Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 0705.4597

The RMS Survey: 13CO observations of candidate massive YSOs in the southern hemisphere

J. S. Urquhart·A. L. Busfield·M. G. Hoare·S. L. Lumsden·R. D. Oudmaijer·T. J. T. Moore·A. G. Gibb·C. R. Purcell·M. G. Burton·L. J. L. Marechal
View original source ↗Read source document ↗Export metadata ↓

Abstract

Abridged: The Red MSX Source (RMS) survey is an ongoing multi-wavelength observational programme designed to return a large, well-selected sample of massive young stellar objects (MYSOs). Here we present 13CO observations made towards 854 MYSOs candidates located in the 3rd and 4th quadrants. We detected 13CO emission towards a total of 751 of the 854 RMS sources observed (~88%). In total 2185 emission components are detected above 3$σ$ level. Multiple emission profiles are observed towards the majority of these sources - 455 sources (~60%) - with an average of ~4 molecular clouds along the line of sight. These multiple emission features make it difficult to assign a kinematic velocity to many of our sample. We have used archival CS (J=2-1) and maser velocities to resolved the component multiplicity towards 82 sources and have derived a criterion which is used to identify the most likely component for a further 202 multiple component sources. Combined with the single component detections we have obtained unambiguous kinematic velocities towards 580 sources (~80% of the detections). The 171 sources for which we have not been able to determine the kinematic velocity will require additional line data. Using the rotation curve of Brand and Blitz (1993) and their radial velocities we calculate kinematic distances for all components detected.

Explore related subjects

astro-ph

Keep this discovery

BibTeXRIS

J. S. Urquhart, A. L. Busfield, M. G. Hoare, S. L. Lumsden, R. D. Oudmaijer, T. J. T. Moore, A. G. Gibb, C. R. Purcell, M. G. Burton, L. J. L. Marechal. 2007-06-10. The RMS Survey: 13CO observations of candidate massive YSOs in the southern hemisphere. https://doi.org/10.1017/s1743921307002700

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2019

Rotation Curves of Spiral Galaxies

Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe various methods to derive rotation curves, and review the results obtained. We discuss the basic characteristics of observed rotation curves in relation to various galaxy properties, such as Hubble type, structure, activity, and environment.

astro-ph↗
arXiv2018

Abrupt global events in the Earth's history: a physics perspective

The timeline of the Earth's history reveals quasi-periodicity of the geological record over the last 542 Myr, on timescales close, in the order of magnitude, to 1 Myr. What is the origin of this quasi-periodicity? What is the nature of the global events that define the boundaries of the geological time scale? I propose that a single mechanism is responsible for all three types of such events: mass extinctions, geomagnetic polarity reversals, and sea-level fluctuations. The mechanism is fast, and involves a significant energy release. The mechanism is unlikely to have astronomical causes, both because of the energies involved, and because it acts quasi-periodically. It must then be sought within the Earth itself. And it must be capable of reversing the Earth's magnetic field. The last requirement makes it incompatible with the consensus model of the origin of the geomagnetic field - the hydromagnetic dynamo operating in the Earth's fluid core. In the second part of the paper, I show that a vast amount of seemingly unconnected geophysical and geological data can be understood in a unified way if the source of the Earth's main magnetic field is a ~200-km-thick lithosphere, repeatedly magnetized as a result of methane-driven oceanic eruptions, which produce ocean flow capable of dynamo action. The eruptions are driven by the interplay of buoyancy forces and exsolution of dissolved gas, which accumulates in the oceanic water masses prone to stagnation and anoxia. Polarity reversals, mass extinctions, and sequence boundaries are consequences of these eruptions. Unlike the consensus model of geomagnetism, this scenario is consistent with the paleomagnetic data showing that "directional changes during a [geomagnetic polarity] reversal can be astonishingly fast, possibly occurring as a nearly instantaneous jump from one inclined dipolar state to another in the opposite hemisphere".

astro-ph↗
arXiv2018

Putting The Together A Cyclical Baryonic Universe

There are multiple examples of gravitational losses in neutron stars and black holes. Protons and neutrons have been found to have enormous repulsive pressures that highly squeezed collapsing matter cannot overcome. The case against singularities follows. Galactic black hole gravitational losses can supply the missing dark energy. With highly squeezed nucleons, the big bang could begin as a hot core and a cold dark matter shell. The 21 cm. radiation data has identified baryon sized particles as cold dark matter. Highly squeezed nucleons will not decompose to produce antimatter. The flatness of the Universe is due to a baryonic bounce. The highly correlated galaxies originated from primordial black holes capturing hot core gasses.There is evidence that galaxies have not grown nor merged significantly since formation.

astro-ph↗