The Jansky Very Large Array. Russ Taylor Ins-tute for Space Imaging Science University of Calgary

Transcription

1 The Jansky Very Large Array Russ Taylor Ins-tute for Space Imaging Science University of Calgary

2 The Jansky VLA 27x25m antennas in an upside- down Y, in one of four configura-ons, D (most compact) to A (most extended) Located on Plains of San Agus-n in central New Mexico at 2100m al-tude 2

3 From VLA to JVLA The Jansky Very Large Array is a major upgrade of the Very Large Array. The fundamental goal is to improve all the observa-onal capabili-es of the VLA - - except spa-al resolu-on - - by at least an order of magnitude The project will be completed at the end of this year. 3

4 Key Project Goals Full frequency coverage from 1 to 50 GHz. Up to 8 GHz instantaneous bandwidth New correlator with 8 GHz/polariza-on capability <3 µjy/beam (1- σ, 1- Hr) con-nuum sensi-vity at most bands. <1 mjy/beam (1- σ, 1- Hr, 1- km/sec) line sensi-vity at most bands. Noise- limited, full- field imaging in all Stokes parameters for most observa-onal fields. New so_ware for telescope opera-ons, correlator management, and post- processing. 4

5 Technical capabili-es: receivers/bands 8 wideband receivers Switching receivers can be as fast as 20s Oublows, Winds, and Jets Workshop, March

6 Project Status (March 2012) Installa-on of new wideband receivers now complete at: 4 8 GHz (C- Band) GHz (K- Band) GHz (Ka- Band) GHz (Q- Band) Installa-on of remaining four bands completed late- 2012: 1 2 GHz, 19 now, completed end of GHz, 21 now, completed Sept GHz, 16 now, completed end of GHz, 18 now, completed end of In addi-on (but outside the Project), a new wideband low- frequency ( MHz) receiver (paid for by NRL). Two prototypes now oubijed, the rest by early next year. 6

7 Project Status (March 2012) The last major construc-on component not yet completed is the installa-on of the 3- bit, 4 Gsamp/sec samplers. There are eight such samplers in each antenna. These provide the full 8 GHz/polariza-on capability needed for the high frequency bands (above 4 GHz). Status: Nine antennas now fully oubijed. Five others with half the sampler complement. Oubikng scheduled for comple-on in mid- August. 7

8 The Bandpass Solu-ons (LCP for 5 and Phase 13) ea05 Amp. Phase ea13 Amp. 8

9 The WIDAR Correlator

10 The WIDAR Correlator Installa-on of WIDAR began January, It was turned on for astronomy in early March, Each of the 64 spectral windows: Is independently tunable to any frequency within the baseband. Has a frequency width of any of 128, 64, 32,,.031 MHz Provides 256 spectral channels in its basic mode. Frequency resolu-on ranges from 2 MHz to 0.19 Hz. N chan is from to more than 4 million. Numerous special opera-ng capabili-es, including phased array, fast dumps, burst modes, pulsar binning modes. 10

11 Basic WIDAR Modes now available The basic WIDAR mode now available for OSRO proposals. Two individual tunings ( basebands ) within a single frequency band. Each of these is subdivided into 8 con-guous subbands for both polariza-ons. Subband widths are one of 128, 64, MHz. For each of these 16 subbands is generated four polariza-on products (RR, RL, LR, LL). Each of these four products is subdivided into 64 spectral channels. There are thus: 16*4*64 = 4096 total channels produced. Temporal resolu-on no shorter than 1 second. OSRO capabili-es have grown with -me, as the correlator matures. 11

12 Advanced WIDAR Modes The advanced (new) modes which are undergoing development are available to the RSRO program observers. These now include, in three groups: Almost Here: Non- iden-cal subband widths Hardware Stacking (combining subbands to get higher spectral resolu-on) Flexible subband tuning (not all adjacent) Subarrays (mul-ple independent simultaneous programs). Under Development: Fast Dumps (as short as10 millisecond) Recircula-on (another means of increasing spectral resolu-on). VLBI (phased array) 7- bit correla-on (for high RFI environments). 12

13 JVLA demonstra-on science: IRC IRC (CWLeonis) is a carbon star embedded in a thick dust envelope. The expanding envelope (astrosphere) is a rich source of molecular transi-ons 13

14 Hercules A (Perley and Cojon, demo) 4-9 GHz color- code spectral image (redder is steeper, and older). Moderate redshi_ (z=.154), moderate luminosity radio galaxy. EVLA data: 1 through 9 GHz, all four configura-ons. Data taken in all four configura-ons. Shown is the 4 through 9 GHz. Oublows, Winds, and Jets Workshop, March

15 Relics and jets in Abell GHz, 20-arcmin on a side; color corresponds to spectral index (Owen, Rudnick, Eilek, Rau, Bhatnagar, Kogan) Studies of the complex interactions between galaxies, AGN feedback, ICM, magnetic fields, and dark matter content of clusters Role of radio galaxies and relics in cluster evolution? 15

16 The Blank Field 50 Hours 1.0 µjy rms 20 arcmin 16

17 The Noise Sta-s-cs preliminary (14 out of 57 total hours) Sidelobes (noise) σ=2.2 µjy/beam Beam Center σ=2.5 µjy/beam 17

18 Using the JVLA Next proposal deadline AUGUST 1, 2012 General capabili-es available: Up to 8 GHz bandwidth, full polariza-on for con-nuum science Standard spectral set- ups covering key lines plus con-nuum for each receiver band, for galac-c and extragalac-c applica-ons Fast dumps (subject to a data rate maximum) Mul-ple sub- arrays Mosaics Advanced capabili-es for Resident Shared Risk Observers Complex observing strategies and correlator set- ups E.g., mixing of standard correlator modes and recircula-on for phased array using ultra- fast dumps Any other innova-ve uses of the telescope you can think of! For more informa-on contact the NRAO helpdesk, hjps://science.nrao.edu/observing/helpdesk 18