Astrophysical black hole sources usually show variable accretion flows. These sources are found at different mass scales of the black hole from the cores of active galactic nuclei to gamma ray bursts. Both the gamma-ray bursts and blazars have a relativistic jet pointing towards our line of sight. In such sources, the variability of the inflow can be transmitted to the properties of outflows. It is also possible that these two kinds of sources share similar jet physics. Observational studies have shown correlations between the observed jet variability time-scales and Lorentz factor of the emitted jet. Motivated by these observational properties, we investigate the time variability and the jet structure in such sources with general relativistic magnetohydrodynamic (GRMHD) simulations. We model the central engine of these sources with analytic equilibrium solutions of an accretion disk embedded in a poloidal magnetic field which initiates the accretion of matter onto the black hole. We initially perform axisymmetric simulations of a family of models and investigate the correlations between the jet Lorentz factor and variability timescales. We then particularly focus on the GRB central engines and investigate the dependence of their jet structure and time variability on the formation of a magnetically arrested disk (MAD) state with 3D GRMHD simulations.

Galaxies live in dark matter haloes and hence the galaxy properties are majorly defined by the properties of the haloes. Thus the environmental dependence of dark matter halo properties prompts a correlation between galaxy properties and the environment. In this talk, I will discuss the results from our recent works (arXiv:2102.04177 and arXiv:2201.10480) that explored how luminosities in optical to mid-infrared bands, stellar mass, and star formation rate are correlated with the environment. We use a set of stellar mass-selected and 3.4 μm luminosity-selected galaxies from the Galaxy and Mass Assembly (GAMA) survey. We utilize the galaxy two-point correlation functions and marked correlation functions to investigate the environmental correlations. I will also discuss the impact of various selection effects on the galaxy clustering measurements. Additionally, I will present the results obtained from repeating the measurements in galaxy mocks from simulations.

We study the final stages of the evolution of a binary system consisted of a black hole and a white dwarf star. As a model of a white dwarf star we consider a Bose-Fermi droplet at zero temperature of attractively interacting degenerate atomic bosons and fermions. We implement the full quantum hydrodynamic equations and carry out numerical simulations to follow the evolution of the binary system. Due to nonlinear effects, the accretion disk originated from the white dwarf becomes fragmented. Additionally, quantized vortices present in the bosonic component of the accretion disk are observed.  We also investigate electromagnetic and gravitational radiation generated during the process of TDE. Bursts of ultraluminous radiation are flared at each periastron passage by the white dwarf. When the binary system ends its life, the gravitational radiation, whose power stays lower than the power of electromagnetic radiation, starts to dominate.

We present the catalogue of RadiO sources with Galactic counterparts and Unresolved or Extended morphologies (ROGUE), which is the largest handmade catalogue of visually classified radio objects and optical galaxies. It was created by cross-matching galaxies from the Sloan Digital Sky Survey Data Release 7 as well as radio sources from the First Images of Radio Sky at Twenty Centimetre and the National Radio Astronomical Observatory VLA Sky Survey catalogues. The catalogue is completed, containing 40,310 galaxies with detailed radio and optical morphological classifications. The presented sample can serve as a database for training automatic methods of identification and classification of optical galaxies and radio sources.

Our results for GR description of dark matter (both cold and hot) accretion onto a moving Schwarzschild black hole, and preliminary also for Kerr, will be presented. The dark matter is modeled by the collisionless Vlasov gas, assumed to be in thermal equilibrium at infinity. We derive an exact stationary solutions and provide a compact formulas for the mass, energy and angular momenta accretion rates, with useful analytical limits. Interesting consequences of derived formulas for black holes are (1) runaway accretion, especially efficient in the early universe, causing an unlimited growth of (primordial) black holes; (2) exponential damping of the Kerr parameter for equatorial (2+1) accretion.

We cordially invite you to the exhibition presenting the works of students of the Academy of Fine Arts in Kraków. A short introduction will be given (in Polish) by prof. Katarzyna Stryszowska-Winiarz. The event will take place in Fort.

LOFAR (Low Frequency Array) is currently the largest radio telescope operating at the lowest frequencies that can be observed from Earth. The facility currently consists of 52 stations spread throughout Europe. Thirty-eight of these stations are located in the Netherlands with baselines of up to 120 km and fourteen international stations, which form a Very Long Base-line Interferometrer (LOFAR-VLBI). Calibrating the Dutch stations to achieve 6 arcsec resolution maps in a 20 deg2 field of view at 150 MHz is now relatively routine due to the development of direction-dependent calibration methods at low frequencies. The Dutch stations are used to conduct the LOFAR Two-metre Sky Survey (LoTSS) survey, which will eventually cover whole northern sky at the frequency range of 120-168 MHz. Recently, a calibration strategy has been developed which allows us to produce images at sub-arcsecond resolution using the LOFAR-VLBI. International stations provide baselines of up to 1989 km (from Birr to Lazy), which yield an angular resolution of 0.27 arcsec at 150 MHz. We will demonstrate the processing methods and the first sub-arcsecond resolution images produced with the pipeline installed at Olsztyn.

I will talk about my experience living closed away from society for 15 days simulating a real mission to the moon in a prefabricated dome habitat doing different types of experiments regarding hydroponics, 3D printed tools, EVA suits and studying the physical and psychological effects on long-term space missions.

The classification of radio sources proposed by Fanaroff and Riley is familiar to every radio astronomer. But although it is based on physical differences between sources, it does not give a complete picture of the morphological diversity of observed radio structures. In my presentation, I will summarize how the classification was carried out in the early days of the radio observations and how it is carried out today. I will try to answer the question of whether classical morphological classification schemes are still valid and what is proposed instead.

Active galactic nuclei (AGNs) are very powerful galaxies characterized by extremely bright emissions coming from their central massive black holes. Knowing the redshifts of AGNs provides us with an opportunity to determine their distance to investigate important astrophysical problems, such as the evolution of the early stars and their formation, along with the structure of early galaxies. However, redshift determination is challenging because it requires detailed follow-up of multiwavelength observations, often involving various astronomical facilities. In this presentation I will discuss about the methodology developed by our team, where we apply a powerful machine learning technique called SuperLearner to estimate the redshift of gamma-ray loud AGNs from the Fermi 4 th LAT catalog (4LAC). Using the 4LAC’s observed properties we train the machine learning model on 1112 AGNs, obtaining a correlation of 75% between the predicted and observed redshift. We also explore the application of an imputation method called Multivariate Imputation by Chained Equations (MICE), using which we impute missing data for 24% of the catalog and proceed to investigate its effects on the redshift estimation. Further, we also explore the application of bias corrections and feature engineering for improving our results. Finally, we provide predicted redshift for 300 BL Lacertae Quasars of the 4LAC using our methodology.

The main goal of the IOAA is to promote the growing interest in Astronomy and related STEM subjects, especially through the general education of young people, and enhancing the development of international contacts among different countries in promoting Astronomy and Astrophysics in schools. It is expected that, through events like the IOAA, more bright high-school students will be eager to study astronomy at the university level to become the next generation of astronomy and astrophysics professionals. In 2023 - year of 550 anniversary of the birgh of Copernicus IOAA wil organize i CHorzow. The Polish edition of the Olympiad will require the cooperation of scientific, student and amateur communities. The talk will present the role of the Olympics as well as challenges for judges, authors of tasks and volunteers. So: join IOAA 2023, join the celebration of Copernicus.

NGC 3627 is a popular target for astrophotography amateurs, better known as M66. It belongs to, and interacts with other members of the group called Leo Triplet. Galactic interaction usually leads to unusual magnetic properties. Recent paper by Liu et al. (2023, MNRAS, 519, 1068) prompted me to make some recollection of NGC 3627. I'll present efforts to understand magnetic properties of its ISM.

There is ongoing discussion in the literature on a possible evolution of the covering factor (CF) with redshift in quasars. In our work we aim to verify this evolution and identify selection effects and sources of contamination. We adopt multiwavelength photometry from UV to IR in the two redshift bins containing over 1,800 quasars. As a CF proxy of the sample we use the ratio of torus infrared luminosity (L[ir]) and accretion disk optical luminosity (L[agn]). One important source of systematics is the WISE W4 point, which overestimates IR luminosity. We confirmed apparent luminosity evolution with redshift for L[ir], L[agn] with the statistical test. It is caused by intrinsic sample differences across redshift. The low-z and high-z samples follow, a similar correlation between L[agn]–L[ir]. Although degree of possible contaminations scales with the luminosities or black hole (BH) mass. Thus if we correct for low-z and high-z samples differences by i.e. BH mass cut, then no evolution of the CF was detected.

The main idea of our research is to estimate the physical coalescence time of the double supermassive black hole (SMBH) system in the centre of NGC 6240 based on the X-ray observations from the Chandra space observatory. The spectra of the northern and southern nuclei were fitted by spectral models from Sherpa and both presented the narrow component of the Fe Kα emission line. It enabled us to apply the spectral model to these lines and to find relative offset ≈0.02 keV. The enclosed dynamical mass of the central region of NGC 6240 with radius 1 kpc was estimated ≈2.04×1011M⊙. These data allowed us to carry on the high-resolution direct N-body simulations with Newtonian and post-Newtonian (up to 2.5PN correction) dynamics for this particular double SMBH system. As a result, from our numerical models, we approximated the central SMBH binary merging time for the different binary eccentricities. In our numerical parameters range, the upper limit for the merging time, even for the very small eccentricities, is still below ≈70 Myr. Gravitational waveforms and amplitude-frequency pictures from such events can be detected using pulsar timing array projects at the last merging phase. 

I will present new radio observations of an angularly large, grand-design spiral galaxy NGC 6946 obtained with the LOFAR interferometer at a central frequency of 0.138 GHz. Observations of galaxies at low radio frequencies with high resolution make it possible to study the transport of low-energy CREs at scales smaller than 1 kpc. I aim to investigate the transport of low-energy CREs in the face-on spiral galaxy NGC 6946 in comparison with the transport of CREs at higher radio frequencies. I exploit Herschel 100μm and radio data at higher frequencies to show transition of radio – FIR correlation between arm and inter-arms regions at five radio frequencies. The linear relation in arm regions at high radio frequencies becomes nonlinear at 0.138 GHZ (0.88±0.05), whereas in the inter-arm area the values of the relation flatten from 0.6 for frequencies higher to 0.49±0.06 at 0.138 GHz. In order to explain our results we constructed the model of CREs transport via diffusion and streaming. Our final results show that streaming is the more probable transport in NGC6946 than diffusion which is unexpected. I will also show brief summary of other LOFAR results about nearby galaxies and my future plans.

In the past two years we've been searching TESS photometric data for new pulsating hot subdwarfs, both O- and B-type (sdO na sdB respectively). The search was done by cross-matching known catalogues of sdB stars with the TESS input catalogue. This led to the list of 1389 hot subdwarfs candidates. Majority of them were already present on the TESS Asteroseismic Science Consortium Working Group 8 (the collaboration of the scientific community that focuses on utilizing TESS data for asteroseismology) list of compact pulsators but 63 were new. In the result of our search, 10 known p-mode pulsators had to be re-classified as p+g-mode hybrid pulsators. Our data analysis of pulsating sdBV candidates also led to the extension of the hybrid pulsators occurence in the instability strip from just a narrow part of the strip into the whole sdBV instability strip. Since variable hot subdwarfs were identified based on periodograms calculated from TESS light curves, "a side effect" of our search was finding a sample of ~400 eclipsing binary candidates out of which 46 were new.

There is ongoing discussion in the literature on a possible evolution of the covering factor (CF) with redshift in quasars. In our work we aim to verify this evolution and identify selection effects and sources of contamination. We adopt multiwavelength photometry from UV to IR in the two redshift bins containing over 1,800 quasars. As a CF proxy of the sample we use the ratio of torus infrared luminosity (L[ir]) and accretion disk optical luminosity (L[agn]). One important source of systematics is the WISE W4 point, which overestimates IR luminosity. We confirmed apparent luminosity evolution with redshift for L[ir], L[agn] with the statistical test. It is caused by intrinsic sample differences across redshift. The low-z and high-z samples follow, a similar correlation between L[agn]–L[ir]. Although degree of possible contaminations scales with the luminosities or black hole (BH) mass. Thus if we correct for low-z and high-z samples differences by i.e. BH mass cut, then no evolution of the CF was detected.

In this presentation, we delve into the realm of satellite image analysis, focusing on the assessment of water body surfaces using IBM technologies. We illustrate the capabilities of our web application developed during IBM Krakow Software Lab internships. Drawing on real-world applications and research, we demonstrate how the integration of IBM technologies, such as Watson AI and IBM Cloud, can effectively streamline the process of data acquisition, processing, and analysis, providing robust, accurate, and scalable solutions. This presentation aims to shed light on the practical application of these advanced technologies, emphasizing their potential to drive scientific inquiry, enhance resource management, and facilitate environmental monitoring.

The imaging atmospheric Cherenkov telescopes (IACTs) exploit Cherenkov radiation emitted in the optical - UV range to perform indirect, ground-based observations of very-high-energy radiation. The technique relies on the detection of short Cherenkov light flashes caused by the air showers generated during collisions of ultrarelativistic particles (gamma-ray photons or hadrons) with particle nuclei in the upper layer of the Earth's atmosphere. The ground-based detectors register an image of the shower event, leading to a precise identification of the primary particle, i.e. to measure its initial energy, establish the direction of emission, and determine the nature of the source of radiation.
The Large-Sized Telescopes (LSTs) constitute a sub-array of four 23 meter diameter IACTs, a part of the future North site of the Cherenkov Telescope Array (CTA) Observatory, located at the Roque de los Muchachos Observatory on La Palma - one of the Spanish Canary Islands. The only currently operating and gathering the data telescope is LST-1, being in the advent of its commissioning phase. The entire LST subarray is planned to be built by mid-2024. These telescopes are designed to reach the full sub-system sensitivity in the low-energy range from 20 to 150 GeV and extremely fast pointing to any observable position in the sky.
Despite the current testing phase of LST-1, this telescope is used for scientific observations of many astrophysical sources, including the Galactic center, Galactic transients, active galactic nuclei, gamma-ray bursts. Nowadays, joint observations of LST-1 with two 17 meter diameter Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes are underway. This approach allows for the development of a suitable and refined method of stereo observations and data analysis, which can then be implemented in the CTA.

Despite its low contribution to the total mass of the interstellar medium, dust plays a crucial role in the evolution of galaxies, and it has the biggest impact on the shape of their total spectral energy distribution. Dust attenuates the stellar light by absorbing the short wavelength photons incoming from the newly-formed stars, and emits them thermally in the infrared. To account for dust attenuation in models, one should assume a dust attenuation law which describes how stellar emission is absorbed by dust. Despite the growing knowledge in the field of extragalactic astronomy, key questions remain unanswered: What dust attenuation law one should use at high redshift? What are the physical conditions on which dust attenuation curves depend? In this talk, I will present the key physical processes that affect the curve of dust attenuation, in a large study of dusty star-forming galaxies from the early Universe until the present times.