Własności optyczne galaktyk macierzystych gigantycznych radioźródeł

Giant radio sources are the largest single objects in the Universe. The projected linear size of their radio structures, larger than 0.7 Mpc, makes them valuable objects to study many astrophysical problems. It is still unclear why only a small fraction of radio sources reaches such a large size. It is considered that it may be due to special external conditions, such as lower intergalactic medium density. Other investigators pointed out the internal properties of the "central engine" or an advanced age of the radio structure and/or recurrent radio activity as a possible cause. In my Thesis I investigate the hypothesis that the giant radio sources can have very large radio structures due to specific properties of their central active nuclei. Because of lack of a representative sample of such objects, as many radio sources were not recognised to be giants, this hypothesis was not investigated in detail. By comparing the radio and optical surveys, a lot of gigantic-size radio sources have been recently discovered. I selected a sample of giant radio sources and compared the fundamental physical parameters of their active nuclei (such as black hole masses and accretion rates) with parameters of observed radio structures. As a result, I found out that when taking into account the optical and radio properties, giant radio sources have properties similar to those of smaller size and that giants do not have more powerful central engines than other radio sources. The results obtained in this work are consistent with evolutionary models of extragalactic radio sources, that predict that giants could be the more evolved (aged) sources compared with smaller ones. In addition, I discovered that the environment may play only a minor role in the formation of large-scale radio structures. In my thesis I showed out that giants have relatively large number of old star with solar-like metalicity. The stellar population composition of giant radio galaxies could be the only property that distinguishes them from other radio sources. This fact may suggest that different histories of the host galaxy formation may be the main reason why some of radio sources evolved to giant size

Giant radio quasars: sample and basic properties

We present the largest sample of giant radio quasars (GRQs), which are defined as having a projected linear size greater than 0.7 Mpc. The sample consists of 272 GRQs, of which 174 are new objects discovered through cross-matching the NRAO VLA Sky Survey (NVSS) and the Sloan Digital Sky Survey 14$^{\rm th}$ Data Release Quasar Catalogue (DR14Q) and confirmed using Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio maps. In our analysis we compare the GRQs with 367 smaller, lobe-dominated radio quasars found using our search method, as well as with quasars from the SDSS DR14 Quasar Catalogue, investigating the parameters characterizing their radio emission (i.e. total and core radio luminosity, radio core prominence), optical properties (black hole masses, accretion rates, distribution in Eigenvector 1 plane) and infrared colours. For the GRQs and smaller radio quasars we find a strong correlation between [OIII] luminosity and radio luminosity at 1.4 GHz, indicating a strong connection between radio emission and conditions in the narrow-line region. We spot no significant differences between GRQs and smaller radio quasars, however we show that most extended radio quasars belong to a quasar population of evolved AGNs with large black hole masses and low accretion rates. We also show that GRQs have bluer W2-W3 colours compared to SDSS quasars with FIRST detections, indicating differences in the structure of the dusty torus.Comment: 30 pages, 14 figures, accepted for publication in ApJS

Central black holes in giant radio quasars

We analysed optical properties of giant radio quasars (with radio structures larger than 0.7 Mpc). To this day it is unclear why only a small fraction of radio sources attain such large sizes. There are a number of hypotheses attempting to explain this phenomenon, however the one treated in this paper has not yet been investigated in detail. This hypothesis assumes that the giant linear sizes of radio structures are due to internal properties of their central active galactic nuclei i.e. the specific properties of super-massive black holes and/or their accretion discs. We investigated whether a direct relation exists between the properties of the central "engine" and the origin of the Mpc scale radio structures. In our analysis, we did not find any relation between black hole mass and radio core power, however, we found a weak correlation between the accretion rate and radio core power. We also found a relation between a black hole's mass and linear size of the radio structure. The obtained results may suggest that giant radio quasars are similar to those of smaller size. There are also indications that giant radio quasars may be more evolved sources as compared with smaller radio quasars

Stellar populations in hosts of giant radio galaxies and their neighbouring galaxies

Context: Giant radio galaxies (with projected linear size of radio structure larger than 0.7 Mpc) are very rare and unusual objects. Only $\sim$5% of extended radio sources reach such sizes. Understanding of the processes responsible for their large sizes is crucial to further our knowledge about the radio source's evolution. Aims: We check the hypothesis that giants become extremely large due to the specific history of their host galaxy formation, as well as in the context of the cluster or group of galaxies where they evolve. Therefore we study the star formation histories in their host galaxies and in galaxies located in their neighbourhood. Methods: We studied 41 giant-size radio galaxies as well as galaxies located within a radius of 5 Mpc around giants to verify whether the external conditions of the intergalactic medium somehow influence the internal evolution of galaxies in the group/cluster. We compared the results with a control sample of smaller-sized Fanaroff--Riley type II radio galaxies and their neighbouring galaxies. We fit stellar continua in all galaxy spectra using the spectral synthesis code STARLIGHT and provide statistical analysis of the results. Results: We find that hosts of giant radio galaxies have a larger amount of intermediate age stellar populations compared with smaller-sized FRII radio sources. The same result is also visible when we compare neighbouring galaxies located up to 1.5 Mpc around giants and FRIIs. This may be evidence that star formation in groups with giants was triggered due to global processes occurring in the ambient intergalactic medium. These processes may also contribute to mechanisms responsible for the extremely large sizes of giants.Comment: 20 pages, 9 figures, to be publish in A&

Coaching in the professional and personal development of nurses

Wprowadzenie . Deficyt pielęgniarek obserwowany w UE (Unii Europejskiej) może mieć różne przyczyny m. in.: mało atrakcyjne warunki pracy, niepodejmowanie pracy w tej profesji (pomimo posiadanego wykształcenia) oraz wysoki wskaźnik wypalenia zawodowego. Wyzwaniem dla pracodawców oraz instytucji zajmujących się problemami współczesnego pielęgniarstwa pozostaje problem zachęcenia adeptów kierunku do podjęcia pracy w zawodzie i pozostania w nim na dłużej. Także duże znaczenie ma nauczenie pielęgniarek jak chronić się przed wypaleniem zawodowym, łączyć ambicje zawodowe z potrzebami rodziny a przede wszystkim osobistą satysfakcją z życia. Pośród potencjalnych rozwiązań wspomagających świadome zaplanowanie życia osobistego i dalszego rozwoju zawodowego, warto rozważyć wsparcie coacha, podobnie jak to ma miejsce w innych zawodach. Cel. Analiza sytuacji zawodowej pielęgniarek w kontekście potrzeby indywidualnego rozwoju z zastosowaniem metody coachingu. Metodyka. Zastosowano metodę analizy i krytyki piśmiennictwa naukowego. Podsumowanie i wnioski. Wykorzystanie elementów coachingu stwarza szansę, by pielęgniarka/pielęgniarz w sposób świadomy i planowy projektowali przebieg swojego rozwoju zawodowego synchronicznie z potrzebami i oczekiwaniami w życiu osobistym, rodzinnym i społecznym. Dodatkowymi korzyściami z zastosowania tej formy wsparcia są umiejętność lepszego radzenia sobie ze stresem, zachowanie równowagi pomiędzy pracą a życiem osobistym (tzw. work-life balance) oraz prewencja wypalenia zawodowego.Introduction . Shortage of nurses reported in the EU (European Union) among other causes is related to: non-attractive work conditions, lack of willingness to take up job as a nurse (despite their education), and high risk of professional burnout. Encouraging graduates to take up a job in the profession and remain is a challenge for employers and institutions involved in the problems of modern nursing. Teaching nurses how to: protect themselves from professional burnout, how to combine career ambitions, family needs and above all personal satisfaction is of utmost importance. Amongst possible solutions which enhance planning of career and personal development in a deliberate manner, as is the case in other professions, it may be worth considering the support of a coach. Aim. Analysis of the professional situation of nurses in the context of need for individual development using the coaching method. Method. A method of analysis and criticism of the literature was used. Conclusions and results. Coaching gives an op po rtun ity for conscious planning process of nurse professional development in synchrony with needs and expectations for personal, family and social life. Better stress management, maintaining work-life balance and professional burnout prevention are benefits provided by this approach

Period changes of the sample of eclipsing binaries with active chromospheres

In this work we present results derived from analysis of the O-C behaviour of ten eclipsing binary systems: AR Lac, CG Cyg, HP Aur, MM Her, RS CVn, RT And, SV Cam, V471 Tau, WW Dra and CF Tuc. It was proved on the basis of moments of minima compiled from the literature and new ones determined from recent observations, that these binaries show long term (19-91 years) modulations of their orbital periods, clearly visible in their O-C diagrams. Two possible explanations for this effect are considered: (1) the light-travel time effect due to the presence of a third body orbiting the eclipsing systems; (2) the Applegate mechanism predicting period modulation by changes in the distribution of angular momentum as a star goes through its activity cycles. It was found that in the case of four systems the existence of a third star, orbiting the binary, is a more plausible explanation of observations