scholarly journals Water in Star-forming Regions with theHerschel Space Observatory(WISH). I. Overview of Key Program and First Results

2011 ◽  
Vol 123 (900) ◽  
pp. 138-170 ◽  
Author(s):  
E. F. van Dishoeck ◽  
L. E. Kristensen ◽  
A. O. Benz ◽  
E. A. Bergin ◽  
P. Caselli ◽  
...  
Keyword(s):  
Space Observatory ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results

scholarly journals VSOP, A Space VLBI Programme

1990 ◽  
Vol 123 ◽  
pp. 263-269
Author(s):  
H. Hirabayashi
Keyword(s):  
Active Galactic Nuclei ◽  
Phase Transfer ◽  
Galactic Nuclei ◽  
Satellite Orbit ◽  
Radio Sources ◽  
Space Observatory ◽  
Stellar Objects ◽  
Radio Observatory ◽  
Star Forming ◽  
Star Forming Regions

AbstractVSOP, VLBI Space Observatory Programme, is an approved space VLBI programme of ISAS for the study of very compact radio sources with the synthesized aperture of 30,000 km diameter, by connecting an orbiting radio observatory with ground radiotelescopes. The VSOP satellite carrying 10 m antenna with 1.6, 5, and 22 GHz band receivers will be launched in early 1995 by M-V rocket of ISAS into an eccentric orbit with 20,000 km in apogee height. The tracking network will be formed for the satellite orbit determination, phase transfer and IF down-link. VSOP aims imaging capability with best resolution of 0.0001 arc second in 22 GHz band. Imaging of active galactic nuclei, star forming regions and stellar objects, and radioastrometry are main scientific targets.

Sardinia Radio Telescope (SRT) observations of Local Group dwarf galaxies

2017 ◽  
Vol 13 (S336) ◽  
pp. 109-112
Author(s):  
A. Tarchi ◽  
P. Castangia ◽  
G. Surcis ◽  
A. Brunthaler ◽  
K. M. Menten ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Radio Continuum ◽  
Maser Emission ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Ngc 6822 ◽  
Almost All

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.

scholarly journals First Results from ATCA at Millimetre Wavelengths

2004 ◽  
Vol 221 ◽  
pp. 275-282
Author(s):  
Vincent Minier
Keyword(s):  
Star Formation ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Dust Emission ◽  
Protoplanetary Disks ◽  
High Angular Resolution ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Excellent Tool

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.

scholarly journals THE CO(J=2-1)/CO(J=1-0) Luminosity Ratio in the Orion Giant Molecular Clouds

1994 ◽  
Vol 140 ◽  
pp. 232-233
Author(s):  
Seiichi Sakamoto ◽  
Tetsuo Hasegawa ◽  
Masahiko Hayashi ◽  
Toshihiro Handa ◽  
Tomoharu Oka
Keyword(s):  
Molecular Clouds ◽  
Giant Molecular Clouds ◽  
Large Area ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Galaxies Active

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.

scholarly journals Ices in Star-Forming Regions: First Results from VLT-ISAAC

2002 ◽  
pp. 238-245
Author(s):  
Ewine F. van Dishoeck ◽  
E. Dartois ◽  
W. F. Thi ◽  
L. d’Hendecourt ◽  
A. G. G. M. Tielens ◽  
...  
Keyword(s):  
Star Forming ◽  
Star Forming Regions ◽  
First Results

scholarly journals Rotational parallaxes of nearby galaxies

2012 ◽  
Vol 8 (S289) ◽  
pp. 226-226
Author(s):  
Andreas Brunthaler
Keyword(s):  
High Mass ◽  
Mass Star ◽  
Proper Motions ◽  
Star Forming ◽  
Star Forming Regions ◽  
Long Baseline ◽  
First Results ◽  
Systematic Effects ◽  
Nearby Galaxies ◽  
Water Masers

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).

scholarly journals A Search for Disk Emission in Young Brown Dwarfs: L'-band Observations of σ Orionis and TW Hydrae

2003 ◽  
Vol 211 ◽  
pp. 139-140 ◽  
Author(s):  
Ray Jayawardhana ◽  
David R. Ardila ◽  
Beate Stelzer
Keyword(s):  
Brown Dwarfs ◽  
Early Evolution ◽  
Systematic Search ◽  
Stellar Objects ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
L Band

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.

scholarly journals Online database of water masers in the star-forming regions: the first results

2021 ◽  
Author(s):  
D. A. Ladeyschikov ◽  
Keyword(s):  
Detection Probability ◽  
Generalized Linear Model ◽  
Physical Parameters ◽  
Online Database ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Water Masers ◽  
The Moment ◽  
Water Maser

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.

scholarly journals Ices in Star-Forming Regions: First Results from VLT-ISAAC

2003 ◽  
pp. 238-246
Author(s):  
Ewine F. van Dishoeck ◽  
E. Dartois ◽  
W. F. Thi ◽  
L. d’Hendecourt ◽  
A. G. G. M. Tielens ◽  
...  
Keyword(s):  
Star Forming ◽  
Star Forming Regions ◽  
First Results
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