A MERLIN study of 6 GHz excited OH & 6.7 GHz methanol masers in ON1

AbstractMERLIN observations of 6.668-GHz Methanol and 6.035-GHz OH emission from the known massive star-formation region ON1 are presented. Maser components are found to lie at the southern edge of the UCHII with consistent polarization angles across the strongest features. Zeeman splitting of OH shows magnetic field strengths between +0.4 to −5.3 mG and from cross-correlation a tentative methanol magnetic field of −18mG is detected.

Download Full-text

VLBA Imaging of 12.2 GHz Methanol Masers

International Astronomical Union Colloquium ◽

10.1017/s0252921100046005 ◽

1998 ◽

Vol 164 ◽

pp. 375-376

Author(s):

S. P. Ellingsen ◽

P.M. McCulloch ◽

P. J. Diamond ◽

R. P. Norris

Keyword(s):

Star Formation ◽

Velocity Distribution ◽

Massive Star ◽

Star Formation Region ◽

Formation Region ◽

Maser Emission ◽

Methanol Maser ◽

Upper Limit ◽

Methanol Masers ◽

Right Ascension

AbstractWe have used the VLBA to image the 12.2 GHz (20-3−1 E) masing transition of methanol toward the massive star formation region G345.01+1.79. The maser spots are distributed in a curved structure with a near monotonic velocity distribution along the curve. The cluster of maser emission covers an area of approximately 200 milli-arcseconds in right ascension and 70 milli-arcseconds in declination.Comparison of the positions of the 12.2 GHz methanol maser spots in G345.01+1.79 as determined from the 1995 VLBA observations with 1988 Parkes-Tidbinbilla Interferometer observations shows that the relative positions of the maser spots detected in both epochs has changed by less than 5 milli-arcseconds during that interval. Assuming a distance of 2.3 kpc to G345.01+1.79 implies an upper limit on the relative tangential velocities of the maser spots of 7 km s−1.

Download Full-text

Molecular & photodissociated gas in the massive star formation region NGC 6334

10.1063/1.52805 ◽

1997 ◽

Author(s):

Kathleen E. Kraemer ◽

James M. Jackson

Keyword(s):

Star Formation ◽

Massive Star ◽

Massive Star Formation ◽

Star Formation Region ◽

Formation Region ◽

Ngc 6334

Download Full-text

Zeeman splitting of OH masers and the galactic magnetic field

Symposium - International Astronomical Union ◽

10.1017/s0074180900222730 ◽

2002 ◽

Vol 206 ◽

pp. 371-374 ◽

Cited By ~ 3

Author(s):

Vincent L. Fish ◽

Mark J. Reid ◽

Alice L. Argon ◽

Karl M. Menten

Keyword(s):

Magnetic Field ◽

Star Formation ◽

Large Scale ◽

Massive Star ◽

Milky Way ◽

Zeeman Splitting ◽

Galactic Magnetic Field ◽

Massive Star Formation ◽

The Magnetic Field

Zeeman measurements of OH masers are used to probe the magnetic field around regions of massive star formation. Previous observations suggested that OH maser field directions were aligned in a clockwise sense in the Milky Way, but recent data from a large-scale VLA survey do not support this hypothesis. However, these observations suggest that the magnetic field of the Milky Way is correlated on kiloparsec scales.

Download Full-text