Radio astronomers at Bonn have reached a scientific milestone. One of the world's largest radio telescopes, the Effelsberg 100-m dish, surveyed the entire northern sky in the light of the neutral hydrogen (HI) 21-cm line.
This effort, led by Jürgen Kerp (AIfA) and Benjamin Winkel (MPIfR), began in 2008 and has culminated today in the initial data release of the Effelsberg-Bonn HI Survey (EBHIS).
The EBHIS data base is now freely accessible for all scientists around the world. In addition to the Milky Way data, the EBHIS project also includes unique information about HI in external galaxies out to a distance of about 750 million light years from Earth.
Hydrogen is THE ELEMENT of the universe. Consisting of a single proton and an electron it is the simplest and most abundant element in space. One could almost consider the universe as a pure hydrogen universe, albeit with some minor "pollution" by heavier elements, among these carbon, the fundamental component of all organisms on Earth.
The 21-cm line is a very faint but characteristic emission line of neutral atomic hydrogen (or HI). It is not only feasible to detect the weakest signals from distant galaxies with the 100-m Effelsberg antenna, but also to determine their motion relative to Earth with high precision.
A special receiver was required in order to enable the EBHIS project. With seven receiving elements observing the sky independently from each other, it was possible to reduce the necessary observing time from decades to about five years only.
Field Programmable Gate Array (FPGA) spectrometers were developed within the course of the EBHIS project, allowing real time processing and storage of about 100 million individual HI spectra with consistently good quality. The individual HI spectra were combined using high-performance computers into a unique map of the entire northern sky and provide unsurpassed richness in detail of the Milky Way Galaxy gas.
Astronomy students at Bonn University had unique access to the pre-release EBHIS data. In 2013 the European Space Agency (ESA) signed a memorandum of understanding with the Bonn HI radio astronomers.
ESA was granted exclusive access to EBHIS data for their Planck satellite mission and, in return, Bonn students were given unique access to Planck data for their thesis projects. Twelve Bachelor, nine Master, and five Doctoral thesis projects have been successfully completed since 2008.
The Square Kilometer Array (SKA), the world's largest future radio astronomical facility, to be constructed in Australia and South Africa, will benefit directly from the EBHIS data.
Owing to the construction of SKA as a radio interferometer, it is inherently insensitive to the faint and extended HI emission of the Milky Way and nearby external galaxies. Since the HI gas is measured very well by EBHIS, only combining SKA and EBHIS data will allow one to derive a comprehensive view of the interstellar HI gas.
The Effelsberg-Bonn HI Survey will be a rich resource for science in the near and far future. Independent attempts to survey the entire northern sky with a 100-m class telescope are not scheduled. The EBHIS data will thus set the quality standard for the Milky Way Galaxy HI for the next decades.
EBHIS is based on observations with the 100-m telescope of the Max-Planck-Institut für Radioastronomie (MPIfR) at Effelsberg. The project was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) for six years.
The Effelsberg–Bonn HI Survey: Milky Way gas. First data release, B. Winkel, J. Kerp, L. Flöer, P. M. W. Kalberla, N. Ben Bekhti, R. Keller, and D. Lenz, 2016, Astronomy & Astrophysics, A&A 585, A41.
Dr. Benjamin Winkel,
Max-Planck-Institut für Radioastronomie, Bonn.
Fon: +49 2257 301-167
Priv.-Doz. Dr. Jürgen Kerp,
Argelander-Institut für Astronomie, Universität Bonn.
Fon: +49 228 73-3667
Dr. Norbert Junkes,
Press and Public Outreach,
Max-Planck-Institut für Radioastronomie.
Fon: +49 228 525-399
http://www.mpifr-bonn.mpg.de/pressreleases/2015/9 (Press Release)
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/585/A41 (EBHIS Data Base at CDS)
Norbert Junkes | Max-Planck-Institut für Radioastronomie
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences