LOFAR Science Highlights

 

For a comprehensive overview of LOFAR scientific results, please check the LOFAR slides repository.

Featured Highlights

Spectro-polarimetry of the entire Hetdex region from the LOFAR Tier1 survey. Image: C. Van Eck.

 
Current best 2-sigma upper limits (at different redshifts) from several experiments aiming to (statistically) detect signals from the Epoch of Reionisation. Image: A. Offringa.

Discovering millisecond pulsars with LOFAR. Image: C. Bassa

Discovering millisecond pulsars with LOFAR. Image: C. Bassa

A three-colour image from the LOFAR Multifrequency Snapshot Sky Survey (MSSS). Image C. Riseley, G. Gurkan, G. Heald and the MSSS team.

 

 

Fine Structures of a Shock Signature in the Solar Corona. Image P. Zucca.

 

The Bootes field as observed by the Surveys team. Image W. Williams.

 

 

Long Baseline Imaging with LOFAR

The Polish stations were completed at the end of 2015 and were added to the rest of the array early in 2016.  The first image obtained by including them in the observing setup is presented below. Left: 117 MHz, PSF 0.40"x0.50". Right: 173 MHz, PSF 0.25"x0.35". From A. G. de Bruyn (ASTRON).

 

 

Galactic Star Formation

Gas clouds of hydrogen and formation of massive stars in the Milky Way Galaxy. This image was obtained using LOFAR's High Band Antennas. From Glen White (Open University/Rutherford Appleton Laboratories).

 

Galactic Star Formation

 

Re-imaging of MSSS survey: towards a low frequency counterpart of NVSS

A three-colour image from the LOFAR Multifrequency Snapshot Sky Survey (MSSS). The angular resolution is 45 arcsec, i.e. identical to the 1.4 GHz NVSS. The nearby galaxies M81 and M82 are visible, along with the giant radio galaxy 4C 73.08.

 

 

Discovering millisecond pulsars with LOFAR.

Thanks to GPU accelerated coherent dedispersion software, LOFAR is now capable of searching for radio pulsars spinning at millisecond spin periods. Three millisecond pulsars have so far been discovered, including one that spins 707 times per second, the second fastest spinning neutron star known in our Galaxy.

 

Largest Sample of milli-second Pulsars at Low Frequencies

This is the largest sample of milli-second pulsars ever observed and detected with a single telescope at LOFAR frequencies.   Regular monitoring of pulsar dispersion, rotation measures and scattering can provide a "weather report" of the interstellar medium to improve pulsar timing precision.

 

Bubble of Gas from a Super-massive Black Hole

Astronomers have used LOFAR to produce the best image ever taken of a bubble of gas being blown our of a super-massive black hole. The image at left below shows the gas glowing a low frequencies, while the image at right shows the corresponding optical image. Further details can be found here.

 

Super-Massive Black Hole

 

Magnetic Structures in the Milky Way

Polarized emission in the Tier 1 survey HETDEX region, colorized by degree of Faraday rotation (Faraday depth), showing structure in the magnetic field and ionized medium of our Galaxy. The gradients (e.g, top right) in particular are features that can't be identified with higher frequency data. 

 

Detecting signals from the Epoch of Reionisation: current status.

Current best 2-sigma upper limits (at different redshifts) from several experiments aiming to (statistically) detect signals from the Epoch of Reionisation.

 

Jets from Black Hole in Radio Galaxy

The enigmatic radio galaxy Cygnus A is one of the brightest objects that LOFAR can see. This image by John McKean shows plasma jets from the black hole that stretch 2,000 light-years from the core of Cygnus A.

 

Cygnus A

 

  Fine Structures of a Shock Signature in the Solar Corona.

A shock in the solar corona may emit radio waves producing a signature called type II solar radio burst. Panel (a) shows a dynamic spectrum of a type II burst where the harmonic emission is divided in sub-lanes marked as 1-1a and 2-2a (band-splitting phenomenon). Zucca et al. using LOFAR LBA observations have found a different location for two pairs of sub-lanes. Panel (b) shows the contours of the radio sources located at the flank of an expanding CME measured with the coronagraph SOHO/LASCO. For the first time, a state of the art 3D reconstruction of the Mach number along the CME front showed that the two pairs of the type II lanes are located in two regions of the corona showing high Mach number (panel c).

 

Variety of Sources in the Bootes Field

This image by Wendy Williams of the Surveys KSP illustrates the variety of radio sources to be seen in the Bootes field.

 

 

LOFAR Radio Images of the Solar Eclipse

A partial solar eclipse on 20th March 2015 provided a rare opportunity to image such an event at radio frequencies.  With more than 80% of the Sun obscured by the moon at maximum eclipse, the solar corona becomes clearly visible in this LOFAR image taken at 150MHz by Michiel Brentjens.

 

 

Design: Kuenst.    Development: Dripl.    © 2020 ASTRON