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Articles on this Page
- 06/15/16--17:00: _Live fringe-plots f...
- 06/16/16--17:00: _An extraordinary bi...
- 06/19/16--17:00: _LFAA AAVS1 concrete...
- 06/18/16--17:00: _Astronomy Concert
- 06/20/16--17:00: _CEP3 cluster change...
- 06/21/16--17:00: _The LOFAR Imaging C...
- 07/14/16--17:00: _The missing link: t...
- 07/13/16--17:00: _Good to see an old ...
- 07/12/16--17:00: _MICADO Consortium M...
- 07/11/16--17:00: _The new generation
- 07/10/16--17:00: _ASTRON new analog l...
- 07/17/16--17:00: _Another piece of th...
- 07/18/16--17:00: _The Connecting Stre...
- 07/19/16--17:00: _Pokemon at ASTRON
- 07/20/16--17:00: _Today's Colloquium:...
- 07/21/16--17:00: _Long-baseline image...
- 07/24/16--17:00: _Traditional MIDPREP...
- 07/25/16--17:00: _Satellite rescue by...
- 07/26/16--17:00: _Fringe-fitting in CASA
- 07/27/16--17:00: _In Memoriam Karin S...
- 06/15/16--17:00: Live fringe-plots for Jive Uniboard Correlator
- 06/16/16--17:00: An extraordinary binary system
- 06/19/16--17:00: LFAA AAVS1 concrete bases - site arrival
- 06/18/16--17:00: Astronomy Concert
- 06/20/16--17:00: CEP3 cluster changes access policy
- 06/21/16--17:00: The LOFAR Imaging Cookbook v.19 is out!
- 07/13/16--17:00: Good to see an old friend
- 07/12/16--17:00: MICADO Consortium Meeting at NOVA-ASTRON
- 07/11/16--17:00: The new generation
- 07/10/16--17:00: ASTRON new analog lab environment
- 07/17/16--17:00: Another piece of the puzzle: the fast HI outflow in Mrk 231
- 07/18/16--17:00: The Connecting Strength of Big Science Projects
- 07/19/16--17:00: Pokemon at ASTRON
- 07/20/16--17:00: Today's Colloquium: MeerKAT status update
- 07/24/16--17:00: Traditional MIDPREP summer pancake dinner
- Tammo Jan Dijkema (ASTRON)
- Lerato Sebokolodi (RU)
- Theophilus Narh (RU)
- Ulrich Armel (RU)
- Arnold van Ardenne (ASTRON)
- Truus van den Brink (ASTRON)
- David Prinsloo (ASTRON)
- Jan-Willem Steeb (SU)
- Nelis Wilke (SU)
- Marcellin Atemkeng (RU)
- Kshitij Thorat (RU)
- Zsolt Paragi (JIVE)
(*) MIDPREP is an FP7 (EU) program that is part of the preparations for mid-frequency aperture arrays (MFAA) for SKA.
- 07/25/16--17:00: Satellite rescue by CAMRAS
- 07/26/16--17:00: Fringe-fitting in CASA
- 07/27/16--17:00: In Memoriam Karin Spijkerman (1963-2016)
© screenshot by Harro VerkouterOne of the applications developed for the versatile UniBoard computing platform(*) is a full FX-architecture VLBI correlator. The correlator firmware is developed by JIVE and has demonstrated first fringes (http://www.astron.nl/dailyimage/index.html?main.php?date=20130623). This marked the start of an extensive commissioning period during which the output of the JIVE UniBoard Correlator (JUC) was compared in-depth to that of SFXC, the current, JIVE-developed, software production correlator.
During this commissioning many, sometimes subtle, bugs in the firmware and control software were found and fixed. The road to a production correlator, however, leads along other paths than just the verification of the correlator itself. Many aspects come into play: integration with the high level control software used at JIVE, administration of correlation jobs and userfriendlyness such that the correlator can be run by others than its developers, to name but a few.
One of the more important requirements is the ability correlate the VLBI data directly from the disk packs on which it is recorded at the stations. The monitoring-and-control software of the JUC was extended to support this, previously, the JUC could only correlate from pre-processed files on disk. Presently the JUC can be run from the standard correlator control interface used by the operators after loading an experiment's hard disks. In the operator control software a target correlator can be selected, of which the JUC now is an eligible party.
A final step towards productification of the JUC is monitoring the output of the correlator. VLBI observing is still not push-button and many, many things can go wrong at the telescopes. In contrast to hardware failures (e.g. "my elevation motor broke"), problems with the data itself usually lack direct identification (e.g. swapped IF cables or a corruption of the data). Such problems are, however, immediately visible in the output of the correlator when either the weight of the correlation products drops below 100% (i.e. not all data could be recovered) or when fringe(s) disappear.
It is true that those problems can be identified off-line and sometimes fixed by recorrelation with different settings, but having proper (near) real-time diagnostic tools means early identification of problems. This in itself prevents waste of (correlation)time and in fact is even an absolute requirement for real-time VLBI where the data cannot be recorrelated and problems must be fixed immediately.
Today's AJDI shows a screenshot of one of those tools: the UniBoard fringeplot monitor. It is run in parallel with the correlator and reads the output of the correlator, filters out the correlation functions on baselines to a reference station and computes the fringes thereof (remember, it is an FX correlator) and plots the results in a graphical user interface. The plots are updated if new data is available from the correlator.
In this plot we see fringes from the JUC on all baselines to Westerbork for scan No0001 of the European VLBI Network (EVN) network monitoring experiment (NME) N16C1. Those NMEs are special observations conducted in the EVN in each session for each observing band in order to allow trouble shooting of the equipment and configuration(s) before the observing session proper begins. As can be seen, the correlator seems to be in good working order but Effelsberg's data shows a problem which needs to be investigated.
(*) Click this overview of UniBoard related topics on the AJDI: http://www.astron.nl/dailyimage/index.html?search_archive.php?search=uniboard
© Cees Bassa, Gemma JanssenPSR J1024-0719 (FIRST radio image) is a seemingly ordinary radio millisecond pulsar (MSP) while 2MASS J10243869-0719190 (DSS2 optical image) is a seemingly ordinary main sequence star. Together, they make an extraordinary binary system (Bassa et al. 2016).
Binary evolution predicts that MSPs are spun up by mass transfer from a binary companion. The end result is a pulsar spinning at millisecond spin periods, typically orbiting a white dwarf in a day to year long orbit. Some MSPs are isolated, probably because their energetic radiation evaporated the companion.
Ever since its discovery in 1994, PSR J1024-0719 has been classified as an isolated MSP. Already in 2001, it was noticed that 2MASS J10243869-0719190 was on almost the same position in the sky as the pulsar. However, this positional coincidence was attributed to chance, as a main-sequence star could not be the companion of the pulsar.
It took 22 years of very high precision timing with the Effelsberg, Lovell, Nancay and Westerbork telescopes to show that the pulsar was ever so slightly accelerated towards us. Furthermore, that acceleration seemed to vary with time. Optical images and spectra of 2MASS J10243869-0719190 taken with the VLT in 2001 and 2015 showed that besides the positional coincidence, its proper motion and spectroscopic distance were consistent with the proper motion and parallax of PSR J1024-0719, confirming that both objects are associated and gravitationally bound.
The timing observations of the pulsar and properties of the main sequence star show that they must be in an extremely wide orbit, with a period of several hundreds to thousands of years. These properties are unlike any other MSP binary that we know of. An exotic formation scenario for the binary system is required, either evolving from a triple system, or being ejected from a dense star cluster.
© ICRAR/CurtinThe Local Infrastructure work package (LINFRA, lead: ICRAR/Curtin) of the SKA Low Frequency Aperture Array (LFAA) has been making impressive progress. This daily image reports on the arrival of the concrete bases.
After site clearing, power and fibre deployment and groundplane deployment, the next step into realising the AAVS1 stations, is the deployment of the concrete bases.
The concrete bases will host the log-periodic antennas, making sure the antennas will remain at their position, facing the severe weather conditions at the MRO.
Especially items like wind load, including wind gusts, are quite a challenge, from a design point of view.
Time will tell whether this solution is the correct way towards SKA1_LOW.
As we are working towards the AADC CDR, several other options will also be investigated and reported upon.
© Jochem KooiIn my spare time I play the violin in KamerFilharmonie Der Aa, a symphony orchestra consisting of amateur players from the north of The Netherlands. This time we are brininging an astronomy-themed concert with as main work The Planets of Gustav Holst. The historical Eise Esinga planetarium in Franeker plays a major role in the programme. He built this planetarium to show that alignment of the planets was not such an extraordinary event and would not cause the end of the world. This is where "From the Apocalypse" by Anatli Ljadov comes in. The Sun is depicted by Camille Saent-Saens' Phaeton, and we will also play music from Star Wars by John Williams. The programme will be conducted by guest conductor Peter Biloen.
Concerts are on June 18 at 20:15, in the Immanuelkerk in Groningen, and on June 19 at 19:30, in de Koornbeurs in Franeker.
More information can be found on http://www.deraa.nl
© ASTRONThe CEP3 cluster allows LOFAR users to run data processing close to the CEP2 production cluster. The cluster has been active since 1.5 years and more than 200 time slots have been assigned to users to perform advanced processing on their Cycle data. The cluster has also allowed several important activities like commissioning of new processing schemes, development and testing of new software tools. Additionally, it provided important processing resources for Busy Weeks and LOFAR Data School.
The CEP3 policy aims to ensure CEP3 access to a large number and different type of users. During the CEP3 lifetime user needs have been evolving, therefore an assessment of CEP3 access policy based on the cluster usage over the past two observing cycles was recently performed and results were presented at the Lofar Status Meeting on May 11th.
Based on the results, the radio observatory changed the default access policy, by extending the time access from a 4-weeks period to 8-weeks.
Details about CEP3 cluster access policy can be found at: http://astron.nl/radio-observatory/observing-capabilities/depth-technical-information/cep-and-lta-computing-facilitie
© Aleksandar ShulevskiOn June 13 2016, version 19.0 of the LOFAR Imaging Cookbook has been released.
The first version of the manual was published more than 5 years ago, when the first LOFAR commissioners met together during the commissioning Busy Weeks to test and validate the new reduction software for processing LOFAR data which was becoming available.
Since 2010, the manual has developed significantly. Its content has become very comprehensive of all the data reduction steps needed to achieve outstanding LOFAR imaging results. The topics cover a range from data inspection to flagging, calibration, imaging, and source extraction. More recently, important chapters have been included on advanced methods to remove the A-team signal from the visibilities, advanced tools to inspect the calibration solutions, the automated self-calibration algorithm, and a description of the LOFAR CEP 3 processing cluster.
v.19 includes a description of the new facet calibration pipelines, WSclean imager, and has been significantly re-structured.
The LOFAR Imaging Cookbook is edited by Aleksandar Shulevski, who coordinates the large group of experienced LOFAR commissioners in charge of updating the chapters of the manual: G. van Diepen, T. J. Dijkema, F. de Gasperin, M. Iacobelli, J. McKean, M. Mevius, A. Offringa, E. Orru ́, D. Rafferty, C. Tasse, B. van der Tol, V. Vacca, R. van Weeren, W. Williams and S. Yatawatta.
© AstronAs part of the RadioLife project, we have made detailed observations of the so-called “Outer Filament" of the radio galaxy Centaurus A to study the effect of a radio jet blasting through a gas cloud. Earlier results obtained from MUSE observations (see Daily Image "A start is born!" http://www.astron.nl/dailyimage/main.php?date=20160517 ) had shown that this kind of interaction can result in new stars being born. In general, new stars form from clouds of molecular gas so if new stars are forming in the Outer Filament, there have to be such clouds. To check what these clouds look like, and what we can learn from them, we had a look with the Atacama Pathfinder EXperiment (APEX).
In a Letter now accepted by Astronomy & Astrophysics ("The missing link: tracing molecular gas in the outer filament of Centaurus A" http://arxiv.org/abs/1605.06598 by Morganti, Raffaella; Oosterloo, Tom; Oonk, J. B. Raymond; Santoro, Francesco; Tadhunter, Clive) we report the detection of molecular gas in the region of the Outer Filament. We detect CO(2-1) at all observed locations, which were selected to represent regions with very different physical conditions (see Figure). Normally, molecular gas is found close to clouds of cold, atomic hydrogen (the contours), but in the Outer Filament this is not quite the case. Surprisingly, the stronger detections of the molecular gas are instead in the region of the hot, ionised filaments. Even more unusual is that the star formation occurs where the gas has the most disturbed kinematics. In fact, we find variations in the widths of the CO(2-1) lines throughout the region, with broader lines in the region of the ionised gas, i.e. where the jet-cloud interaction is strongest, and narrow profiles in the HI cloud. This may indicate that the molecular gas in the region of the ionised gas has the energy and momentum of the jet-cloud interaction encoded in it, in a similar way as the ionised gas. These molecular clouds may therefore be the result of very efficient cooling of the down-stream gas photo/shock-ionised by the interaction.
© Madroon Community Consultants (MCC)It's always nice to spot an old friend in the corridors of ASTRON. Dion Kant has built many systems for WSRT, LOFAR and SKA, and has represented us in the higher technical councils of the international SKA project. Just search for his name in our AJDI archive (click the button at the top of the page).
Some time ago Dion has ventured out on his own as a technical consultant. Since he drives a very nice car, he is obviously doing well. At the same time, his appreciation for ASTRON as a high-tech organization has grown since he has left. So he is happy to be retained for specific projects like PAASAR, to mutual satisfaction.
© NOVAThe ESO European Extremely Large Telescope (E-ELT) has been approved for construction with a targeted first light in 2024. MICADO is selected as a first light instruments for the E-ELT, and in October 2015 the MICADO consortium signed an agreement with ESO for the development of this instrument.
MICADO is the Multi-Adaptive Optics Imaging Camera for Deep Observations. It will be the first dedicated imaging camera for the E-ELT and takes the Adaptive Optics technique to the next level, working with the multi-conjugate adaptive optics module, MAORY. The design of MICADO is driven by a desire for high sensitivity and resolution, astrometric accuracy, and wide wavelength coverage spectroscopy. The project is in the preliminary design phase.
A MICADO Consortium Meeting is organised 12 and 13 July 2016 at NOVA-ASTRON in Dwingeloo. The meeting is preceded by a Data Flow Software meeting on Monday 11 July. The consortium meeting consists of plenary meetings, splinter meetings and many discussions on requirements, interfaces, design options and performance predictions. In addition there is a delicious BBQ on the sunny ASTRON roof terrace. This social event is important to get to known all our colleagues from 11 different institutes all over Europe, who are developing MICADO together.
© NOVAAs in every other institute during the summer holidays, in the corridors, labs and offices it is more quiet and peaceful than at other times. In these periods, occasionally, a couple of young 'employees' can be seen. These two were spotted in the METIS office by 'Picture-of-the-day' editor Jan Noordam, with whom the same day they had a 'business' lunch.
These young workers turn out to be Dusan and Uros Bettonvil. Once in a while they may join their father at work and see what he actually does. Dusan and Uros are real techno-kids, and apart from being interested in papa's activities, they also participate once a year in a scientific conference. In addition, they had the good fortune to grow up at 'our' telescopes on La Palma. Often they can be seen at the University observatory Sonnenborgh in Utrecht, where they guide other kids through the museum.
Young pre-scientists as they are, they have the luck that also at school they get ample education on science and technology. It clearly forms a basis for a new generation of scientists and ingenieurs.
Surely for the Dutch astronomy as well.
© Nico EbbendorfAfter 20 years we are saying goodbye to our lab furniture. Following the nice office floors in the new ASTRON building, it is time for a face-lift of our analog laboratory.
This lab area was created back in 1996 and served as a modern development environment where famous radio astronomy systems have been created. Among them are the Multi Frequency Front-Ends (MFFE) for the WSRT, the WSRT back-end system IVC, LOFAR and recently the APERTIF Front-Ends. In addition to these operational systems, many research and development projects in the area of phased array systems such as THEA and EMBRACE and Photonics experiments have been successfully carried out here.
The pictures show the preparation for the construction of a wall that will house cabinets for laboratory parts and provide an (ESD) safe and friendly environment. An accumulation of 20 years of dust has been broomed out after removing the old cabinets.
Shortly, more pictures will show the result of all this hard work. Watch this space.
© AstronIn the RadioLife ERC project we study the life cycle of AGN. This life cycle is regulated by the balance between how much, and how, matter a galaxy accretes and how much and how it expels. Gas which falls in makes the central massive black hole grow and it provides the fuel that makes this black hole emit enormous amounts of matter and energy (i.e. it is called active). In turn, the matter and energy expelled this way has the opposite effect; it stops the growth of the black hole and inhibits star formation. Both effects are very important for the evolution of the galaxy.
Different mechanisms can produce these outflows of mass and energy. One possibility is that they are driven by narrow plasma jets being shot into space by the black hole. An alternative is that the general environment of the black hole causes a wide wind out of the galaxy. We have used the HI 21-cm line of atomic hydrogen to observe fast outflows in absorption to study them in a number of objects to see where and how the gas is pushed out. In many radio galaxies, it is the fast radio jet coming from the black hole that pushes out the gas. However, it now turns out that not in every radio galaxy this is the case!
This time we pointed the WSRT and the VLA to the ultra-luminous infrared galaxy, Mrk 231, a galaxy still in the process of settling down after a major collision with another galaxy, as can be seen from the Hubble Space Telescope image on the left. Although in this object we do not see, at the resolution of the VLA (about 1", middle image), a kpc-scale jet, we did detect a fast HI outflow. This outflow is seen as shallow HI absorption blue-shifted 1300 km/s with respect to the systemic velocity of the host galaxy. It was first discovered with the WSRT and later confirmed at higher spatial resolution by the VLA observation. Our results suggest that in this object the HI outflow is a wide-angle wind, driven by the environment of the black hole and not by a radio jet. This is interesting because it indicates that an HI component can be present in fast outflows regardless of the acceleration mechanism (wind vs jet driven) and that it must be connected with common properties of the pre-interaction gas involved. This opens opportunities to identify many more of these systems with Apertif.
This result is presented in a paper accepted by Astronomy & Astrophysics:
"Another piece of the puzzle: the fast HI outflow in Mrk231" by Raffaella Morganti, Sylvain Veilleux, Tom Oosterloo, Stacy Teng and David Rupke. http://arxiv.org/abs/1606.01640
© Organizing Committee@EUNL16The NWO institutes ASTRON and Nikhef used their connections to fill a day of inspiring presentations showing the marvelous science, experiments, and their connections in all possible aspects. The day was inspired by the guiding principles expressed by the EU Presidency holder during the first 6 months of 2016, the Netherlands. These guiding principles are a Union that focuses on the essentials, a Union that focuses on growth and jobs through innovation, and a Union that connects with civil society.
ASTRON and Nikhef organized together a one day conference at the ASTRON premises entitled "The Connecting Strength of Big Science Projects" for an audience of about 70 scientists, industry and innovation contacts and policy makers. World-class science topics were selected from both fields on two originally far separated research fields, radio astronomy and particle physics. The day showed that there are many connections, in science through astroparticle physics and in spin offs. Each agenda item had 2 speakers, each highlighting one aspect of the connection. Connecting science with science, connecting science with industry and connecting science with education were some of the liaisons that came across.
Connections between the presentations, speakers and audience were made by the chair Mark Beumer in a lively manner.
Both speakers and audience loved the new standard of connecting presentations. Mark Beumer went even so far as to connect the audience to their neighbours and to the presenters by reversing the Q&A session and asking questions to the audience and really activating the interaction and the look for innovation possibilities.
The next day a select group of participants paid an inspiring visit to the LOFAR super-terp where they could experience the connection of Big Science Projects with nature development.
We would like to see this event as the start of a series and a start of a new standard in presenting. Next opportunity should be aiming for a wider public. The first step is set in this AJDI.
© .The Pokémon Go hype has also hit ASTRON, even before the game is officially released in The Netherlands. It even turns out that our favorite telescope is part of the game. The road towards the telescope is now littered with these little creatures. However, at the telescope Pokéstop you can stock up with free items to "catch'em all".
May we remind all Pokemon tourists to switch their phones to airplane mode, in which the game should still work.
© Oleg SmirnovMeerKAT Array Release 1 (AR1), with 16 dishes out of the full complement of 64 operational, has recently gone live in the Karoo desert, in the Northern Cape province of South Africa.
I will present initial results from the telescope, and give an overview of other happenings in South Africa.
© Neal Jackson, Adam Deller, for the Long Baseline Working Group Busy Week team.The LOFAR long baselines are capable of making maps at 0.3 arcsecond resolution, with sub-mJy sensitivity. The data processing is a formidable challenge, however, especially in the large datasets of the Surveys KSP.
A Long Baseline Working Group busy week was held at ASTRON in June in order to demonstrate source mapping in a Survey field region (centred at 1350+55 and with 16ch/subband and 1-s integrations). We used calibrators from the LOBOS (LBCS) survey to start the mapping off, and then transferred delay and phase solutions around the field, which is a few degrees across, forming the tied core station at each source and combining with the international stations to make maps.
The central picture is an overview of the field, derived by fringe-rate mapping on a baseline from the combined core to Juelich (DE605). The surrounding pictures are maps of sources in the field, with long-baseline (0.3-0.4 arcsec) resolution. These have been made so far with 12 subbands.
© AvAOne might wonder why the MIDPREP Pancake Party was held inside rather than in the bright Dutch summer light. This was because, starting with last year's event, the pancake dinner is traditionally held inside, in weak, watery, winterish light. Admittedly the thunderish weather outside just happily collaborated!
It is good to see such a broad exchange of able and motivated (young) researchers at ASTRON, with visitors from Rhodes University (RU, Grahamstown) and Stellenbosch University (SU, both in South Africa (ZA). The RU and SU people were from the groups of Prof Oleg Smirnov and Prof David Davidson respectively, both valuable associates of ASTRON.
As the MIDPREP program(*) will formally end in September, this may also be a historical picture, although a no-cost extension till the end of this year has been applied for. Let us then hope that MIDPREP contributed to motivate, and contribute to careers in radio astronomy and life-long experiences in support of that!
The picture shows from left to right:
© Erik TiddensSince its beginning, CAMRAS has booked impressive results with using the 25m Dwingeloo Telescope (DT) for ham-radio EME contacts. After the recent restoration, this "Grande Dame" of the radio astronomy community has shown the flexibility of operating in a wide range of applications. This has not been lost on other organisations, so ESA requested CAMRAS to assist them in communicating with a quirky satellite.
The satellite was a CubeSat (10x10x10 cm) for educational and ham-radio mission. It was developed for demonstrating the autonomous active attitude control capabilities based on magnetic actuation and was launched last April 26th, http://www.cubesatteam-polito.com . After the launch, the signals from the e-st@r-II satellite were not as expected, and too weak for reception by the ground station in Italy. So CAMRAS was asked to use the 25m DT to search for the telemetry signal. Useful signals were recorded on May 10th, which rekindled hope to regain control over the satellite.
On May 12th, with support from ESA, telemetry commands were sent to the CubeSat, but there was no response from the satellite. The whole DT system was checked again but the CAMRAS operators could not find any reason for this failure. Only after checking the telemetry code it was found that the code conversion to the AX.25 protocol was not correct.
A new attempt to send the commands by the DT was on 7th of July. This time the e-st@r-II satellite responded as expected and the control center in Italy confirmed the telemetry messages. Once more the DT has shown its strong capabilities as a useful instrument for space and astronomical tasks.
The picture shows DT operator Jan van Muijlwijk venting his happiness after the successful operation. The next period will be used to look for possible reasons for the low signal level of the CubeSat, and the DT is ready to swing back into action again if necessary.
© (c) Des Small, 2016Averaging over larger time and frequency intervals allows radio astronomers to observe fainter objects. In VLBI this is particularly challenging: due to the long baselines, small instrumental errors cause the phases to wind much faster with time and frequency than in traditional radio astronomy. To achieve phase stability, a fringe-fitting algorithm is used to calculate phase delays (as function of frequency) and phase rates (as function of time).
Until now, this has generally been done in the AIPS software package; the lack of a fringe-fitting task in CASA has made it unsuitable for VLBI data processing. As part of the BlackHoleCam and SKA-NL Roadmap projects, JIVE is working to add full VLBI capability to CASA, including fringe-fitting.
A prototype of the fringe fitter code is now available and supporting functionality for applying the delay and rate solutions is being implemented in CASA.
Fringe fitting is usually a two step process. A bright fringe-finder source is used to determine the overall instrumental delays and apply these to the entire observation. In the second step, a fainter phase-reference is used to correct the residual variations in delay, and determine the phase rate. Phase referencing is a standard VLBI technique in which observations alternate between the target and a nearby phase reference source. The corrections derived for the phase reference source are applied to the target.
The first image shows the phases as function of frequency for the phase reference source after applying the instrumental delay, but *before* applying the residual delay solutions over the entire frequency band. The second image shows the phases *after* the residual delay is applied. As expected, the phases are successfully flattened across the full width of the frequency range and on all baselines.
The fringe-fitter prototype is now fully functional, and will be implemented in CASA soon, as the new task "fringecal".
© ASTRONNa een kort maar hevig ziekbed is op 16 juli 2016 jongstleden onze collega Karin Spijkerman overleden in de leeftijd van 52 jaar.
Karin was sinds 2008, als projectcontroller in dienst bij ASTRON en werkte op de afdeling Finance Planning & Control. In de afgelopen jaren is ze als projectcontroller betrokken geweest bij meerdere subsidieprojecten en heeft deze ondersteund en/of financieel afgehandeld. Het ging hierbij om o.a. de vernieuwbouw van ASTRON, Apertif, DOME, MidPrep, ALERT en SNN projecten zoals LOFAR SNN II en SKA-TSM. Tevens heeft ze de projectcontrol werkzaamheden voor NOVA verricht.
Samen met haar collega Emmy Boerma vormde ze jarenlang het gezicht van project control. Beide waren verantwoordelijk voor het verder professionaliseren van project control en het administratief structureren van de projectportfolio van ASTRON. Met name SNN projecten vergden veel administratieve inspanning vanwege de grote hoeveelheid papieren en af te leggen verantwoording. Menig collega herinnert zich de strenge blik wanneer zijn of haar urenverantwoording te laat was. Een van de krachten van Karin was om spreadsheets te maken en allerlei formulieren te ontwikkelen. Alles om projecten makkelijker te laten verlopen en het werk van zowel de projectleider als haar zelf eenvoudiger te maken.
Karin laat een echtgenoot en twee volwassen dochters na.