Unveiling the Radio Sky with the JVLA and VLASS Julie Hlavacek-Larrondo Canada Research Chair, Université de Montréal
Very Large Array What is it? Located in Southern New Mexico at 2100 m altitude Composed of 27 antennas (25 meters) reconfigurable on baselines 35m (Darray) to 36km (A-array, 1 arcsecond resolution at 1.4 GHz). Changes happen every ~4 months.
Very Large Array 1972 Approved by Congress 1975 First Antenna put into place 1980 Full science operations ($80 million) 2001 Complete electronics upgrade approved by NSF 2012 Jansky VLA full science operations
Very Large Array What is it? Located in Southern New Mexico at 2100 m altitude Composed of 27 antennas (25 meters) reconfigurable on baselines 35m (Darray) to 36km (A-array, 1 arcsecond resolution at 1.4 GHz). Changes happen every ~4 months.
MS0735, McNamara et al. 2005 Hydra A, Kirkpatrick et al. 2009 Credit: Hercules Perseus A, NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), Fabian and et the al. Hubble 2008 Heritage Team (STScI/AURA)
Radio Astronomy Powerhouse Present from 1980 to The Success Present of the VLA ~12,000 refereed papers with ~500,000 citations ~500 PhD theses The VLA has been among the most productive telescopes ever!
Karl G. Jansky Very Large Array (JVLA) Full frequency coverage from 1 to 50GHz. Provided by 8 wide frequency bands with cryogenic receivers. Up to 8GHz instantaneous bandwidth per polarization. New WIDAR correlator. Designed, funded, and constructed by Canada (HIA/DRAO). Unprecedented flexibility in matching resources to attain science goals. Noise-limited, full field imaging in all Stokes parameters for most observational fields. New software for telescope operations, etc. Credit: van Moorsel
Karl G. Jansky Very Large Array (JVLA) Parameter VLA JVLA Factor Current (OSRO) Point Source Cont. Sensitivity (1σ,12hr.) 10 µjy 1 µjy 10 2 µjy Frequency coverage from 1 to 50 GHz (rms ~ 1 µjy/beam) Maximum BW in each polarization 0.1 GHz 8 GHz 80 2 GHz # of frequency channels at max. BW 16 16,384 1024 4096 Maximum number of freq. channels 512 4,194,304 8192 4096 Upgraded low-frequency system P-band (230-470 MHz) (bandwidths of 240 MHz vs 6 MHz) Coarsest frequency resolution 50 MHz 2 MHz 25 2 MHz Finest frequency resolution 381 Hz 0.12 Hz 3180 0.12 khz # of full-polarization spectral windows 2 64 32 16 (log) Frequency Coverage (1 50 GHz) 22% 100% 5 100% Completed in 2012
Science Highlights (synergy between JVLA and ALMA)
Synergy between SKA, JVLA and ALMA Thermal Imaging on mas Scales at λ ~ 0.3cm to 3cm Terrestrial zone planet formation 1AU @ 140pc Credit: NRAO.
HL TAU (450 light-years away) Thermal Imaging on mas Scales at λ ~ 0.3cm to 3cm Credit: Carrasco-Gonzalez. à Combined ALMA (red) and Jansky VLA (yellow) image (2016). à Central regions too opaque at ALMA wavelengths. à Jansky VLA image reveals clump (3-8 Earth masses).
Science Highlights (large frequency coverage)
JVLA observations of A2256, a merging cluster of galaxies Radio relic Steep spectrum complex Radio tail Spectral index map: VLA 1-8 GHz observations; Owen et al. 2014 Radio tail
Science Highlights (large instantaneous bandwidths and spectral coverage)
HI Detection of Galaxies in COSMOS Thermal Imaging on mas Scales at λ ~ 0.3cm to 3cm Fernandez et al. 2013
Science Highlights (increased sensitivity; before/after)
X-rays (Chandra) Radio 328 MHz (VLA) Perseus cluster of galaxies; Credit: SDSS, CXC/IoA/ACFabian, NRAO/VLA/GBTaylor and MLGendron-M./JHlavacek-L.
NEW JVLA Observations 270-430 MHz NRAO Press Release Gendron-Marsolais, Hlavacek-Larrondo et al. 2017 (see arxiv 1701.03791).
VLASS (passed review and began 7 September 2017!) NRAO VLA Sky Survey (NVSS) Faint Images of the Radio Sky at 21cm (FIRST) VLA Sky Survey (VLASS) à Complete survey of the northern Sky (>-40 degrees). à 3 epochs, separated by 32 months (rms = 70 µjy/beam). à I, Q, U polarization at 2-4 GHz (S-band, resolution 2.5 ). à Around 10,000,000 sources to be detected (!).
Unveiling the Radio Sky with the JVLA and VLASS Julie Hlavacek-Larrondo Canada Research Chair, Université de Montréal