evn imaging of methanol masers towards massive protostars anna bartkiewicz marian szymczak huib jan...
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EVN imaging of methanol masers towards massive protostars
Anna Bartkiewicz Marian Szymczak
Huib Jan van Langevelde
8th EVN Symposium Torun 2006
The ring G23.657-00.127:
Ellipse: e=0.38133 mas x 123 masi.e.1400 AUx 1300 AUat 10.5 kpcor700 AUx 630 AUat 5.1 kpc
A disc at i=67 deg?Vlsr=Vrot * cos i * cos A
A(deg)
VLBA observations on November 2005:
12.2 GHz
6.7 GHz?
IRAS2MASSMSX
540 Kand 80 K(Walsh et al. 1999)
Arc-like sources: G24.541+00.312 & G23.707-00.198
370(560) AU
370(750) AU
Model by Moscadelli, Cesaroni & Rioja, 2000
Complex distribution:
Conclusions:
• new structures of 6.7 GHz methanol masers were detected at maps with milliarcsecond resolution (esp. ring),
• the arc-like masers were explained well by the bipolar outflow model,
• complex structures arose likely through propagation of a few shock fronts driven by protostars.
Future work:• further investigation of the ring G23.657-00.127 including
proper motion studies and measurements of the parallax,
• high resolution studies of radio continuum and infraredcounterparts.