Welcome to the Department of Astrophysics, Radboud University, Nijmegen. We are a part of the Institute for Mathematics, Astrophysics and Particle Physics (IMAPP). On our dedicated website you will hopefully find all the information you need about the Department and its people.
The News page with the most recent news flashes will be in Dutch, but the most important information can be found in this English section of our website.
Low-frequency radio astronomical receiver to be sent on orbit behind the moon
Researchers at Radboud University Nijmegen together with a joint Dutch-Chinese team are designing and developing a low-frequency radio astronomical receiver to send in an orbit behind the Moon in 2018. This receiver will be mounted on the Chang’e 4 relay satellite and is considered a pathfinder mission for a future low-frequency space-based or Moon-based radio interferometer, which has the detection and tomography of the 21-cm Hydrogen line emission from the Dark Ages period as the principle science objective. The baseline design of this payload involves three co-located, orthogonal, monopole antenna elements each of ~5 meters in length. The analogue signals of each antenna are digitalized in a DSP system on which dedicated science modes ae implemented in a flexible software-defined radio system. This receiver will be designed and build by a strong consortium led by the Radboud Radio Lab of the Radboud University Nijmegen (PI – Prof. Heino Falcke), Astron and the Delft company Innovative Solutions in Space (ISIS).
Read the press release here — News edited on June 29, 2016.
Black hole binary in quiescence identified outside a globular cluster for the first time
Our PhD candidate Serena Repetto, together with an international group of astronomers, has confirmed the nature of a binary system that contains a low-mass star and a black hole accreting gas from its companion at a very slow rate: VLA J213002.08+120904. This system was thought to belong to the globular cluster M15, featured in the image. Black holes are usually identified by characteristic X-ray emission related to accretion of material into the black hole. But this system is accreting at very low rate, and it was only recently that it was reported as a possible black hole binary. In fact, the authors of the study have used a wealth of observations in different wavelengths from radio to X-rays in order to constrain the nature of the system, determining for instance that the system is five times closer than M15. Therefore, VLA J2130 is a foreground object, and it is the first system of its type that is found outside a globular cluster. The authors of the study also conclude that the system is old, and the companion star is only 0.1 - 0.2 times the mass of our sun. The consequences of this discovery point to a much larger population of these objects in our galaxy than previously anticipated by the theory.
Read the press release here
Read the scientific paper here
Image credits: X-ray: NASA/CXC/Univ. of Alberta/B.Tetarenko et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA. — News edited on June 28, 2016.
Public observation of the Transit of Mercury on May 9th
On Monday 9th May, Mercury will pass right between the earth and the sun and we will observe a transit. From 13:12 to 20:40, Mercury will appear as a small, dark dot against the bright solar disk. The size of the dark dot is seven times smaller than we can distinguish with naked eye, so a telescope is needed. At 16:56, the planet will reach the closest point to the centre of the solar disk, blocking about 0.003% of Sun’s light. This transit of Mercury is visible in its entirety from Nijmegen (see the simulation). The next chances are in 2019 and 2032, but only a fraction of those transits will be visible.
The Radboud University Observatory will be open for a public visit of the transit. Members of the Astronomische Kring Nijmegen (AKN) and the Radboud Sterrenkunde department will show visitors the transit of Mercury using our telescopes and will provide further explanation of this beautiful event. Remember that observing the sun without the proper equipment is extremely dangerous. It is possible that it is cloudy here, in that case we will connect with one of the live broadcasts from somewhere else.
Visitors should book free tickets for one the nine 45-minutes sessions throughout the event. Tickets can be booked here. This is because the observatory has limited capacity, please be mindful of other visitors.
The telescopes are at the roof the Huygensgebouw, Heyendaalseweg 135. Please note that the observatory is only accessible by stairs. If you have further question, please contact email@example.com (English) or firstname.lastname@example.org (Dutch).
Possible Extragalactic Source of High-Energy Neutrinos: Coincidence of a highly energetic outburst of an active galactic nucleus with a neutrino event at PeV energy
Neutrinos are among the most fascinating fundamental particles. They are the fastest and lightest ones and they interact very little with anything they encounter. This makes them incredibly difficult to detect, but because of this they also provide insight into physical processes and environments that cannot be explored through the study of light. The blazar PKS B1424-418, underwent a dramatic outburst that was observed with the Fermi Gamma-Ray Space Observatory between 2012 and 2013 shining 15 to 30 times as bright as the average prior to this event. Intriguingly, the position and the time of the outburst of PKS B1424-418 coincides with the detection of a 2PeV neutrino (dubbed “Big Bird”) by the IceCube collaboration. Using multiwavelength data from the TANAMI program and information from other telescopes and space observatories, an international team of astronomers including Dr. Cornelia Müller (Radboud University) conclude that the total energy emitted by PKS B1424-418 is sufficient to produce such a very high-energy neutrino. The study that was recently published in Nature Physics suggests that these events are linked.
Original Paper: Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event. Kadler, M.; Krauß, F.; Mannheim, K.; Ojha, R.; Müller, C.; Schulz, R.; et al. 2016, Nature Physics, DOI 10.1038/nphys3715
Read more: ASTRON News
Inspiring children in the language of ancient mayan astronomers
Kristhell López (Radboud University and SRON), originally from Guatemala, has opened a new window for education in astronomy in the mayan language. The website SpaceScoop, already translated into 26 languages in 61 countries, is now accessible also in mayan k’iche’. SpaceScoop is a project within the Universe Awareness initiative created in Leiden that tries to educate children between 4 and 10 years old (especially those from unprivileged communities) in astronomy and astrophysics. Using the latest astronomical news, children learn about science and get surprised by the mysteries of the universe.
K. López works as a volunteer for the Universe Awareness initiative, extending the target audience to the two million mayan k’iche’ native speakers. Together with her collaborators, Elena Tambriz, Luis Jamínez and Ricardo Guarcha, López wants to promote the k’iche’ language, and provide more teaching resources for Guatemalan families and children. Teaching children astronomy stimulates their interest in science and technology, and can inspire young generations to become astronomers when they grow up. This is especially important for thousands of Guatemalan children, as their cultural heritage is deeply connected to astronomy. The mayan civilization built large astronomical observatories and their achievements, such as complex solar and lunar calendars, have become known world wide. López’s contribution to the Universe Awareness initiative is a way of bringing cutting-edge astronomy back to the cultural inheritors of these ancient mayan astronomers.
Payaswini Saikia receives Frye Stipendium 2015
Payaswini Saikia, PhD student of the department of Astrophysics, has received a Frye Stipendium. The stipendium is called after dr. I.B.M. Frye, who was one of the first female scientists at the Radboud University of Nijmegen, in 1953. The scholarship has been installed to encourage female PhD students to continue a career in science, after finishing their dissertations. The scholarship comes with a reward of 3.500 € and are granted to ten female researchers of different faculties once every year.
Payaswini studies the properties of black holes in the centers of distant galaxies and nearby stellar black holes in binary stars. She finds empirical connections between the basic observables of these intriguing black holes of vastly different masses.
Radboud Excellence Fellowships
Radboud University offers 2-year Excellence Fellowships for independent research to postdoctoral researchers that are 2-10 years after their PhD award. The Department of Astrophysics invites applications in the areas of astronomy, astrophysics and astroparticle physics. Closing date is October 1, 2015. More information to be found on Vacancies.
Honorary doctorate Professor Shrinivas Kulkarni
On the 92nd dies natalis of Radboud University an honorary doctorate was awarded to astronomer Shri Kulkarni, for his achievements for the development of astrophysics. Kulkarni is professor of astronomy and planetary sciences at the California Institute of Technology ( CalTech), and famous for his discoveries in the fields of millisecond pulsars, brown dwarfs, gamma-ray bursts and synoptic surveys. At Radboud University Kulkarni collaborates with astronomers Groot, Verbunt and Nelemans, among others on the joint development of two new powerful telescopes ( ZTF en BlackGEM), that aim to find the optical counterparts to gravitational wave sources.
Radboud Radio Lab receives 1.3 million Euro investment
Radboud University will invest 1.3 million Euros in the establishment of the new ‘Radboud Radio Lab’, a centre of excellence dedicated to a strong asset of the Nijmegen astronomers: radio interferometry. With this technique it is possible to image and localise radio sources on earth and in space extremely precisely – from cosmic black holes to man-made radio transmitters. Nijmegen astronomers have a leading role in several international projects in the field of radio measurements. The new radio lab allows them to strengthen this leading position and further develop the cooperation between research institutions and companies. Astronomer Marc Klein Wolt will be the general director of the Radboud Radio Lab, whereas Professor Heino Falcke the scientific director.
Read more on Radboud News.
Exploding stars help to understand thunderclouds on Earth
How is lightning initiated in thunderclouds? This is difficult to answer – how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 22nd. The measurements were performed by radio astronomers and astroparticle physicists with the LOFAR radio telescope located in the Netherlands. Read more: Radboud News
PDF version of article
Come and enjoy the solar eclipse at Radboud University, March 20 at 09:00-12:00
Next Friday 20th March a partial solar eclipse will be visible from Nijmegen. The eclipse will start at 09:28 and will end at 11:46. The maximum will happen at 10:35, when the moon will be covering 84% of the sun. Even though the eclipse will not be total from Nijmegen, the spectacle is still very impressive! See the simulation.
Everyone is welcome to come to the observatory anytime between 9 and 12, and enjoy this magnificent phenomenon with us. We will project the eclipse using the telescopes, as well as observe it directly with special glasses (observing the sun without the proper equipment is extremely dangerous). In case it is cloudy here, we will connect with one of the live broadcasts from somewhere else. Next solar eclipse will be in 2021, and will not be as spectacular as this one!
Registration is not needed.
The telescopes are at the roof the Huygensgebouw, Heyendaalseweg 135. Please note that the observatory is only accessible by stairs. In case large groups come to the event, there is a maximum number of people that we can accommodate at the observatory.
If you have further questions, you can ask to the secretaries of the Department of Astronomy, accessible during office hours except on Thursday afternoon.
Planck Mission 2015 results (Seminar)
Date: 5 February 2015
Time: 16.00 hrs.
Location: Linnaeus building, room 6
Speaker: Dr. Jörg P. Rachen
Description: Seminar about the latest results of the Planck Mission - just one hour after the public release of the 2015 data. The Planck Mission is ESA’s premier cosmology satellite mission, measuring the cosmic background radiation and hence measures in great detail the properties of our universe and the big bang. Of course, by now changes in our cosmological model become more and more incremental, but still, this is - by a huge margin - the most quoted and most influential astronomical experiment in the world. It recently made some headlines again, since it disproved the Harvard (BICEP2) claim of the detection of gravitational waves from the Big Bang that was all over the news last year. About the speaker: Jörg Rachen is the only 'Dutch' member of the Planck collaboration. He has been involved in the Planck Mission for many years.
Two million euro for intermediate mass black hole research
Peter Jonker (SRON and Radboud University) has been awarded the prestigious European Research Council Consolidator grant for independent ground breaking research. Jonker is going to tackle one of the great mysteries in high-energy physics: the question of whether intermediate black holes truly exist. Astronomers think that these elusive intermediate sizes – with masses ranging from hundreds to a hundred thousand solar masses – must have been created when the universe was very young from the first generation of giant stars or enormous gas clouds that collapsed into black holes. If that is the case, then the space surrounding galaxies should be full of them. Although there are strong indications for the existence of intermediate black holes, no direct evidence has been found as yet. Jonker therefore wants to use ESA's new Gaia space telescope and the largest Earth-based telescopes to study objects and phenomena that can exist only due to the effects of an intermediate black hole. For more information, see the press release.
Stijn Buitink receives 1.5 M euro ERC starting grant for research with LOFAR
Stijn Buitink has received a 1.5 million euro ERC starting grant. Buitink, postdoctoral researcher at the Radboud University and starting as Assistant Professor at the Free University of Brussels soon, will use the grant to search for short bursts of radio emission created by cosmic particles in the Earth's atmosphere, with the LOFAR radio telescope. The origin of these extremely energetic particles is still unknown. Buitink will study their intricate radiation patterns and find out whether they come from our own Galaxy or from violent sources much further away, like gamma-ray bursts or active black holes. Furthermore, he will develop a new observation technique to search for radio pulses from ultra-high-energy neutrinos hitting the Moon, effectively turning the whole Moon into a giant cosmic particle detector.
The riddle of the 'missing' stars: Hubble observations cast further doubt on how globular clusters formed
A team led by Radboud University astronomer Søren Larsen has made the mystery on the origin of globular clusters even bigger. From observations of four globular clusters - large balls of stars that orbit the centres of galaxies - around the small nearby galaxy Fornax, it appears that these are similar to the clusters around our Milky Way, and thus should have been generated in the same way. However, the absence of old stars in the Fornax dwarf galaxy, which can be found in our Milky Way, makes one conclude that the best theory that describes the origin of globular clusters, can not be correct. The new work, in which observations were done with the Hubble Space Telescope, is detailed in a paper published last Wednesday, 20 November 2014, in The Astrophysical Journal.
Hubble/ESA Press release
DEPARTMENT OF ASTROPHYSICS PARTIALLY MOVED
On Friday November 14, a great deal of the employees of astrophysics have moved internally. All the employees and students who used to have an office on the 3rd or 4th floor of Wing 7, but also the secretariat, have moved to other offices, all on the 2nd floor. Most of the people have an office in wing 7, a few department members have an office in the corridor near wing 7 or 8, on the 2nd floor. If you need to find members of our department, it's best to check the 'who's who' on our website for the latest update.
Stratos II Rocket with Radboud Payload launch cancelled
The Stratos II rocket for which the Radboud University (RU) provided a payload, has not been launched due to technical issues and an unfavourable wind. The experiment had initially been aimed to observe ionospheric radio emission and man-made RFI but would be further investigated for space radio interferometry.
Moreover, the antenna on-board Stratos II would be used for an interferometric measurement to determine the location of the rocket very precisely, where the antenna is one part of an array of antennas on the ground.
The payload mainly included a radio antenna, analogue front-end circuit and a high performance digital receiver that has been built by Hamid Pourshaghaghi, Peter Dolron, and Amin Aminaei supervised by Marc Klein Wolt, with support from the TechnoCenter of the Faculty of Science. The digitizer is a novel minimal design of a receiver for space radio astronomy, which will be used for future radio projects like SKA or “LOFAR on the moon”. This digitizer is made in a cube-sat size and provides us with a low-power, high-performance multiprocessor hardware/software system for radio astronomy experiments. This wpuld have been the first time that radio astronomy hardware would fly on a rocket and it would actually be the first for a Dutch astronomy project. Hence the Stratos II experiment is considered as the first step toward a radio telescope on the moon as one ultimate goal of researchers at the RU.
For more news on and background information on the Stratos/DARE project, one can follow it on twitter or check the the project website.
Open Observatory night on Friday October 31, 2014
Friday evening October 31, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors again. You will receive a tour through our domes where you can have a look through the telescopes. If it is cloudy, you can also listen to a lecture on an astronomical subject or see a short astronomical movie. Between 19.00 and 21.00 hrs excursions to the domes will start on a regular basis, and each tour will take about 1 hour. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. You can park your car (for free)underneath the Huygens Building P11,(North side!).
N.B.: Please keep in mind that the temperature in the domes is about the same as the temperature outside, and that the domes can only be reached by stairs.
The data for open observing nights during this “winter season” (2014-2015) are:
Friday September 26, 2014 : 19.30 - 21.00
Friday October 31, 2014 : 19.00 - 21.00
Friday November 28, 2014: 19.00 - 21.00
Friday January 30, 2015: 19.00 - 21.00
Friday February 27, 2015: 19.00 - 21.00
Friday March 27, 2015 : 19.30 - 21.00
12 M€ for Netherlands contribution to design of the Square Kilometre Array
A consortium consisting of ASTRON and the Universities of Amsterdam, Groningen, Leiden and Nijmegen has been awarded 12M€ for their participation in the design of the Square Kilometre Array (SKA). The SKA will be the World’s largest and most powerful radio telescope. Construction will start in 2018 in Australia and South Africa, the first results are expected from 2020. The announcement of funding from the second call of the Netherlands Roadmap for Large-Scale Research Facilities was made by Sander Dekker, the State Secretary for Education, Culture and Science, and Jos Engelen, chair of the Governing Board of Netherlands Organisation for Scientific Research NWO at an event in Leiden on July 1st.
The SKA Project is an international effort to design and build a telescope composed of hundreds of dishes and hundreds of thousands of antennas connected by optical fibre to massive data processing facilities. It will address questions that only observations of the Universe at radio wavelengths can answer.
Eleven consortia have been selected to design elements of the telescope. ASTRON, the Netherlands Institute for Radio Astronomy is leading the international consortia responsible for the design of the Low Frequency Aperture Array (LFAA) and Mid Frequency Aperture Array (MFFA) – two types of smart antenna that will operate at lower frequencies than the more conventional dishes. The Roadmap funding will also be used to develop the software and hardware required to process the vast amounts of data that will come from the telescope. Astronomers from the NL Universities, amongst others Heino Falcke, and ASTRON will be closely involved in these activities, in particular to ensure that the telescope is ready to address the most urgent topics studied by Dutch astronomers.
Read more on the SKA telescope web page.
Heino Falcke elected as member of the Royal Netherlands Academy of Science (KNAW)
Heino Falcke has been elected as new member of the Royal Netherlands Academy of Science ('Koninklijke Nederlandse Akademie van Wetenschappen', KNAW). The KNAW has elected 17 new members. Members of the KNAW, all prominent scientists from every discipline, are elected by nominations of peers from both in- and outside the Academy. The KNAW has 500 members in total, distributed over Arts and Science, and includes a committee of top scientists, an advisor for the government on scientific practice, and is responsible for 17 research institutes. On Monday September 8 2014 the new Academy members will be installed at the Trippenhuis of the KNAW in Amsterdam.
Open Observatory night on Friday March 28, 2014
Friday evening March 28, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors again. You will receive a tour through our domes where you can have a look through the telescopes. If it is cloudy, you can also listen to a lecture on an astronomical subject or view a short astronomical movie. Between 19.30 and 21.00 hrs excursions to the domes will start on a regular basis, and each tour will take about 1 hour. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. You can park your car (for free)underneath the Huygens Building P11,(North side!).
N.B.: Keep in mind that the temperature in the domes is about the same as the temperature outside, and that the domes can only be reached by stairs.
Soon we will present here the data for open observing nights during the coming “winter season” (2014-2015).
Observations of supernova SN2014J at Radboud University of Nijmegen
On January 21st, an undergraduate training session at the University of London Observatory led Steve Fossey to discover supernova SN2014J. Located in the galaxy M82, this is the closest type Ia supernova since 1972; even though light has travelled for almost twelve million years to reach our planet. This supernova happened in a stellar binary system with white dwarfs. White dwarfs are remnants of normal stars, whose nuclear fusion has ceased. However, mass transfer from one star to an other can trigger major explosions, visible on Earth as a supernova.
SN2014J is already a very popular target among professional and amateur astronomers and, of course, it has awakened the interest of a group of PhD students at the Astronomy Department. They organised observations using the optical telescopes on the roof of the Huygens Building to actually get to see the supernova. Several sets of images were taken with CCD cameras at both telescopes (35cm and 20cm) by Thomas Kupfer, Emilio Enriquez, Carlo Abate and Roque Ruiz Carmona. The picture shows the galaxy M82 as a spiral galaxy viewed edge-on. The supernova is the brightest source in the galaxy, to the top right. The students made pictures in several wavelengths (using filters B, V and R) and then combined the images in fake colour to end up with this beautiful result.
ERC Synergy Grant for team of Heino Falcke for research on Black Holes
The BlackHoleCam team, lead by Prof. Heino Falcke (RU/Astron) receives a 14 million Euro grant from the European Research Council (ERC) to be the first to make images of the black hole in the Galactic center. The BlackHoleCam team consists of Prof. Michael Kramer (MPfR, Bonn) and Prof. Luciano Rezzolla (Albert Einstein Institute). The team will connect all sub millimeter telescopes on the globe, for the first time, to form a long-base-line interferometer, and combine this with the best possible simulations of the light-bending around the supermassive black hole. For more information, please read RU press release or the ASTRON press release.
Live launch of European Gaia mission Thursday 10am at Astronomy department
This Thursday at 10:12 hours the European Space Agency will launch the Gaia mission and we have a live broadcast in the coffee room of the Astrophysics department (wing 7, second floor). Interested colleagues of the RU are welcome to join us between 10 and 10:30 to watch and get more information.
The Gaia mission will map the positions, distances and velocities of about a billion objects in our Milky Way galaxy and observe the sky on average about 80 times in the next 5 years. The very high precision and enormous amount of objects measured will forever change many aspects of Astrophysics. In addition, the repeated observations will open a new way to study flashes from exotic (explosive) phenomena. We are looking forward to using the data!
Unique SOS signal from torn apart star points to medium-size black hole
On the edge of the nearby galaxy Messier 86, a team of astronomers led by Peter Jonker have observed a strange X-ray flash. This flash has almost certainly been caused by a rare cosmic accident in which a small star is pulled apart by a medium-sized black hole. The discovery may provide the missing evidence for the existence of medium-size black holes. More information on SRON website...
Open Observatory night on Friday November 29
Friday evening November 29, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors. You will receive a tour through our domes where you can have a look through the telescopes. If it is cloudy, you can also listen to a lecture on an astronomical subject or view a short astronomical movie. Between 19.00 and 21.00 hrs excursions to the domes will start regularly, and each tour will take about 1 hour. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. You can park your car (for free)underneath the Huygens building P11,(North side!).
N.B.: Keep in mind that the temperature in the domes is about the same as the outside temperature, and that the domes can only be reached by stairs.
During this “winter season” there will be open observing nights on the following days: 27 September 2013, 25 October 2013, 29 November 2013, 31 January 2014, 28 February 2014 and 28 March 2014.
Marianne Heida receives Frye Stipendium
Marianne Heida, PhD student at the department of Astrophysics and at SRON (Netherlands Institute for Space Research), has received the Frye Stipendium. The stipendium is called after dr. I.B.M. Frye, who was one of the first female scientists at the Radboud University of Nijmegen, in 1953. The scholarship has been installed to encourage female PhD students to continue a career in science, after finishing their dissertations. The scholarship comes with a reward of 3.500 € and are granted once every year.
Heino Falcke new member of the Academia Europaea
Heino Falcke is one out of eleven scientists from the Radboud University Nijmegen who have become to be members of the Academia Europaea this year. The Academia Europaea is a European community of top scientist - amongst others some nobel prize winners - from all science disciplines.
More information can be found at the RU news website (in Dutch).
Astronomers discover pulsar around supermassive black hole
Together with a team of colleague astronomers, Heino Falcke has for the first time ever discovered a pulsar in the direct vicinity of a suppermassive black hole at the centre of the Galaxy.
For a longer time, astronomers are predicting the presence of thousands of pulsars, around the centre of the Galaxy, which are rapidly rotating stars with electromagnetic radiation, only, they've never been able to find one. The pulsar that has now been found, with an axial rotation of 3.76 seconds, has been discovered with the Swift-space telescope (a satellite). With the Swift telescope, there was an observation of an X-ray flash, at little distance from the centre of the Galaxy. The astronomers aimed the radio telescope of Effelsberg (of the MPI) directly at the flash, thus discovering the pulsar.
The discovery is extraordinary because pulsars can shed more light on the characteristics of supermassive black holes. This pulsar has certainly done so: Falcke and his team got to know much more about the matter absorbed by the nearby black hole. Balck holes are long known to take in gas and dust, but the team was surprised to discover, that it also seems to 'consume' from its “own” magnetic field.
Astronomers propose explanation for mysterious radio bursts
Radio telescopes have picked up some bright radio flashes that appear for only a brief moment on the sky and do not repeat. So, what causes these unusual radio signals? Heino Falcke (Nijmegen) and Luciano Rezzolla (Potsdam) suggest that this could be the final farewell greetings of a supramassive rotating neutron star collapsing into a black hole and shedding its magnetic field.
Story in NewScientist by Govert Schilling
Read more ...
Eight PhD positions in the Department of Astrophysics
The Department of Astrophysics has 8 PhD positions available, to start in September 2013. For details please follow the link to the AAS Job Register advertisement or the internal link to our Vacancies page.
Open Observatory night on Friday March 22
Friday evening March 22, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors. You will receive a tour through our domes where you can have a look through the telescopes. If it is cloudy, you can also listen to a lecture on an astronomical subject or view a short astronomical movie. Between 19.30 and 21.00 hrs excursions to the domes will start regularly, and each tour will take about 1 hour. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. You can park your car (for free)underneath the Huygens building P11,(North side!).
N.B.: Keep in mind that the temperature in the domes is about the same as the outside temperature, and that the domes can only be reached by stairs.
Second Dutch Gravitational Wave Meeting in Nijmegen
The second Dutch Gravitational Wave Meeting will take place on Thursday Jan 31 in the Huygens building of the Radboud University. More and more research in the Netherlands is related to the emerging interdisciplinary field of Gravitation Waves in which astronomers and physicists collaborate. More information
Chameleon pulsar baffles astronomers
An international team - led by Dutch astronomers (SRON, NOVA and ASTRON) - has made a tantalizing discovery about the way pulsars emit radiation. The emission of X-rays and radio waves by these pulsating neutron stars is able to change dramatically in seconds, simultaneously, in a way that cannot be explained with current theory. It suggests a quick change of the entire magnetosphere. In their research the team combined observations from the X-ray space telescope XMM-Newton and the radio telescope LOFAR (among others); the journal Science published the results on January 25. Read more.
Giant outflows from Milky Way centre caused by millions of star births
A continuous stream of charged particles is erupting from the centre of our galaxy, the Milky Way. This is a by-product of the birth of new stars, astronomers among whom Marijke Haverkorn conclude on 3 January in Nature. The outflow would also seem to play a part in the Milky Way’s magnetic field. Read more.
Open Observatory night on Friday January 25
Friday evening January 25, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors. You will receive a tour through our domes where you can have a look through the telescopes. If it is clouded, you can also listen to a lecture on an astronomical subject or view a short astronomical movie. Between 19.00 and 21.00 hrs excursions to the domes will start regularly, and each tour will take about 1 hour. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. Parking underneath the Huygens building P11,(North side!).
N.B.: Bear in mind that the temperature in the domes is about equal to that outside, and that the domes can only be reached by stairs.
Super-massive black hole inflates giant bubble
Using the LOFAR radio telescope, a group of astronomers, in collaboration with astronomers from the Radboud University, have produced one of the best images ever made at the lowest frequencies (20-160 MHz) of giant bubbles produced by a super-massive black hole. The picture shows what looks like a giant balloon filled with radio emitting plasma, which exceeds the size of an entire galaxy.
More information can be found here. Image credit: Francesco de Gasperin, on behalf of the LOFAR collaboration.
Double White dwarf for eLISA
Astronomers have detected the small changes in the orbit of a double white dwarf binary that follow the predictions of General Relativity. This source will be an important verification source for the future gravitational wave mission eLISA in which the departments participates. Gijs Nelemans is interviewed in New Scientist on this finding. On-line article
NWO-VIDI grant for Elmar Körding
The Dutch science foundation NWO has announced that Elmar Körding is one of the recipients of a VIDI grant (800 kEuro) for his project on disentangling the effects of general relativity in accretion onto compact object (black holes, neutron stars and white dwarfs). The project will focus in particular on the launching of jets, which have been often detected in neutron stars and black holes, but which have now also been detected, by Elmar, in white dwarf binaries.
The Ulrich J. Schwarz Radio Interferometer
On Friday 29 June, the Department of Astrophysics celebrated the completion of the renewed Radboud Radio Interferometer on the roof of the Huygens building. Dean Stan Gielen officially opened the radio interferometer, which is now named the 'Ulrich J. Schwarz Radio Interferometer'. Ulrich Schwarz is a poineer in radio astronomy. After his retirement, Ulrich became the guardian of the Radio Interferometer at the Radboud University. He supervised student projects and added the interferometer to the student curriculum. Ulrich played a large role in the move and refurbishment of the Radio Interferometer. For more information, click here. Photo credit: Dick van Aalst
Radboud astronomy new member of Virgo collaboration
On June 18, the Virgo collaboration was officially expanded with the gravitational wave astronomy group of the Department of Astrophysics of the Radboud University. The groups of Gijs Nelemans and Paul Groot are now part of Virgo, and in particular responsible for the population synthesis calculations of merging neutron star and black hole binaries, as well as the electromagnetic counterpart detection of gravitational wave sources. To achieve these objectives an ERC Synergy grant on the BlackGEM array is under review. Last week the NWO science foundation committed 2 million Euro towards the Dutch participation in Virgo, which also comprises the National Institute for Nuclea and High Energy Physics, the Nikhef.
LOFAR on Nature.com: Radio array starts work
Giant low-frequency sensor system on track to probe the birth of the first stars.
Falcke and his colleagues defied the doubters by presenting their first results on 9 January at a meeting of the American Astronomical Society in Austin, Texas. “The message today is: the basic things all work. We can do this,” he said.
Mapping the low-frequency sky requires an expansive telescope as well as the ability to tune out noise. When completed later this year, the array will contain 2,700 slender dipole antennas tuned to 30–80 megahertz, and 43,000 antennas embedded in flat tiles a few metres square that are sensitive to 120–240 megahertz. The antennas will be concentrated in 40 stations across the Netherlands; 8 other stations in the United Kingdom, France, Germany and Sweden give the array extra angular resolution for fine-scale imaging.
For the complete article, see http://www.nature.com/news/radio-array-starts-work-1.9762.
Frye Stipend for Silvia Toonen
Silvia Toonen received one of the Dr. I.B.M. Frye Stipends on Tuesday. The yearly Frye Stipends are awarded by the Radboud University Nijmegen to ten promising female PhD students from all faculties of the university. The award, which involves 3500 euros, can be used by the laureates for work-related travel and visits in order to increase the collaboration with other leading scientists in the field, and hence the level of their own research. Ms. Toonen (MSc) receives the stipend for her research on compact binary stars, and in particular those compact binaries that contain one or more white dwarfs, and are possible progenitors of type-Ia supernovae. She will use her stipend to visit the University of Warwick, which houses experts on the observation of compact binaries, and to visit the University Tübingen, where leading research on the theory of these binaries is conducted.
Nature: Red giants have rapidly spinning cores
An international team of astronomers led by PhD student Paul Beck from Leuven University in Belgium have managed to look deep inside some old stars and discovered that their cores spin at least ten times as fast as their surfaces. The result appeared today in the renowned journal nature. It is the fourth top publication in 2011 of Conny Aerts, professor of Asteroseismologie at the RU. Read more...
Nijmegen Astronomers observed close fly-by of large asteroid 2005 YU55
Only in 2028 will another asteroid of this size get as close to the Earth again as the 400 m diameter asteroid 2005 YU55 did on November 8th. A team of scientists from the department of Astronomy in Nijmegen and from the Astronomische Kring Nijmegen (AKN) were able to observe the fly-by with the 35 cm telescope of the department and succeeded in making a movie of this rare event. The asteroid passed the Earth at a distance of only 85% of the distance from the Earth to the Moon.
In the video you can see the asteroid coming from the top and moving to the bottom of the picture. This video has been composed from single images that have been taken between 2:07 and 2:27 at November 10 in Nijmegen.
The thumbnail image shows a Nasa/JPL-Caltech radar image of the asteroid.
Physics and Astronomy programme at the Radboud University comes out as best in the Netherlands
In an inquiry by Elsevier and ResearchNed the Physics and Astronomy programme of the Radboud University Nijmegen has managed to score significantly higher than the other dutch Universities.
Aspects of the studies examined were, amongst others, the facilities, the organization and communication, teachers and the educational aspects in general (for example the match with previous education, quality of studing material etc.). Scores for our study were highest on account of facilities (i.e. available seats, digital studying environment and availability of studying material) and teachers (availability, supervision, capabilities and motivation), a 7.6 and 7.7 respectively. In total, the study for Physics and Astronomy scored a 7.4, which was significantly higher than the scores of universities such as the University of Leiden or the University of Amsterdam.
ESO and Chile sign agreement on mountain for E-ELT
In Santiago on October 13, Chile and the European Southern Observatory ESO have signed an agreement on the future home of the E-ELT on the mountain Armazones in the northern part of Chile. At the same time a large area around Armazones will now be a protected area. Cerro Armazones lies next to Cerro Paranal where ESO is already operating the Very Large Telescope (VLT). “This is a big step towards the E-ELT becoming reality”, according to Tim de Zeeuw, the director-general of ESO. The Netherlands is playing an active role in the construction of the E-ELT, among others through the Micado instrument that will partially be built by NOVA and that Nijmegen astronomers hope to use to study the details of our Milky Way Galaxy.
Students from High School in Goch at RU Nijmegen
Students from the Gymnasium Gaesdonck in Goch have conducted an internship at the Department of Astrophysics in August 2011. The students have been selected as the best students in natural sciences. They spend one week at the department of astrophysics, doing research with the radio telescope and the optical telescope of the department.
Heino Falcke receives Spinoza award from State Secretary Zijlstra on September 9 in The Hague
Heino Falcke was awarded his NWO Spinoza prize officially last Friday September 9, by Halbe Zijlstra, State Secretary of Education, Culture and Science, in the Nieuwe Kerk in The Hague. Before this ceremony started, Heino Falcke and the other laureates gave a lecture on their topics and their plans for spending the 2.5 million euro.
Heino will use part of his Spinoza funding for innovative educational projects aimed at children throughout the world. For the younger children aged 4 to 10 years, he will work together with the Universe Awareness (UNAWE) project to create inspirational material that will use astronomy to open children's minds, introduce them to science and engineering, and stimulate them to adopt a multicultural viewpoint.
For older pupils (age 14 and higher) he will develop school projects, providing hands-on access to radio telescopes. This will highlight the excitement of radio astronomy and allow children to explore the universe with their own minds, letting them further develop their talents and skills in science and technology.
The outreach projects will be developed in close collaboration between the Radboud University, the NOVA Information Office, ASTRON in Dwingeloo, the Max-Planck-Insitut für Radioastronomie in Bonn (D), and UNAWE.
The research component of Falcke's project will focus on the experimental verification of the existence of an event horizon in black holes. Some fraction of the money will be used# to upgrade the CARMA telescope in California, in collaboration with the Radio Astronomy Lab at the University of Berkeley. CARMA is a radio interferometer working at frequencies around 100 GHz. Together with other high-frequency radio telescopes, such as ESO's new ALMA observatory, it can be combined to form a global virtual radio telescope. This technique, called mm-wave VLBI (Very Long Baseline Interferometry), has in principle the sensitivity and resolution to detect the shadow of the black hole in the supermassive black hole at the center of our Milky Way as predicted by Falcke. Such a finding would be of fundamental importance for astrophysics and prove one of the most extreme predictions of Einstein's theory of General Relativity. The experiment is very difficult and requires a good collaboration between different groups around the world. It therefore likely will take a couple of years before it could succeed.
Here's a short video recording of the award ceremony video Spinoza 09 09 2011.
Palomar Transient Factory finds new supernova Type Ia in the Pinwheel Galaxy
This week the Palomar Transient Factory has found a new supernova Type Ia in the nearby M101 (Pinwheel Galaxy) at a distance of only 20 million light years. The image shows the supernova brightening from invisibility to the brightest 'star' in the galaxy. The supernova is still getting brighter since it was caught very soon after the explosion. Supernovae Type Ia are exploding white dwarfs used to track the accelerated expansion of our Universe. The trigger for the explosion in a binary system containing the white dwarf is unclear and an active research area of Gijs Nelemans and his group in Nijmegen. Understanding supernova Type Ia triggers is one of the biggest questions in astrophysics today. Paul Groot is a member of the Palomar Transient Factory and is currently spending his sabbatical at Caltech, from where this survey is coordinated.
Collapse and fire in radio/TV tower as seen in LOFAR data
On July 15, 2011 the TV & Radio communication tower at Hoogersmilde in the province of Drenthe caught fire and eventually collapsed. This caused a major disruption of TV and radio service in the Netherlands.
The tower is located in the same province as the LOFAR radio telescope, which was operational at the time measuring radio emission from cosmic particles for the LOFAR Cosmic Ray Key Science project using the transient buffer boards (TBBs). The TBBs allow one to record raw data from all antenna and do offline processing after an event has happened.
The figure shows three radio spectra from low-band antennas (LBAs) in the FM band with 1 kHz resolution right after the fire had started: During the fire the signal strength goes down and then shuts off completely. The data was taken through the side-lobes of the antennas and through a low-pass filter to suppress the FM band, so is highly suppressed, but nonetheless clearly visible.
Dutch Astrophysics Olympiad 2011
The finals of the Dutch Astrophysics Olympiad 2011, from 14 to 16 June at the Radboud University, has been won by the 18-year old Nastasha Wijers from Heerhugowaard. She is awarded with an observing trip to the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands.
After a few fore rounds, the final 3-day round took place, which existed of a series of lectures - a.o. by Spinoza Prize winner Heino Falcke - on different astronomical topics such as gravity, compact binaries, supernovas, black holes and cosmic rays, completed by an exam. Fourteen high school students participated in the finals. The three finalists with the highest scores were awarded. The second prize was given to Jeroen Winkel from Nijmegen, third prize to Eline de Weerd from Fochteloo. All 14 finalists received a certificate and a book on astronomy.
Between all the action, lecturing etc, the participants have been able to observe sun during day time, and - even though cloudy (!) -the Lunar Eclipse and Saturn, on Wednesday evening.
Heino Falcke wins Spinoza prize
Heino Falcke (1966), professor of Astroparticle Physics and Radio Astronomy has been awarded the Spinoza Prize of the Netherlands Organisation for Scientific Research. The Spinoza prize is the most prestigious prize for science in the Netherlands (sometimes referred to as the Dutch Nobelprize). Heino receives the prize in recognition of his contributions to radio astronomy and astropartice physics
See also NWO page...
Paul Groot quoted in New York Times
In an article in the New York Times on light pollution Paul Groot is interviewed when observing at the MMT telescope in Arizona. Link to article...
Festive and educational re-opening of Astrophysics
Several joyous events that happened at our department, called for a celebration.
On 11 May, a toast was made to 4 events, which are the move of our department, which was becoming a great necessity, while Astrophysics expands continuously, the introduction of 2 new members of staff and the introduction of our temporary chair of department.
One of these people who we were happy to welcome as new member of our group is Dr. Elmar Körding, as Assistant Professor, since 2010.
Secondly, Dr. Marijke Haverkorn has been chosen as the best candidate for the Joliot Curie Fellowship and has accepted a position as Assistant Professor at our department, starting Spring 2011.
Last but not least, since Paul Groot is on sabbatical leave from January until December 2011, Heino Falcke was introduced as chair, during the re-opening ceremony.
The re-opening celebration was, next to being a social event, an informative introduction to our department as well, with experimental settings, screens with information of the variation of research topics, while at the same time posters informed our guests on these results and topics as well.
First multi-site video lectures
Modern techniques facilitate new possibilities for giving lectures! Last Thursday, March 24, the first multi-site video lecture has taken place at the Dept. of Astrophysics. Professor Paul Groot, on sabbatical leave at Caltech, L.A., at this moment, presented his lecture on compact binaries through video conferencing parallel for students in Nijmegen, Eindhoven, Tilburg and Cardiff. The students got the opportunity to follow the lecture, ask questions and react by means of the video conference system, from all different places at the same time.
Department moved within the Huygens building
On February 24 the Department has moved most of its offices within the Huygens building. Because of the increased size of the Department, as well as of the IMAPP institute as a whole, previous premises had become too small. The Department now also occupies a number of offices on the 2nd floor of wing 7, one floor directly below the current location. The entrance to the Department as well as the secretariat are located on the 2nd floor. The offices at the front side of the building on the 3rd and 4th floor will remain in use by the Department. Phone numbers of the Department have remained unchanged. New room numbers can be found in Who's who
Open Observatory night on Friday February 25
Friday evening of February 25, the Department of Astrophysics, in cooperation with the 'Astronomen Kring Nijmegen'/Astronomical Circle Nijmegen(AKN), will open her doors. You will receive a tour through our domes where you can have a look through the telescopes. If it is clouded, you can also listen to a lecture on an astronomical subject or view a short astronomical movie. Between 19.00 and 20.30 hrs excursions to the domes will start regularly, and each tour will take around 45 minutes. Location is the Huygens building, Heijendaalseweg 135, Nijmegen, gather at the reception. Free entry, pre-registration not necessary. Parking underneath the Huygens building,(North side!).
N.B.: Bear in mind that the temperature in the domes is about equal to that outside, and that they can only be reached by stairs.