A new sky survey may reveal further evidence of massive ‘super Jupiters’ orbiting distant stars. The National Science Foundation’s Very Large Array (VLA) is being used to conduct the survey at 74 MHz, a frequency far lower than those used for conventional radio astronomy. Normally, Earth’s ionosphere makes low-frequency radio imaging difficult, but the survey has employed a set of techniques that promise to reveal new categories of deep-sky objects.
“We expect to find very distant radio galaxies — galaxies spewing jets of material at nearly light speed and powered by supermassive black holes,” said Joseph Lazio of the Naval Research Laboratory in Washington, DC. “By determining just how distant these radio galaxies are, we will learn how early the black holes formed in the history of the Universe,” he added.
As for those ‘super Jupiters,’ they may show up through bursts of radio emission at the frequencies this survey is studying. Other possible catches include previously undiscovered pulsars — spinning neutron stars — and the halos produced by ancient galactic collisions. The survey will use some 800 hours of VLA observing time. Images and data are available at the NRAO Web site.
VLA Antennas Getting Modern Electronics To Meet
New Scientific Challenges
http://www.spaceref.com/news/viewpr.html?pid=24789
“When completed in 2012, the EVLA will be 10 times
more sensitive, cover more frequencies, and provide far
greater analysis capabilities than the current VLA. In addition,
it will be much simpler to use, making its power available
to a wider range of scientists.”
The EVLA: Prospects for HI
Authors: Juergen Ott, Rick Perley, Michael Rupen, the EVLA team
(Submitted on 29 May 2008)
Abstract: To continue the unparalleled success of the Very Large Array (VLA) for radio astronomy, the facility is currently being converted to become the ‘Expanded VLA’ (EVLA). The EVLA will radically improve the VLA in order to cover the full 0.93-50 GHz radio wavelength range without gaps, provide up to an order of magnitude better sensitivity, and to allow observations at much larger bandwidths and spectral resolution as currently possible.
For observations of the 21 cm line of atomic neutral hydrogen (HI), the EVLA offers thousands of km/s velocity coverage at sub-km/s resolution for targeted observations as well as an improved spectral baseline stability. In addition, every L-band (21 cm) continuum or targeted HI observation can be set-up to simultaneously observe a full z=0-0.53 HI redshift survey at a velocity resolution of a few km/s. In turn, every HI observation will also yield deep radio continuum images of the field. These synergies will deliver a wealth of data which opens up a wide ‘discovery space’ to study the details of galaxy evolution and cosmology.
Comments: to appear in the proceedings to the conference: “The Evolution of Galaxies through the Neutral Hydrogen Window”, Arecibo, PR, USA
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0805.4595v1 [astro-ph]
Submission history
From: Juergen Ott [view email]
[v1] Thu, 29 May 2008 18:09:13 GMT (7kb)
http://arxiv.org/abs/0805.4595
The Expanded Very Large Array
Authors: R. Perley (1), P. Napier (1), J. Jackson (1), B. Butler (1), B. Carlson (2), D. Fort (2), P. Dewdney (3), B. Clark (1), R. Hayward (1), S. Durand (1), M. Revnell (1), M. McKinnon (1) ((1) NRAO, (2) DRAO/NRC, (3) SKA PDO)
(Submitted on 8 Sep 2009)
Abstract: In almost 30 years of operation, the Very Large Array (VLA) has proved to be a remarkably flexible and productive radio telescope. However, the basic capabilities of the VLA have changed little since it was designed. A major expansion utilizing modern technology is currently underway to improve the capabilities of the VLA by at least an order of magnitude in both sensitivity and in frequency coverage.
The primary elements of the Expanded Very Large Array (EVLA) project include new or upgraded receivers for continuous frequency coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and wide bandwidth data transmission systems to carry signals with 16 GHz total bandwidth from each antenna, and a new digital correlator with the capability to process this bandwidth with an unprecedented number of frequency channels for an imaging array. Also included are a new monitor and control system and new software that will provide telescope ease of use.
Scheduled for completion in 2012, the EVLA will provide the world research community with a flexible, powerful, general-purpose telescope to address current and future astronomical issues.
Comments: Added journal reference: published in Proceedings of the IEEE, Special Issue on Advances in Radio Astronomy, August 2009, vol. 97, No. 8, 1448-1462 Six figures, one table
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:0909.1585v1 [astro-ph.IM]
Submission history
From: Mark McKinnon [view email]
[v1] Tue, 8 Sep 2009 22:01:52 GMT (580kb)
http://arxiv.org/abs/0909.1585