Spatial distribution and kinematics of the molecular material associated with eta Carinae

Journal Article · Sat Dec 10 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/833/1/48· OSTI ID:22868363

Loinard, Laurent; Menten, Karl M. ^[1]; Kamiński, Tomasz ^[2]; Serra, Paolo ^[3]; Zapata, Luis A.

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1. Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
2. ESO, Alonso de Córdova 3107, Vitacura, Casilla, 19001, Santiago (Chile)
3. CSIRO Astronomy, Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

Single-dish submillimeter observations have recently revealed the existence of a substantial, chemically peculiar molecular gas component located in the innermost circumstellar environment of the very massive luminous blue variable star, η Carinae. Here, we present 5″-resolution interferometric observations of the 1→0 rotational transition of hydrogen cyanide (HCN) toward this star obtained with the Australia Telescope Compact Array. The emission is concentrated in the central few arcseconds around η Carinae and shows a clear 150 km s{sup −1} velocity gradient running from west-north-west (blue) to east-south-east (red). Given the extent, location, and kinematics of this molecular material, we associate it with the complex of dusty arcs and knots seen in mid-infrared emission near the center of the Homunculus nebula. Indeed, the shielding provided by this dust could help explain how molecules survive in the presence of the intense UV radiation field produced by η Carinae. The dust located in the central few arcseconds around η Carinae and the molecular component described here most likely formed in situ and out of material expelled by the massive interacting binary system. Thus, η Carinae offers us a rare glimpse of the processes that lead to the formation of dust and molecules around massive stars, which are relevant to the interpretation of dust and molecule detections at high redshifts.

• OSTI ID: 22868363
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 833; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPACTS
COSMIC DUST
EMISSION
HYDROGEN CYANIDES
MASS TRANSFER
NEBULAE
RED SHIFT
RESOLUTION
SPATIAL DISTRIBUTION
STELLAR WINDS
TELESCOPES
ULTRAVIOLET RADIATION
VARIABLE STARS