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- 11/14/18--16:00: Colloquium - Late-phase radiative transfer of Type Ia supernovae
- 11/15/18--16:00: ADASS coming to the Netherlands in 2019!
- 11/18/18--16:00: Impressie Telescooploop 2018
- 11/19/18--16:00: Cosmic serpent reveals new way massive stars die
© ASTRONUsually, efficiently operating the world's largest Low Frequency Array (LOFAR) radio telescope is a task enough to keep an astronomical observatory busy. But scientists and engineers at ASTRON are further pushing the envelope to turn LOFAR into a truly multi-tasking radio telescope without changing the collecting elements. The central theme is to upgrade the existing COBALT correlator, which receives the signals from LOFAR stations spread across Europe, and combine them in real time to astronomical data. The main challenge was to come up with an optimal design for the new correlator COBALT 2.0, capable enough to simultaneously deliver astronomical data for several science cases in parallel (Mega-Mode Observing https://www.nwo.nl/actueel/nieuws/2017/magw/nwo-investeert-in-onderzoeksinfrastructuur.html ).
The COBALT 2.0 team took this task head-on by successfully coming up with a super-optimized configuration involving the most appropriate set of components/CPUs/GPUs/technologies and network topologies. Thanks to their smart work, the resulting COBALT 2.0 can even do significantly more than the LOFAR Mega Mode requirements. The new correlator would be one of the most flexible and "greenest" (energy efficient) computing machines of its kind. In addition its future viability has been very well kept in mind during the design. This becomes even more impressive given the limited financial resources.
Yesterday, via a flawless and a successful tender process ( https://www.tenderned.nl/tenderned-tap/aankondigingen/143048 ), the final order for COBALT 2.0 hardware has been placed. This marks a giant step towards LOFAR Mega-Mode operations expected sometime next year.
Interested to know more? In the next few months, we will provide more details in our presentations as the next stage of challenging but exciting commissioning period commences. And most importantly, this increased efficiency of LOFAR (by several times) will lead to many more exciting scientific discoveries, in the years to come.
© ColloquiumType Ia supernovae are well-studied objects, largely because of their usefulness as precise distance indicators for cosmology and their role in the production of Fe-peak elements for chemical evolution.
However, while Type Ia supernova almost certainly involve the thermonuclear explosion and unbinding of a carbon-oxygen white dwarf, understanding the possible role of a binary companion and the mechanism of explosion remain open problems in supernova research. Multi-band observations including radio and X-ray have placed deep upper limits on the density of the surrounding medium and disfavour most scenarios involving a non-degenerate companion. Several other scenarios remain, and thanks to theoretical developments in the last decade, we now have a variety of 3D hydrodynamic explosion models available. These can can be tested with nucleosynthesis and radiative transfer simulations to compare to observational light curves and spectra.
The image shows synthetic spectra of a Chandrasekhar-mass model (W7) and two sub-Chandrasekhar-mass detonation models with no gravitational settling (S0) and with 5.5 Gyr of extremely efficient settling (S5.5) in the white dwarf progenitor prior to explosion. The model with more gravitational settling explodes with a greater concentration of neon-22 in the centre, which leads to more production of stable isotope nickel-58, particular noticeable in the spectral feature at 7378 A. Also shown is a typical Type Ia supernova SN2013ct observed by Maguire at al. (2016).
© R. PizzoA delegation from ASTRON and other astronomical institutes in the Netherlands is attending ADASS XXVIII this week, at the University of Maryland (USA). ADASS (Astronomical Data Analysis Software and Systems) is a forum for astronomers, computing scientists, software engineers, faculty members and students working in areas related to algorithms, software and systems for the acquisition, reduction, analysis, and dissemination of astronomical data. As such, ADASS is a crucial opportunity to present and advance the analysis and reduction techniques that push forward our discovery space in astronomy.
ADASS is held each year at a different hosting astronomical institution. In 2019, ADASS will come to the Netherlands and will be held at MartiniPlaza, in Groningen, between 6-10 October 2019. The conference website is already live: www.adass2019.nl. The organisation of ADASS XXIX is lead by ASTRON, in collaboration with various Dutch astronomical institutions: JIVE, University of Amsterdam, University of Groningen, University of Leiden, University of Nijmegen, and ALMA ARC. Hosting ADASS in the Netherlands in 2019 will be important to give crucial exposure to the data-analysis and software techniques developed in our country and to showcase LOFAR and APERTIF to the global technical astronomy community. Indeed, the conference programme will also include tours to our observing facilities. To both advertise next year conference and show the important technologies and astronomical software we develop in our country we have set up a booth at ADASS this year. The picture shows, together with the poster of the conference, the team who has helped in this effort and who will, with the rest of the LOC, be hard at work to ensure a very successful ADASS conference next year!
© Ger van Diepen, Eric Kooistra, Alex BenjaminsOn Wednesday October 17th the Personeelsvereniging has organised the
4th Telescooploop, the ASTRON event to run or walk from one telescope to
another. Maybe it should be renamed to Telescooptocht because in this
edition cyclists could also take part.
After an exceptional Dutch summer it was another exceptional day with
outstanding weather, ideal for walking, running or cycling. Various
routes through the beautiful fields, heath and forests of Drenthe had been
prepared touching all 3 ASTRON telescopes: LOFAR, WSRT and
Dwingeloo. GPS tracks and paper maps were made available of all
routes which ranged from 56 to 112 km cycling and 8 to 48 km walking or running.
In total 33 people took part in the event:
- 4 cyclists did the 112 km tour Dwingeloo-LOFAR-WSRT-Dwingeloo.
- 6 cyclists did the 56 km LOFAR-WSRT-Dwingeloo route.
- 3 walkers did the 48 km LOFAR-WSRT-Dwingeloo route.
- The 24.3 km WSRT-Dwingeloo route was done by 3 runners and 4 walkers.
- A shorter part of the last route (8 or 15 km) was run or walked by
Taxis had been organised to bring the people (and their bikes) to the
starting point of a route. The first taxi (with the 48 km walkers)
left Dwingeloo already at 6am. At the end drinks and snacks were
available in the Dwingeloo canteen where people could share their
experiences. The participants have enjoyed it a lot and many of them
asked if it could be turned into an annual instead of bi-annual event.
The Personeelsvereniging would like to thank the volunteers Alex Benjamins
and Pieter Jager who supplied the participants with food and drinks
along the route.
© ESO / Callingham et al.An international team of researchers led by Joe Callingham (ASTRON) have used the VISIR instrument on ESO's Very Large Telescope to capture this stunning image of a newly discovered massive triple star system. Nicknamed Apep, this may be the first ever gamma-ray burst progenitor found. The mid-infrared image shows the dust encircling the system, which is produced downstream of the energetic colliding winds found in the inner binary. Such a pattern encodes the orbital and rotational parameters of the stars and system, providing an insight into how the massive stars are losing mass. Apep is also the brightest colliding wind binary discovered in the radio outside of the enigmatic Eta Carinae. The paper detailing the discovery and physics of Apep is published today in Nature Astronomy and on arXiv.
The Nature blog detailing the discovery of the system is detailed available here: https://goo.gl/fuX9Sg
Public relations details about the system can be found here: https://www.astron.nl/cosmic-serpent-reveals-new-way-massive-stars-die and https://www.eso.org/public/news/eso1838/