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Przeglądanie wg autora "Szymczak, Marian"

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Przeglądanie wg autora "Szymczak, Marian"

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  • 6.7 GHz variability characteristics of new periodic methanol maser sources 
    Olech, Mateusz; Szymczak, Marian; Wolak, Paweł; Sarniak, Rafał; Bartkiewicz, Anna (Monthly Notices of the Royal Astronomical Society, 2019-04-01)
    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 five new periodic sources from a monitoring ...
  • A Giant Water Maser Flare in the Galactic Source IRAS 18316-0602 
    Volvach, L. N.; Volvach, A. E.; Larinov, M. G.; MacLeod, G. C.; van den Heever, S. P.; Wolak, P; Olech, Mateusz; Ipanov, A. V.; Ivanov, D. V.; Mikhailov, A.G.; Melnikov, A.E.; Menten, K.; Belloche, A.; Weiss, A.; Mazumdar, P.; Schuller, F. (Astronomy Reports, 2019-01-01)
    The results of long-term monitoring of the Galactic maser source IRAS 18316-0602 (G25.65+1.05) in the water-vapor line at frequency f = 22.235 GHz (6_16-5_23 transitioin) carried out on the 22-m Simeiz, 26-m HartRAO, and ...
  • A highly variable methanol maser in G111.256-0.770 
    Durjasz, Michał Tomasz; Szymczak, Marian; Olech, Mateusz (Royal Astronomical Society, 2019)
    G111.256-0.770 is a high-mass young stellar object associated with a weak 6.7 GHz methanol maser showing strong variability. We present results of a multi-epoch monitoring program of the target, conducted with the Torun ...
  • A search for the OH 6035 MHz line in high-mass star-forming regions 
    Szymczak, Marian; Wolak, Paweł; Bartkiewicz, Anna; Aramowicz, Mirosława; Durjasz, Michał (EDP Sciences, 2020)
    Context. 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 these objects and also provide ...
  • European VLBI Network imaging of 6.7 GHz methanol masers 
    Bartkiewicz, Anna; Szymczak, Marian; van Langevelde, Huib Jan (EDP Sciences, 2016)
    Context. Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. Aims. We aimed to determine the morphology and velocity structure for a ...
  • European VLBI Network observations of 6.7 GHz methanol masers in clusters of massive young stellar objects 
    Bartkiewicz, Anna; Szymczak, Marian; van Langevelde, Huib Jan (EDP Sciences, 2014)
    Context. Methanol masers at 6.7 GHz are associated with high-mass star-forming regions (HMSFRs) and often have mid-infrared (MIR) counterparts characterized by extended emission at 4.5 μm, which likely traces outflows from ...
  • Giant burst of methanol maser in S255IR-NIRS3 
    Szymczak, Marian; Olech, Mateusz; Wolak, Paweł; Gerard, Eric; Bartkiewicz, Anna (EDP Sciences, 2018)
    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. Recently reported ...
  • Long-term multi-frequency maser observations of the intermediate-mass young stellar object G107.298+5.639 
    Olech, Mateusz; Szymczak, Marian; Wolak, Paweł; Gérard, Eric; Bartkiewicz, Anna (Astronomy & Astrophysics, 2020-02-01)
    Context: 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 luminosities. Aims: We seek to ...
  • Milliarcsecond structure of water maser emission in two young high-mass stellar objects associated with methanol masers 
    Bartkiewicz, Anna; Szymczak, Marian; van Langevelde, Huib Jan (EDP Sciences, 2012)
    Context. The 22.2 GHz water masers are often associated with the 6.7 GHz methanol masers but owing to the different excitation conditions they likely probe independent spatial and kinematic regions around the powering young ...
  • Monitoring observations of 6.7 GHz methanol masers 
    Szymczak, Marian; Olech, Mateusz; Sarniak, Rafał; Wolak, Paweł; Bartkiewicz, Anna (Oxford University Press, 2018-02)
    We report results of 6.7 GHz methanol maser monitoring of 139 star-forming sites with theTorun 32 m radio telescope from June 2009 to February 2013. The targets were observedat least once a month, with higher ...
  • New evidence for Dicke's superradiance in the 6.7 GHz methanol spectral line in the interstellar medium 
    Rajabi, F.; Houde, M.; Bartkiewicz, Anna; Olech, Mateusz; Szymczak, Marian; Wolak, Paweł (Royal Astronomical Society, 2019-01)
    We present new evidence for superradiance (SR) 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 shows that some of the flux–density ...
  • The nature of the methanol maser ring G23.657–00.127 II. Expansion of the maser structure 
    Bartkiewicz, Anna; Sanna, Alberto; Szymczak, Marian; Moscadelli, Luca; van Langevelde, Huib Jan; Wolak, Paweł (2020-05)
    Context. Ring-like distributions of the 6.7 GHz methanol maser spots at milliarcsecond scales represent a family of molecular structures of unknown origin associated with high-mass young stellar objects. Aims: We aim to ...