Bipolar symbiotic planetary nebulae in the thermal infrared: M2-9, Mz 3, and He 2-104

We present thermal-infrared images of three extreme bipolar objects, M2-9, Mz 3, and He 2-104. They are bipolar planetary nebulae with bright central stars and are thought to be powered by symbiotic binary systems. The mid-infrared images spatially resolve the spectral energy distributions of the central engines from the surrounding nebulae. A warm dust component of several hundred degrees can account for the core emission, while a cooler component of ~100 K produces the more extended emission from the bipolar lobes. In every case, the dust mass for the unresolved core region is orders of magnitude less than that in the extended lobes, raising doubts that the hypothetical disks in the core could have been responsible for pinching the waists of the nebulae. We find total masses of roughly 0.5–1 M⊙ in the nebulae of M2-9 and Mz 3, requiring that this material was donated by intermediate-mass progenitor stars. The mass of He 2-104's nebula is much lower, and any extended emission is too faint to detect in our images. Extended dust emission is detected around both M2-9 and Mz 3, in both cases resembling the distribution of ionized gas. Our images of Mz 3 have the highest signal-to-noise ratio in the extended polar lobes, and we show that the fairly uniform color temperature derived from our images can explain the 110 K dust component that dominates the far-infrared spectral energy distribution. In the case of Mz 3, most of the mass traced by dust is concentrated at high latitudes, and we note possible evidence for grain destruction in shocks indicated by an anticorrelation between [Fe II] and dust emission. Except for these regions with enhanced [Fe II] emission, the dust continuum closely resembles the distribution of ionized gas.

[1]  G. Mellema,et al.  Radiation gasdynamics of planetary nebulae - V. Hot bubble and slow wind dynamics , 1995 .

[2]  P. Roche,et al.  8–13 μm spectrophotometry of compact planetary nebulae and emission line objects , 1982 .

[3]  J. P. Phillips,et al.  Density and Excitation Mapping of M2-9 , 1999 .

[4]  B. Balick,et al.  Simultaneous Production of Disk and Lobes: A Single-Wind MHD Model for the η Carinae Nebula , 2004, astro-ph/0408034.

[5]  K. Sellgren,et al.  The optically thin dust shell of Nova Cygni 1978 , 1980 .

[6]  M. Redman,et al.  A 500 km s−1 outflow from the young bipolar planetary nebula Mz 3 , 2000 .

[7]  H. E. Schwarz,et al.  HE 2-104: A LINK BETWEEN SYMBIOTIC STARS AND PLANETARY NEBULAE , 1989 .

[8]  R. Gehrz.  Infrared studies of classical novae and their contributions to the ISM , 1999 .

[9]  Bruce Balick,et al.  Shapes and Shaping of Planetary Nebulae , 2002 .

[10]  N. Smith,et al.  Keck LWS Images of the Compact Nebula around RY Scuti in the Thermal Infrared , 2001 .

[11]  Robert D. Gehrz,et al.  Mass and Kinetic Energy of the Homunculus Nebula around η Carinae , 2003 .

[12]  R. Gehrz,et al.  Proper Motion and Excitation Structure of the Expanding Ionized Rings around RY Scuti , 2001 .

[13]  R. C. Gilman.  Planck Mean Cross-Sections for Four Grain Materials , 1974 .

[14]  N. Smith,et al.  A Disrupted Circumstellar Torus inside η Carinae’s Homunculus Nebula , 2002, astro-ph/0201489.

[15]  N. Smith,et al.  The Purple Haze of η Carinae: Binary-induced Variability?* , 2004, astro-ph/0406408.

[16]  N. Smith.  Spatial distribution of near‐infrared and optical emission properties in the bipolar nebula Menzel 3 , 2003 .

[17]  B. Balick,et al.  The Evolving Morphology of the Bipolar Nebula M2-9 , 2000 .

[18]  M. Livio,et al.  The Southern Crab from a New Perspective , 2001 .

[19]  Studies of bipolar nebulae. IV - MZ 3 /= PK 331 - 1 deg 1/ , 1978 .

[20]  J. Meaburn,et al.  The structure and dynamics of the bi-polar nebula MZ – 3 , 1983 .

[21]  J. Hackwell,et al.  The evolution of the dust shell of Nova Serpentis 1978 , 1980 .

[22]  B. Balick.  M2-9 - A planetary nebula with an eruptive nucleus? , 1989 .

[23]  Where is the Doughnut? Luminous Blue Variable Bubbles and Aspherical Fast Winds , 1998, astro-ph/9805162.

[24]  R. Goodrich.  Proto-planetary nebulae. I, The extreme bipolar nebulae M2-9 and M1-91 , 1991 .

[25]  Menzel 3: Dissecting the Ant , 2004, astro-ph/0406551.

[26]  R. Gehrz,et al.  The Infrared Morphology of η Carinae , 1998 .

[27]  10-µm imaging of the bipolar protoplanetary nebula Mz-3 , 1996 .

[28]  DAVID S. Evans.  Notes on Five Southern Gaseous Nebulae , 1959 .

[29]  Bipolar outflows and the evolution of stars , 1998, astro-ph/9805275.

[30]  E. Guenther,et al.  Optical and Infrared Spectroscopy of Circumstellar Matter , 1999 .

[31]  Nathan Smith,et al.  Dissecting the Homunculus nebula around Eta Carinae with spatially resolved near-infrared spectroscopy , 2002, astro-ph/0211614.