Ionized filaments and ongoing physical processes in massive-star-forming sites around l = 345.°5

Abstract

Numerous research studies on dust and molecular filaments have been conducted in star-forming sites, but only a limited number of studies have focused on ionized filaments. To observationally study this aspect, we present an analysis of multi-wavelength data of an area of ∼74\rlap.′6 × 55′ around l = 345○.5. Using the 843 MHz continuum map, two distinct ionized filaments (i.e., IF-A (extent ∼8\rlap.′5) and IF-B (extent ∼22\rlap.′65)) hosting ionized clumps powered by massive OB stars are identified. Using the 13CO(2–1) and C18O(2–1) line data, the parent molecular clouds of IF-A and IF-B are studied in a velocity range of [−21, −10] km s−1, and have filamentary appearances. At least two cloud components around −18 and −15 km s−1 toward the parent clouds of IF-A and IF-B are investigated, and are connected in velocity space. These filamentary clouds also spatially overlap with each other along the major axis, backing the filamentary twisting/coupling nature. Noticeable Class I protostars and massive stars appear to be observed toward the common zones of the cloud components. These findings support the collision of two filamentary clouds around 1.2 Myr ago. The existence of the ionized filaments seems to be explained by the combined feedback of massive stars. The molecular filaments associated with IF-A and IF-B favour the outcomes of the most recent model concerning the escape and the trap of the ionizing radiation from an O star formed in a filament.

New Insights in the Bubble Wall of NGC 3324: Intertwined Substructures and a Bipolar Morphology Uncovered by JWST

“…In general, in the case of massive zero-age main-sequence stars, the value of P HII exceeds the values of P rad and P wind (e.g., Dewangan et al 2016b). Note that Wolf-Rayet stars are an exception to this argument, where the P wind value predominates over P HII and P rad values (e.g., Lamers & Cassinelli 1999;Dewangan et al 2016a;Baug et al 2019;Dewangan et al 2022). Therefore, only the values of P HII are computed in this paper at D s = [0.5, 1] pc.…”