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Moscow presentation, Sept, 2007 L. Kogan National Radio Astronomy Observatory, Socorro, NM, USA EVLA, ALMA –the most important NRAO projects.

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Presentation on theme: "Moscow presentation, Sept, 2007 L. Kogan National Radio Astronomy Observatory, Socorro, NM, USA EVLA, ALMA –the most important NRAO projects."— Presentation transcript:

1 Moscow presentation, Sept, 2007 L. Kogan National Radio Astronomy Observatory, Socorro, NM, USA EVLA, ALMA –the most important NRAO projects

2 Moscow presentation, Sept, 2007 EVLA

3 Moscow presentation, Sept, 2007 Artist's conception of the ALMA antennas in a compact array. Image courtesy of NRAO/AUI and ESO

4 Moscow presentation, Sept, 2007 The ALMA’s site Image courtesy of NRAO/AUI

5 Moscow presentation, Sept, 2007 EVLA and ALMA will require new algorithms and more efficient use of existing algorithms in order to obtain the images which reach the sensitivity, resolution and fidelity that these new arrays can achieve.

6 Moscow presentation, Sept, 2007 The algorithms especially needed by EVLA and ALMA wide-field, wide-bandwidth (MFS) EVLA deep imaging problem. mosaicing problems that are more important for ALMA than the EVLA.

7 Moscow presentation, Sept, 2007 EVLA Phase I - Key Science Examples Measuring the three-dimensional structure of the Sun's magnetic field Mapping the changing structure of the dynamic heliosphere Measuring the rotation speed of asteroids Observing ambipolar diffusion and thermal jet motions in young stellar objects Measuring three-dimensional motions of ionized gas and stars in the center of the Galaxy Mapping the magnetic fields in individual galaxy clusters Conducting unbiased searches for redshifted atomic and molecular absorption Looking through the enshrouding dust to image the formation of high- redshift galaxies Disentangling starburst from black hole activity in the early universe Providing direct size and expansion estimates for up to 100 gamma-ray bursts every year

8 Moscow presentation, Sept, 2007 EVLA Phase I - Capabilities Sensitivity: Continuum sensitivity improvement by up to a factor of 5 (below 10 GHz) to more than 20 (between 10 and 50 GHz). Frequency Accessibility: Operation at any frequency between 1.0 and 50 GHz. Two pairs of signals, each pair with opposite polarizations up to 4 GHz bandwidth, making a total available bandwidth of 8 GHz at each polarization, and independently tunable at any frequency within any given band. Spectral Capabilities: The WIDAR correlator will provide many frequency channels (minimum of 16,384, up to 262,144), process the wide bandwidths, and give frequency resolution better than 1 Hz if necessary. Operational Changes: Phase I will provide dynamical scheduling: observing blocks will be scheduled on the basis of weather, array configuration, and science. "Default" images will be routinely and automatically produced for all observing programs, and be made available to users.

9 Moscow presentation, Sept, 2007 Phase I - Technical Advances Wideband receiver systems State-of-the-art, flexible correlator Fiber-optic data transmission system New digital electronics New powerful on-line control system

10 Moscow presentation, Sept, 2007 EVLA Phase II - Key Science Examples AU-scale imaging of local star forming regions and proto-planetary disks Resolving the dusty cores of galaxies to distinguish star formation from black hole accretion Imaging at the highest resolution at any wavelength of the earliest galaxies (z~30) Imaging of galaxy clusters with 50 kpc or better resolutions at arbitrary redshifts Imaging of thermal sources at milliarcsecond scales Resolving individual compact HII regions and supernova remnants in external galaxies as distant as M82 Tying together the optical and radio reference frames with sub-milliarcsecond precision Measuring accurate parallax distances and proper motions for hundreds of pulsars as distant as the Galactic Center Providing 50 pc or better resolution for galaxies at any redshift Monitoring and imaging the full evolution of the radio emission associated with X-ray and other transients

11 Moscow presentation, Sept, 2007 EVLA Phase II - Capabilities Resolution: Angular resolution improvement by an order of magnitude (better than 10 mas at 18 to 50 GHz), providing tens of Kelvin brightness temperature sensitivity. Fidelity: Fast, high fidelity imaging of low-brightness (~10 microKelvin) emission with tens of arcseconds angular resolution of objects whose extent exceeds the antenna primary beam.

12 Moscow presentation, Sept, 2007 Phase II - Technical Advances Eight new antennas, providing baselines up to 350 km Modification of Pie Town and Los Alamos VLBA antennas for full compatibility Connection of the new and upgraded antennas to the WIDAR correlator by fiber-optic lines Construction of compact E configuration, providing baselines from 30 to 250 meters Real-time correlation of the new and upgraded antennas with the other 27 using the WIDAR correlator Implementation of WIDAR design to allow correlation of disk recorded data from VLBA antennas with real-time data

13 Moscow presentation, Sept, 2007 The red/blue circles are the existed VLA / new pads. The circles diameters are in scale. The configuration is optimized to minimize side lobes.

14 Moscow presentation, Sept, 2007 ALMA Atacama Large Milimeter Array Up to sixty-four 12-meter antennas located at an elevation of 16,400 feet in Llano de Chajnantor, ChileantennasLlano de Chajnantor, Chile Imaging instrument in all atmospheric windows between 10 mm and 350 microns Array configurations from approximately 150 meters to 10 km Spatial resolution of 10 milliarcseconds Able to image sources arcminutes to degrees across at one arcsecond resolution Velocity resolution under 0.05 km/s Largest and most sensitive instrument in the world at millimeter and submillimeter wavelengths

15 Moscow presentation, Sept, 2007 Alma compact configuration optimized having topography file of the roads. The side lobes optimized inside of a part of the primary beam. Maximum side lobe ~0.009


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