J.B.Raymond Oonk's home page

                                   (work in progress)


Information

Room      : HL 423
Telephone : +31 (0)71 527 8486
E-mail    : oonk@strw.leidenuniv.nl


Occupation and Study

I am currently a Postdoc at the Leiden Observatory (The Netherlands) and the
Netherlands Institute for Radio Astronomy (ASTRON). I obtained a Master degree
in Astronomy in 2007 and a Ph.D in Astronomy (2011), both from the Universitry
of Leiden. My Ph.D was carried out under the supervision of Prof.dr. W. Jaffe.


Research Interests

I primarily work on multi-wavelength spectroscopic data from X-rays to the
low-frequency radio regime. Current I focus on understanding the role of
cold atomic and molecular gas in the evolution of galaxies.


Research Groups

(A) LOFAR RRL group (2014 - now):

I lead this Leiden based research group, that currently
consists of 2 PostDocs, 2 PhD students and 1 MSc student. In this group we
obtain and analyze low frequency (10-1700 MHz) spectral lines from recombining
atoms. At these frequency these atoms provide important information on the
physical conditions of the cold neutral medium in galaxies. The most recent
publications from our group are:

2018: Mapping low frequency carbon radio recombination lines towards Cassiopeia A at 340, 148, 54 and 43 MHz (Salas et al.)
2017: LOFAR observations of decameter carbon radio recombination lines towards Cassiopeia A (Salas et al.)
2017: Carbon and hydrogen radio recombination lines from the cold clouds towards Cassiopeia A (Oonk et al.)
2017: Low-frequency Carbon Radio Recombination Lines. II. The Diffuse Interstellar Medium (Salgado et al.)
2017: Low-frequency Carbon Radio Recombination Lines. I. Calculations of Departure Coefficients (Salgado et al.)


(B) LOFAR e-infra group (2015 - now):

I lead this Leiden based e-Science group, In thiss collaboration between Leiden
Observatory and SURFsara we focus on enabling robust, automated and scalable
user data processing with high throughput (HTC) and high performance (HPC) for
the large data sets that the astronomical community has measured with the
international Low Frequency Array (LOFAR). We focus on developing a generic
solution (platform & framework) to implement our own as well as community
provided pipelines. To date we have migrated several pipelines, including
preprocessing (LGPPP; Oonk et al. in prep), PreFactor (Mechev et al. 2017),
DDFacet/Killms, interferometric spectroscopy and tied-array imaging & spectroscopy.
Particular emphasis in our group is given to providing a full solution from data
retrieval through processing, quality control and outpruct dissemination. In
addition we are dedicated to providing user support and training. The most recent
publications by our group are:

2018: Radio astronomical reduction on distributed and shared processing platforms: a platform for LOFAR (Oonk et al., in prep.)
2017: An Automated Scalable Framework for Distributing Radio Astronomy Processing Across Clusters and Clouds (Mechev et al.)


Our LOFAR e-infra solutions have been available, on a limited basis, to the
LOFAR Surveys and RRL community since 2016. We hope to make these solutions
more generally available in 2018.

The first scientific papers by the LOFAR community that use our solutions
have now been published (and there are many more in preparation):

2018: Mapping low frequency carbon radio recombination lines towards Cassiopeia A at 340, 148, 54 and 43 MHz (Salas et al.)
2018: Low Frequency Absorption in Cassiopeia A (Arias et al.)
2018: LOFAR discovery of an ultra-steep radio halo and giant head-tail radio galaxy in Abell 1132 (Wilber et al.)
2017: The LOFAR Two-metre Sky Survey. I. Survey description and preliminary data release (Shimwell et al.)