OGHReS: Large-scale filaments in the outer Galaxy
  Filaments are a ubiquitous morphological feature of the molecular
interstellar medium and are identified as sites of star formation. In recent
years, more than 100 large-scale filaments (with a length $>10$\,pc) have been
observed in the inner Milky Way. As they appear linked to Galactic dynamics,
studying those structures represents an opportunity to link kiloparsec-scale
phenomena to the physics of star formation, which operates on much smaller
scales. In this letter, we use newly acquired Outer Galaxy High Resolution
Survey (OGHReS) $^{12}$CO(2-1) data to demonstrate that a significant number of
large-scale filaments are present in the outer Galaxy as well. The 37 filaments
identified appear tightly associated with inter-arm regions. In addition, their
masses and linear masses are, on average, one order of magnitude lower than
similar-sized molecular filaments located in the inner Galaxy, showing that
Milky Way dynamics is able to create very elongated features in spite of the
lower gas supply in the Galactic outskirts.
