Abstracts

Presentations

Rene Hudec: 15 years of IBWS Workshops

I will briefly discuss the history and recent status of IBWS workshops

Giovannelli Franco: An updated view of our Universe in the gravitational-wave Era

I will discuss the main pillars of the Bridge between the Big Bang and Biology using the updated results coming from the big and small experiments space- and ground-based in the new era of Gravitational Wave Astronomy. I will present a selection of solved and open problems that in my opinion marked the evolution of our knowledge of the physics governing our Universe.

Rene Hudec: Astrophysics with digitized astronomical plate archives

I will discuss recent status of astrophysical analyses with digitized astronomical plate archives with emphasis on high energy and transient astrophysics.

Rene Hudec: Digitization and astrophysical use of Hewitt Camera Archive, UK

We will briefly present the status of digitization and astrophysical use of Hewitt Camera Archive, UK. These wide field images, so far litte used for astrophysical work, covers both northern as well as southern sky down to lim mag 13.

Tomas Báča: On X-Ray orbital data from VZLUSAT-1 nanosatellite

We present current results of X-Ray camera payload onboard VZLUSAT-1 nanosatellite, the first Czech CubeSat launched into Earth\\\'s orbit. Embedded hardware and software was designed from the ground up to allow real-time image processing, filtering and compressing of captured images onboard the 10 x 10 x 20 cm CubeSat. Together with miniature lobster-eye optics, the satellite can capture X-Ray photons from astronomical objects. The satellite was successfully launched on June 23rd, 2017 to a 510 km Sun-synchronous Low-Earth orbit. The embedded electronics onboard, for the X-Ray and gamma-ray telescope, utilizes the Timepix sensor which also serves as a dosimetric unit. Besides its primary mission, the payload successfully produces data for global maps of ionizing radiation in Low-Earth orbit. Currently, in February 2017 the sensor captured nearly 20 000 images, most of which were successfully downloaded. We will discuss and interpret the measured data in the context of X-Ray astronomy and radiation mapping, which are inherently interconnected.

Petr Skala: Astrometric calibration of ultra wide-field images

This work will introruce new method of astrometric calibration tailored specially for ultra wide-field systems like WILLIAM. Standard astrometric solution often fail to provide any result if processed image contain large amount of distortion as for examlpe from fish eye lens. Some algorithms produce result but accuracy is satisfactory only at center of field of view. This work analised such images and propose new method that lead to mutch higher accuracy and succes ratio of calibration.

Arman Tursunov: Ultra-high-energy fragments from beta-decay in the vicinity of supermassive black holes

Origin and mechanism of production of ultra-high-energy (UHE) particles with detected energies above 10^{20} eV in cosmic rays remain a subject of intensive discussions. It is generally believed that the sources of detected UHE particles should be of extragalactic origin. I will show that such particles can be produced within a neutron beta-decay in the dynamical environment and vicinity of supermassive black holes (SMBH) located at the centers of galaxies by extracting out the energy of the central SMBH. Magnetic fields, which are usually present around black holes, play the role of catalyzing element that increases the efficiency of the energy extraction. Taking into account the back-reaction of individual charged particles one can put constraints on the mass of SMBH and magnetic fields in its vicinity to produce UHE particles within the model. From this, it follows that these are more likely protons, which may escape from SMBH, while Sgr A* at the Galactic Center cannot serve as a source of such UHE particles, mainly due to its relatively low mass.

Tobias März: Detecting Radio Frequency Interferences using a Recurrent Neural Network

An increasing threat in radio astronomy is RFI. The mobilization and digitization of the society leads to an increasing communication through radio waves. Radio wave observations, as performed by astronomers, are often polluted by radio frequency interferences(RFI). A special case of this problem develops in the usage of large telescope arrays for radio interferometry measurements. Because of the amount and the large distances between the telescopes, individual signals can endanger the whole measurement. This thesis proposes a recurrent neural network(RNN), a machine learning algorithm, to detect and filter the measurements which are RFI-polluted. The RNN uses a Long Short-Term Memory(LSTM)-cell implementation for the RNN, to evaluate and save the current state of the network. To label the test and training data, an algorithm is developed, that compares each value with its neighbors, in order to determine, whether the measurement is RFI-polluted at that place. The RNN learns of these labels, to evaluate the measurements. The batch size is a parameter of the RNN that is examined in more detail. It represents the amount of images, that the network gets inputted in one step. To find a good fitting batch size, the RNN is tested with several different batch sizes, with the other parameters staying constant. For a batch size of 2, the networks displays a remarkably good prediction, while also having smaller fluctuations. Upcoming telescope arrays, as for example the SKA, will generate enormous amount of data, thus using a lot of memory space. Advantages of a neural network for this task are, that it can adapt to new forms of data, it can improve with new data and that it can recognize correlations between data people can not see and therefore do not use in traditional algorithms. The measurement data used for training and testing the network come from the Giant Metrewave Radio Telescope (GMRT), located in India.

Mannheim Karl: The location of the gamma-ray emitting zone in blazars

Gamma-rays can be expected from the ergospheres surrounding black holes, due to the Penrose process or its ramifications. However, due to the presence of accretion flows, the optical depth on the event horizon scale is generically very high. Therefore, gamma-ray in blazars are presumably emitted far from the central black hole, and this is in line with the obserrved absence of pair-absorption features due to recombination photons from the BLR. The frequent occurence of flares on ultrashort time scales is difficult to explain in this context, leaving only very few options which will be discussed in this presentation.

Andrea Gokus: The Spectral Energy Distribution of the Candidate Neutrino Source TXS0506+056

The origin of extragalactic neutrinos with energies above 1 PeV is still unclear. One of the best candidates are jets from Active Galactic Nuclei (AGN), in which particles are accelerated to relativistic speeds. Blazars, a subclass of AGN, show jet orientations towards Earth and are therefore of specific interest in the search for neutrinos, because we can directly look into the jet and observe the underlying physical processes caused by the relativistic particles. Based on hadronic emission models of the jet, interacting protons can produce cascades, in which neutrinos are generated. These models predict a tight correlation between the neutrino flux and the time-variable gamma-ray emission, which could be proven by linking neutrino detections to gamma-ray flares. On September 22th, IceCube detected the first extremely high energy (EHE) event that is spatially and temporally coincident with the increase of gamma-ray emission from a single source (TXS0506+056). We develop a model of a time-resolved, hybrid (leptonic & hadronic) spectral energy distribution, and compare the results with multi-wavelength observations.

Istvan Racz: The Fermi GBM GRBs\' multivariate statistics

Studying the GRBs\' gamma-ray spectra may reveal some physical information of bursts. The Fermi satellite observed more than two thousand GRBs. The FERMIGBRST catalogue contains GRB parameters (peak energy, spectral indices, intensity) estimated for both the total emission (fluence), and the emission during the interval of the peak flux. We used the Contingency analysis method to reveal an ordering of the spectra into a power law - Comptonized - smoothly broken power law - Band series. We found a relationship with linear discriminant analysis between the spectral categories and the model independent physical data. We interpreted this result as a temporal variation of the spectrum during the outburst. Our results show that there is a significant synchrotron radiation in the GBM spectra, but we found also a cooling effect appear in the later spectrum.

Paul Ray Burd: The Prospects of Machine Learning Algorithms in Radio Astronomy

to be submitted

Jonas Ringholz: Large Scale Structure of Blazars at Low Radio Frequencies

Florian Rösch: Structural and Multiband Variability Analysis of 4C +01.28

The BL Lac object 4C +01.28 is a bright and very variable radio and gamma-ray emitter. At both energy bands, high-amplitude variability is observed on time scales of days to years. We study the radio and gamma-ray light curves observed by the Submillimeter Array (SMA) and Fermi/LAT and the parsec-scale jet structure observed by the Very Long Baseline Array (VLBA) over a period of more than eight years. We find a prominent bright and compact newly ejected feature in the parsec-scale jet, which seems to be associated with a prominent outburst in the millimeter and gamma-ray bands.

Sandor Pinter: Gamma-ray bursts in our HEART

I will briefly present the results and the future goals of our High Energy Astronomy Research Team (HEART) which is a joint collaboration of different researchers of several academic institutions (Czech, Japanese, American, and Hungarian) to better understanding the underlying physics of gamma-ray bursts (GRB). Our project is a multi-messenger investigation for the properties of GRBs and their host environments. For this on the one hand we are analysing the GRB light curves to separate the effects of the central engine from the intrinsic jet properties, on the other hand by revealing its fine structure and composition we are refining the Galactic foreground of the interstellar medium. By studying the GRBs\' spatial distribution we have discovered two of the largest-known formation in the Universe, also by studying the observed parameters of the known GRBs we have identified a third GRB class beside short and long GRBs.

Schilling Klaus: Satellite Formations for Scientific Observations

Formations of satellites offer exciting innovative potential for scientific observations, but require challenging autonomous reaction capabilities in order to coordinate attitude and orbit control. Distributed networked, cooperating very small satellites exhibit here increasing capabilities. Modern miniaturization technologies support realization of robust, cost-efficient small satellites with growing performance related to attitude and orbit control. Thus, networks of detectors composed of pico-satellites are possible, enabling by cooperating formations improved observation characteristics. In combination with sensor data fusion, innovative application approaches to Earth observation, but also for astronomical observations are supported.

Michal Zajaček: Passages of stars close to the Galactic center: can we detect any signal?

Over the past 20 years, several bright stars were detected to orbit the supermassive black hole in the Galactic center. Their pericenter orbital speeds are several 1000 km/s. Given the properties of the local interstellar medium, we analyze the conditions for the formation of shocks while stars reach the pericentre. In addition, the observability of these shocks is discussed across the whole electromagnetic spectrum.

Vladimír Dániel: Lessons learnd from VZLUSAT-1 CubeSat mission

Brief summary of the flight phase of VZLUSAT-1 CubeSat will be presented. The CubeSat VZLUSAT-1 was launched on June 2017 and is still operating on the orbit. The Operations, OBC, ADCS and Payload behaviour will be summarized.

Radka Bonacková: Bayerisch-Tschechische Hochschulagentur

Short presentation about the Bavarian-Czech Academic Agency

Ivo Vertat: Low Cost Camera System for Short Term Sounding Rocket Experiment

In this talk the preparation of low cost industrial camera system for short term sounding rocket experiment will be described. The main purpose of prepared camera system during only several minutes mission in space is to confirm the right pointing of roentgen optics telescope to the target nebula. The secondary goal of the camera system is its testing in space environment for potential usage in small satellites. Space qualified camera systems for satellites are very expensive in order of several tens thousands of Euro and for short term and low-cost missions of sounding rockets or CubeSat missions there are inappropriate. We prepared a relatively common industrial camera Ximea MQ013CG-E2 with ThorLabs MVL50M23 lens for this purpose. The price of this camera hardware is less than 500 Euro. The preparation of camera includes mitigation of real camera properties and enhancing of image properties. There was also prepared a special regime of camera utilization during mission, because of many unknown aspects of sounding rocket mission and unknown real camera behavior in space. This covers shooting of images with variety of exposure settings, shooting of dark reference images during all space mission and logging the temperature condition of camera sensor during image shooting.

Jan Ebr: Photometry at FRAM

I will talk about photometric measurements at obotic telescopes used for atmospheric monitoring at astroparticle observatories.

Robert Filgas: Space weather monitoring with Timepix

Space radiation monitors have lately become increasingly interesting for space agencies and satellite developers. During the lifetime of the satellite, the dynamic development of the radiation environment caused by geomagnetic storms or solar eruptions can be studied. Continuous Earth magnetosphere monitoring allows us to obtain information on the composition, flux, spectrum and direction of the arrival of energetic particles, including time and space fluctuations of these parameters. In addition to scientific research, these data provide very valuable information about the effects of dangerous cosmic rays on satellites and spacecraft crews. I will present an overview of Timepix-based radiation monitors currently in space and in future missions.

Sergey Karpov: Photometric calibration of a wide-field sky survey data from Mini-MegaTORTORA

In this talk I will briefly present the results and problems of an on-going activities to photometrically calibrate the data acquired over the last 4 years with Mini-MegaTORTORA wide-field monitoring system on various time scales. (This talk is suggested for an image processing session)

Anabella Araudo: Truncation of AGN jets by their interaction with an stellar cluster

We are interested in the effects of interaction of jets in Active Galactic Nuclei when they encounter various obstacles, namely, stars in Nuclear Star Cluster surrounding the nucleus and globular clusters passing across the inner jet, as well as dense clouds from the Broad Line Region. The interaction provides a scenario to address non–thermal processes. In jet–star interactions a double bow–shock structure is formed where particles get accelerated via diffusive mechanism. Individual encounters have a limited effect, however, dense clusters of massive stars can truncate the jet as the cluster crosses the jet line near the jet launching region. Much of the jet kinetic energy density is transferred to the shock and it becomes available to accelerate particles. We conclude that the interaction of jets with clusters of massive stars is a promising way to explain detectable levels of gamma rays from Fanaroff–Riley class I of edge–brightened radio galaxies.

Kateřina Goluchová: On one-parametric formula relating the frequencies of twin-peak quasi-periodic oscillations

Twin-peak quasi-periodic oscillations (QPOs) are observed in several low-mass X-ray binary systems containing neutron stars (NSs). Timing analysis of X-ray fluxes of more than dozen of such systems reveals remarkable correlations between the frequencies of two characteristic peaks present in the power density spectra. The individual correlations clearly differ, but they roughly follow a common individual pattern. High values of measured QPO frequencies and strong modulation of the X-ray flux both suggest that the observed correlations are connected to orbital motion in the innermost part of an accretion disc. Several attempts to model these correlations with simple geodesic orbital models or phenomenological relations have failed in the past. We find and explore a surprisingly simple analytic relation that reproduces individual correlations for a group of several sources through a single parameter. When an additional free parameter is considered within our relation, it well reproduces the data of a large group of 14 sources. The very existence and form of this simple relation supports the hypothesis of the orbital origin of QPOs and provides the key for further development of QPO models.

Masanori Ohno: Future follow-up observations of gravitational wave sources with a fleet of nano-satellite

The gravitational wave astronomy era has begun since the detection of an electromagnetic counterpart from the gravitational wave of the double neutron star merger event GW170817. This event brought a great success of the electromagnetic follow-up observations in any wavelengths. However, an association of the gamma-ray emission is not conclusive yet, which is very important to investigate a relation between the compact object merger and short duration gamma-ray bursts (short GRBs). Continuous follow-up observations in gamma-ray band will bring a smoking gun for the origin of short GRBs. Another important role for the gamma-ray observation is a localization of the gravitational wave sources because only a gamma-ray observation can realize a simultaneous detection of the electromagnetic counterpart utilizing its all-sky coverage. For efficient following observations by other wavelengths, an arc-minutes scale localization is desired. We are planning to achieve such all-sky gamma-ray observations with arc-minutes localization accuracy by the idea of a fleet of nano-satellite. A preliminary estimation of localization accuracy by nine sets of 3U cube-sat equipped ~270cm^2 CsI scintillator revealed that we can localize about 10 short GRBs per year within 20 arc-minutes radius accuracy assuming an actual GRB parameter distribution reported in the Fermi-GBM catalog. In this contribution we will demonstrate our idea and latest results of localization accuracy analyses.

Vladimir Tichy: Optimization of lobster eye geometric parameters

A method of analytical calculating of effective collecting area (length) is presented. The method is applied to few reflectivity models. The method allows searching for optimal values of all geometric parameters of lobster eye with respect to common design considerations. The method is applicable for Schmidt as well as for Angel lobster eye design.

Ronan Cunniffe: Upgrading RTS2 for high-speed adaptive observing

The RTS2 observatory control system (BART, FRAM, BOOTES, D50....) was designed around the traditional observing model: pre-scripted observations made by slow cameras. Modern cameras can achieve video framerates at low noise, with hugely increased data rates at the price of much more sophisticted image processing. We are working on re-engineering RTS2\\\'s camera architecture to support high-performance cameras, and the corresponding data pipeline. Separately, we are examining how to increase the flexibiility of the RTS2 programming model, to use this improved feedback in real time.

Jakob Stierhof: High precision calibration of interstellar oxygen absorption

I will shortly present the results of our experiments performed at BESSY to measure the transition energies of neutral oxygen. We used a portable electron beam ion trap (EBIT) to produce He-like ions of nitrogen and recorded the fluorescence of the 1s-np transitions with large area solid-state detectors. Simultaneously we recorded the photoion yield in an O2 gas cell. We achieved a precision of 30 meV in our measurements by calibrating the O2 Rydberg spectrum against the 1s-6p and 1s-7p transitions of He-like N VI.

Ladislav Pína: Multifoil Optics tests at Panter facility

Stanislav Vitek: Real-Time Image Processing In Astronomy

In this talk, I will briefly summarize the general ideas of real-time image processing in astronomy, and also introduce problems and challenges related to this topic. I will also show some examples of real-time processing pipelines.

Filip Novotný: Variable stars detection and classification in the archive of the D50 telescope

We present our approach to search for new variable stars in archival data of the D50 telescope. The pipeline uses a maximum variance method combined with a minimum path criteria to eliminate false positives. Both single-night and multi-night approaches are tested.

Martin Jelinek: Robotic Telescopes in Ondřejov

There are two robotic telescopes in Ondřejov. Their primary task is to follow up and search for optical transients. I will present the recent upgrades as well as achievements of the two telescope systems.

Rene Hudec: LDS spectroscopy with cubesats and photographic plates

I will briefly present the proposal for UV experiment based on LDS low dispersion spectroscopy of stars for cubesat mission as well as potential of LDS with digitized photographic plates taken by mostly Schmidt telescopes.

Posters

Thorsten Döhring: Applications of iridium for satellites and in other high technology areas

Due to its unique physical and chemical properties the rare noble metal iridium is enabling fascinating applications for satellites and in other high technology areas. For example: The coating laboratory at Aschaffenburg University of Applied Sciences is sputtering thin iridium reflection layers for space-based astronomical X-ray mirrors and iridium coatings as diffusion barrier for hydrogen isotopes in sophisticated scientific experiments. Background on different applications of iridium and on some experimental realizations will be presented.

Agnes Johanna Hortobagyi: Studying the variability of the X-ray spectral parameters of high-redshift host galaxies

Several results of measuring high-redshift X-rays are available for GRBs that have been detected by Swift. The standard process of fitting is usually by using general starting parameters - the variability of fittings hasn’t been examined yet throughoutly, as is the case with the robustness properties of the X-ray spectral fittings. With the available, more precise input datas we can examine the robustness of previous fittings, and test how sensitive is the result to the changes of the starting parameters.

Sergey Karpov: Testing the non-linearity of G4-16000 CCD

In a process of photometric calibration of FRAM wide-field camera sky survey we encountered a serious non-linearity of Moravian Instruments G4-16000 CCD (based on Kodak KAF-16803 chip), which is quite widely used. So we performed a set of dedicated laboratory experiments for its proper characterization, and are presenting now the results on its non-linearity and bias level stability.

Elena Fedorova: X-ray properties of RL AGN 3C111: detailed case-study

X-ray properties of radio loud Sy1 AGN 3C111: detailed case-study E. Fedorova, B.I. Hnatyk, V.I. Zhdanov 3C111 is a broad line radio galaxy with signatures of FSRQ and Seyfert type disk corona in X-ray spectrum. We use all X-ray data publicly accessible in INTEGRAL, XMM-Newton, SWIFT and Suzaku database to recover the contribution of thermal disk corona emission and nonthermal SSC quasar jet emission to the total X-ray spectrum of 3C111. We show that the both components are time-variable what results in variability of equivalent widths (EWs) of Fe lines. From obtained observational data set on EWs of Fe lines and total spectral fluxes of continuum emission at E=6.4 keV for different observational periods, we recover parameters of disk corona and jet spectra. Future investigation of polarization of 3C111 in IR-optical band, where synchrotron emission of jet dominates, will allow to constrain the parameters of SSC emission in 3C111 and to improve the disk corona model, including the parameters of a central BH.

Gabriela Urbancova: Orbital motion of test particles around a rotating neutron star

Rotating neutron stars can be characterized by three main parameters - a gravitational mass $M$, an angular momentum $J$ and a quadrupole moment $Q$. In this presentation we will demonstrate combinations of $M$, $J$, $Q$ allowed by realistic equations of state of a dense nuclear matter. We will also discuss how these parameters affect orbital motion of test particles around rotating neutron stars. Our motivation is based on X-ray observations of binary systems with a neutron star accreting matter from its companion.

Jan Štrobl: D50 & BART : tandem of robotic telescopes in Ondrejov

D50 & BART are autonomous robotic telescopes, located in Ondrejov Observatory. As expected, this poster will summarize the actual parameters, capabilities and observational program of these telescopes, which could be interesting especially for the BART telescope, as it\\\'s design and specialization has been changed radically. We would like to present also the idea of intended automated cooperation of both telescopes.

Debora Lančová: Thin accretion disc in strong gravity influenced by interaction with radiation field

We develop a numerical model of a thin accretion disc filled by not-interacting test-particles around a spinning compact object. The disc structure is influenced by the constant radiation pressure and the general relativistic Poynting-Robertson effect. The radiation is shielded by the material of the disc. This permits to determine the Poynting-Robertson radius which separates the region close to the central source fully exposed to the radiation field and the radiation-shielded region where there behaviour is modeled as a standard viscous thin disc. We follow the disc structure evolution, analysing and comparing its proprieties with the observations and already well confirmed disc models.

Martin Blazek: Tests of WHIDE deconvolution on D50 globular clusters

WHIDE method is based on Richardson-Lucy deconvolution. Here we present the tests on real images of globular clusters from D50 telescope.

Ondrej Nentvich: VZLUSAT-1: Health monitoring system, preliminary results

Health monitoring system placed on VZLUSAT-1 measures non-destructively mechanical and thermal properties of newly developed carbon fibre material for space usage. The carbon material is exposed to the vacuum, radiation and temperature changes in space. It could be used as a substitute for currently used aluminium compounds because it has lower mass density and better mechanical properties compared to aluminium. The health monitoring payload evaluates the quality changes of material according to a difference of Young modulus. Young modulus of elasticity is a characteristic property of every solid material and on VZLUSAT-1 it is measured in dependence on eigenfrequencies of a free hanged beam. In this poster are presented first data measured in orbit. Namely, the eigenfrequencies, attenuation and six temperatures from carbon fibre panel. Based on these data, mechanical properties quality and time stability are determined by VZLUSAT-1 lifetime span.

Martin Urban: Volatiles monitor on VZLUSAT-1: Preliminary results

The first current results of Volatiles monitor onboard the first Czech CubeSat launched into Earth\'s orbit. VZLUSAT-1 was launched in June 2017 as a technological satellite and is still operating in orbit. The newly developed carbon fibre reinforced plastic, which can be used as a radiation shield, is one of the tested items onboard. Water vapour creates a large part of matter outgassed from mounted composite and other components. Thus a novel monitoring device based on humidity sensors was proposed to be used on board of VZLUSAT-1 nanosatellite as one of the payloads. The preliminary results from two types of sensors (capacitive polymer sensors and the inorganic aluminium oxide sensors) are presented in this poster.

Veronika Stehlikova: Radiation resistance monitor on VZLUSAT-1: preliminary results

The technological CubeSat VZLUSAT-1 was launched in June, 2017 and carries a number of scientific and commercial experiments aboard. Several of them are focused on in-orbit investigation of a novel carbon-fibre composite developed by 5M company; examination of residual liquids evaporation, change of eigenfrequencies of the material according to the ageing of it, and shielding abilities against cosmic radiation. The quality of shielding is evaluated as a comparative measurement between three channels with different shielding. Each channel contains a calibrated biased PIN diode as a radiation sensor, which is sensitive to radiation in 2 keV to 20 keV energetic range. Preliminary results from the in orbit measurements are presented in this paper.

Kundera Tomasz: Searching for data on Cracow astroplates

We shortly described our problems with gathering our astroplates in one place. Many reasons have caused they have not been properly preserved and stored.