Astronomy & Astrophysics

All Figures

$\begin{figure} \par\psfig{figure=1135fig1.ps,width=12.0truecm} \end{figure}$ Figure 1: HST image of LkH $\alpha$ 198, taken with the NICMOS camera at 1.1 $\mu$ m. North is up and East to the left. The source approximately 6'' due north of LkH $\alpha$ 198 is the already known companion LkH $\alpha$ 198 B. A fan-shaped trail of emission is visible to the east of this companion. The new speckle companion, LkH $\alpha$ 198 A2, lies within 60 mas of the primary and is not discernable in this image (see Fig. 2). The directions to various associated HH objects and other structures are indicated. The various structures comprising HH 164 were identified by Corcoran et al. (1995) as the jet of LkH $\alpha$ 198. The HH object HH 161 is believed to be powered by the companion LkH $\alpha$ 198 B, and the arrow pointing to this object is shown originating from the position of this object. Interesting streamer-like structure can be seen to the east of LkH $\alpha$ 198 with the same position angle as HH 161, perhaps indicating that the HH 161 flow interacts with the material around LkH $\alpha$ 198. The axis of the biconical nebula mapped by Perrin et al. (2004) is indicated, running nearly exactly North-South. The opening angle of this structure is approximately 30 $^{\circ }$ , and so the outflow HH 164 emerges from within the supposed bipolar cavity, even though its direction is not exactly aligned with the axis.
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In the text

$\begin{figure} \par {\hspace*{4mm} \psfig{figure=1135fg2a.eps,width=6.0truecm}\hspace*{4mm}} \\ \psfig{figure=1135fg2b.ps,width=7.0truecm} \end{figure}$ Figure 2: Top: contour map of the LkH $\alpha$ 198 system constructed from speckle observations on the 26th October 1999. Bottom: the position of the LkH $\alpha$ 198 companion relative to the primary. The scale is given in mas and AU for an assumed distance of 600 pc. The solid line is a circle of radius 37 AU, for an assumed distance of 600 pc, centred on the primary
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In the text

$\begin{figure} \par\psfig{figure=1135fg3a.ps,width=8.0truecm}\hspace*{3mm} \psfi... ...8.0truecm}\hspace*{3mm} \psfig{figure=1135fg3d.ps,width=8.0truecm} \end{figure}$ Figure 3: Orbit fits to the motion of the LkH $\alpha$ 198 companion for various choices of initial parameters. The main panel of each plot shows the fitted orbit projected on the plane of the sky. North is up and east to the left. The measured data points are plotted as open squares and the corresponding points in the fit are plotted with open triangles. A dash-dotted line marks the major axis, and a solid line marks the line of nodes (i.e. the line of intersection between the orbital plane and the plane of the sky). The ascending and descending nodes are labelled "a'' and "d''. In the inset at upper right in each figure, we show the segment of the orbit with the data points on a larger scale. The data points are shown with errorbars, and the fitted points are again plotted as open triangles. The first and last points are labelled with the observing epoch. In the inset at lower right, we show the projection in a plane perpendicular to the plane of the sky. North is up and the radial direction (pointing away from the observer) is to the left. The coordinate systems are indicated in each panel of the top left-hand plot. a) Fit for an assumed primary mass of 1.6 $M_{\odot }$ and secondary mass 1.0 $M_{\odot }$ . The initial guess for the fit involves a low velocity in the R direction and a small displacement from the plane of the sky. As a result, the fitted orbit lies close to the plane of the sky. b) The same low starting values for R position and velocity, but for an assumed primary mass of 4.0 $M_{\odot }$ and secondary mass 2.5 $M_{\odot }$ . c) A fit with an assumed primary mass of 4.0 $M_{\odot }$ and secondary mass 2.5 $M_{\odot }$ , with starting conditions chosen to produce a near-circular orbit. d) This fit has masses of 4 and 2.5 $M_{\odot }$ and a high initial radial velocity, which is intended to produce an orbital plane as highly inclined as possible to the plane of the sky.
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In the text

$\begin{figure} \par {\hspace*{9mm}\psfig{figure=1135fg4a.ps,width=5.8truecm}\hsp... ...{9mm}}\\ \par\psfig{figure=1135fg4b.ps,angle=270.,width=7.8truecm} \end{figure}$ Figure 4: Top: the 2d power spectrum of Elias 1 from 2003.76. Bottom: a cut across the fringes, with a cosine fit.
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In the text

$\begin{figure} \par {\hspace*{4mm} \psfig{figure=1135fg5a.eps,width=5.6truecm}\h... ...{4mm}}\\ \vspace*{2mm} \psfig{figure=1135fg5b.ps,width=6.6truecm} \end{figure}$ Figure 5: Top: contour map of Elias 1 made from the 2003 observations. Bottom: the position of the Elias 1 companion relative to the primary. The primary position is marked with a dot.
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In the text

$\begin{figure} \par\psfig{figure=1135fg6a.eps, width=6.8truecm}\hspace*{3mm} \ep... ...5fg6f.eps, width=8.8truecm,bbllx=100,bblly=-50,bburx=651,bbury=325} \end{figure}$ Figure 6: Bispectrum speckle interferometry reconstructions of HK Ori. Contour plots on the left show the relative positions of the sources and wire-frame plots on the right illustrate the relative brightnesses. The components A and B are identified in the topmost contour plot.
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In the text

$\begin{figure} \par\psfig{figure=1135fig7.ps,width=7.0truecm} \end{figure}$ Figure 7: The position of the HK Ori companion B relative to the primary. The separate optical positions from 1995 and separate H and K positions for epoch 1997.8 have each been averaged to produce one position for each date. The solid line is a circle of radius 155 AU for an assumed distance of 460 pc centred on the primary.
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In the text

$\begin{figure} \par\psfig{figure=1135fig8.ps,width=10.3truecm, angle=0.} \end{figure}$ Figure 8: The SED of HK Ori's components. Data: open symbols stand for the primary and filled ones for the secondary. Separate photometric measurements for HK Ori A and HK Ori B from this work are marked with squares. Flux ratios measured by LRH97 and normalised to separate fluxes by reference to the composite photometry of Hillenbrand et al. (1992) are marked with triangles. For other points (diamonds), we have subtracted the model fit to HK Ori B from the total system flux as measured by Hillenbrand et al. (1992) to obtain supposed values for the flux of HK Ori A. We also show the 1.3 mm upper limit obtained by Henning et al. (1998), also with the flux of the HK Ori B model subtracted. In U, B, and V, the uncertainties result from the reported variability. At NIR wavelengths, the measurement uncertainties are of order 10% and are not plotted for the sake of clarity. Model for HK Ori A: a two-layer disk model by Lachaume et al. (2003), including irradiation by the central star and heating by viscosity fits the data very well at all wavelengths (solid line). For comparison's sake similar models, in which irradiation or viscous heating is turned off, are displayed (dashed line is without irradiation and dash-dotted line is without viscous heating). Model parameters are shown in Table 3. Model for HK Ori B: the SED of the secondary does not hint at an infrared excess, so a photosphere model is fit to the data (dotted lines). It should be noted that excess emission from distant reprocessing material cannot be ruled out.
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In the text

$\begin{figure} \par\psfig{figure=1135fig9.ps,width=6.0truecm} \end{figure}$ Figure 9: (H - K) vs. (J - H) colour-colour diagram showing the positions of the primary and secondary in the HK Ori system. Component A is shown with a circular point and component B with a triangle. The colours have been corrected for the effects of interstellar reddening. The main sequence (from Bessell & Brett 1988) and the direction of interstellar reddening are also shown.
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In the text

$\begin{figure} \par {\hspace*{5mm}\psfig{figure=1135f10a.eps,width=6.0truecm}\hspace*{5mm}}\\ \psfig{figure=1135f10b.ps,width=7.0truecm}\end{figure}$ Figure 10: Top: contour plot of the V380 Ori system. Bottom: position of the V380 Ori companion relative to the primary. The solid line is a circle of radius 60 AU centred on the primary. The data point of LRH97 is shown with an open diamond. This position was obtained by LRH97 from data taken over a period of 3 years. Our data point is marked with a filled symbol.
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In the text

$\begin{figure} \par {\hspace{4mm} \psfig{figure=1135fg2a.eps,width=6.0truecm}\hspace{4mm}} \\ \psfig{figure=1135fg2b.ps,width=7.0truecm} \end{figure}$	Figure 2: Top: contour map of the LkH $\alpha$ 198 system constructed from speckle observations on the 26th October 1999. Bottom: the position of the LkH $\alpha$ 198 companion relative to the primary. The scale is given in mas and AU for an assumed distance of 600 pc. The solid line is a circle of radius 37 AU, for an assumed distance of 600 pc, centred on the primary
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$\begin{figure} \par {\hspace*{9mm}\psfig{figure=1135fg4a.ps,width=5.8truecm}\hsp... ...{9mm}}\\ \par\psfig{figure=1135fg4b.ps,angle=270.,width=7.8truecm} \end{figure}$	Figure 4: Top: the 2d power spectrum of Elias 1 from 2003.76. Bottom: a cut across the fringes, with a cosine fit.
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$\begin{figure} \par {\hspace{4mm} \psfig{figure=1135fg5a.eps,width=5.6truecm}\h... ...{4mm}}\\ \vspace{2mm} \psfig{figure=1135fg5b.ps,width=6.6truecm} \end{figure}$	Figure 5: Top: contour map of Elias 1 made from the 2003 observations. Bottom: the position of the Elias 1 companion relative to the primary. The primary position is marked with a dot.
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$\begin{figure} \par\psfig{figure=1135fg6a.eps, width=6.8truecm}\hspace*{3mm} \ep... ...5fg6f.eps, width=8.8truecm,bbllx=100,bblly=-50,bburx=651,bbury=325} \end{figure}$	Figure 6: Bispectrum speckle interferometry reconstructions of HK Ori. Contour plots on the left show the relative positions of the sources and wire-frame plots on the right illustrate the relative brightnesses. The components A and B are identified in the topmost contour plot.
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$\begin{figure} \par\psfig{figure=1135fig7.ps,width=7.0truecm} \end{figure}$	Figure 7: The position of the HK Ori companion B relative to the primary. The separate optical positions from 1995 and separate H and K positions for epoch 1997.8 have each been averaged to produce one position for each date. The solid line is a circle of radius 155 AU for an assumed distance of 460 pc centred on the primary.
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$\begin{figure} \par\psfig{figure=1135fig9.ps,width=6.0truecm} \end{figure}$	Figure 9: (H - K) vs. (J - H) colour-colour diagram showing the positions of the primary and secondary in the HK Ori system. Component A is shown with a circular point and component B with a triangle. The colours have been corrected for the effects of interstellar reddening. The main sequence (from Bessell & Brett 1988) and the direction of interstellar reddening are also shown.
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$\begin{figure} \par {\hspace{5mm}\psfig{figure=1135f10a.eps,width=6.0truecm}\hspace{5mm}}\\ \psfig{figure=1135f10b.ps,width=7.0truecm}\end{figure}$	Figure 10: Top: contour plot of the V380 Ori system. Bottom: position of the V380 Ori companion relative to the primary. The solid line is a circle of radius 60 AU centred on the primary. The data point of LRH97 is shown with an open diamond. This position was obtained by LRH97 from data taken over a period of 3 years. Our data point is marked with a filled symbol.
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