Query : 2015A&A...578A..97L

2015A&A...578A..97L - Astronomy and Astrophysics, volume 578A, 97-97 (2015/6-1)

G-virial: Gravity-based structure analysis of molecular clouds.


Abstract (from CDS):

We present the G-virial method which aims to quantify (1) the importance of gravity in molecular clouds in the position-position-velocity (PPV) space; and (2) properties of the gas condensations in molecular clouds. Different from previous approaches that calculate the virial parameter for different regions, our new method takes gravitational interactions between all the voxels in 3D PPV data cubes into account, and generates maps of the importance of gravity. This map can be combined with the original data cube to derive relations such as the mass-radius relation. Our method is important for several reasons. First, it offers the ability to quantify the centrally condensed structures in the 3D PPV data cubes, and enables us to compare them in an uniform framework. Second, it allows us to understand the importance of gravity at different locations in the data cube, and provides a global picture of gravity in clouds. Third, it offers a robust approach to decomposing the data into different regions which are gravitationally coherent. To demonstrate the application of our method we identified regions from the Perseus and Ophiuchus molecular clouds, and analyzed their properties. We found an increase in the importance of gravity towards the centers of the individual molecular condensations. We also quantified the properties of the regions in terms of mass-radius and mass-velocity relations. Through evaluating the virial parameters based on the G-virial, we found that all our regions are almost gravitationally bound. Cluster-forming regions appear are more centrally condensed.

Abstract Copyright:

Journal keyword(s): gravitation - ISM: structure - ISM: kinematics and dynamics - stars: formation - methods: numerical - ISM: clouds

Simbad objects: 7

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Number of rows : 7
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 NGC 1333 OpC 03 29 11.3 +31 18 36           ~ 1407 1
2 Barnard 1 MoC 03 33 16.3 +31 07 51           ~ 317 0
3 NAME Perseus Cloud SFR 03 35.0 +31 13           ~ 1311 0
4 [DB2002b] G159.83-18.56 DNe 03 40.0 +31 58           ~ 11 0
5 IC 348 OpC 03 44 31.7 +32 09 32           ~ 1368 1
6 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3533 1
7 LDN 1689 DNe 16 32 22.5 -24 28 29           ~ 132 0

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