Diapositiva 1

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SUB-ARCSEC MORPHOLOGY OF PLANETARY NEBULAE
Luis F. Miranda(1), Gerardo Ramos-Larios(1,2)
Martín A. Guerrero(1)
(1) Instituto de Astrofísica de Andalucía CSIC
(Granada, Spain) (2) Instituto de Astronomía y
Meteorología (Guadalajara, Mexico)
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Morphological classifications of Planetary
Nebulae Balick (1987) Stanghellini et al.
(1993) Manchado el al. (1996) Sahai et al.
(2007) Classification based on basic geometrical
shapes small-scale structures Connected to
models to explain the formation of
PNe (Interacting winds, collimated outflows)
NGC6720
Abell 39
MyCn18
IC4634
(Jacoby)
(HST)
(HST)
Point-symmetry (Multiple structures)
Round (Circular)
Elliptical
Bipolar (Hour-glass)
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HST images have shown a large variety of shapes
and small-scale structures in PNe, whose origin
is not well understood These observations have
motivated new scenarios to explain the formation
of PNe (binary stars, magnetic fields, etc)
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NORDIC OPTICAL TELESCOPE (La Palma, Spain)
ALFOSC
(Andalucía Faint Object Spectrograph and Camera)
Selected PNe Bipolar PNe in the Manchado et al.s
Catalogue with HaNII images and/or poor
spatial resolution Other bipolar PNe with
microstructures
Observations Date 2006 June and 2008
September Seeing 0.5 and 0.9 (scale 0.19
pixel-1) Filters Ha - NII6584 - OIII5007
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Small Planetary Nebulae with FLIERs
NGC6826
NGC7009
IC 351
Vy 1-1
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Hu1-2
Hu1-2 Bipolar or elliptical PN ? Bow-shock-like
polar knots (FLIERS) Peculiar structure in the
equator
OIII Ha NII
OIII Ha NII
NGC 6778
NGC 6778 Bipolar or elliptical PN ? Two pairs of
jets along different directions filaments and
cometary knots Peculiar structure in the equator
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K3-17
OIII Ha NII
K3-17 Bipolar PN Spindle-like bipolar lobes
Collimated outflows shaping the lobes Bubbles in
the equatorial region Stellar wind
protruding through or breaking an equatorial
structure OR equatorial flows
K3-46
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THE VARIETY OF BIPOLAR PLANETARY NEBULAE
HaTr 10
NGC 650
BV 5
M 2-48
M 4-17
K3-46
OIII Ha NII
Evolutionary effects Inclination angle
Differences in the process of their formation
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IC5217
IC5217 (edge-on) bipolar PN with
point-symmetric structures Size along the major
axis 90 Ring radius 2, thickness 0.8 !!!
The ring cannot collimate (hydrodynamically) the
bipolar lobes High collimation close to the
central star? Magnetic field ? Binary central
star?
OIII Ha SII
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KjPn6. Peculiar morphology
The morphology of KjPn6 does not fit into the
typical morphological classes.
IC 5217 (central region)
KjPn6 ring-like or bipolar (with extremely faint
bipolar lobes?) PN
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M1-79 a case of PN with multiple structures at
different orientations
Ellipsoidal shell (Weinberger 1979)
Various episodes of slow wind/fast wind ejection
at different directions. The density contrast in
the slow wind should be oriented in a different
direction in each episode.
One episode of slow wind ejection collimated
outflows/wind at different directions
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FINAL COMMENTS
The observations of PNe with high spatial
resolution reveal morphologies in poorly
studied PNe that are already observed in well
studied PNe
(e.g., IC351, Vy1-1) new or
complex structures that imply new phenomena in
the formation of PNe.
(e.g., K3-17, NGC6778,
M1-79) The observed structures requiere
alternative models for the formation of these
objects.
The formation processes that occur in some PNe,
do not occur in other PNe. Bipolar PNe exhibit a
large variety of morphologies that suggest the
existence of different formation processes.
Many physical phenomena contribute to the
formation/shaping of a PN magnetic fields,
interacting winds, photoionization, binary nature
of the central star.
IN ADDITION The contribution of these agents
changes with time.
Some (forgotten) objects (e.g., M1-79, K3-17,
Hu1-2, NGC6778) reveal interesting structures and
require more observations. They show a large
size suitable for ground-based observations.