Discovery of an HI Counterpart to the Extended Tail of Mira

Abstract

We report the detection of an HI counterpart to the extended, far-ultraviolet-emitting tail associated with the asymptotic giant branch star Mira (o Ceti). Using the Nancay Radio Telescope (NRT), we have detected emission as far as 88' north of the star, confirming that the tail contains a significant atomic component (M_HI ~ 4x10e-3 M_sun). The NRT spectra reveal a deceleration of the tail gas caused by interaction with the local interstellar medium. We estimate an age for the tail of ~1.2x10e5 years, suggesting that the mass-loss history of Mira has been more prolonged than previous observational estimates. Using the Very Large Array (VLA) we have also imaged the HI tail out to ~12' (0.4 pc) from the star. The detected emission shows a ``head-tail'' morphology, but with complex substructure. Regions with detected HI emission correlate with far-ultraviolet-luminous regions on large scales, but the two tracers are not closely correlated on smaller scales (<1'). We propose that detectable tails of HI are likely to be a common feature of red giants undergoing mass-loss.

accepted to ApJ; version with full-resolution figures available at: http://www.cfa.harvard.edu/~lmatthew/Mira_HI.pdf

References in corpus (6)

• The interaction of planetary nebulae and their AGB progenitors with the interstellar medium
• Three-dimensional hydrodynamic simulations of asymmetric pulsar wind bow shocks
• Vortices in the wakes of AGB stars
• It's a wonderful tail: the mass loss history of Mira
• The formation of a detached shell around the carbon star Y CVn
• VLA Observations of HI in the Circumstellar Envelopes of Asymptotic Giant Branch Stars

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