60 citations · 558 across the 26 of their papers we have counts for
26 papers
Discovery of synchronized periodic variability of methanol maser features in G26.598-0.024
P. Wolak, M. Szymczak, A. Kobak +5
Aims. We report the discovery of periodic maser variability of an unusual pattern in the high-mass young stellar object G26.598-0.024. Methods. A ten-year monitoring of the 6.7 GHz…
Physical conditions around high-mass young star-forming objects via simultaneous observations of excited OH and methanol masers
A. Kobak, A. Bartkiewicz, K. L. J. Rygl +3
Astrophysical masers are widely used in star formation studies. In particular, they are valuable in investigations of high-mass star-forming regions that are difficult to observe a…
Superradiance and Periodic 6.7 GHz Methanol Flaring in G22.356+0.066
T. Rashidi, V. Anari, A. Bartkiewicz +3
We present a comprehensive analysis of the periodic flares observed in the 6.7 GHz methanol transition in G22.356+0.066, utilizing the Maxwell-Bloch equations (MBEs) as a framework…
Proper motion study of the 6.7 GHz methanol maser rings. I. A sample of sources with little variation
A. Bartkiewicz, A. Sanna, M. Szymczak +5
Methanol masers at 6.7~GHz are well-known signposts of high-mass star-forming regions. [...] We aim to understand the origin of the ring-like structures outlined by methanol maser…
Seven-year periodic variations in the methanol maser line displayed by the massive protostar IRAS 20216+4104
M. Szymczak, M. Durjasz, S. Goedhart +5
Aims: We report the discovery and analysis of a periodic methanol maser in the massive protostar IRAS 20216+4104. Methods: To obtain the light curve, we used the 6.7 GHz methanol m…
Preserving your skies since 1988 -- Committee on Radio Astronomy Frequencies (CRAF) -- Periodic Review 2011-2021
Committee on Radio Astronomy Frequencies, Benjamin Winkel, Simon Garrington +43
The Committee on Radio Astronomy Frequencies (CRAF) is an Expert Committee of the European Science Foundation. It aims to provide a cost-effective single voice on frequency protect…
Connecting repeating and non-repeating fast radio bursts via their energy distributions
F. Kirsten, O. Ould-Boukattine, W. Herrmann +11
Fast radio bursts (FRBs) are extremely energetic, millisecond-duration radio flashes that reach Earth from extragalactic distances. Broadly speaking, FRBs can be classified as repe…
Multi-frequency VLBI observations of maser lines during the 6.7~GHz maser flare in the high-mass young stellar object G24.330.14}
A. Kobak, A. Bartkiewicz, M. Szymczak +13
Recent studies have shown that 6.7 GHz methanol maser flares can be a powerful tool for verifying the mechanisms of maser production and even the specific signatures of accretion r…
A burst storm from the repeating FRB 20200120E in an M81 globular cluster
K. Nimmo, J. W. T. Hessels, M. P. Snelders +20
The repeating fast radio burst (FRB) source FRB 20200120E is exceptional because of its proximity and association with a globular cluster. Here we report bursts detected with…
Molecular line search toward the flaring 6.7-GHz methanol masers of G24.33+0.13 and G359.6-0.243: rare maser transitions detected
Tiege McCarthy, Gabor Orosz, Simon Ellingsen +8
We have performed a molecular line search toward the flaring 6.7-GHz masers G24.33+0.13 and G359.62-0.24 using the Australia Telescope Compact Array. We present spectra of the 6.7-…
Observations of 12.2 GHz methanol masers towards northern high-mass protostellar objects
M. Durjasz, M. Szymczak, P. Wolak +1
Context. Class II methanol masers at 6.7 and 12.2 GHz occur close to high-mass young stellar objects (HMYSOs). When they are observed simultaneously, such studies may contribute to…
A search for the OH 6035 MHz line in high-mass star-forming regions
M. Szymczak, P. Wolak, A. Bartkiewicz +2
The excited states of OH masers detected in the environment of high-mass young stellar objects (HMYSOs) are important for improving our understanding of the physical conditions of…
Long-term multi-frequency maser observations of the intermediate-mass young stellar object G107.298+5.639
Mateusz Olech, Marian Szymczak, Paweł Wolak +2
Periodic flares of maser emission are thought to be induced either by variations of the seed photon flux in young binary systems or the pump rate regulated by stellar and accretion…
Detection statistics of the RadioAstron AGN survey
Y. Y. Kovalev, N. S. Kardashev, K. V. Sokolovsky +57
The largest Key Science Program of the RadioAstron space VLBI mission is a survey of active galactic nuclei (AGN). The main goal of the survey is to measure and study the brightnes…
6.7 GHz variability characteristics of new periodic methanol maser sources
Mateusz Olech, Marian Szymczak, Paweł Wolak +2
Discovery of periodic maser emission was an unexpected result from monitoring observations of methanol transitions in high-mass young stellar objects. We report on the detection of…
New evidence for Dicke's superradiance in the 6.7 GHz methanol spectral line in the interstellar medium
F. Rajabi, M. Houde, A. Bartkiewicz +3
We present new evidence for superradiance in the methanol 6.7 GHz spectral line for three different star-forming regions: S255IR-NIRS3, G24.329+0.144, and Cepheus A. Our analysis s…
Giant burst of methanol maser in S255IR-NIRS3
Marian Szymczak, Mateusz Olech, Paweł Wolak +2
Context: High-mass young stellar objects (HMYSOs) can undergo accretion episodes that strongly affect the star evolution, the dynamics of the disk, and its chemical evolution. Rece…
The high brightness temperature of B0529+483 revealed by RadioAstron and implications for interstellar scattering
S. V. Pilipenko, Y. Y. Kovalev, A. S. Andrianov +22
The high brightness temperatures, K, detected in several active galactic nuclei by RadioAstron space VLBI observations challenge theoretical limits. R…
Monitoring observations of 6.7 GHz methanol masers
Marian Szymczak, Mateusz Olech, Rafał Sarniak +2
We report results of 6.7 GHz methanol maser monitoring of 139 star-forming sites with the Torun 32 m radio telescope from June 2009 to February 2013. The targets were observed at l…
Single-dish and VLBI observations of Cygnus X-3 during the 2016 giant flare episode
E. Egron, A. Pellizzoni, M. Giroletti +34
In September 2016, the microquasar Cygnus X-3 underwent a giant radio flare, which was monitored for 6 days with the Medicina Radio Astronomical Station and the Sardinia Radio Tele…
Discovery of periodic and alternating flares of the methanol and water masers in G107.298+5.639
M. Szymczak, M. Olech, P. Wolak +2
Methanol and water vapour masers are signposts of early stages of high-mass star formation but it is generally thought that due to different excitation processes they probe distinc…
Discovery of four periodic methanol masers and updated light curve for a further one
M. Szymczak, P. Wolak, A. Bartkiewicz
We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The…
6.7GHz methanol maser variability in Cepheus A
M. Szymczak, P. Wolak, A. Bartkiewicz
6.7 GHz methanol maser emission from the well-studied star-forming region Cepheus A was monitored with the Torun 32 m radio telescope. We found synchronized and anticorrelated chan…
Long-term polarimetric observations of OH127.8+0.0
P. Wolak, M. Szymczak, E. Gerard
OH 1612 and 1667 MHz masers from the well known object OH127.8+0.0 were mon- itored in full-polarization mode over a period of 6.5 years and mapped with MERLIN at one epoch. The OH…