arXiv subjects

Anna Wojtowicz

Publications and source records attributed to Anna Wojtowicz.

5 recordsLinked to original sources

arXiv2026

Size measurements and characterization of the astrophysical properties of multiple-component radio-AGNs in the ROGUE I catalog

We present hand-curated size measurements for a sample of 2,002 multiple-component radio AGNs in the Radio sources associated with Optical Galaxies and having Unresolved or Extended morphologies I (ROGUE I) catalog. The sources span total angular sizes of $\sim 5^{\prime\prime}$-1,100$^{\prime\prime}$ which translates to projected linear sizes $\sim$10 kpc- $\sim$2 Mpc across 0.01$\leq$z$\leq$0.54. About 10% of the sample are compact ($\leq$60 kpc) while $\sim$3% are giant radio sources ($\geq$700 kpc). Roughly 34\% are associated with galaxy clusters, and 16\% exhibit an arm-length asymmetry ratio $\geq$2. The cluster association fractions are comparable across Fanaroff-Riley (FR) I, II, and hybrid type morphological classes. Arm-length asymmetries occur at similar rates in FR I and hybrid classes but are about a factor of 2-4 less common in FR II, supporting the view that their jets are more stable and collimated, and thus less prone to disruption in dense cluster environments. In contrast, bent-angle sources (wide- and narrow-angle tails) show arm-length asymmetries about a factor of four less frequently than cluster-associated sources, suggesting that asymmetries are smoothed out by the local intracluster medium conditions. The mean galaxy number densities of FR I, II, hybrid, wide-angle, narrow-angle, and head-tail sources are comparable, supporting the dominant role of local intra-cluster medium conditions in shaping bent morphologies. Radio power-linear size tracks for FR IIs show that the population is dominated by AGNs with jet kinetic powers $\leq$10$^{38}$ erg/s, comprising both young (10 Myr) and old (100 Myr) AGNs. We also compare z, angular and linear sizes, core and total radio luminosities, optical magnitudes, black hole, and stellar masses across the morphological classes.

astro-ph.GA↗

arXiv2024

Optically active and optically inactive radio galaxies as sub-populations of the main galaxy sample of the SDSS

We use the ROGUE I and II catalogues of radio sources associated with optical galaxies to revisit the characterization of radio active galactic nuclei (AGNs) in terms of radio luminosities and properties derived from the analyses of the optical spectra of their associated galaxies. We propose a physically based classification of radio galaxies into `optically inactive' and `optically active' (OPARGs and OPIRGs). In our sample, there are 14082 OPIRGs and 2721 OPARGs.After correcting for the Malmquist bias, we compared the global properties of our two classes of radio galaxies and put them in the context of the global population of galaxies. To compare the Eddington ratios of OPARGs with those of Seyferts, we devised a method to obtain the bolometric luminosities of these objects, taking into account the contribution of young stars to the observed line emission. We provide formulae to derive bolometric luminosities from the [Oiii] luminosity. We find that the distributions of radio luminosities of OPARGs and OPIRGs are undistinguishable. On average, the black hole masses and stellar masses in OPIRGs are larger than in OPARGs. OPARGs show signs of some recent star formation. Plotting the OPARGs in the BPT diagram and comparing their distribution with that of the remaining galaxies, we find that there is a sub-family of very high excitation OPARGs at the top of the AGN wing. This group is slightly displaced towards the left of the rest of the AGN galaxies, suggesting a stronger ionizing radiation field with respect to the gas pressure. Only very-high excitation radio galaxies (VHERGs) have Eddington ratios higher than 0.01, which are canonically considered as the lower limit for the occurrence of radiative efficient accretion. If our estimates of the bolometric luminosities are correct, this means than only a small proportion of mainstream HERGs are indeed radiatively efficient.

astro-ph.GA↗

arXiv2021

A Novel Method for Estimating the Ambient Medium Density Around Distant Radio Sources from Their Observed Radio Spectra

The dynamical evolution and radiative properties of luminous radio galaxies and quasars of the FRII type, are well understood. As a result, through the use of detailed modeling of the observed radio emission of such sources, one can estimate various physical parameters of the systems, including the density of the ambient medium into which the radio structure evolves. This, however, requires rather comprehensive observational information, i.e. sampling the broad-band radio continua of the targets at several frequencies, and imaging their radio structures with high resolution. Such observations are, on the other hand, not always available, especially for high-redshift objects. Here we analyze the best-fit values of the source physical parameters, derived from an extensive modeling of the largest currently available sample of FRII radio sources, for which good-quality multi-wavelength radio flux measurements could be collected. In the analyzed dataset, we notice a significant and non-obvious correlation between the spectral index of the non-thermal radio emission continuum, and density of the ambient medium. We derive the corresponding correlation parameters, and quantify the intrinsic scatter by means of Bayesian analysis. We propose that the discovered correlation could be used as a cosmological tool to estimate the density of ambient medium for large samples of distant radio galaxies. Our method does not require any detailed modeling of individual sources, and relies on limited observational information, namely the slope of the radio continuum between the rest-frame frequencies 0.4GHz and 5GHz, possibly combined with the total linear size of the radio structure.

astro-ph.GA↗

arXiv2017

The Eclipse Integrated Computational Environment

Problems in modeling and simulation require significantly different workflow management technologies than standard grid-based workflow management systems. Computational scientists typically interact with simulation software in a feedback driven way were solutions and workflows are developed iteratively and simultaneously. This work describes common activities in workflows and how combinations of these activities form unique workflows. It presents the Eclipse Integrated Computational Environment as a workflow management system and development environment for the modeling and simulation community. Examples of the Environment's applicability to problems in energy science, general multiphysics simulations, quantum computing and other areas are presented as well as its impact on the community.

cs.SE↗

arXiv2014

A domain-specific analysis system for examining nuclear reactor simulation data for light-water and sodium-cooled fast reactors

Building a new generation of fission reactors in the United States presents many technical and regulatory challenges. One important challenge is the need to share and present results from new high-fidelity, high-performance simulations in an easily usable way. Since modern multiscale, multi-physics simulations can generate petabytes of data, they will require the development of new techniques and methods to reduce the data to familiar quantities of interest (e.g., pin powers, temperatures) with a more reasonable resolution and size. Furthermore, some of the results from these simulations may be new quantities for which visualization and analysis techniques are not immediately available in the community and need to be developed. This paper describes a new system for managing high-performance simulation results in a domain-specific way that naturally exposes quantities of interest for light water and sodium-cooled fast reactors. It describes requirements to build such a system and the technical challenges faced in its development at all levels (simulation, user interface, etc.). An example comparing results from two different simulation suites for a single assembly in a light-water reactor is presented, along with a detailed discussion of the system's requirements and design.

cs.CE↗