New insights on the complex planetary nebula Hen 2-113

Lagadec, E.; Chesneau, O.; Matsuura, M.; Marco, Orsola De; Pacheco, J. A. de Freitas; Zijlstra, A. A.; Acker, A.; Clayton, Geoffrey C.; López, B.

doi:10.1051/0004-6361:20053803

Cited by 30 publications

(43 citation statements)

References 38 publications

(44 reference statements)

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“…Whereas the environment around Hen2-113 appeared sufficiently extended to be fully resolved with the spatial resolution of a single 8m telescope (about 250 mas at 10 µm) revealing a 0.5 wide ring (Lagadec et al 2006), fringes were obtained from CPD-56…”

Section: Cpd-56mentioning

confidence: 99%

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A close look into the carbon disk at the core of the planetary nebula CPD-56°8032

Chesneau¹,

Collioud²,

Marco

et al. 2006

A&A

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Aims. We present high spatial resolution observations of the dusty core of the Planetary Nebula with Wolf-Rayet central star CPD-56• 8032, for which indications of a compact disk have been found by HST/SITS observations. Methods. These observations were taken with the mid-infrared interferometer VLTI/MIDI in imaging mode providing a typical 300 mas resolution and in interferometric mode using UT2-UT3 47m baseline providing a typical spatial resolution of 20 mas. We also made use of unpublished HST/ACS images in the F435W and F606W filters. Results. The visible HST images exhibit a complex multilobal geometry dominated by faint lobes. The farthest structures are located at 7 from the star. The mid-IR environment of CPD-56• 8032 is dominated by a compact source, barely resolved by a single UT telescope in a 8.7 µm filter (∆λ = 1.6 µm, contaminated by PAH emission). The infrared core is almost fully resolved with the three 40-45 m projected baselines ranging from −5• to 51• but smooth oscillating fringes at low level have been detected in spectrally dispersed visibilities. This clear signal is interpreted in terms of a ring structure which would define the bright inner rim of the equatorial disk. Geometric models allowed us to derive the main geometrical parameters of the disk. For instance, a reasonably good fit is reached with an achromatic and elliptical truncated Gaussian with a radius of 97 ± 11 AU, an inclination of 28 ± 7• and a PA for the major axis at 345• ± 7• . Furthermore, we performed some radiative transfer modeling aimed at further constraining the geometry and mass content of the disk, by taking into account the MIDI dispersed visibilities, spectra, and the large aperture SED of the source. These models show that the disk is mostly optically thin in the N band and highly flared. As a consequence of the complex flux distribution, an edge-on inclination is not excluded by the data.

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Section: Cpd-56mentioning

confidence: 99%

“…• 8032 in terms of spectral energy distribution (SED) and stellar properties, see Lagadec et al 2006). Moreover, a putative companion bright enough to be detected by MIDI would exhibit a photometric and spectroscopic signature that would have been already detected by existing observations.…”

Section: Geometric Modelsmentioning

confidence: 99%

A close look into the carbon disk at the core of the planetary nebula CPD-56°8032

Chesneau¹,

Collioud²,

Marco

et al. 2006

A&A

Self Cite

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“…For instance, the accretion disk of an active galactic nuclei is considered as unresolved in order to retrieve its environment (Kishimoto et al 2013). A method of separation of the star from its environment was invoked for asymptotic giant branch stars (Hillen et al 2013), or planetary nebulae (Lagadec et al 2006).…”

Section: Introductionmentioning

confidence: 99%

SPARCO : a semi-parametric approach for image reconstruction of chromatic objects

Kluska

Malbet

Berger

et al. 2014

A&A

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Context. The emergence of optical interferometers with three and more telescopes allows image reconstruction of astronomical objects at the milliarcsecond scale. However, some objects contain components with very different spectral energy distributions (SED; i.e. different temperatures), which produces strong chromatic effects on the interferograms that have to be managed with care by image reconstruction algorithms. For example, the gray approximation for the image reconstruction process results in a degraded image if the total (u, v)-coverage given by the spectral supersynthesis is used. Aims. The relative flux contribution of the central object and an extended structure changes with wavelength for different temperatures. For young stellar objects, the known characteristics of the central object (i.e., stellar SED), or even the fit of the spectral index and the relative flux ratio, can be used to model the central star while reconstructing the image of the extended structure separately. Methods. We present a new method, called SPARCO (semi-parametric algorithm for the image reconstruction of chromatic objects), which describes the spectral characteristics of both the central object and the extended structure to consider them properly when reconstructing the image of the surrounding environment. We adapted two image-reconstruction codes (Macim, Squeeze, and MiRA) to implement this new prescription. Results. SPARCO is applied using Macim, Squeeze, and MiRA on a young stellar object model and also on literature data on HR 5999 in the near-infrared with the VLTI. We obtain smoother images of the modeled circumstellar emission and improve the χ 2 by a factor 9. Conclusions. This method paves the way to improved aperture-synthesis imaging of several young stellar objects with existing datasets. More generally, the approach can be used on astrophysical sources with similar features, such as active galactic nuclei, planetary nebulae, and asymptotic giant branch stars.

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“…(1) Werner & Herwig (2006); (2) Mendez & Niemela (1977); (3) Heap (1977); (4) Drilling (1983); (5) Tylenda et al (1993); (6) Phillips (2003); (7) Corradi & Schwarz (1995); (8) Jordan et al (2005); (9) Lagadec et al (2006). than 600 G, or that the field has a complex structure.…”

Section: Introductionmentioning

confidence: 99%

Weak magnetic fields in central stars of planetary nebulae?

Steffen

Hubrig

Todt

et al. 2014

A&A

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Context. It is not yet clear whether magnetic fields play an essential role in shaping planetary nebulae (PNe), or whether stellar rotation alone and/or a close binary companion, stellar or substellar, can account for the variety of the observed nebular morphologies. Aims. In a quest for empirical evidence verifying or disproving the role of magnetic fields in shaping planetary nebulae, we follow up on previous attempts to measure the magnetic field in a representative sample of PN central stars. Methods. We obtained low-resolution polarimetric spectra with FORS 2 installed on the Antu telescope of the VLT for a sample of 12 bright central stars of PNe with different morphologies, including two round nebulae, seven elliptical nebulae, and three bipolar nebulae. Two targets are Wolf-Rayet type central stars.Results. For the majority of the observed central stars, we do not find any significant evidence for the existence of surface magnetic fields. However, our measurements may indicate the presence of weak mean longitudinal magnetic fields of the order of 100 Gauss in the central star of the young elliptical planetary nebula IC 418 as well as in the Wolf-Rayet type central star of the bipolar nebula Hen 2-113 and the weak emission line central star of the elliptical nebula Hen 2-131. A clear detection of a 250 G mean longitudinal field is achieved for the A-type companion of the central star of NGC 1514. Some of the central stars show a moderate night-to-night spectrum variability, which may be the signature of a variable stellar wind and/or rotational modulation due to magnetic features. Conclusions. Since our analysis indicates only weak fields, if any, in a few targets of our sample, we conclude that strong magnetic fields of the order of kG are not widespread among PNe central stars. Nevertheless, simple estimates based on a theoretical model of magnetized wind bubbles suggest that even weak magnetic fields below the current detection limit of the order of 100 G may well be sufficient to contribute to the shaping of the surrounding nebulae throughout their evolution. Our current sample is too small to draw conclusions about a correlation between nebular morphology and the presence of stellar magnetic fields.

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New insights on the complex planetary nebula Hen 2-113

Cited by 30 publications

References 38 publications

A close look into the carbon disk at the core of the planetary nebula CPD-56°8032

A close look into the carbon disk at the core of the planetary nebula CPD-56°8032

SPARCO : a semi-parametric approach for image reconstruction of chromatic objects

Weak magnetic fields in central stars of planetary nebulae?

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