BIMA CO Observation of EP Aqr the Semiregular Pulsating Star with a Double Component Line Profile

Abstract

This paper reports the results of a Berkeley-Illinois-Maryland array interferometric observation of EP Aqr, a semiregular pulsating star with a double component line profile in the CO J=1-0 line. The broad component shows a flat-top profile, and the narrow component shows a spiky strong peak. Though the previous single dish observations suggested that the CO J=2-1 line exhibits a Gaussian-like profile, the CO J=1-0 line does not. The spatial distributions of both the narrow and broad components appears to be roughly round with the same peak positions. No significant velocity gradient is seen. The spatial-kinetic properties of the molecular envelope of EP Aqr are reminiscent of a multiple shell structure model rather than a bipolar flow and disk model. A problem of this interpretation is that no evidence of interaction between the narrow and broad component regions is seen. A Gaussian-like feature seen in the CO J=2-1 line might play a key role to understand the spatio-kinetic properties of the molecular envelope of EP Aqr.

arXiv comment10 pages, 3 figures; accepted for publication in ApJ

References in corpus (8)

• Multiple Molecular Winds in Evolved Stars I. A Survey of CO(2-1) and CO(3-2) Emission from 45 Nearby AGB Stars
• Mass loss rates of a sample of irregular and semiregular M-type AGB-variables
• `Thermal' SiO radio line emission towards M-type AGB stars: a probe of circumstellar dust formation and dynamics
• Detections of SiO and H${}_2$O Masers in the Bipolar Nebula IRAS 19312+1950
• Disk-Like Structure in the Semi-Regular Pulsating Star, X Her
• Study of the Bipolar Nebula IRAS 19312+1950. I. Mapping Observations
• BIMA Array Observations of the Highly Unusual SiO Maser Source with a Bipolar Nebulosity, IRAS 19312+1950
• Detection of Bipolar Flow toward an Unusual SiO Maser Source IRAS 19312+1950

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• VLA Observations of HI in the Circumstellar Envelopes of Asymptotic Giant Branch Stars
• The morpho-kinematics of the circumstellar envelope around the AGB star EP Aqr
• 12CO emission from EP Aqr: Another example of an axi-symmetric AGB wind?
• CO J=3-2 Emission from the "Water Fountain" Sources IRAS 16342-3814 and IRAS 18286-0959
• ALMA observations of the circumstellar envelope around EP Aqr