EPoS Contribution
EPoS Contribution
Filament Mass-Length relation: origin and interpretation

Alvaro Hacar
U Vienna, Vienna, AT
During the last decade a large community effort has been devoted to the characterization of the filamentary structure of the Interstellar Medium (ISM) focusing on the systematic analysis of key local properties such as the filament radius, mass-per-unit-length, or velocity dispersion. Aiming to describe the global properties of the filamentary ISM, our team collected information of 49 observational studies including a total of more than 22,000 filaments across the Milky Way. This novel meta-study allows us to connect the variation in mass and length properties of all types of filamentary structures across 6 orders of magnitude in scale and 4 orders of magnitude in length. Our unique sample reveals that filaments follow a well defined Mass-Length (M-L) scaling relation that can be explained by a combination of their hierarchical structure and dynamic properties. During my talk I will explore the origin of this M-L relation and how these new findings provide new insights on some of the classical scaling relations previously reported in molecular clouds.
Caption: Mass and length measurements for all filaments in our catalog. Points are colour-coded according to the corresponding filament: Nearby Filaments, Galactic Plane Surveys, IRDCs, Giant Filaments, Dense Fibers, Striations, and HI Filaments (see legend). In the case of Galactic Plane Surveys a subcategory identifies those detected by ground-based observations (GB). Some prototypical filaments are also included in this plot (see symbols in legends). Black dotted lines indicate constant m = 1, 10, 100, 1000 Msun pc−1 values, the black dashed line corresponds to mcrit(10 K) = 16.4 Msun pc−1. The expected maximum filament size set by the Toomre length for the Galactic midplane at the Sun’s radius is indicated by a blue dashed line. The red solid line shows mvir including turbulent motions. The red dashed line corresponds to the column density Nshield required for self-shielding.
Collaborators:
S.E. Clark, Stanford, US
F. Heitsch, UNC-Chapel Hill, US
J. Kainulainen, Chalmers, SE
G. Panopoulou, Caltech, US
D. Seifried, U Cologne, DE
R.J. Smith, U Manchester, UK


Suggested Session: Filaments