© None

Some of us were locked up in prison cells while others in a mental health clinic with nothing else to aid us than our quirky minds. We opened numerous locks, got out of handcuffs and strait jackets, formed an electric wire by holding hands, played with magnets, freezers, chess pieces, X-ray screens and many other objects.

Unfortunately, none of the teams has managed to escape on time, but thanks to the nice lads and gents of The Great Escape we were still able to get out and enjoy some drinks and bites while enthusiastically discussing our adventures.

© ASTRON

In the coming months similar Internship Events will be organised by the trainees of the other ICD partners.

(*) ICD is an internationally active ecosystem of collaborating high-tech companies and knowledge institutes operating at the forefront of innovation and competitive on the global market. In 2017 ASTRON became a member of the ICD.

© ASTRON

In all these years Ronald was a pleasure to work with. His knowledge and his contribution to projects like MeqTrees, LOFAR, COBALT and SKA SDP has been highly appreciated. The same applies to his role as Competence Group Leader Computing and his role as a member of the R&D MT.

As you can see from the pictures, attention has been paid to Ronald's farewell in different ways. Besides affectionate words from his colleagues, and a lilting song by the Computing Group, Ronald received the traditional farewell picture and several thoughtful presents.

Ronald, thank you very much for being our colleague for so many years. We wish you all the best for you and your family in your new job and the new place to live!

(*) When being interviewed for a job at ASTRON, Ronald carried a heavy bag of documents about his recent work at NLR, the Dutch AeroSpace laboratory. It dealt with detecting early signs of mechanical trouble in the deafening noise of a running jet engine. An excellent preparation for working at ASTRON. Fortunately, one of his interviewers expressed interest in it.

(**) Ronald will continue his career at the Dutch Naval Academy (KIM) in Den Helder. An institute about which several ASTRON employees have fond memories. We might see him again in the future.

© Yogesh Maan and the ARTS team

The observations above used a single TAB. The real-time survey for fast radio bursts (FRBs) and pulsars will utilize hundreds of such TABs, filling the complete field of view facilitated by Apertif. The firmware that is being developed for this massively multi-TAB observing was recently successfully synthesized for the final chip for the first time. Together with these first TAB observations, the full sensitivity FRB and pulsar survey with Apertif seems to enter reality in very near future.

© Drents Archief / Peter Veen and Dick Hoogenraad

The film was digitized by Drents Audio Visueel Archief, part of Drents Archief.

Bonus points for anyone who can recognize current or past ASTRON employees.

The full video can be viewed here.

© Madroon Community Consultants (MCC)

For more Daily Images about the close relationship between ASTRON and writer Anke den Duyn(*), type "Anke" in the Archive search page (click the button at the top), and see what you get.

(*) Anke den Duyn is a member of the very select group of ASTRON "house writers". The other one is Harry Mulisch, with his Magnum Opus "De Ontdekking van de Hemel" (use search keyword "Baneke" in the AJDI Archive).

© Ross Burns

In order to promote local skills - further support was provided in the way of a radio astronomy training course, organised as part of the JUNPINGJIVE (NL) and DARA (UK) projects. Trainees were guided through a wide variety of topics including technical operations: hardware and software, principles of radio astronomy and interferometry, scheduling and observing VLBI experiments, programming and data reduction, and the science that can be done when combining these techniques.

Over the three week course the classes and exercises were met with enthusiasm from the trainees who were keen to further their skills at summer schools and workshops around the world. Keep an eye out for these JUMPINGJIVE and DARA trainees when reading applications and proposals~

© ASTRON / NLeSC

This was the charge of the ADDER project, an Alliance collaboration between ASTRON and the Netherlands eScience Center (NLeSC) in Amsterdam. Starting in 2016, we have created an automatic system that automatically groups common features, so called "clusters", in LOFAR visibility spectrogram plots. The machine learning algorithm was trained with roughly 100 LOFAR measurement sets, and the results are spectacular in the sense that it actually gives clusters that capture the kind of features we are looking for. Using this tool it is now possible to quickly trace anomalies. Another beauty of this approach is that it works well with the (about 100 MByte size HDF5) compressed data sets, so that the processing time required is minimal.

The figure shows the graphical environment (GUI) that was used for the April ADDER busy day aimed at testing the approach. The "cluster space" graph shows the identified visibility clusters, each depicted with a colour, and containing baselines with specific common features in some abstract two-dimensional space. The "station locations" figure shows all Dutch and ILT telescope positions on a concentric logarithmic plane, so that it is easy to see which baselines belong to a specific cluster. The upper-right four figures show typical cluster members for the (XX, XY, YX and YY) correlation spectrograms. In this example it was one station that broke down, but we found many more subtle features and underlying causes as well.

The automatic creation of the compressed LOFAR HDF5 files is now part of the LOFAR online system, integrating the new inspection tooling in day to day operations is a next step. The very successful ADDER project is now finished, and follow-up research will be conducted in a new collaboration that starts in the course of this year.

© M. Boeck (2012), PhD thesis

most extreme and least well understood feedback mechanism. In jets, matter is accelerated to relativistic speeds and focused within small solid angles. Related BH engines have been influential throughout the formation of the universe. In my talk, I will discuss Active Galactic Nuclei, which harbor supermassive BHs. I focus on the prominent and nearby example of a young radio galaxy, PKS 1718-649, that shows jetted feedback still being embedded in its galactic cradle. I present recent and intriguing results that tentatively draft a coherent picture. On one hand, we investigated the large-scale environment and its X-ray signatures. On the other hand, we anticipate to probe the innermost parsec-scale environment of this AGN by searching for correlated free-free and photo-absorption simultaneously in the radio and X-rays.

While the time scales of ongoing processes are very long in Active Galaxies, they break down to the observable regime in stellar-mass NSs or BHs accreting from a companion star. I am presenting a novel method to study the extremes of accretion-feedback in so-called "Ultraluminous X-ray Sources". Me and my collaborators anticipate to

self-consistently describe the extended and ionized nebulae observed around many of these objects with physical descriptions of the underlying feedback mechanisms.

© M. Mevius

The most prominent effect of the ionosphere is a frequency dependent phase delay, due to propagation effects of the electromagnetic signal through the ionized plasma. To first order this effects goes with 1/frequency although for the lowest frequencies higher order terms (1/frequency^3) become important. Combined with the Earth magnetic field the propagation through the ionosphere causes a splitting of right and left handed signal phases, effectively causing a frequency dependent rotation of the linear polarization, an effect well known as Faraday rotation. The signals at two arms of an interferometer experience a slightly different ionospheric Faraday rotation, resulting in a net polarization in the cross correlation of the signal, even for unpolarized sources. Finally, amplitude scintillation due to small scale structures in the ionosphere is a non negligible effect at LBA frequencies.

Here we show one of the highlights of this paper. From the phase solutions of a calibrator observation we were able to detect 3 different ionospheric effects. Using the different frequency behavior over the wide frequency band

we were able to separate from the diagonal phases the clock errors (top left), the first order differential ionospheric TEC (top right) and also the third order ionospheric effect (lower right) versus time. Where the ionospheric TEC gives the integrated electron density along the line of sight, the third order effect is related to the vertical distribution of the electrons in the ionosphere. The plot on the lower left shows the differential Faraday rotation. Each line represent a single station. The different ionospheric effects are clearly correlated.

https://arxiv.org/abs/1804.07947

© A.J. Boonstra / ASTRON

After a while the tension starts building up, and then a roar comes from the valley below. With loud noise and fumes the rocket lifts and starts penetrating the dark sky. Very slowly at first, and after several seconds it seemed not to speed up and it even seemed to bend its course a little towards us.

But then it gained strength and pursued its course towards the moon. The sky was clear and many stars were visible, and I saw Mars shining bright. The torch bended towards the planet, but then passed it and continued. I realized that at this early time of day there were no airplanes in the sky, and then I saw a bright dot, most likely a satellite, coming towards the rocket. Fortunately, the two crossed without colliding. A stripe of exhaust fume was clearly visible, and with a visible puff the first stage appeared to be ejected. All this with a lot of noise of course, and I thought of our radio instrument being subjected to all this vibration, but it had survived vibration tests on Earth, right?

Then it soared higher and higher till it disappeared, following its route towards the moon. It left a patch of exhaust fume colouring blue-purple high in the skies.

The moon, of course, will never again be the same for us. And as honoured guests we were given the front row to watch the spectacle, which left me speechless.

The first phase of the NCLE project is now finished, the ASTRON - Radboud University - ISIS - NAOC receiver is on its way towards the moon. Big thanks to CNSA, ESA/PRODEX, NSO and our other scientific partners. Now it's time to prepare for the next phase, commissioning and science, unravelling cosmic mysteries.

© Jesper Spraakman, Koos Kegel, Jeroen Herrewijnen, Sjouke Kuindersma, Gijs Schoonderbeek, Paula Fusiara; BrainBricks from SunIdee

Ask the Mechanical Group!

We can facilitate your innovation process with a very simple, but effective approach towards concepts creation (it is suitable for team building as well!). Here is the recipe:

You will need the following ingredients:

(contents of P.'s brainstorm Magic Box, no it is not a pancake baking kit according to some:))

- 3 decks of BrainBricks

- Set of colorful hexagonal post-its

- Stationary

- Fuel for the mind

- 10 sheets of A3

- Set of uninhibited & open minds (obviously these are not included in the Magic Box, you have to seek & arrange those minds yourself, challenging enough?)

- Multidisciplinary team (make sure NOT to invite those who reveal any signs of features leaning towards strong or narrow-minded conservatisms)

- 1 small furnished office

Rules of the game

You lock up 1 Digital &Embedded Signal Processing Engineer in a small furnished office together with 1 System Engineer, 2 Mechanical Engineers, 1 Research Instrument maker and a Mechanical Engineering Graduate;

Give them a set of BrainBricks (a facilitator is needed, otherwise chaos is guaranteed)

Tell them that they are free to say anything (I mean really anything, a free opinion zone); no idea is bad, freaky ideas are more than welcome, criticism is forbidden!

Give them at least 2 hours (do not forget to FUEL* them)

Example Goal:

Come up with 10 creative ideas for generic cooling for Gemini Project.

But first, DO the warm up:

Show 1 card at a time, induce associations to each uncovered card; straightforward descriptions will not be rewarded, facilitator will only accept associations. A person with the tallest deck of cards ... gets a cookie*** (if there are any left).

BrainBricks? What kind of cards are these, you may ask? A good mix of pictures of all kinds of animals (biomimicry is all around us, yay!! definitely!), landscapes, objects, people, events, buildings ... everything that can trigger the mind and generate associations.

Shake & stir 'em up (the brains), have a good facilitator and give your team sufficient time to settle and you will be amazed with the result.

Ideas are in all of you!

We can help you unveil them.

*Their motivation and quality of their input is strongly correlated** with fuel quality

** not really scientifically proven, just a bold assumption

*** if your brainstorm team consists of mainly blue & green type of 'communication styles' forget telling them "the person who has the tallest deck wins!". Only do that when the red types are around. So better bribe (ooopss!!!... sorry, wrong expression) MOTIVATE them with a cookie/fruit/chocolate etc...

© Photos: ASTRON / RH

Heavy pressure was felt in delivering in time the design for the NCLE system. Rockets do not wait for additional payload when a launch date is set! So Mark and Sieds returned to their office after sending off their families back home assuming the yearly ASTRON-JIVE BBQ (summer 2017) was about to finish. "The window of My Eyes" song still could be heard as played by our L-band (ASTRON-JIVE's house rock-band) while the after-party at the first floor went on.

However, the window of the eyes of Mark and Sieds where oriented to the Mentor Graphics CAD tool which was applied to design this complex RF board for the NCLE system.

The Netherlands Chinese Low-Frequency Explorer (NCLE) actually is a 3 monopole antenna system with receiver suitable for receiving frequencies from 80 kHz .. 80 MHz. Frequencies, which normally are blocked by Earth atmosphere.

The LNA board conditions the (three) received antenna signals to be transported to the Analog Interface System board. It determines the frequency band, sets a large portion of the receiver noise figure and amplifies the signal to the required level.

The NCLE instrument is developed and built by engineers from ASTRON, the Netherlands Institute for Radio Astronomy in Dwingeloo, the Radboud Radio Lab of Radboud University in Nijmegen, and the Delft-based company ISIS. NCLE greatly is supported by the Netherlands Space Organisation NSO. More about the NCLE mission can be found here.

Apparently, the team met all deadlines as the Chinese Chang'e-4 relay satellite with on board the NCLE system, successfully lifted off atop a Long March 4C rocket from the Xichang Satellite Launch Centre at 23:28 CET on Sunday 20th (05:28 Beijing time, May 21) and is on a nine day journey to the second Earth-Moon Lagrange point (L2) some 60-80,000 kilometers beyond the Moon and nearly half a million kilometers from our planet Earth...

© Benito Marcote

Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors and covering the energy gap between INTEGRAL and Fermi, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the most powerful Galactic and extragalactic sources, elucidating the nature of their relativistic outflows and their effects on the surroundings.

e-ASTROGAM will exhibit unique polarization capabilities and a line sensitivity one to two orders of magnitude better than previous generation instruments. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and LISA. e-ASTROGAM was submitted as a M5 mission to the recent ESA call for proposals to be launch in 2018. Unfortunately, it has not been selected for the short list published these weeks for further study in this call (the three chosen ones are SPICA, THESEUS, and EnVision). But this will not be the end of the project!

For further information about e-ASTROGAM, see the White Book about the mission and the science cases in de Angelis et al. (2017, arXiv:1711.01265).

© Colloquium

The figure shows the power spectrum of bispectrum phase on a triad of antennas as a function of line of sight spatial modes at three different redshifts using fiducial models for the EoR 21 cm temperature fluctuations and foregrounds. The separation between the red (foregrounds + noise) and gray/black curves (foregrounds + EoR + noise) at line of sight spatial scales wavenumbers > 0.5 h Mpc^-1 is a measure of the the line-to-continuum ratio of 21 cm fluctuations from the EoR and the foreground spectra on these spatial scales at different redshift/frequency bands. Such a measurement of the line-to-continuum ratio is independent of antenna calibration and errors, and can be a robust measure of the astrophysical properties which can be used to infer the presence of the EoR signal. If a reliable foreground model is available, this approach can be used to constrain the rms of 21 cm brightness temperature fluctuations from the EoR. It provides a complementary approach to verify the results from traditional approaches to detect 21 cm fluctuations from EoR using power spectrum.

© astropix.nl

In the image, IC 983 is the large spiral on the left. But there is another Arp galaxy in the field, the strikingly blue small spiral just right and below center of the image. This is Arp 79 (NGC 5490C) a spiral with a high surface-brightness companion projected on one of its arms.

This image is a composition of 50 LRGB filtered integrations of 600s each. The telescope is in my remote observatory that is located in rural Germany and the images were acquired automagically by the APC Expert scheduler software during several nights in May 2018.

The full image can be seen here: https://www.astrobin.com/full/345374/D/

In that image, on the left, a bright reflection of Arcturus is visible, a very bright star located about two degrees away from the imaged field.

© ASTRON

Several astronomers from the NL SKA science working groups and focus groups gave a series of update talks. Besides, some great scientific highlights were presented. As well as current and future plans with the SKA precursors and pathfinders. Initial thoughts on how these groups could potentially evolve into key science projects were shared, and some roadblocks that are impeding progress were also described.

In addition to the series of talks, two lively and productive discussion sessions were held. These discussions covered the topics of the formation of key science projects, and science input for regional data centres.

It was clear from the meeting that the SKA-NL community is a strong and active one, displaying leadership and carrying out high-impact science with the precursors and pathfinders. During the meeting, a number of clear themes and synergies emerged, which will now be further explored and built upon such that the SKA-NL community continues to play a leading role in ensuring that the SKA will be a truly transformational facility.

Photo: the group of participants of the SKA-NL Science meeting

© ICRAR/Curtin University

In an important engineering milestone, a full station of 256 low-frequency antennas has been deployed and is undergoing tests at CSIRO's Murchison Radio-astronomy Observatory (MRO) in outback Western Australia. The demonstrator, known as the Aperture Array Verification System (AAVS1) is being used to help test and finalise the design of the low frequency antennas for the Square Kilometre Array (SKA), known as SKA-low. It was installed by an international team from Australia, Italy, Malta, the Netherlands and the United Kingdom over many months, sometimes in harsh conditions.

The work on AAVS1 is part of a global effort by 12 international engineering consortia representing 500 engineers and scientists in 20 countries. Nine of the consortia focus on a component of the telescope, each critical to the overall success of the project, while three others focus on developing advanced instrumentation for the telescope. After four years of intense design work, the nine consortia are having their Critical Design Review or CDR in 2018. In this final stage, the proposed design must meet the project's tough engineering requirements to be approved, so that a construction proposal for the telescope can be developed.

© ASTRON

The instruments we are developing and operating are becoming increasingly more complex from a technical and organisational perspective. Furthermore, there is also an increasing need to keep our projects better under control. In order to achieve this, the System Engineering and Project Management (SE&PM) group has been created within the R&D department. The goal of this group is to lift these two skills to the next level within ASTRON.

To give us all a jump start into the fascinating world of Systems Engineering, the SE&PM group organised a Systems Engineering course. The course is being given by Robert Halligan from Project Performance International (PPI) in Australia. PPI plays a leading role within the systems engineering community and provided training to professionals worldwide, across all sectors, including astronomy and space companies (e.g. Astrium, CSIRO, Dutch Space, ESO, NASA, SRON, SKA South-Africa, the SKA office in the UK).

© PV ASTRON / JIVE

At Omni Drones the members split up in two different groups. One group started with some drone theory and background information about the Omni Drones Academy and the possibilities for using drones in the Netherlands in different facets. The second group immediately started with some practical exercises with small drones. This way they got the hang of flying with a small drone without a stabiliser.

After about 2 hours the two groups switched, so the second group could have some fun with flying the drones. The clinic finished around 5 PM. Under the enjoyment of a drink and a snack, the participants were having a lot of conversations about the fun of flying with drones. But also, the more serious subjects like the various drone techniques and possibilities for using drones at ASTRON.

Since there was a lot of enthusiasm for joining this PV event, the PV will try to setup this event again later this year.