A Herschel study of G214.5-1.8: a young, cold and quiescent giant molecular filament on the shell of a HI superbubble

Abstract

We present an analysis of the outer Galaxy giant molecular filament (GMF) G214.5-1.8 (G214.5) using Herschel data. We find that G214.5 has a mass of $\sim$ 16,000 M${}_{\odot }$, yet hosts only 15 potentially protostellar 70 $\mu$m sources, making it highly quiescent compared to equally massive clouds such as Serpens and Mon R2. We show that G214.5 has a unique morphology, consisting of a narrow `Main filament' running north-south and a perpendicular `Head' structure running east-west. We identify 33 distinct massive clumps from the column density maps, 8 of which are protostellar. However, the star formation activity is not evenly spread across G214.5 but rather predominantly located in the Main filament. Studying the Main filament in a manner similar to previous works, we find that G214.5 is most like a 'Bone' candidate GMF, highly elongated and massive, but it is colder and narrower than any such GMF. It also differs significantly due to its low fraction of high column density gas. Studying the radial profile, we discover that G214.5 is highly asymmetric and resembles filaments which are known to be compressed externally. Considering its environment, we find that G214.5 is co-incident, spatially and kinematically, with a HI superbubble. We discuss how a potential interaction between G214.5 and the superbubble may explain G214.5's morphology, asymmetry and, paucity of dense gas and star formation activity, highlighting the intersection of a bubble-driven interstellar medium paradigm with that of a filament paradigm for star formation.

Accepted in MNRAS. 26 pages, 24 figures

References in corpus (34)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc
• Identifying the Low Luminosity Population of Embedded Protostars in the c2d Observations of Clouds and Cores
• A Compendium of Distances to Molecular Clouds in the Star Formation Handbook
• The Milky Way Imaging Scroll Painting (MWISP): Project Details and Initial Results from the Galactic Longitude of 25.8deg to 49.7deg
• Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ }<\ell <67.0^{\circ }$)
• On the nature of star-forming filaments: I. Filament morphologies
• Large-scale filaments associated with Milky Way spiral arms
• The Bones of the Milky Way
• The Cloud Factory I: Generating resolved filamentary molecular clouds from galactic-scale forces
• The Hi-GAL compact source catalogue -- II. The 360° catalogue of clump physical properties
• Hunting for Supermassive Black Holes in Nearby Galaxies with the Hobby-Eberly Telescope
• Gravity, Magnetic Field, and Turbulence: Relative Importance and Impact on Fragmentation in the Infrared Dark Cloud G34.43+00.24
• A Census of Large-Scale ($\ge$ 10 pc), Velocity-Coherent, Dense Filaments in the Northern Galactic Plane: Automated Identification Using Minimum Spanning Tree
• The CARMA-NRO Orion Survey: The filamentary structure as seen in C${}^{18}$O emission
• Investigating the Global Collapse of Filaments Using Smoothed Particle Hydrodynamics
• Understanding star formation in molecular clouds IV. Column density PDFs from quiescent to massive molecular clouds
• Formation of the Musca filament: Evidence for asymmetries in the accretion flow due to a cloud-cloud collision
• Are fibres in molecular cloud filaments real objects?
• The evolution of Giant Molecular Filaments
• Magnetized interstellar molecular clouds: II. The Large-Scale Structure and Dynamics of Filamentary Molecular Clouds
• The prevalence of star formation as a function of Galactocentric radius
• Mass segregation and sequential star formation in NGC 2264 revealed by Herschel
• Distance biases in the estimation of the physical properties of Hi-GAL compact sources-I. Clump properties and the identification of high-mass star forming candidates
• Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub
• The role of Galactic HII regions in the formation of filaments. High-resolution submilimeter imaging of RCW 120 with ArTéMiS
• The "Carina Flare" Supershell: Probing the Atomic and Molecular ISM in a Galactic Chimney
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- XII: Fragmentation and multi-scale gas kinematics in protoclusters G12.42+0.50 and G19.88-0.53
• The hierarchical fragmentation of filaments and the role of sub-filaments
• Dense gas formation in the Musca filament due to the dissipation of a supersonic converging flow
• Determining the presence of characteristic fragmentation length-scales in filaments
• Synthetic CO emission and the $X_{\mathrm{CO}}$ factor of young molecular clouds: a convergence study
• RJ-plots: An improved method to classify structures objectively
• The isothermal evolution of a shock-filament interaction

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