EVLA / VLA

EVLA / VLA

The EVLA Project will provide a radio telescope of unprecedented sensitivity, frequency coverage, and imaging capability by modernizing the existing Very Large Array. When complete, the EVLA will provide the following capabilities:

Sensitivity: Continuum sensitivity improvement over the VLA by factors of 5 to 20: point-source sensitivity after one hour between 2 and 6 μJy (between 1 and 50 GHz, dependent on band).

Frequency Accessibility: Operation at any frequency between 1.0 and 50 GHz, with up to 8 GHz bandwidth per polarization, 64 independently tunable sub-band pairs, each providing full polarization capabilities.

Spectral Capability: A minimum of 16,384 and a maximum of 4,194,304 channels, adjustable frequency resolution between 2 MHz and 0.2 Hz, and extensive capabilities to allocate correlator resources.

Imaging Capability: Spatial dynamic range greater than 106, frequency dynamic range greater than 105, with noise-limited, full-field imaging in all Stokes parameters.

Operations: Dynamic scheduling, based on weather, array configuration, and science requirements. "Default" images automatically produced, with all data products archived.

With these new capabilities, the EVLA will complement next-generation instruments at other wavelengths, such as ALMA, the James Webb Space Telescope (JWST), and the European Extremely Large Telescope (E-ELT). The EVLA will be easy to use, providing simplified proposal submission, automated scheduling, and default images. These will allow astronomers to take full advantage of the scientific opportunities available at radio wavelengths.

The Magnetic Universe

Magnetic fields are important in most astrophysical contexts, but are difficult to observe. The sensitivity, frequency agility, and spectral capability of the EVLA will allo astronomers to trace the magnetic fields in X-ray emitting galaxy clusters, image the polarized emission in thousands of spiral galaxies, and map the 3D structure of magnetic fields on the Sun.

The Obscured Universe

Phenomena such as star formation and accretion onto massive black holes occur behind dense screens of dust and gas that render optical and infrared observations impossible. The EVLA will observe through these screens to probe the atmospheres of giant planets, measure thermal jet motions in young stellar objects, and to image the densest regions in nearby starburst galaxies.

The Transient Universe

Astronomical transient sources tend to be compact objects that emit synchrotron radiation from high-energy particles, radiation best observed at radio wavelengths. The EVLA will be ideal for studies of variable sources because of its high sensitivity, its ability to observe day and night under most weather conditions, and the rapid response enabled by dyanmic scheduling. The EVLA sensitivity will allow observations at higher frequencies, providing improved spatial resolution. The EVLA will, e.g., image novae and relativistic jets anywhere in the Milky Way, and measure the sizes of many tens of GRBs each year.

The Evolving Universe

The formation of stars and galacies, and the evolution of the gas content of the Universe, are exciting topics for scientists using the EVLA. Radio data can trace the evolution of neutral hydrogen and molecular gas, and provide extinction-free measurements of synchrotron, thermal free-free, and dust emission. The EVLA will distinguish dust from free-free emission in disks and jets within local star-forming regions, and will measure the star-formation rate, irrespective of dust extinction, in high-z galaxies.

Connect with NRAO

The NSF National Radio Astronomy Observatory and NSF Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NSF NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NSF NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NSF NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NSF NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The U.S. National Science Foundation (U.S. NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

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