B. Nikiel-Wroczyński
A5088100723- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Remote Sensing and LiDAR Applications
- Scientific Research and Discoveries
- Radio Wave Propagation Studies
- Diverse Musicological Studies
- Solar and Space Plasma Dynamics
- GNSS positioning and interference
- Superconducting and THz Device Technology
- Geophysics and Gravity Measurements
- Calibration and Measurement Techniques
- Ionosphere and magnetosphere dynamics
Jagiellonian University
2014-2023
Leiden University
2019
University of Hertfordshire
2018
Nicolaus Copernicus Astronomical Center
2009
The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this release 424 square degrees, or 2% eventual coverage, in region HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45$^\circ$00$'$00$''$ 57$^\circ$00$'$00$''$) were mapped using a fully automated direction-dependent calibration imaging...
In this data release from the LOFAR Two-metre Sky Survey (LoTSS) we present 120-168MHz images covering 27% of northern sky. Our coverage is split into two regions centred at approximately 12h45m +44$^\circ$30' and 1h00m +28$^\circ$00' spanning 4178 1457 square degrees respectively. The were derived 3,451hrs (7.6PB) High Band Antenna which corrected for direction-independent instrumental properties as well direction-dependent ionospheric distortions during extensive, but fully automated,...
We associate the existence of short-lived compact radio sources with intermittent activity central engine caused by a radiation pressure instability within an accretion disk. Such objects may constitute numerous sub-class Giga-Hertz Peaked Spectrum sources, in accordance population studies radio-loud active galaxies, as well detailed investigations their morphologies. perform model computations assuming viscosity parametrization proportional to geometrical mean total and gas pressure. The...
We present the Multifrequency Snapshot Sky Survey (MSSS), first northern-sky LOFAR imaging survey. In this introductory paper, we describe in detail motivation and design of Compared to previous radio surveys, MSSS is exceptional due its intrinsic multifrequency nature providing information about spectral properties detected sources over more than two octaves (from 30 160 MHz). The broadband frequency coverage, together with fast survey speed generated by LOFAR's multibeaming capabilities,...
We present the source associations, cross-identifications, and multi-wavelength properties of faint radio population detected in deep tier LOFAR Two Metre Sky Survey (LoTSS): LoTSS Deep Fields. The first Fields data release consists imaging at 150~MHz ELAIS-N1, Lockman Hole, Bo\"{o}tes fields, down to RMS sensitives around 20, 22, 32$~\mu$Jy\,beam$^{-1}$, respectively. These fields are some best studied extra-galactic northern sky, with existing deep, wide-area panchromatic photometry from...
A Faraday rotation measure (RM) catalogue, or RM Grid, is a valuable resource for the study of cosmic magnetism. Using second data release (DR2) from LOFAR Two-metre Sky Survey (LoTSS), we have produced catalogue 2461 extragalactic high-precision values across 5720 deg$^{2}$ sky (corresponding to polarized source areal number density $\sim$0.43 deg$^{-2}$). The linear polarization and properties were derived using synthesis Stokes $Q$ $U$ channel images at an angular resolution 20''...
The Square Kilometre Array (SKA) will answer fundamental questions about the origin, evolution, properties, and influence of magnetic fields throughout Universe. Magnetic can illuminate phenomena as diverse star formation, galactic dynamics, fast radio bursts, active nuclei, large-scale structure, dark matter annihilation. Preparations for SKA are swiftly continuing worldwide, community is making tremendous observational progress in field cosmic magnetism using data from a powerful...
Context. Cosmic rays and magnetic fields are key ingredients in galaxy evolution, regulating both stellar feedback star formation. Their properties can be studied with low-frequency radio continuum observations, free from thermal contamination. Aims. We define a sample of 76 nearby (< 30 Mpc) galaxies, rich ancillary data the infrared CHANG-ES KINGFISH surveys, which will observed LOFAR Two-metre Sky Survey (LoTSS) at 144 MHz. Methods. present maps for 45 them as part LoTSS release 2...
Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of Universe. Measuring IGMF is important to determine its origin (i.e. primordial or otherwise). Using data from LOFAR Two Metre Sky Survey (LoTSS), we present Faraday rotation measure (RM) and depolarisation properties giant radio galaxy J1235+5317, at a redshift $z = 0.34$ 3.38 Mpc in size. We find mean RM difference between lobes $2.5\pm0.1$ rad/m$^2$ , addition small...
Low-frequency radio continuum observations of edge-on galaxies are ideal to study cosmic-ray electrons (CREs) in halos via synchrotron emission and measure magnetic field strengths. We obtained new the spiral galaxy NGC 891 at 129-163 MHz with LOw Frequency ARray (LOFAR) 13-18 GHz Arcminute Microkelvin Imager (AMI) combine them recent high-resolution Very Large Array (VLA) 1-2 GHz, enabling us over two orders magnitude frequency. The spectrum integrated nonthermal flux density can be fitted...
Context. Low-frequency radio continuum studies of star-forming edge-on galaxies can help to further understand how cosmic-ray electrons (CRe) propagate through the interstellar medium into halo and this is affected by energy losses magnetic fields. Aims. Observations with Very Large Array (VLA) from Continuum Haloes in Nearby Galaxies – an EVLA Survey (CHANG-ES) are combined those LOw Frequency ARray (LOFAR) LOFAR Two-metre Sky (LoTSS ) identify prevailing mode transport spiral galaxy NGC...
We present new radio continuum images of the edge-on starburst galaxy NGC 5775, from LOFAR (140 MHz) and Karl G. Jansky Very Large Array CHANG-ES survey (1500 MHz). trace non-thermal halo up to 13 kpc disc, measuring spectral index estimating total equipartition magnetic field strength ($\approx13\mu$G in disc $\approx7\mu$G above plane). The has a similar extent at both frequencies, displays evidence for localized cosmic ray streaming coinciding with prominent H$\alpha$ filaments vertical...
Context. Magnetic fields are key to understand galaxy evolution, regulating stellar feedback and star formation in galaxies. Aims. We probe the origin of magnetic late-type galaxies, measuring field strengths, exploring whether only passive constituents interstellar medium, or they active being part local energy equilibrium. Methods. measure equipartition strengths 39 galaxies from LoTSS-DR2 using LOFAR observations at 144 MHz with 6 arcsec angular resolution which (0.1-0.7 kpc). For a...
We present results of the VLA radio continuum total power and polarised intensity observations Stephan's Quintet at 1.43 4.86 GHz along with complementary 4.85 8.35 Effelsberg observations. Our study shows a large envelope emission encompassing all member galaxies hence volume intergalac- tic matter. Infall galaxy NGC 7318B produces ridge intergalactic, emission, for which magnetic field strength was estimated as 11.0 \pm 2.2 {\mu}G, an ordered component 2.6 0.8 {\mu}G. The energy density...
Low-mass galaxies are subject to strong galactic outflows, in which cosmic rays may play an important role, they can be best traced with low-frequency radio continuum observations, less affected by spectral ageing. We present a study of the nearby star burst dwarf irregular galaxy IC 10 using observations at 140 MHz LOw-Frequency ARray (LOFAR), 1580 Very Large Array (VLA) and 6200 VLA 100-m Effelsberg telescope. find that has halo, manifests itself as second component (thick disc) minor axis...
We report on the discovery in LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with projected size 2.56 ± 0.07 Mpc sky. It is associated triplet UGC 9555, within which one identified as broad-line Sloan Digital (SDSS) at redshift 0.05453 1 × 10-5, and velocity dispersion 215.86 6.34 km s-1. From archival observations we see that this hosts compact flat-spectrum source, conclude it active galactic nucleus (AGN) responsiblefor generating lobes. The luminosity...
The new generation of broad-band radio continuum surveys will provide large data sets with polarization information. New algorithms need to be developed extract reliable catalogs linearly polarized sources that can used characterize those and produce a dense rotation measure (RM) grid probe magneto-ionized structures along the line sight via Faraday rotation. aim paper is develop computationally efficient rigorously defined source-finding algorithm for sources. We calibrated set from LOw...
We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 is part LOFAR Two-metre Sky Survey fields data release I. For six eight-hour observing epochs, we align polarization angles and stack 20"-resolution Stokes $Q$, $U$-parameter cubes. This produces a 16 deg$^2$ image with 1$\sigma_{\rm QU}$ sensitivity 26 $\mu$Jy/beam in central area. In this paper, demonstrate feasibility...
Cosmic rays play a pivotal role in launching galactic winds, particularly quiescently star-forming galaxies where the hot gas alone is not sufficient to drive wind. Except for Milky Way, much known about transport of cosmic galaxies. In this Letter, we present low-frequency observations nearby edge-on spiral galaxy NGC 4565 using LOw-Frequency ARray (LOFAR). With our deep 144-MHz observations, obtain clean estimate emission originating from old cosmic-ray electrons (CRe), which almost free...
Context. Radio continuum (RC) emission in galaxies allows us to measure star formation rates (SFRs) unaffected by extinction due dust, of which the low-frequency part is uncontaminated from thermal (free–free) emission. Aims. We calibrate conversion spatially resolved 140 MHz RC SFR surface density ( Σ ) at 1 kpc scale. spectral indices give us, means ageing, a handle on transport cosmic rays using electrons as proxy for GeV nuclei. Methods. used recent observations three (NGC 3184, 4736,...
We report the discovery of a dwarf galaxy in Leo Triplet. Analysis neutral hydrogen distribution shows that it rotates independently tidal tail NGC 3628, with radial velocity gradient 35–40 km s−1 over approximately 13 kpc. The has an extremely high gas content, accounting for large amount its total dynamic mass and suggesting low dark matter. It is located at tip gaseous tail, which strongly suggests origin. If this case, would be one most confident nearest (to Milky Way) detections and,...
Aims. The magnetic fields of the member galaxies NGC 3628 and 3627 show morphological peculiarities, suggesting that interactions within group may be caused by stripping field. This process could supply intergalactic space with magnetised material, a scenario considered as possible source (as seen eg. in Taffy pairs galaxies). Additionally, plumes are likely to tidal dwarf galaxy candidates. Methods. We performed radio continuum mapping observations at 2.64 GHz using 100-m Effelsberg...