scholarly journals Discovery of the new class I methanol maser transition at 23.4 GHz

2011 ◽  
Vol 413 (4) ◽  
pp. 2339-2344 ◽  
Author(s):  
M. A. Voronkov ◽  
A. J. Walsh ◽  
J. L. Caswell ◽  
S. P. Ellingsen ◽  
S. L. Breen ◽  
...  
Keyword(s):  
Class I ◽  
Methanol Maser ◽  
New Class

scholarly journals Discovery of a New Class I Methanol Maser Transition at 266.8 GHz

2019 ◽  
Vol 877 (2) ◽  
pp. 90 ◽  
Author(s):  
Xi Chen ◽  
Simon P. Ellingsen ◽  
Zhi-Yuan Ren ◽  
Andrej M. Sobolev ◽  
Sergey Parfenov ◽  
...  
Keyword(s):  
Class I ◽  
Methanol Maser ◽  
New Class

scholarly journals New class I methanol masers

2012 ◽  
Vol 8 (S287) ◽  
pp. 433-440 ◽  
Author(s):  
M. A. Voronkov ◽  
J. L. Caswell ◽  
S. P. Ellingsen ◽  
S. L. Breen ◽  
T. R. Britton ◽  
...  
Keyword(s):  
Class I ◽  
High Mass ◽  
Mass Star ◽  
Star Forming ◽  
Methanol Maser ◽  
New Class ◽  
Star Forming Regions ◽  
Rare Class ◽  
New Type ◽  
Methanol Masers

AbstractWe review properties of all known collisionally pumped (class I) methanol maser series based on observations with the Australia Telescope Compact Array (ATCA) and the Mopra radio telescope. Masers at 36, 84, 44 and 95 GHz are most widespread, while 9.9, 25, 23.4 and 104 GHz masers are much rarer, tracing the most energetic shocks. A survey of many southern masers at 36 and 44 GHz suggests that these two transitions are highly complementary. The 23.4 GHz maser is a new type of rare class I methanol maser, detected only in two high-mass star-forming regions, G357.97-0.16 and G343.12-0.06, and showing a behaviour similar to 9.9, 25 and 104 GHz masers. Interferometric positions suggest that shocks responsible for class I masers could arise from a range of phenomena, not merely an outflow scenario. For example, some masers might be caused by interaction of an expanding Hii region with its surrounding molecular cloud. This has implications for evolutionary sequences incorporating class I methanol masers if they appear more than once during the evolution of the star-forming region. We also make predictions for candidate maser transitions in the ALMA frequency range.

Class I Methanol Maser Emission in NGC 4945

2017 ◽  
Vol 13 (S336) ◽  
pp. 105-108
Author(s):  
Tiege P. McCarthy ◽  
Simon P. Ellingsen ◽  
Xi Chen ◽  
Shari L. Breen ◽  
Maxim A. Voronkov ◽  
...  
Keyword(s):  
Large Scale ◽  
Class I ◽  
Molecular Gas ◽  
Low Velocity ◽  
Extragalactic Source ◽  
Maser Emission ◽  
Methanol Maser ◽  
Methanol Masers

AbstractWe have detected maser emission from the 36.2 GHz (4−1 → 30E) methanol transition towards NGC 4945. This emission has been observed in two separate epochs and is approximately five orders of magnitude more luminous than typical emission from this transition within our Galaxy. NGC 4945 is only the fourth extragalactic source observed hosting class I methanol maser emission. Extragalactic class I methanol masers do not appear to be simply highly-luminous variants of their galactic counterparts and instead appear to trace large-scale regions where low-velocity shocks are present in molecular gas.

scholarly journals Detection of 84 GHz Class I Methanol Maser Emission toward NGC 253

2018 ◽  
Vol 867 (1) ◽  
pp. L4 ◽  
Author(s):  
Tiege P. McCarthy ◽  
Simon P. Ellingsen ◽  
Shari L. Breen ◽  
Maxim A. Voronkov ◽  
Xi Chen
Keyword(s):  
Class I ◽  
Maser Emission ◽  
Methanol Maser

Analysis of theD-region products ofH-2444using monoclonal antibodies reveals the expression of a new class I-like molecule

1987 ◽  
Vol 25 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Saswati Chatterjee-Das ◽  
Erik P. Lillehoj ◽  
Diana M. Hernandez ◽  
John E. Coligan ◽  
David H. Sachs
Keyword(s):  
Monoclonal Antibodies ◽  
Class I ◽  
New Class

Cellular Distribution and Expression Regulation of HA Molecules (New Class I-Like Antigens)

1989 ◽  
pp. 170-173
Author(s):  
R. Fauchet ◽  
M. Boscher ◽  
N. Genetet ◽  
O. Bouhallier ◽  
B. Genetet ◽  
...  
Keyword(s):  
Expression Regulation ◽  
Class I ◽  
Cellular Distribution ◽  
New Class

Zeeman Effect Observations in Class I Methanol Masers

2018 ◽  
Vol 14 (A30) ◽  
pp. 140-140
Author(s):  
Emmanuel Momjian ◽  
Anuj P. Sarma
Keyword(s):  
Zeeman Effect ◽  
Linear Structure ◽  
Class I ◽  
Star Forming ◽  
Methanol Maser ◽  
Star Forming Regions ◽  
Splitting Factor ◽  
Maser Line ◽  
Methanol Masers ◽  
Expected Values

AbstractWe report the detection of the Zeeman effect in the 44 GHz Class I methanol maser line toward the star forming region DR21W. The 44 GHz methanol masers in this source occur in a ∼3” linear structure that runs from northwest to southeast, with the two dominant components at each end, and several weaker maser components in between. Toward a 93 Jy maser in the dominant northwestern component, we find a significant Zeeman detection of −23.4 ± 3.2 Hz. If we use the recently published result of Lankhaar et al. (2018) that the F=5-4 hyperfine transition is responsible for the 44 GHz methanol maser line, then their value of z = −0.92 Hz mG−1 yields a line-of-sight magnetic field of Blos =25.4 ± 3.5 mG. If Class I methanol masers are pumped in high density regions with n∼107–8 cm−3, then magnetic fields in these maser regions should be a few to several tens of mG. Therefore, our result in DR21W is certainly consistent with the expected values.Using the above noted splitting factor in past Zeeman effect detections in Class I methanol masers reported by Sarma & Momjian (2011) and Momjian & Sarma (2017) in the star forming regions OMC-2 and DR21(OH) result in Blos values of 20.0 ± 1.2 mG and 58.2 ± 2.9 mG, respectively. These are also consistent with the expected values.

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