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arXiv · 2501.13931

HP2 Survey V. Ophiuchus: Filament formation in a dispersing cloud complex

João Alves·Marco Lombardi·Charles Lada
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Abstract

We search for potential ``birthmarks'' left from the formation of filamentary molecular clouds in the Ophiuchus complex. We use high dynamic-range column density and temperature maps derived from \textit{Herschel}, \textit{Planck}, and \textit{2MASS/NICEST} extinction data. We find two distinct types of filaments based on their orientation relative to nearby massive stars: radial (R-type) and tangential (T-type). R-type filaments exhibit decreasing mass profiles away from massive stars, while T-type filaments show flat but structured profiles. We propose a scenario where both filament types originate from the dynamic interplay of compression and stretching forces exerted by a fast outflow emanating from the OB association. The two formation mechanisms leave distinct observable ``birthmarks'' (namely, filament orientation, mass distribution, and star formation location) on each filament type. Our results illustrate a complex phase in molecular cloud evolution with two simultaneous yet contrasting processes: the formation of filaments and stars via the dispersal of residual gas from a previous massive star formation event. Our approach highlights the importance of taking into account the wider context of a star-forming complex, rather than concentrating exclusively on particular subregions.

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João Alves, Marco Lombardi, Charles Lada. 2025-01-23. HP2 Survey V. Ophiuchus: Filament formation in a dispersing cloud complex. https://doi.org/10.1051/0004-6361%2F202452881

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