Romana Mikus̆incová
A5058158298- Astrophysical Phenomena and Observations
- Mechanics and Biomechanics Studies
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Medical Imaging Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
Roma Tre University
2022-2024
Institute for Space Astrophysics and Planetology
2024
Charles University
2018
Abstract We report on an observational campaign the bright black hole (BH) X-ray binary Swift J1727.8–1613 centered around five observations by Imaging Polarimetry Explorer. These track for first time evolution of polarization a BH across hard to soft state transition. The 2–8 keV degree decreased from ∼4% ∼3% observations, but angle remained oriented in north–south direction throughout. Based with Australia Telescope Compact Array, we find that intrinsic 7.25 GHz radio aligns polarization....
Abstract We report the first detection of X-ray polarization bright transient Swift J1727.8−1613 with Imaging Polarimetry Explorer. The observation was performed at beginning 2023 discovery outburst, when source resided in hard state. find a time- and energy-averaged degree 4.1% ± 0.2% angle 2.°2 1.°3 (errors 68% confidence level; this translates to ∼20 σ significance detection). This finding suggests that hot corona emitting bulk detected X-rays is elongated, rather than spherical....
After about 16 years since its first outburst, the transient neutron star low-mass X-ray binary XTE J1701$-$462 turned on again in September 2022, allowing for study of polarimetric characteristics by a dedicated observing program with Imaging Polarimeter Explorer (IXPE). Polarimetric studies have been expected to improve our understanding accreting weakly magnetized stars, particular, physics and geometry hot inner regions close compact object. The IXPE data two triggered observations were...
We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data the bright atoll source GX 9+9 with Imaging Polarimetry Explorer (IXPE) NuSTAR. The is significantly polarized in 4--8 keV band, degree $2.2\% \pm 0.5\%$ (uncertainty at 68% confidence level). NuSTAR broad-band spectrum clearly shows an iron line, well described by model including thermal disk emission, Comptonized component, reflection. From spectro-polarimetric fit, we obtain upper limit to...
Abstract The launch of the Imaging X-ray Polarimetry Explorer (IXPE) on 2021 December 9 has opened a new window in astronomy. We report here results first IXPE observation weakly magnetized neutron star, GS 1826−238, performed 2022 March 29–31 when source was high soft state. An upper limit (99.73% confidence level) 1.3% for linear polarization degree is obtained over 2–8 keV energy range. Coordinated INTEGRAL and NICER observations were carried out simultaneously with IXPE. spectral...
ABSTRACT We report on an X-ray polarimetric observation of the high-mass binary LMC X-1 in high/soft state, obtained by Imaging Polarimetry Explorer (IXPE) 2022 October. The measured polarization is below minimum detectable 1.1 per cent (at 99 confidence level). Simultaneously, source was observed with Neutron Star Interior Composition (NICER), Nuclear Spectroscopic Telescope Array (NuSTAR), and Spectrum-Rontgen-Gamma (SRG)/Astronomical Roentgen – Concentrator (ART-XC) instruments, which...
Abstract A large energy-dependent X-ray polarization degree is detected by the Imaging Polarimetry Explorer (IXPE) in high-soft emission state of black hole binary 4U 1630–47. The highly significant detection (at ≈50 σ confidence level) an unexpectedly high polarization, rising from ∼6% at 2 keV to ∼10% 8 keV, cannot be easily reconciled with standard models thin accretion disks. In this work, we compare predictions different theoretical IXPE data and conclude that observed properties are...
We present the results of first X-ray polarimetric observation low-mass binary 4U 1957+115, performed with Imaging Polarimetry Explorer in May 2023. The system has been a high-soft spectral state since its discovery and is thought to host black hole. ∼571 ks reveals linear polarisation degree 1.9%±0.6% angle −41.°8±7.°9 2–8 keV energy range. Spectral modelling consistent dominant contribution coming from standard accretion disc, while data suggest significant role returning radiation:...
ABSTRACT We report spectro-polarimetric results of an observational campaign the bright neutron star low-mass X-ray binary Cyg X-2 simultaneously observed by IXPE, NICER, and INTEGRAL. Consistently with previous results, broad-band spectrum is characterized a lower-energy component, attributed to accretion disc kTin ≈ 1 keV, plus unsaturated Comptonization in thermal plasma temperature kTe = 3 keV optical depth τ 4, assuming slab geometry. measure polarization degree 2–8 band P 1.8 ± 0.3 per...
Abstract The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole binary 4U 1630–47 in steep power-law (or very high) state. observations reveal a linear polarization degree of 2–8 keV X-rays 6.8% ± 0.2% at position angle 21.°3 0.°9 east north (all errors 1 σ confidence level). Whereas increases with energy, stays constant within accuracy our measurements. We compare source state previous IXPE measurement high soft find that, even though flux and spectral shape are significantly...
Abstract X-ray polarization is a powerful tool to investigate the geometry of accreting material around black holes, allowing independent measurements hole spin and orientation innermost parts accretion disk. We perform spectropolarimetric analysis an binary system in Large Magellanic Cloud, LMC X-3, that hosts stellar-mass hole, known be persistently since its discovery. report first detection X-3 with Imaging Polarimetry Explorer, find average degree (PD) 3.2% ± 0.6% constant angle −42° 6°...
ABSTRACT Measurements of the angular momentum (spin) astrophysical black holes are extremely important, as they provide information on hole formation and evolution. We present simulated observations an X-ray binary system with Imaging Polarimetry Explorer (IXPE), aim to study robustness spin geometry measurements using polarimetry. As a representative example, we used parameters GRS 1915+105 in its former unobscured, soft state. In order simulate polarization properties, modelled source...
Large energy-dependent X-ray polarization degree is detected by the Imaging Polarimetry Explorer ({IXPE}) in high-soft emission state of black hole binary 4U 1630--47. The highly significant detection (at $\approx50\sigma$ confidence level) an unexpectedly high polarization, rising from $\sim6\%$ at $2$ keV to $\sim10\%$ $8$ keV, cannot be easily reconciled with standard models thin accretion discs. In this work we compare predictions different theoretical {IXPE} data and conclude that...
We report on the coordinated observations of neutron star low-mass X-ray binary (NS-LMXB) GX 5−1 in X-rays (IXPE, NICER, NuSTAR , and INTEGRAL), optical (REM LCO), near-infrared (REM), mid-infrared (VLT VISIR), radio (ATCA). This Z-source was observed by IXPE twice March–April 2023 (Obs. 1 2). In band source detected, but only upper limits to linear polarization were obtained at a 3 σ level 6.1% 5.5 GHz 5.9% 9 Obs. 12.5% 20% 2. The mid-IR, near-IR, suggest presence compact jet that peaks...
Abstract How astrophysical systems translate the kinetic energy of bulk motion into acceleration particles to very high energies is a pressing question. SS 433 microquasar that emits TeV γ -rays indicating presence high-energy particles. A region hard X-ray emission in eastern lobe was recently identified as an site. We observed this with Imaging Polarimetry Explorer and measured polarization degree range 38%–77%. The indicates magnetic field has well-ordered component if X-rays are due...
We report on an X-ray polarimetric observation of the high-mass binary LMC X-1 in high/soft state, obtained by Imaging Polarimetry Explorer (IXPE) October 2022. The measured polarization is below minimum detectable 1.1 per cent (at 99 confidence level). Simultaneously, source was observed with NICER, NuSTAR and SRG/ART-XC instruments, which enabled spectral decomposition into a dominant thermal component Comptonized one. low 2-8 keV did not allow for strong constraints black-hole spin...
The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole binary 4U 1630-47 in steep power law (or very high) state. observations reveal a linear polarization degree of 2-8 keV X-rays 6.8 +/- 0.2 % at position angle 21{\deg}.3 0{\deg}.9 East North (all errors 1{\sigma} confidence level). Whereas increases with energy, stays constant within accuracy our measurements. We compare source power-law state previous IXPE measurement high soft find that even though flux and spectral shape...
We report on a campaign the bright black hole X-ray binary Swift J1727.8$-$1613 centered around five observations by Imaging Polarimetry Explorer (IXPE). This is first time it has been possible to trace evolution of polarization across hard soft state transition. The 2--8 keV degree slowly decreased from $\sim$4\% $\sim$3\% observations, but remained in North-South direction throughout. Using Australia Telescope Compact Array (ATCA), we measure intrinsic 7.25 GHz radio align same direction....
The Imaging X-ray Polarimetry Explorer (IXPE) has confirmed that polarimetry is a valuable tool in astronomy, providing critical insights into the emission processes and geometry of compact objects. IXPE was designed to be sensitive 2–8 keV energy range for three primary reasons: (1) celestial sources are bright within this range, (2) optics effective, (3) most across various classes were expected exhibit some level polarization. Indeed, great success, its discoveries necessitating revision...
Accreting stellar-mass black holes represent unique laboratories for studying matter and radiation under the influence of extreme gravity. They are highly variable sources going through different accretion states, showing various components in their X-ray spectra from thermal emission disc dominating soft state to up-scattered Comptonisation component an corona hard state. polarisation measurements particularly sensitive geometry scatterings can thus constrain orientation relative positions...
X-ray polarization is a powerful tool to investigate the geometry of accreting material around black holes, allowing independent measurements hole spin and orientation innermost parts accretion disk. We perform spectro-polarimetric analysis an binary system in Large Magellanic Cloud, LMC X-3, that hosts stellar-mass hole, known be persistently since its discovery. report first detection X-3 with Imaging Polarimetry Explorer, find average degree 3.2% +- 0.6% constant angle -42 deg 6 over 2-8...
We report the first detection of X-ray polarization bright transient Swift J1727.8-1613 with Imaging Polarimetry Explorer. The observation was performed at beginning 2023 discovery outburst, when source resided in hard state. find a time- and energy-averaged degree 4.1%+/-0.2% angle 2.2+/-1.3 degrees (errors 68% confidence level; this translates to about 20-sigma significance detection). This finding suggests that hot corona emitting bulk detected X-rays is elongated, rather than spherical....
We report on the coordinated observations of neutron star low-mass X-ray binary (NS-LMXB) \gx in X-rays (IXPE, NICER, Nustar and INTEGRAL), optical (REM LCO), near-infrared (REM), mid-infrared (VLT VISIR), radio (ATCA). This Z-source was observed by \IXPE twice March-April 2023 (Obs. 1 2). In band, source detected, but only upper-limits to linear polarization were obtained at a $3\sigma$ level $6.1\%$ 5.5 GHz $5.9\%$ 9 Obs.~1 $12.5\%$ 5.5~GHz $20\%$ 9~GHz Obs.~2. The mid-IR, near-IR suggest...