Gas velocity structure of the Orion A integral-shaped filament

González Lobos V.; Stutz A.M.

Abstract

We present analysis of the gas kinematics of the integral-shaped filament (ISF) in Orion A using four different molecular lines, (CO)-C-12 (1-0), (CO)-C-13 (1-0), NH3 (1,1), and N2H+ (1-0). We describe our method to visualize the position-velocity (PV) structure using the intensity-weighted line velocity centroid, which enables us to identify structures that were previously muddled or invisible. We observe a north-to-south velocity gradient in all tracers that terminates in a velocity peak near the centre of the Orion Nebula Cluster (ONC), consistent with the previously reported 'wave-like' properties of the ISF. We extract the velocity dispersion profiles and compare the non-thermal line widths to the gas gravitational potential. We find supersonic Mach number profiles, yet the line widths are consistent with the gas being deeply gravitationally bound. We report the presence of two (CO)-C-12 velocity components along the northern half of the ISF; if interpreted as circular rotation, the angular velocity is omega = 1.4 Myr(-1). On small scales we report the detection of N2H+ and NH3 'twisting and turning' structures, with short associated time-scales that give the impression of a torsional wave. Neither the nature of these structures nor their relation to the larger scale wave is presently understood.

Más información

Título según WOS: Gas velocity structure of the Orion A integral-shaped filament
Título según SCOPUS: Gas velocity structure of the Orion A integral-shaped filament
Título de la Revista: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volumen: 489
Número: 4
Editorial: OXFORD UNIV PRESS
Fecha de publicación: 2019
Página de inicio: 4771
Página final: 4782
Idioma: English
DOI:

10.1093/mnras/stz2512

Notas: ISI, SCOPUS