First call for proposals for Onsala’s LOFAR station

Credit: Onsala Space Observatory/VästkustflygGot an idea? The Onsala station is ready to try it out. Credit: Onsala Space Observatory/Västkustflyg

For the first time, Onsala’s part of LOFAR is available for observing proposals from the Swedish research community. About 10% of the time of the Onsala LOFAR station is for standalone time when the station is used on its own and not as part of the International LOFAR telescope. Observing proposals for this mode are now open as part of the general Onsala National Facility general call for proposals, with deadline 15 October 2013. Read the Call for proposals here.

Not sure how to proceed? At Onsala we want to give as much help as we can in turning raw science ideas into proposals, and then processing these data. See the contact information in the Call for proposals.

What might you want to do? Here are just some possible science uses for single station mode.

Transient searches – potentially both all-sky and targeted transient searches toward individual objects can be carried out. Examples of the former include followup on the recent discovery of fast radio bursts (Thornton et al 2013; see Trott et al 2013 on the prospects for low frequency detection prospects.)

Credit: Onsala Space Observatory/LOFARThe single-station sky over Onsala at 52 MHz on 18 september 2013. Credit: Onsala Space Observatory/LOFAR

All-sky low (few degree) resolution imaging (large area surveys, short spacing information).

Radio recombination lines

Pulsar timing (timing, DM monitoring, RM monitoring, and so on), pulsar emission properties,

Solar spectrum monitoring

Interplanetary scintillation

Ionospheric science

Space Weather

Bistatic (passive) radar for detection of meteors

Read the full Call for proposals here

Single-station mode at Onsala is also making its public debut on 28 September 2013 during Sweden’s Day and Night of Astronomy. Participants at the star party Onsala stjärnträff (Wirström & Cumming 2013) will be, we think, the first members of the public to try observing with LOFAR.

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Transient science with LOFAR at Onsala after the Chameleon pulsar discovery

The first LOFAR paper to make the pages of Science is about the bizarre pulsar PSR B0943+10, whose unexpected changes of state in both radio and X-rays are showing us that we really don’t understand pulsar magnetospheres. You can read the Science paper, or the press release at Onsala in Swedish, at ASTRON and at ESA.
The data for the paper were collected with the LOFAR core in the Netherlands, but observations of pulsars and other transient sources are already being done with the Onsala LOFAR station.

Early pulsar data with the new backend: PSR B0329+54 recorded at the Onsala LOFAR station in October 2012 (Credit: Onsala Space Observatory)

In particular, we’ve borrowed a backend developed at the University of Oxford which searches for transient signals using graphics processors of the sort you find in games consoles.
“In principle it allows us to carry out fast pulsar searches, which require significant computing to dedisperse and fold the data,” says Wouter Vlemmings, Onsala Space Observatory.
The backend can also look for other transients too, not just pulsars. This is the topic for a new masters’ project at Chalmers that has just started.
“We will be using it for transient experiments like this, and for looking for sources of interference”, says John Conway.

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Supermassive black hole inflates giant bubble: LOFAR’s view of M87

The galaxy M87 as seen by LOFAR (radio emission is show in yellow/orange, visible light in blue/white). At the centre, the brightest radio emission shows where the jet powered by the supermassive black hole is located. Credit: Francesco de Gasperin, on behalf of the LOFAR collaboration. Optical image: SDSS

Using LOFAR, astronomers have produced one of the best images ever made at the lowest frequencies of giant bubbles produced by a supermassive black hole. The observations were performed at between 20 and 160 MHz, frequencies normally used for communications by airline pilots. The picture shows what looks like a giant balloon filled with radio emitting plasma, which exceeds the size of an entire galaxy.

The image was made during the test-phase of LOFAR, and targeted the giant elliptical galaxy Messier 87, at the centre of a galaxy cluster in the constellation of Virgo. This galaxy is 2000 times more massive than our Milky Way and hosts in its centre one of the most massive black holes discovered so far, with a mass six billion times that of our Sun. Every few minutes this black hole swallows an amount of matter similar to that of the whole Earth, converting part of it into radiation and a larger part into powerful jets of ultra-fast particles, which are responsible for the observed radio emission.

To determine the age of the bubble, the authors added radio observations at different frequencies from the Very Large Array in New Mexico (USA), and the Effelsberg 100-meter radio telescope near Bonn (Germany). The team found that this bubble is surprisingly young, just about 40 million years, which is a mere instant on cosmic time scales. The low-frequency observation does not reveal any relic emission outside the well-confined bubble boundaries, this means that the bubble is not just a relic of an activity that happened long ago but is constantly refilled with fresh particles ejected by the central black hole.

Read the whole press release at ASTRON or the paper by de Gasperin et al. at Astronomy & Astrophysics or at ArXiV.

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LOFAR unravels a colliding galaxy cluster

Galaxy cluster Abell 2256: a cosmic collision on a huge scale. Credit: ASTRON/R. J. van Weeren

An international team of astronomers has used the International LOFAR Telescope to study the formation of the galaxy cluster Abell 2256. This cluster of hundreds of galaxies, 800 million light years distant, turns out to be more complex than expected.

New, deep, low-frequency LOFAR observations of the cluster, made just before the Onsala station joined the network, show that Abell 2256 is probably a merger of two or more galaxy clusters. For more details, see the paper by van Weeren et al., either at ASTRON or on ArXiv.

You can read the press release in Swedish at Onsala Space Observatory or in English at ASTRON.

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LOFAR presents first science and starts All-Sky Survey

Scientists from the International LOFAR Telescope (ILT) today announced the kick-off of the project’s first all-sky survey at low radio frequencies and its first open call for observing proposals from the international astronomical community.

See complete press release at Onsala Space Observatory in English and in Swedish. And here’s the presentation at the AAS 219th meeting in Austin, Texas on 9 January 2012.

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Inaugurated: Onsala’s LOFAR station

On Monday 26 September 2011, Sweden’s minister for Education and Science Jan Björklund inaugurated Sweden’s part of the International LOFAR telescope.

Hans Olofsson visar upp en LOFAR-antenn
Hans Olofsson introduces the minister to a LOFAR HBA antenna while other guests look on. (Credit: Onsala Space Observatory/Jan-Olof Yxell)

Over 140 guests took part at the inauguration day at Onsala Space Observatory. Local and international guests mingled with staff from the observatory and Chalmers’ Department of Earth and Space Sciences, along with a number of local and regional journalists from TV, radio and newspapers (see links below).

LOFAR-data togs emot i Nederländerna
With a mouseclick and a little help from John Conway minister Jan Björklund sent Onsala’s LOFAR data to ASTRON in Groningen, Netherlands, where Jurjen Sluman (below right) and colleagues confirmed “You are now part of the network!”. (Credit: Onsala Space Observatory/Jan-Olof Yxell)

A marquee in the shadow of the observatory’s 25-metre telescope, opened in 1964, was the venue for the inauguration ceremony. Department head Gunnar Elgered introduced five speakers, starting with Karin Markides, president of Chalmers. Observatory director Hans Olofsson explained the scientific drivers for LOFAR, the new window on the universe that the telescope opens and the promise of discovering the era of reionisation a few hundred million years after the Big Bang.

Karin Markides
Karin Markides, president of Chalmers, was the first to speak at the inauguration of Onsala’s LOFAR station. Credit: Onsala Space Observatory/Jan-Olof Yxell

Rene Vermeulen, director of the International LOFAR Telescope, put the new station in context and explained how it will enable LOFAR to create high-resolution images. Göran Östlin, Stockholm University, underlined the importance of international scientific projects and research infrastructure. In her address, Kerstin Eliasson, chair for the Swedish Research Council’s Council for scientific research infrastructure, called on Sweden’s astronomers both to work together in projects like LOFAR and to plan and prioritise for the future of Swedish astronomy.

Finally, minister Jan Björklund described astronomy as a science which both addresses our biggest questions about the universe, and which awakens interest in people of all ages. He also took up the importance of basic science.

“I think it would be a big mistake for Sweden and for Europe to believe that cuts in basic scientific research will solve any problems. On the contrary, we create long-term problems if we reduce our ambitions in this area”, he said.

See below for links to the inauguration addresses.

As the moment of inauguration approached, John Conway guided the minister through the computer program that started Onsala’s LOFAR station. A pause followed while the data was processed, then the guests could see for themselves the first image in radio waves of the sky above the LOFAR station. Radio waves from our galaxy, the Milky Way, dominate the picture, along with the Sun and supernova remnant Cassiopeia A. To create the sharpest images, data from alla LOFAR’s stations needs to be combined. With a mouseclick, Jan Björklund started data transfer over a high-speed link to the Netherlands, making Onsala’s station a part of the International LOFAR Telescope.  Staff in the Netherlands confirmed by video link that the data was arriving – so it was time to cork up the champagne!

Jan Björklund bland LOFAR-antenner
Education minister Jan Björklund visited the newly inaugurated LOFAR station in Onsala. Behind him: the station’s low-frequency antennas. (Credit: Onsala Space Observatory/Haukur Sigurðarson)

A guided tour of the LOFAR station was next on the programme. Here a number of media interviews were also made, with the minister and with Hans Olofsson, Carina Persson and Robert Cumming from the observatory staff among the station’s 192 new antennas. The day was rounded off with lunch, coffee and visits to the Observatory’s exhibition hall and its other telescopes and instruments.

Utbildningsministern med Hans Olofsson
Hans Olofsson greeted education minister Jan Björklund outside Onsala Space Observatory’s exhibition hall. Credit: Onsala Space Observatory/Jan-Olof Yxell

What was it like to be there? Somehow, we struck a perfect balance between ceremony and celebration, science and delight in something new and exciting. After a cloudy start the sun broke gradually through the clouds, reflecting the optimistic mood of the occasion. From the response of the guests both on the day and afterwards, we’re convinced that everyone was happy to have taken part.
A number of news reports from the inauguration were broadcast on the evening after: see below for links.
Read the inauguration addresses

Here you can read Jan Björklund’s, Kerstin Eliasson’s and Karin Markides’ addresses to the LOFAR inauguration in Onsala on September 26, 2011. Jan Björklund’s and Karin Markides’ addresses are in Swedish.

Onsala’s LOFAR station and the inauguration in the Swedish media

(text: Daniel Johansson and Robert Cumming)

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Swedes make world’s largest telescope bigger (Chalmers press release)

The 192 radio antennas that make up Onsala’s LOFAR station cover an area the size of a soccer pitch. Credit: Onsala Space Observatory/Leif Helldner

On Monday 26 september, Sweden’s Minister for Education and Research, Jan Björklund, will open Onsala Space Observatory’s newest telescope. Part of LOFAR, the world’s largest radio telescope, it is the biggest telescope built in Sweden in the last 35 years. Lofar will map radio signals which have travelled across the universe for billions of years. Scientists expect Lofar to answer questions about the nature of our universe.

LOFAR (Low Frequency Array) is a new kind of radio telescope. It can see radio waves with low frequencies, similar to those that give us FM radio. Rather than collecting signals from individual radio sources, LOFAR continuously monitors large swathes of sky. LOFAR is more sensitive to the longest observable radio waves than any other telescope. It can see many billions of light years out into space, back to the time before the first stars formed, a few hundred million years after the big bang.

The 192 new radio antennas at Onsala’s LOFAR station look modest enough. But the radio signals they collect will be linked together with 47 similar stations over the whole of Europe, and sent over Internet to a central supercomputer in the Netherlands. This means huge amount of data traffic: the equivalent of over 7000 DVD films per day just from the Swedish station. The telescope creates images of the sky using a unique combination of computer power and innovative software. Together, LOFAR’s antennas form a single telescope with a diameter of 1300 kilometres.

Hans Olofsson is director of Onsala Space Observatory and professor at Chalmers.

“For astronomers like me, Lofar means that we can see far enough to be able to study the universe’s early history. We want to discover traces of the clouds of hydrogen gas that filled the universe 13 billion years ago, and find out just why today’s universe looks the way it does,” he says.

Scientists expect LOFAR to discover hitherto unknown types of astronomical objects. It will also investigate the environments of black holes, find extreme galaxies and pulsars, and search for planets around other stars.

Onsala Space Observatory was founded in 1949 and was led for three decades by Professor Olof Rydbeck. Since its inception the observatory has contributed to the forefront of research in radio astronomy, both through interpretation of observations and developing new technology. Since 1990 the observatory is the Swedish National Facility for Radio Astronomy. It is financed by the Swedish Research Council and operated by Chalmers.

“Onsala Space Observatory has always been a prominent centre for radio astronomy research, and now it’s part of the world’s most exciting radio telescope. In the future we plan to develop the technology that makes Lofar unique when we build the next generation of radio telescopes, says René Vermeulen of Astron, the Netherlands national institute for radio astronomy, and director of the International Lofar Telescope.

Lofar is one of many examples of Onsala Space Observatory’s increasing involvement in international projects. Chalmers is one of three international partners in the submillimetre telescope APEX in Chile, which recently discovered hydrogen peroxide in space. Last winter Chalmers delivered sensitive new receivers to the ALMA Observatory, the world’s largest astronomy project, currently being built in Chile’s Atacama desert. The observatory is also planning for the radio observatory SKA (Square Kilometre Array), to be built in Australia or South Africa, in which LOFAR’s new technology will be developed even further. SKA is expected to give answers about the origins of both the universe itself and life in space.

“Space research is also critical for our understanding of the earth and its climate, and it invariably leads to spin-off effects. International facilities like LOFAR foster strong cooperation across both scientific and cultural borders,” says Karin Markides, President of Chalmers.

“I believe LOFAR in particular will have great importance for our ability to handle very large amounts of data,” she adds.

During the inauguration ceremony at Onsala Space Observatory on Monday Minister of Education and Research Jan Björklund will take some of the first ever images of the sky with the Swedish LOFAR station. He will also visit the station together with around a hundred invited guests.

Invitation to media representatives:
Journalists are invited to participate in the inauguration program between 10:00 and 14:00 on Monday 26 September 2011. The visit to the LOFAR station will end around noon. For accreditation and info on travel arrangements, please register to before Friday afternoon. Cellphones must be switched off at the gates to the observatory.

Images free for publication:

More about Onsala Space Observatory:

For further information, please contact:
Hans Olofsson, professor at Chalmers director for Onsala Space Observatory, +46 31-772 55 35,
Robert Cumming, astronomer and information officer at Onsala Space Observatory, press contact for Lofar in Sweden, +46 31-772 55 00 or +46 70-49 33 114,

Please note: Swedish Astronomers’ Days held in Gothenburg from 29 Sep-1 Oct 2011
Onsala Space Observatory is the host for Sweden’s biannual Astronomers’ Days. The meeting will be held at Chalmers in Gothenburg, starting on Thursday September 29. More information here.

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Education minister to open Onsala’s LOFAR station (Chalmers press release)

The Swedish LOFAR station will be opened in September by education minister and deputy prime minister Jan Björklund. The inauguration ceremony, which will take place at Onsala Space Observatory on 26 September 2011, will mark the opening of the country’s largest new radio telescope since the observatory’s 20-meter telescope in 1976.

The photo shows the two halves of the Onsala LOFAR station. Above, the 96 high-band antennas in their protective ’tiles’. Below, the 96 low-band antennas with their characteristic tepee shape. (Credit: Onsala Space Observatory/Leif Helldner. Click for high-res version.)

Construction has been completed according to schedule and all of the station’s antennas are now in place. Chalmers scientists expect that the education minister will be able to take part in the station’s first observations.

The Swedish station in the European radio telescope LOFAR (Low Frequency Array) consists of 192 antennas. Together with around 5000 antennas at sister stations spread over the whole of northern Europe, they open a new window on the early universe – and promise other, unexpected, discoveries.

Original Chalmers press release in Swedish

Contact: Robert Cumming, Onsala Space Observatory, press contact for LOFAR in Sweden. Email, tel. +46 31 772 5500, mobile +46 70 49 33 114.

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Onsala’s LOFAR station: ready for the universe

We now have a finished field of LBA antennas and the station is already complete. Leif will doubtless update with the facts and figures. In the meantime, this is a picture I took yesterday afternoon of the new LBA field in the afternoon sunshine under a clear blue sky. The new header picture shows both the LBA and HBA arrays.

Next we have to make sure that everything is working. A team from ASTRON i the Netherlands will visit sometime after mid-August to verify the installation. That’s when we’ll get our ‘first light’: an image of whole northern sky made from cross-correlation signals from all the antennas.

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Installation Week #4


HBA field is finally installed, last tile placed June 22 2011.
All the tools have been sent to the next installation site,
which starts a week from now at Kilpisjärvi, Finland.

All LBA meches have been placed, and 69 LBA antennas is erected.
The station is now moose proof, with a two meter high fence surrounding the area.

Team picture from the last day of HBA installation (June 22 2011)

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