Discovery of an energetic cosmic neutrino source due to very high energy gamma ray observations
On September 22nd last year the Ice Cube Neutrino Observatory at the South Pole detected a high energy neutrino with a likely cosmic origin. A single neutrino does not suffice to identify its source. Very soon after its detection telescopes working at different wavelengths of the electromagnetic spectrum started to observe the location it came from. Already 4 hours after the detection the HESS telescope located in Namibia started the observations. It was soon followed by VERITAS telescope (Arizona, USA), which started observing 12 hours after the alert. Next day the MAGIC telescope (Canary Islands) joined the campaign. These initial observations provided upper limits on the brightness of the source. The MAGIC telescope continued the monitoring campaign until October 4th, observing for a total of 13 hours. During these observations the source brightened up and became clearly detectable.
The observations that were performed with the telescopes sensitive from the radio band all the way to the very high energy gamma-rays indicate that the source is the TXS 0506+056 galaxy, about 4 billion light years away. The galaxy is a blazar, that hosts an accreting black hole which launches powerful jets of matter at speeds close to the speed of light. We observe blazars along the jet direction. Particles are accelerated to high energies in jets, however observing only gamma rays does not allow to distinguish if these are electrons, protons, or even nuclei. Fast protons collide with the particles of the interstellar gas creating pions, which in turn decay emitting neutrinos.
The discovery of gamma rays long with neutrinos is extremely exciting, because their origin must be connected with the acceleration of cosmic rays. The origin of cosmic rays has been a puzzle for more than 100 year since their discovery. The observation of gamma as and neutrinos indicates that blazars host environments where cosmic rays are formed, providing the direct evidence for the existence of a cosmic proton accelerator in these objects. The present discovery is another success of the multimessenger astronomy, a new branch of astrophysics which connects not only observations at different wavelengths, but also those with different types of radiation: electromagnetic waves, neutrinos, cosmic rays and gravitational waves.
The paper entiled „Multimessenger Observations of a flaring blazar coincident with high energy neutrino IceCube-170922A” that describes the observational campaign and its results has been published in Science on July 13 this year. Prof. M. Ostrowski and dr hab. Marek Jamrozy as well as two PhD students, N. Żywucka-Hejzner and A. Priyama Noel from the Astronomical Observatory of Jagiellonian University are among the authors of this paper.
There is a big Polish group of astronomers and physicists participating in gamma ray observations of the Universe. Scientists from UJ as well as from UW, CAMK PAN, UNK, and IFJ PAN take part in the HESS observatory operation and data analysis, and a group from UŁ takes part in the MAGIC observatory.
Category A+ for the Faculty of Physics, Astronomy and Applied Computer Science
I have a great pleasure to inform you that by appeal against the decision of KEJN and the Ministry of Science and Higher Education of 22 November 2017, the Minister of Science and Higher Education approved WFAIS UJ application of 28 December 2017 to reconsider the case and awarded the Faculty scientific category A+ (decision no. ODW-628/KAT/2018).
Nonacene joined the class of long acenes
Acenes composing a class of the narrowest graphene nanoribbons consist of linearly fused aromatic benzene rings. These molecules have been subject of extensive studies due to their unique electronic and magnetic properties which make them promising candidates to be implemented in (opto)electronics and spintronics. Unfortunately along with the increase of number of fused rings the acenes become unstable and in air conditions the longest stable form is pentacene. Recently the use of crystal substrates, on which chemical reactions are performed leading to compounds labile and unstable under different conditions, is more and more popular. This approach has been adopted by physicians of the Department of Physics of Nanostructures and Nanotechnologies who in cooperation with chemists from ICIQ Centre in Spain (professor Antonio M. Echavarrena’s group) and professor Mariusz Krawiec (UMCS Lublin) produced nonacenes on the gold surface and as the first examined its electron structure. In order to obtain the nonacenes they deposited partially “hydrogenated” stable molecular precursors on gold surface in ultra-high vacuum conditions and using techniques of molecular manipulation they abstracted “excessive” hydrogen atoms and thus produced nonacenes. Production of nonacenes composed of nine linearly fused benzene rings was confirmed by high-resolution atomic force microscopy.
High-resolution image of produced nonacene received by means of noncontact atomic force microscopy (nc-AFM)
You can read more about the research in September issue of ACS Nano: Rafał Zuzak, Ruth Dorel, Mariusz Krawiec, Bartosz Such, Marek Kolmer, Marek Szymoński, Antonio M. Echavarren, Szymon Godlewski, Nonacene Generated by On-Surface Dehydrogenation. ACS Nano 2017, 11, 9321−9329, DOI: 10.1021/acsnano.7b04728
The article entitled “H2 and (H2)2 molecules with an ab initio optimization of wave functions in correlated state: electron-proton couplings and intermolecular microscopic parameters" published in New Journal of Physics, co-authored by Andrzej P. Kądzielawa MSc and professor Józef Spałek has been recognized by the Institute of Physics Publishing as one of the most important and groundbreaking works of the year.
Congratulations to the authors.