scholarly journals The relationship between Class I and Class II methanol masers at high angular resolution

2018 ◽  
Vol 477 (1) ◽  
pp. 507-524 ◽  
Author(s):  
T P McCarthy ◽  
S P Ellingsen ◽  
M A Voronkov ◽  
G Cimò
Keyword(s):  
Angular Resolution ◽  
Class Ii ◽  
Class I ◽  
High Angular Resolution ◽  
Methanol Masers ◽  
The Relationship

scholarly journals Interferometry of class I methanol masers, statistics and the distance scale

2017 ◽  
Vol 13 (S336) ◽  
pp. 158-161
Author(s):  
Maxim A. Voronkov ◽  
Shari L. Breen ◽  
Simon P. Ellingsen ◽  
Christopher H. Jordan
Keyword(s):  
Angular Resolution ◽  
Class I ◽  
High Angular Resolution ◽  
Current Form ◽  
Young Stellar Object ◽  
Linear Distance ◽  
Kinematic Method ◽  
Future Potential ◽  
Methanol Masers ◽  
Compact Array

AbstractThe Australia Telescope Compact Array (ATCA) participated in a number of survey programs to search for and image common class I methanol masers (at 36 and 44 GHz) with high angular resolution. In this paper, we discuss spatial and velocity distributions revealed by these surveys. In particular, the number of maser regions is found to fall off exponentially with the linear distance from the associated young stellar object traced by the 6.7-GHz maser, and the scale of this distribution is 263±15 milliparsec. Although this relationship still needs to be understood in the context of the broader field, it can be utilised to estimate the distance using methanol masers only. This new technique has been analysed to understand its limitations and future potential. It turned out, it can be very successful to resolve the ambiguity in kinematic distances, but, in the current form, is much less accurate (than the kinematic method) if used on its own.

Extragalactic class I methanol maser: A new probe for starbursts and feedback of galaxies

2017 ◽  
Vol 13 (S336) ◽  
pp. 99-104
Author(s):  
Xi Chen ◽  
Simon P. Ellingsen
Keyword(s):  
Active Galactic Nuclei ◽  
Angular Resolution ◽  
Galactic Nuclei ◽  
Active Galaxies ◽  
Class I ◽  
High Angular Resolution ◽  
Methanol Maser ◽  
Methanol Masers

AbstractWe report progress on research relating to 36.2 GHz extragalactic class I methanol masers, including a review of published work and new observations at high angular resolution. These observations reveal that extragalactic class I masers are excited in shocked gas and maybe associated with starbursts, galactic-scale outflows from active galactic nuclei (AGNs) feedback, or the inner-end region of the galactic bar. The current observational results suggests that extragalactic class I methanol masers provide a new probe for starbursts and feedback in active galaxies.

Methanol Masers in the Andromeda Galaxy

2017 ◽  
Vol 13 (S336) ◽  
pp. 113-116
Author(s):  
Ylva M. Pihlström ◽  
Loránt O. Sjouwerman
Keyword(s):  
Proper Motion ◽  
Milky Way ◽  
Local Group ◽  
Angular Resolution ◽  
Transverse Velocity ◽  
High Angular Resolution ◽  
Dynamic Force ◽  
Group Members ◽  
Methanol Masers ◽  
Motion Studies

AbstractIs M31 going to collide with the Milky Way, or spiral around it? Determining the gravitational potential in the Local Group has been a challenge since it requires 3D space velocities and orbits of the members, and most objects have only had line-of-sight velocities measured. Compared to the less massive group members, the transverse velocity of M31 is of great interest, as after the Milky Way, M31 is the most dominant constituent and dynamic force in the Local Group. Proper motion studies of M31 are preferentially done using masers, as continuum sources are much weaker, and are enabled through the high angular resolution provided by VLBI in the radio regime. The challenges of achieving high astrometric accuracy at high VLBI frequencies (> 20 GHz) makes observations at lower frequencies attractive, as long as sufficient angular resolution is obtained. In particular, we have discovered 6.7 GHz methanol masers in M31 using the VLA, and here we will address their feasibility as VLBI proper motion targets using a set of global VLBI observations.

scholarly journals Class I and Class II methanol masers in high-mass star-forming regions

2010 ◽  
Vol 517 ◽  
pp. A56 ◽  
Author(s):  
F. Fontani ◽  
R. Cesaroni ◽  
R. S. Furuya
Keyword(s):  
Class Ii ◽  
Class I ◽  
High Mass ◽  
Mass Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Methanol Masers

scholarly journals Imaging of selected sources from the Methanol Multibeam Survey

2007 ◽  
Vol 3 (S242) ◽  
pp. 184-185
Author(s):  
D. Wong-McSweeney ◽  
G. A. Fuller ◽  
S. Etoka
Keyword(s):  
Angular Resolution ◽  
Galactic Plane ◽  
High Angular Resolution ◽  
Maser Emission ◽  
Methanol Maser ◽  
Preliminary Results ◽  
Methanol Masers ◽  
Maser Sources

AbstractHigh angular resolution observations are essential for understanding the nature of maser emission and the sources which excite it. Here we present preliminary results from MERLIN observations of three methanol masers from the Toruń survey. These MERLIN observations are being analysed as part of the interferometric component of the Methanol Multibeam (MMB) Survey which is surveying the Galactic plane at |b|≤2° for 6.67 GHz methanol maser sources.

scholarly journals Comparison of the population occlusal characteristics in 3 Brazilian regions

2020 ◽  
Vol 9 (10) ◽  
pp. e1839108586
Author(s):  
Marcio da Costa Almeida ◽  
Paula Cotrin ◽  
Fabricio Pinelli Valarelli ◽  
Rodrigo Hermont Cançado ◽  
Ricardo Cesar Gobbi de Oliveira ◽  
...  
Keyword(s):  
Class Ii ◽  
Open Bite ◽  
Class I ◽  
Class Iii ◽  
Chi Square ◽  
Posterior Crossbite ◽  
Individual Traits ◽  
Orthodontic Patients ◽  
Relationship Of ◽  
The Relationship

The objective of this work was to determine the prevalence of individual traits of malocclusion in a sample of three Brazilian regions orthodontic patients and to detect interregional population differences in the prevalence of certain occlusal characteristics.  The present study was based on the examination of dental casts, intraoral photographs and panoramic radiographs of 947 orthodontic patients from 3 cities: 363 from Fortaleza (CE), 270 from Maringá (PR) and 314 from Bauru (SP), respectively, representing the Northeast, South and Southeast Brazilian regions. The relationship of the first maxillary and mandibular molars according to Angle’s classification, overjet, overbite, crowding, posterior crossbite and maxillary median diastema were examined. The chi-square and ANOVA tests were used to determine potential differences in the distribution of malocclusion when stratified Brazilian regions. Class I malocclusion was found in 499 (52.69%), Class II in 395 (41.71%) and Class III malocclusion in 53 (5,59%) subjects of all examined. Deep overbite (3.59%), midline diastemas (5.17%) and posterior crossbite (4.75%) were observed more frequently in Bauru; however, in Maringá, normal overbite (13.3%) and open bite (4.75%) were more prevalent. The results of this study showed that Class I malocclusion was the most prevalent, followed by Class II and Class III malocclusions. These occlusal relationships evaluated in the three Brazilian regions follow the same pattern of frequency as the result presented by the general population of the sample.

scholarly journals 44 GHz Methanol Maser Surveys

2012 ◽  
Vol 8 (S287) ◽  
pp. 133-140
Author(s):  
S. E. Kurtz
Keyword(s):  
Star Formation ◽  
Formation Process ◽  
Class Ii ◽  
Class I ◽  
High Mass ◽  
Mass Star ◽  
Star Forming ◽  
Methanol Maser ◽  
Star Forming Regions ◽  
Methanol Masers

AbstractClass I 44 GHz methanol masers are not as well-known, as common, or as bright as their more famous Class II cousins at 6.7 and 12.2 GHz. Nevertheless, the 44 GHz masers are commonly found in high-mass star forming regions. At times they appear to trace dynamically important phenomena; at other times they show no obvious link to the star formation process. Here, we summarize the major observational efforts to date, including both dedicated surveys and collateral observations. The principal results are presented, some that were expected, and others that were unexpected.

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