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.