom in spectrally on target region and leave one 2 GHz baseband for continuum EVLA CO redshift survey: 40-50 GHz is lowest redshift z=1.4-1.9 for J=1-0 z=3.8-4.8 for J=2-1 5 km/s resolution QSO absorption line surveys C. Carilli Arp 220, z=8 EVLA: Sensitivity VLA EVLA 1σ, 12h Sensitivity gain from increased bandwidth, improved efficiency and lower system temperature. High frequency EVLA is MUCH more sensitive: 35 mas observations feasible for many sources with a factor of 25 better sensitivity 1) Much more bandwidth:  100 MHz to 8 GHz (per polarization) -- a factor of 80. 2)  Better receivers.  Probably a 20% reduction in Tsys, due to improvements. 3) Improved efficiency -- holographic adjustments have doubled (at least) the efficiency. EVLA: 8 GHz (z=1.4 to 1.9 for CO J=1-0; z=3.8 to 4.8 for 2-1)‏ 16384 spectral channels (1 MHz res’n= 5.0 km/s)‏spectral channels (1 MHz res’n= 5.0 km/s)‏ Example: Image Fidelity Wide bandwidth improvement in image fidelity (SNR) in a 30 minute observation at 8 GHz. VLA EVLA EVLA: Faraday Rotation and Depolarization Faraday rotation & depolarization studies with powerful new capabilities to probe a wide range of environments (magnetic field orientation and strength) 0.15” 15 GHz 43 GHz band (up to 0.035” resolution) more than 25 times better sensitivy than VLA! All bands are broad-band (2 GHz/IF) giving instantaneous Faraday rotation and depolarization A2256 0.2” 43 GHz 43 GHz is Cyg A hotspot 15 GHz is M87 Color is 3C31 EVLA: Spectral Studies Resolved spectral index measurements and spectral curvature of jets, hotspots and lobes All bands are broad-band (2 GHz/IF) giving instantaneous spectral index measurements Two tunings ‘anywhere’ can be used to trace spectral curvature Time to observe 1 square degree to 40 microJy/beam rms doesn’t include overhead (--> x1.5, from NVSS) rms chosen to ensure at least 20s/ptg EVLA Examples: Survey Speed Square degrees observed per hour as a function of frequency, to an rms of 40 microJy/bm 1 0.1 0.01 Square Degrees per hour ν (GHz) ν (GHz) Time (mins) 10 20 30 40 0 0 10 20 30 40 50 104 103 102 101 Survey Speed Survey Speed: 1 Sq. degree EVLA: Other Areas of Interest to RG Physics Mosaic imaging at 35 mas of many sources for comparison with low frequencies and X-rays Stacked recombination line studies Study of ionized hydrogen and its velocity field near AGN Molecular transition studies including CO J=1-0 at redshift > 1.3 All spectral lines ‘free’ with every observation Maser searches over wide velocity range Fast and deep surveys Rapid response time for good light curves and ‘bonus’ spectral information Many background sources in most fields ‘Piggy back’ surveys, e.g. every spectral line experiment provides deep continuum data Atacama Large Millimeter Array Baselines up to 15 km (15 mas at 300 GHz) in ‘zoom lens’ configurations Sensitive, precision imaging between 30 GHz and 950 GHz (10 mm to 350 μm) Flexible correlator with high spectral resolution at wide bandwidth Full polarization capabilities Regional science centers and pipeline products 10 Frequency bands coincident with atmospheric windows have been defined. Bands 3, 6, 7 and 9 will be available from the start. Bands 4, 8 and 10 will be built by Japan. Some band 5 receivers built with EU funding. ALMA: Frequency and Resolution 10 Frequency bands coincident with atmospheric windows have been defined. Bands 3, 6, 7 and 9 will be available from the start, other bands will be added later. Order of magnitude or more improvements in all areas of (sub)mm including resolution, sensitivity and frequency coverage HST/NGST resolution Chandra resolution ALMA: A Few Areas of Interest to RG Physics High resolution imaging of radio hot spots and jets (particle acceleration and losses) Measure hot spot magnetic field strength and relativistic energy density Particle acceleration processes in the inner jet region Probing 50 Rs region of M87 where jet collimation occurs (VLBI w/ ALMA) Imaging molecular gas in high redshift QSO’s to determine dynamical mass of host galaxy Search for flat spectrum, mm-loud AGN (possibly very young radio jets) for X-ray follow-up Map molecular reservoir within a few pc in nearby AGN to study gas flow and BH masses Trace SF in cores for IC studies Separate synchrotron emission from dust Long Wavelength Array Full frequency coverage between 20 MHz and 80 MHz (15 m to 3.75 m) with multiple ‘beams’ Final array is located in NM and will have baselines of 400 km (2 asec at 80 MHz) and mJy sensitivity Intermediate array of 16 stations operational in 2012 will have baselines of 200 km Flexible correlator with high spectral resolution at wide bandwidth (100 Hz resolution, 8 MHz bandwidth) Full polarization capabilities NM Low Frequency Array Low and high frequency arrays will be co-spatial covering ranges of 10-80 MHz and 120-240 MHz NL will have baselines of 100 km, EU extension to 1000 km Final instrument will have ~40 stations in NL Core Station 1 completed in 2007, 20 NL stations to be operational by 2009-2010 Multiple ‘beams’ to undertake LOFAR Key Projects Full polarization, wide bandwidth and high spectral resolution Low Frequency Science: Radio Galaxy History 8465 MHz 1400 MHz 330 MHz ? 4835 MHz Clarke et al. (2005) Abell 2597 Low frequencies trace electrons with low energy and/or in weak magnetic field Synchrotron losses are lower at low frequencies so they trace old electrons Low Frequencies: RG Physics Survey of high redshift radio galaxies to study cosmological evolution of SMBHs Trace history of AGN activity through multiple outburst episodes; merger history through halos and relics Estimate the total AGN energy input into IGM/ICM through feedback Constrain the relativistic particle content of radio lobes Probe electron population responsible for IC emission Trace magnetic field distribution in jets and lobes Study the physics of shock acceleration in hot spots for low Lorentz factor electrons Probe particle acceleration in relativistic shocks along the radio jets 330 MHz 610 MHz Radio Revolution: Summary Radio resolution will be within a factor of a few of Chandra from frequencies of a few 10’s of MHz up to nearly a THz (15 m to 300 microns) Fundamental studies of Radio Galaxy physics will be routine with the next generation of interferometers Significant advances anticipated in polarization studies, spectral studies, low energy particle content, etc ...Identify ‘fundamental’ first science radio galaxy projects and prepare the upcoming graduate student population (somewhat late advertisement for NRAO Interferometry Summer School). The Future: Square Kilometre Array Many ‘pathfinders’ currently being developed SKA-lo: 100 MHz < ν < 300 MHz SKA-mid: 300 MHz < ν < 3-10 GHz SKA-hi: 5-10 GHz < ν < 25-50 GHz Key Science for SKA: Strong-field Tests of Gravity with Pulsars and Black Holes Galaxy Evolution, Cosmology, and Dark Energy The Origin and Evolution of Cosmic Magnetism Emerging from the Dark Ages The Cradle of Life/Astrobiology Exploration of the Unknown Science with the Square Kilometre Array (2004, eds. C. Carilli & S. Rawlings, New Astron. Rev., 48) Chang Sho Fortune Cookie: 7/10/08 The stars appear every night in the sky. All is well. Lucky Numbers: 10 -- number of antennas for WIDAR first science 16 -- current number of EVLA retrofitted antennas 18 -- expected number of EVLA retrofitted antennas at start of Q4, 2008 27 -- final number of EVLA antennas 30 -- years since first VLA observation of Cen A with > 10 antennas 32 -- # of minutes this 25 minute talk has gone on? WIDAR Correlator Design and construction of correlator by the DRAO correlator group (Penticton, BC, Canada). All costs covered by Canadian NRC. WIDAR accepts 8 inputs, of up to 2 GHz BW each, normally configured as four input (R,L) pairs. Their design is an extraordinarily flexible machine allowing for up to 64 independently defined (in frequency and bandwidth) sub-band pairs within the input bandwidth. Each digitally-defined sub-band pair has 256 channels, to be distributed amongst 1, 2, or 4 polarization products. Recirculation provided for increased frequency resolution. Vast number of ways to share resources internally, trading inputs, or sub-band pairs, or polarization, for more channels. Full polarization, pulsar modes, phased array, VLBI-ready, extensive subarraying, etc.