Recent news and science highlights from e-MERLIN, MERLIN and VLBI
Latest Updates 17th February 2010: MERLIN science press release
A team of astronomers, led by Dr. Wouter Vlemmings at Bonn University, has used the MERLIN radio telescope network centred on the Jodrell Bank Observatory
to
show that magnetic fields play an important role during the birth of massive stars. Magnetic fields are already known to strongly influence the formation of
lower-mass stars like our Sun. This new study reveals that the way in which high-mass and low-mass stars form may be more similar than previously suspected.
The scientists report their work in the journal Monthly Notices of the Royal Astronomical Society. ( ..read more..)
The gravitational lens
system B1608+656 imaged using 3 antennas and a single 128-MHz sub-band
of e-MERLIN (approximately 5 hr of data, taken 15th December
2009).
The components are point sources at this resolution;
it is not possible to image extended emission correctly with only 3
antennas.
The crosses show that the new data are consistent with
the positions of the lensed components taken from MERLIN archive data
observed in 1995.
The peak flux density at 4.9 GHz was 39 mJy
in 1995 and 25 mJy in 2001, so the present recorded peak of 13 mJy at
6.7 GHz is consistent with a continued decline in flux density.
The e-MERLIN data used to image B1608+656
The calibrated visibility amplitudes and phases
are shown in blue. The Fourier transform of the image Clean Components is shown in violet, demonstrating a good fit between data and model.
Data collected at 6.7 GHz on B1608+656 within a week of the
e-MERLIN run with the original MERLIN datastream configuration (15 MHz
bandwidth per polarization) through the old MERLIN
correlator.
The calibrated visibility amplitudes and phases
for the hour-angle range observed with e-MERLIN are again shown in
blue & the Fourier transform of the image Clean Components shown in
violet for the Darnhall-Mk2 baseline (with old MERLIN the baseline is
defined in the opposite sense so the phase data are reversed with
respect to e-MERLIN). Note that the e-MERLIN data on this baseline have
3 times better signal to noise with just a single sub-band as compared
with the old merlin data.
16th December 2009: Jodrell Bank Centre for
Astrophysics
and The University of Manchester will
be hosting the 10th EVN Symposium and Users meeting between 20-24th September 2010.
(... to read more)
15th December 2009:Over the last few months we have been working on commissioning and debugging the correlator configuration software. Alongside this work we have been retro-fitting updates and developments to the telescope timing and digitisation hardware, and implementing the new e-MERLIN local oscillator systems. We have been testing these updates and developments using 3 e-MERLIN antennas (Mk2, Pickmere, and Darnhall). Last weekend we observed a bright point source calibrator in a single IF containing 1024 frequency channels over a total bandwidth of 128MHz at 6.1984GHz. The data have been exported to the AIPS software analysis suite via FITS IDI and calibrated with standard routines (amplitude, phase and bandpass corrections have been applied). Sample plots of corrected amplitudes and phases on the three baselines between Mk2, Pickmere, and Darnhall are shown below. At present, test observations over 4 adjacent sub-bands are being made with a total bandwidth of 512MHz (over 30 times the bandwidth available for original MERLIN, and a quarter of e-MERLIN's final bandwidth).
Digital signals from a 4th antenna (Knockin) are expected to be correlated before the end of the month. Additional correlator hardware will be added early in 2010 which will permit the addition of the remaining e-MERLIN antennas and the extension of the maximum correlation bandwidth to 2GHz in each hand of polarization as set down in the e-MERLIN specification.
Amplitudes and Phases for a single sub-band of
e-MERLIN data (data taken 11th December 2009)
Target source: J2136+006
Pink and turquoise - raw uncalibrated amplitudes and phases respectively
Bright red/green: amplitude and phase with the delay, rate, bandpass,
phase and amplitude calibrations
applied. Note the scatter on the calibrated data is smaller than the
symbol size.
Calibrated Amplitudes and Phases as shown above but rescaled (data
taken 11th December 2009).
Target source: J2136+006
Bright red/green: amplitude and phase with the delay, rate, bandpass,
phase and amplitude calibrations
applied.
24th April 2009: Today e-MERLIN saw first fringes on the 10-km baseline between the Mk2 and Pickmere telescopes (... read more)
UK 'superscope' gets first signals from space20th April 2009: e-MERLIN, a super-powerful new radio telescope network - which will allow astronomers to carry out three years worth of observations in a single day - has received its first signals from space at the University of Manchester's Jodrell Bank. (... read more)
Jodrell Bank to help star gazers travel 'Around the World in 80 Telescopes'2nd April 2009: Scientists at Jodrell Bank are to be at the heart of a global astronomy marathon. 'Around the World in 80 Telescopes' is a 24-hour live video web-cast that will enable star-gazers to see what is happening at observatories around the world. ( ... read more)
European VLBI Network to participate in "100 Hours of Astronomy" with live webcast and
e-VLBI observations
23rd March 2009: The European VLBI Network (EVN) will showcase the e-VLBI astronomical technique in the "100 Hours of Astronomy" with a live
webcast on Friday 3 April and e-VLBI observations on Friday 3 April and Sunday 5 April. "The 100 Hours of Astronomy" is a cornerstone project of the
International Year of Astronomy. (... read more )
13 January 2009: 17 radio telescopes around the world will conduct a nearly continuous 33-hour observation as part of a demonstration at the opening ceremony for the International Year of Astronomy 2009 in Paris 15-16 January. ( ... read more and here) )
Marathon e-VLBI images, educational e-VLBI Web site and Virtual Radio Interferometer now available online. A "movie" of the sequential, automatically-generated images and three hand-crafted images (image 1, image 2, image 3) of the target source J0204+1514, observed during the "marathon" e-VLBI observation 15-16 January, are now available. This observation was demonstrated live during the International Year of Astronomy Opening Ceremony along with an educational web site about e-VLBI and Virtual Radio Interferometer, both of which are also available online.
