First results from observations of southern star forming regions with the swedish ESO submillimetre telescope

Author(s):  
M. Olberg ◽  
B. Reipurth ◽  
R. S. Booth
2017 ◽  
Vol 13 (S336) ◽  
pp. 109-112
Author(s):  
A. Tarchi ◽  
P. Castangia ◽  
G. Surcis ◽  
A. Brunthaler ◽  
K. M. Menten ◽  
...  

AbstractThe dwarf galaxies in the Local Group (LG) reveal a surprising amount of spatial structuring. In particular, almost all non-satellite dwarfs belong to one of two planes that show a very pronounced symmetry. In order to determine if these structures in the LG are dynamically stable or, alternatively, if they only represent transient alignments, proper motion measurements of these galaxies are required. A viable method to derive proper motions is offered by VLBI studies of 22-GHz water (and 6.7-GHz methanol) maser lines in star-forming regions.In 2016, in the framework of the Early Science Program of the Sardinia Radio Telescope (SRT), we have conducted an extensive observational campaign to map the entire optical body of all the LG dwarf galaxies that belong to the two planes, at C and K band, in a search for methanol and water maser emission.Here, we outline the project and present its first results on 3 targets, NGC 6822, IC 1613, and WLM. While no luminous maser emission has been detected in these galaxies, a number of interesting weaker detections has been obtained, associated with particularly active star forming regions. In addition, we have produced deep radio continuum maps for these galaxies, aimed at investigating their star forming activity and providing an improved assessment of star formation rates in these galaxies.


2004 ◽  
Vol 221 ◽  
pp. 275-282
Author(s):  
Vincent Minier

The newly upgraded Australia Telescope Compact Array (ATCA) at millimetre wavelengths is the first millimetre interferometer to be built in the Southern Hemisphere. The full array will be operational in 2004-2005 and will provide arcsec angular resolution at 3 mm and 12 mm. This will be a unique instrument to study at high angular resolution the interstellar chemistry and more generally the star formation process, especially in the bulk of the galactic plane and in the Magellanic Clouds. The upgraded ATCA will also be an excellent tool to detect dust emission from nearby protoplanetary disks. In this paper I will present the first results from the upgraded ATCA at 3 mm and 12 mm. The result review will cover the topics of massive star formation and hot molecular cores dust emission from star-forming regions and detection of protoplanetary disks.


1994 ◽  
Vol 140 ◽  
pp. 232-233
Author(s):  
Seiichi Sakamoto ◽  
Tetsuo Hasegawa ◽  
Masahiko Hayashi ◽  
Toshihiro Handa ◽  
Tomoharu Oka

AbstractThe first results of large-area mapping observations of nearby giant molecular clouds in the CO(J=2-1) emission are presented. The CO(J=2-1)/CO(J=1-0) luminosity ratio is 0.75 and 0.62 for the Orion A and B clouds, respectively. These values are consistent with those observed typically in disks of galaxies (−0.6), and are significantly lower than large values (≳1) often observed in active star-forming regions in galaxies. Active star-forming regions in galaxies cannot be explained by ensemble of Orion-like GMCs; they may contain a different population of molecular clouds with high J-2-1/J=1-0 luminosity ratio.


2011 ◽  
Vol 123 (900) ◽  
pp. 138-170 ◽  
Author(s):  
E. F. van Dishoeck ◽  
L. E. Kristensen ◽  
A. O. Benz ◽  
E. A. Bergin ◽  
P. Caselli ◽  
...  

Author(s):  
Ewine F. van Dishoeck ◽  
E. Dartois ◽  
W. F. Thi ◽  
L. d’Hendecourt ◽  
A. G. G. M. Tielens ◽  
...  

2012 ◽  
Vol 8 (S289) ◽  
pp. 226-226
Author(s):  
Andreas Brunthaler

AbstractAccurate geometric distances, which are inherently free of systematic effects are of very great importance for an independent recalibration of extragalactic distance estimators. Local Group galaxies are close enough for both primary and secondary distance indicators to be readily isolated in ground- and space-based observations. Astrometric accuracies of a few micro-arcseconds based on Very Long Baseline Interferometry (VLBI) observations of water masers in high-mass star-forming regions in nearby galaxies allow a measurement of the proper motions of these masers. Since these high-mass star-forming regions rotate with the galaxies, one can deduce a rotational parallax by comparing the known rotation curve with the proper motions of the masers. I provide an update of our previous rotation parallax of M33 and show first results of observations of the recently discovered water masers in the Andromeda galaxy (M31).


2003 ◽  
Vol 211 ◽  
pp. 139-140 ◽  
Author(s):  
Ray Jayawardhana ◽  
David R. Ardila ◽  
Beate Stelzer

Studies of disks around young brown dwarfs are of paramount importance to our understanding of the origin, diversity and early evolution of sub-stellar objects. Here we present first results from a systematic search for disk emission in a spectroscopically confirmed sample of young objects near or below the sub-stellar boundary in a variety of star-forming regions. Our VLT and Keck L'-band observations of the σ Orionis and TW Hydrae associations suggest that if a majority of brown dwarfs are born with disks, at least the inner regions of those disks evolve rapidly, possibly clearing out within a few million years.


Author(s):  
D. A. Ladeyschikov ◽  

The first results of developing a database of water masers in star-forming regions are presented. The database is stored online at the address http://maserdb.net. The coverage of the database at the time of publication is 84 % of all positive detections of water masers in star-forming regions from the available literature. Preliminary statistical analysis of the data and study of the association between water masers and ATLASGAL 870 μm sources was carried out. A relation was obtained from the generalized linear model to estimate water maser detection probability depending on the physical parameters of clumps from the ATLASGAL catalogue. According to estimates, only ∼25 % of the total number of water masers towards ATLASGAL sources has been detected at the moment.


Author(s):  
Ewine F. van Dishoeck ◽  
E. Dartois ◽  
W. F. Thi ◽  
L. d’Hendecourt ◽  
A. G. G. M. Tielens ◽  
...  

Author(s):  
Jura Borissova ◽  
Radostin Kurtev ◽  
Stuart Folkes ◽  
Étienne Artigau ◽  
Valentin Ivanov ◽  
...  

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