Kinematics of Ultracompact HII Regions Revealed: High Spectral and Spatial Resolution Mapping of the 12.8 micron [NeII] Line in Monoceros R2

Abstract

We present the first results of a study of the kinematics and morphology of ultracompact HII regions using a new observational technique. We used very high spatial (1.5") and spectral (3.4 km/s)resolution observations of the [NeII] line at 12.8 microns to study the ionized gas in Monoceros R2. The [NeII] emission shows an HII region with highest emission measure in a ~24" shell. Line widths are as narrow as 8 km/s at some positions. In places where the lines are complex and broader, the additional width is most likely due to overlap of narrower features along the line of sight. The global kinematics suggest that the 24" shell is expanding at ~10 km/s. However, the spectral profiles toward the southeast side of the shell are not consistent with a simple expansion picture.

arXiv comment25 pages, 7 figures

References in corpus (5)

• Massive Stars: Their Environment and Formation
• TEXES: A Sensitive High-Resolution Grating Spectrograph for the Mid-Infrared
• Clumpy Ultracompact HII Regions I: Fully Supersonic Wind-blown Models
• Low Velocity Ionized Winds from Regions Around Young O Stars
• [Ne II] 12.8 Micron Images of Four Galactic Ultracompact H II Regions: Ionized Neon Abundance as a Tracer of the Ionizing Stars

Cited by in corpus (14)

• Neon Fine-Structure Line Emission By X-ray Irradiated Protoplanetary Disks
• Dynamics of cluster-forming hub-filament systems: The case of the high-mass star-forming complex Monoceros R2
• Hydrodynamics of Cometary Compact HII Regions
• The VLTI/MIDI survey of massive young stellar objects - Sounding the inner regions around intermediate- and high-mass young stars using mid-infrared interferometry
• Mid-infrared PAH and H2 emission as a probe of physical conditions in extreme PDRs
• [Ne II] Observations of Gas Motions in Compact and Ultracompact H II Regions
• From forced collapse to H ii region expansion in Mon R2: Envelope density structure and age determination with Herschel
• Kinematics of the ionized-to-neutral interfaces in Monoceros R2
• Mass Flows in Cometary UCHII Regions
• Herschel observations in the ultracompact HII region Mon R2: Water in dense Photon-dominated regions (PDRs)
• Insights into the Carbon chemistry of Mon R2
• [S IV] in the NGC 5253 Supernebula: Ionized Gas Kinematics at High Resolution
• Ionized Gas Kinematics at High Resolution. II: Discovery of a Double Infrared Cluster in II Zw 40
• Dust and Gas environment of the young embedded cluster IRAS 18511+0146