Water masers accompanying OH and methanol masers in star formation regions

The ATCA has been used to measure positions with arcsecond accuracy for 379 masers at the 22-GHz transition of water. The principal observation targets were 202 OH masers of the variety associated with star formation regions (SFR)s in the Southern Galactic plane. At a second epoch, most of these targets were observed again, and new targets of methanol masers were added. Many of the water masers reported here are new discoveries. Variability in the masers is often acute, with very few features directly corresponding to those discovered two decades ago. Within our current observations, less than a year apart, spectra are often dissimilar, but positions at the later epoch, even when measured for slightly different features, mostly correspond to the detected maser site measured earlier, to within the typical extent of the whole site, of a few arcseconds. The precise water positions show that approximately 79% (160 of 202) of the OH maser sites show coincident water maser emission, the best estimate yet obtained for this statistic; however, there are many instances where additional water sites are present offset from the OH target, and consequently less than half of the water masers coincide with a 1665-MHz ground-state OH maser counterpart. We explore the differences between the velocities of peak emission from the three species (OH, methanol and water), and quantify the typically larger deviations shown by water maser peaks from systemic velocities. Clusters of two or three distinct but nearby sites, each showing one or several of the principal molecular masing transitions, are found to be common. In combination with an investigation of correlations with IR sources from the GLIMPSE catalogue, these comparative studies allow further progress in the use of the maser properties to assign relative evolutionary stages in star formation to individual sites.Comment: 51 pages, 7 figure

A search for 4750- and 4765-MHz OH masers in Southern Star Forming Regions

We have used the Australia Telescope Compact Array (ATCA) to make a sensitive (5-$\sigma$ $\simeq$ 100 mJy) search for maser emission from the 4765-MHz $^2\Pi_{1/2}$ F=1$\to$0 transition of OH. Fifty five star formation regions were searched and maser emission with a peak flux density in excess of 100 mJy was detected toward fourteen sites, with ten of these being new discoveries. In addition we observed the 4750-MHz $^2\Pi_{1/2}$ F=1$\to$1 transition towards a sample of star formation regions known to contain 1720-MHz OH masers, detecting marginal maser emission from G348.550-0.979. If confirmed this would be only the second maser discovered from this transition. The occurrence of 4765-MHz OH maser emission accompanying 1720-MHz OH masers in a small number of well studied star formation regions has lead to a general perception in the literature that the two transitions favour similar physical conditions. Our search has found that the presence of the excited-state 6035-MHz OH transition is a much better predictor of 4765-MHz OH maser emission from the same region than is 1720-MHz OH maser emission. Combining our results with those of previous high resolution observations of other OH transitions we have examined the published theoretical models of OH masers and find that none of them predict any conditions in which the 1665-, 6035- and 4765-MHz transitions are simultaneously inverted. Erratum abstract: Dodson & Ellingsen (2002) included several observations with significant pointing errors, invalidating the upper limits found in these directions. These have now been reobserved or recalculated. A new table of upper limits has been generated, and two more masers that would have been seen have been found.Comment: Included an Erratum with Max as another author. This erratum was rejected by MNRAS (Feb 04) as it contained too much data. Resubmitted as a paper (Jun 04). Rejected (Sep 04) it had too little data. Resubmitted as reduced erratum (Apr 05). Still waitin

12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees

We present the second portion of a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all 207 6.7-GHz methanol masers in the longitude range 186 to 330 degrees for 12.2-GHz counterparts. We report the detection of 83 12.2-GHz methanol masers, and one additional source which we suspect is thermal emission, equating to a detection rate of 40 per cent. Of the 83 maser detections, 39 are reported here for the first time. We discuss source properties, including variability and highlight a number of unusual sources. We present a list of 45 candidates that are likely to harbor methanol masers in the 107.0-GHz transition.Comment: Accepted MNRAS 19 July 201

12.2-GHz methanol maser MMB follow-up catalogue - I. Longitude range 330 to 10 degrees

We present a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) survey in the longitude range 330\circ (through 360\circ) to 10\circ. This is the first portion of the catalogue which, when complete, will encompass all of the MMB detections. We report the detection of 184 12.2-GHz sources towards 400 6.7-GHz methanol maser targets, equating to a detection rate of 46 per cent. Of the 184 12.2-GHz detections, 117 are reported here for the first time. We draw attention to a number of 'special' sources, particularly those with emission at 12.2-GHz stronger than their 6.7-GHz counterpart and conclude that these unusual sources are not associated with a specific evolutionary stage.Comment: accepted to MNRAS 21 Dec 201

Detection of new sources of methanol emission at 107 and 108 GHz with the Mopra telescope

A southern hemisphere survey of methanol emission sources in two millimeter wave transitions has been carried out using the ATNF Mopra millimetre telescope. Sixteen emission sources have been detected in the 3(1)-4(0)A+ transition of methanol at 107 GHz, including six new sources exhibiting class II methanol maser emission features. Combining these results with the similar northern hemisphere survey, a total of eleven 107-GHz methanol masers have been detected. A survey of the methanol emission in the 0(0)-1(-1)E transition at 108 GHz resulted in the detection of 16 sources; one of them showing maser characteristics. This is the first methanol maser detected at 108 GHz, presumably of class II. The results of LVG statistical equilibrium calculations confirm the classification of these new sources as a class II methanol masers.Comment: 11 pages, 6 figures, accepted for publication in MNRAS, mn.sty include

Currents, Vol.1, No.3 (Oct.18, 1982)

The CRAS Story--Research Opportunities Available--Unique Machine Donated--USM Program Helps Voc-Ed--Band Selected For Trip--Campbell Appointed--USM Helps United Way--Boyle on MPBN--Associate Provost Named--What We\u27re Doinghttps://digitalcommons.usm.maine.edu/currents/1229/thumbnail.jp

Currents, Vol.1, No.12 (Mar.14, 1983)

Health/Recreation Task Force Formed--Summer Fellowships Awarded--Volleyball Showdown--Convocation: Diversity, Excitement--Less Tolerance Toward a Tradition--Northwest Artists on Display--More About Computers--Nurses Take To The Road--Faculty Funds--Improved Access--Wroth Drafts Rules of Evidence for Vermont--Distinguished Speakers--Poet Heaney to Read--150 Years of Servicehttps://digitalcommons.usm.maine.edu/currents/1238/thumbnail.jp

Currents, Vol.1, No.10 (Feb.14, 1983)

President Travels to Kennebunk To Assess Community Needs--Counseling Satellite Whirring--Grand Opera in Gorham--Bouchard on Coaching Staff at U.S. Olympic Festival--From Jazz to China-- Lion Announces Cast--Convocation Essay Contest Underway--Nuclear Policy in \u2783--Office Pilfering On The Increase--Postal Policies--Art Newsletter Arrives--Easing Entrance into World of Computers--Computer Survey Shapes Up--Recognition Breakfast-- Super Worker --Eight is Enough--Amnesty Internat\u27l Lecture March 1--International Group Names Dean Wroth Co-Chairhttps://digitalcommons.usm.maine.edu/currents/1236/thumbnail.jp