A potential new phase of massive star formation

Context. Due to the sparsity and rapid evolution of high-mass stars, a detailed picture evolutionary sequence massive protostellar objects still remains be drawn. Some early phases their formation are so short that only select number throughout Milky Way currently find themselves spending time in those phases. Aims. Star-forming regions going through shortest stages star present different observational characteristics than most regions. By studying dust continuum line emission such unusual clouds, one might able set strong constraints on objects. Methods. We analysis G345.88-1.10 hub filament system, which is newly discovered star-forming cloud hosts an unusually bright bipolar infrared nebulosity at its centre. used archival observations from Berschel , WISE, Spitzer 2MASS, SUMSS order fully characterise morphology spectral energy distribution region. further made use APEX 12 CO(2–1), 13 C 18 O(2–1), H30 ? investigate presence outflows map kinematics cloud. Finally, we performed RADMC-3D radiative transfer calculations constrain physical origin central nebulosity. Results. At distance 2.26 -0.21 +0.30 kpc, exhibits network parsec-long converging filaments. junction these filaments lie four infrared-quiet fragments. The fragment H1 densest (with M = 210 ? R eff 0.14 pc) sits right centre wide (opening angle ~90 ± 15°) where column density reaches local minima. CO(2–1) region show infrared-bright cavities spatially associated with powerful molecular outflow centred fragment. Negligible radio no detected towards cavities, seemingly excluding idea ionising radiation drives cavities. Radiative embedded source surrounded by disc and/or dense core unable reproduce observed combination low-luminosity (?500 L ) surrounding high-luminosity (~4000 mid-infrared-bright cavity. This suggests heating protostar cannot responsible for illumination Conclusions. is, our knowledge, first reported object this type. rarity as likely related very phase cluster process has been unidentified thus far. discuss whether mechanical deposition episode or successive episodes mass accretion collapsing explain observations. While promising some aspects, coherent scenario explains luminous cavity infrared-dark elusive point.