7 research outputs found
Optical and Mid-Infrared Observations of the Planetary Nebula NGC 6781
Although the planetary nebula NGC 6781 appears to possess an elliptical
morphology, its kinematic and emission characteristics are in many ways
unusual, and it is possible that it may represent a bipolar source oriented
close to the line of sight. We shall present deep imaging of this nebula in [O
III], Ha and [N II], and using broad-band (F555W and F814W) filters. These were
taken with the 2.56-m Nordic Optical Telescope and Hubble Space Telescope. This
is combined with mid-infrared (MIR) imaging and spectroscopy acquired with the
Spitzer Space Telescope (Spitzer), and near-infrared spectroscopy deriving from
the Infrared Space Observatory (ISO). These reveal details of the complex [N
II] structure associated with extended shell emission, perhaps associated with
highly inclined bipolar lobes. We also note the presence of narrow absorbing
filaments and clumps projected against the surface of the envelope, components
which may be responsible for much of the molecular emission. We point out that
such clumps may be responsible for complex source structure in the MIR, and
give rise to asymmetries in emission along the major axis of the source.Comment: 12 pages, 10 figures, Accepted for publication in MNRAS. 32 pages in
arXi
The origin of dust in galaxies in the Herschel and ALMA era
Meeting Report: Haley Gomez and Mikako Matsuura summarize some of the recent Planck and Herschel data presented at an RAS meeting earlier this year