A MultiWavelength Study of the Symbiotic Mira HM Sge with SOFIA and HST

Abstract

We have targeted the dusty symbiotic mira system HM Sge with four instruments from the IR to the UV. We have used these observations along with archival observations to study how the system has been evolving after its 1975 nova-like outburst. We have detected ro-vibrational water emission in a symbiotic system for the first time using new EXES high spectral resolution infrared spectroscopy. The features, detected in emission, have velocities consistent with the systemic velocity but do not show any clear evidence of high velocity outflows. Mid-infrared photometry and grism spectroscopy show that the oxygen-rich Asymptotic Giant Branch (AGB) dust and dust output has shown little to no change over the past 39 years. In the optical/UV, we detect three main [NII] nebular features that were detected 22 years ago. Two of these features show a small amount of movement corresponding to average outflows speeds of 38 kms and 78 kms since they were previously observed; some previously detected [NII] features are no longer visible. New UV spectroscopy has shown that the nebular environment continues to steadily relax after the system's 1975 outburst. The data suggest however, that the hot component has increased in temperature from 200,000 K in 1989 to now greater than 250,000 K. Our new and archival observations suggest that the evolution of the system after its outburst is swift with little to no major changes after a period of a couple years.

Accepted in ApJ

References in corpus (11)

• Array Programming with NumPy
• The NumPy array: a structure for efficient numerical computation
• The wind speeds, dust content, and mass-loss rates of evolved AGB and RSG stars at varying metallicity
• A Detailed Analysis of the Dust Formation Zone of IRC+10216 Derived from Mid-IR Bands of C2H2 and HCN
• Distance estimates for AGB stars from parallax measurements
• Space Velocity and Time Span of Jets in Planetary Nebulae
• Raman Scattered O VI $\lambda$ 6825 and the Accretion Disk Emission Model in the Symbiotic Stars V1016 Cygni and HM Sagittae
• The Rapidly Evolving AGB Star, V Hya: ALMA finds a Multi-Ring Circus with High-Velocity Outflows
• Bipolar ejection by the symbiotic binary system Z And during its 2006 outburst
• The H${}_2$O Spectrum of the Massive Protostar AFGL 2136 IRS 1 from 2 to 13 $\mu$m at High Resolution: Probing the Circumstellar Disk
• CO line observations of OH/IR stars in the inner Galactic Bulge: Characteristics of stars at the tip of the AGB