LOFAR discovers new giant galaxy in all-sky survey

March 20, 2013
Overlay of the new GRG (blue-white colors) on an optical image from the Digitized Sky survey. The inset shows the central galaxy triplet (image from Sloan Digital Sky Survey). The image is about 2 Mpc across.

A team of astronomers led by ASTRON astronomer Dr. George Heald has discovered a previously unknown gigantic radio galaxy, using initial images from a new, ongoing all-sky radio survey. The galaxy was found using the powerful International LOFAR Telescope (ILT), built and designed by ASTRON.

The team is currently performing 's first all-sky imaging survey, the Multi-frequency Snapshot (MSSS). While browsing the first set of MSSS images, Dr. Heald identified a new source the size of the full moon projected on the sky. The is associated with material ejected from one member of an interacting galaxy triplet system tens to hundreds of millions of years ago. The physical extent of the material is much larger than the galaxy system itself, extending millions of light years across intergalactic space. The MSSS survey is still ongoing, and is poised to discover many new sources like this one.

The new galaxy is a member of a class of objects called Giant Radio (GRGs). GRGs are a type of radio galaxy with extremely large physical size, suggesting that they are either very powerful or very old. LOFAR is an effective tool to find new GRGs like this one because of its extreme sensitivity to such large objects, combined with its operation at low frequencies that are well suited to observing old sources.

The center of the new GRG is associated with one member of a galaxy triplet known as UGC 09555. The central galaxy is located at a redshift of z=0.054536, or 750 million light years from Earth. The central radio source was previously known and has a flat , typical of giant .

LOFAR's MSSS survey is a concerted effort to image the entire northern sky at very low , between 30 and 160 MHz (wavelengths from 2m to 10m). The primary aim of the survey is to perform an initial shallow scan of the sky, in order to create an all-sky model that will support the calibration of much deeper observations. It is comparable in sensitivity and angular resolution to previous surveys with 'classical' radio telescopes like the Very Large Array (VLA) in the USA, ASTRON's Westerbork Synthesis Radio Telescope (WSRT), and the Giant Metrewave Radio Telescope (GMRT) in India. MSSS is unique in that it operates at substantially lower frequencies, and is therefore poised to uncover new sources that were missed by previous surveys. Its broad bandwidth coverage is also novel in all-sky radio surveys, and will be used to provide additional information about the detected objects.

Explore further: LOFAR opens up the low-frequency universe - and starts a new SETI search

Related Stories

LOFAR: Giant radio telescope goes multi-national

February 3, 2011

In the quest to discover more about our Universe and the birth of stars and galaxies, a new UK telescope connected for the first time to others across Europe has delivered its first 'radio pictures'. The images of the 3C196 ...

LOFAR takes the pulse of the radio sky

April 14, 2011

(PhysOrg.com) -- A powerful new telescope is allowing an international team led by University of Manchester scientists to have their “best-ever look” at pulsars – rapidly rotating neutron stars created when ...

Colliding galaxy cluster unravelled

May 24, 2012

An international team of astronomers has used the International LOFAR Telescope from ASTRON, the Netherlands Institute for Radio Astronomy, to study the formation of the galaxy cluster Abell 2256.

Super-massive black hole inflates giant bubble

October 29, 2012

Like symbiotic species, a galaxy and its central black hole lead intimately connected lives. The details of this relationship still pose many puzzles for astronomers. Some black holes actively accrete matter. Part of this ...

A multi-wavelength view of radio galaxy Hercules A

November 29, 2012

(Phys.org)—Spectacular jets powered by the gravitational energy of a super massive black hole in the core of the elliptical galaxy Hercules A illustrate the combined imaging power of two of astronomy's cutting-edge tools, ...

Recommended for you

Image: Hubble sees a dying star's final moments

July 31, 2015

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

Exoplanets 20/20: Looking back to the future

July 31, 2015

Geoff Marcy remembers the hair standing up on the back of his neck. Paul Butler remembers being dead tired. The two men had just made history: the first confirmation of a planet orbiting another star.

Earth flyby of 'space peanut' captured in new video

July 31, 2015

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.

Binary star system precisely timed with pulsar's gamma-rays

July 31, 2015

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

El_Nose
3 / 5 (2) Mar 20, 2013
Headline we just found the biggest ....

....well how big was it????

turns out there is a clue in the caption of the picture - emphasis on clue as it is not the size - but not in the article

a fifth grader might not make that mistake
Fleetfoot
5 / 5 (1) Mar 20, 2013
Does it say "biggest"? The headline just says they've found a GRG that was previously unknown.
El_Nose
1 / 5 (1) Mar 26, 2013
anytime 'gigantic' is used the average person like me wants to know how big gigantic is meant to encompass.
Fleetfoot
not rated yet Mar 26, 2013
The caption says the image is about 2MPc across.

This article from 2007 says J1420–0545 was then the largest known GRG at 4.69MPc so a bit more than double the size. 15 million light years across is big by most standards.

http://iopscience...ulltext/

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.