A research on the ultracompact HII region of NGC 7583-IRS1.
Abstract
From an analysis of VLBI observations of H2CO and OH maser emission in the direction of the ultra-compact HII region NGC 7538-IRS 1, the following model is proposed. The HII region is surrounded by a thick dusty shell which breaks open at the two poles and there is a bipolar outflow. Around it is a rotating gas/dust ring, and matter falls from the ring onto the surface of the HII region. The whole system, HII region and the ring, moves with a sight line velocity of -61.0 km/s inside a large cloud which moves with a sight line velocity of -57 km/s. The H2CO and OH masers occur near the poles of the HII region and within 0.2 R(HII) of the surface. The positions of the H2O maser and other line sources are discussed in terms of this model.
- Publication:
-
Acta Astrophysica Sinica
- Pub Date:
- December 1989
- Bibcode:
- 1989AcApS...9..193Z
- Keywords:
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- Formaldehyde;
- H Ii Regions;
- Hydroxyl Emission;
- Interstellar Masers;
- Molecular Clouds;
- Star Formation;
- Very Long Base Interferometry;
- Absorption Spectra;
- Ammonia;
- Astronomical Models;
- Emission Spectra;
- Water Masers;
- Astrophysics