Study of the sub-AU disk of the Herbig B[e] star HD 85567 with near-infrared interferometry

Vural, Jasmin; Kraus, Stefan; Kreplin, Alexander; Weigelt, G.; Fossat, E.; Massi, F.; Perraut, K.; Vakili, F.

doi:10.1051/0004-6361/201424214

Cited by 7 publications

(7 citation statements)

References 33 publications

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“…The extended halo component contributes with 13 ± 2% (DDN model)/16 ± 4% (geometric model) to the total flux, similar as found in other young stellar objects with extended halo emission (∼9-16%, e.g. Monnier et al 2006;Chen et al 2012;Vural et al 2012Vural et al , 2014a that is interpreted as scattered emission from the outer disk surface or material outside the disk plane, for example, a dusty disk wind (e.g., Bans & Königl 2012).…”

Section: Discussionsupporting

confidence: 80%

Resolving the inner disk of UX Orionis

Kreplin

Madlener

Chen

et al. 2016

A&A

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Aims. The cause of the UX Ori variability in some Herbig Ae/Be stars is still a matter of debate. Detailed studies of the circumstellar environment of UX Ori objects (UXORs) are required to test the hypothesis that the observed drop in photometry might be related to obscuration events. Methods. Using near-and mid-infrared interferometric AMBER and MIDI observations, we resolved the inner circumstellar disk region around UX Ori. Results. We fitted the K-, H-, and N-band visibilities and the spectral energy distribution (SED) of UX Ori with geometric and parametric disk models. The best-fit K-band geometric model consists of an inclined ring and a halo component. We obtained a ring-fit radius of 0.45 ± 0.07 AU (at a distance of 460 pc), an inclination of 55.6 ± 2.4 • , a position angle of the system axis of 127.5 ± 24.5 • , and a flux contribution of the over-resolved halo component to the total near-infrared excess of 16.8 ± 4.1%. The best-fit N-band model consists of an elongated Gaussian with a HWHM ∼ 5 AU of the semi-major axis and an axis ration of a/b ∼ 3.4 (corresponding to an inclination of ∼72 • ). With a parametric disk model, we fitted all near-and mid-infrared visibilities and the SED simultaneously. The model disk starts at an inner radius of 0.46 ± 0.06 AU with an inner rim temperature of 1498 ± 70 K. The disk is seen under an nearly edge-on inclination of 70 ± 5 • . This supports any theories that require high-inclination angles to explain obscuration events in the line of sight to the observer, for example, in UX Ori objects where orbiting dust clouds in the disk or disk atmosphere can obscure the central star.

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Section: Discussionsupporting

confidence: 80%

Resolving the inner disk of UX Orionis

Kreplin

Madlener

Chen

et al. 2016

A&A

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“…′′ 5 is confirmed later (Baines et al 2006). Vural et al (2014) performed NIR interferometric observations to investigate the sub-AU scale disk structure of HD 85567 with the AMBER instrument at the VLTI and found that the inner radius of the disk (R in ∼ 0.67 AU with a temperature of T in ∼ 2200 K) is smaller than that expected from the size-luminosity relation. This implies that an optically thick gaseous inner disk exists to shield the stellar radiation of the central star so that dust can survive closer to the star than the radius of dust sublimation (T ∼ 1500 K).…”

Section: A19 Hd 85567mentioning

confidence: 74%

Polycyclic Aromatic Hydrocarbons in Protoplanetary Disks around Herbig Ae/Be and T Tauri Stars

Seok¹,

Li²

2017

ApJ

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A distinct set of broad emission features at 3. 3, 6.2, 7.7, 8.6, 11.3, and 12.7 µm, is often detected in protoplanetary disks (PPDs). These features are commonly attributed to polycyclic aromatic hydrocarbons (PAHs). We model these emission features in the infrared spectra of 69 PPDs around 14 T Tauri and 55 Herbig Ae/Be stars in terms of astronomical-PAHs. For each PPD, we derive the size distribution and the charge state of PAHs. We then examine the correlations of the PAH properties (i.e., sizes and ionization fractions) with the stellar properties (e.g., stellar effective temperature, luminosity, and mass). We find that the characteristic size of PAHs shows a tendency of correlating with the stellar effective temperature (T eff ) and interpret this as the preferential photodissociation of small PAHs in systems with higher T eff of which the stellar photons are more energetic. In addition, the PAH size shows a moderate correlation with the red-ward wavelength-shift of the 7.7 µm PAH feature that is commonly observed in disks around cool stars. The ionization fraction of PAHs does not seem to correlate with any stellar parameters. This is because the charging of PAHs depends on not only the stellar properties (e.g., T eff , luminosity) but also the spatial distribution of PAHs in the disks. The mere negative correlation between the PAH size and the stellar age suggests that continuous replenishment of PAHs via the outgassing of cometary bodies and/or the collisional grinding of planetesimals and asteroids is required to maintain the abundance of small PAHs against complete destruction by photodissociation.

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“…It is still not clear if this phenomenon is caused by the same physical process because only a few objects have been studied in depth. Optical interferometry is a powerful tool to investigate the close environment of these stars (Weigelt et al 2011;Wheelwright et al 2012Wheelwright et al , 2013Vural et al 2014) and in some cases reveal their binarity (e.g. Millour et al 2009;Kraus et al 2012;Wang et al 2012).…”

Section: Introductionmentioning

confidence: 99%

A disk asymmetry in motion around the B[e] star MWC158

Kluska

Benisty

Soulez

et al. 2016

A&A

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Context. MWC158 is a star with the B[e] phenomenon that shows strong spectrophotometric variability (in lines and in UV and visible continuum) attributed to phases of shell ejection. The evolutionary stage of this star was never clearly determined. Previous interferometric, spectropolarimetric and spectro-interferometric studies suggest a disk morphology for its environment. Aims. We investigate the origin of the variability within the inner astronomical unit of the central star using near-infrared interferometric observations with PIONIER at the VLTI over a two-year period. Methods. We performed an image reconstruction of the circumstellar environment using the SPARCO method. We discovered that the morphology of the circumstellar environment could vary on timescales of weeks or days. We carried out a parametric fit of the data with a model consisting of a star, a disk and a bright spot that represents a brighter emission in the disk. Results. We detect strong morphological changes in the first astronomical unit around the star, that happen on a timescale of few months. We cannot account for such variability well with a binary model. Our parametric model fits the data well and allows us to extract the location of the asymmetry for different epochs. Conclusions. For the first time, we detect a morphological variability in the environment of MWC158. This variability is reproduced by a model of a disk and a bright spot. The locations of the bright spot suggest that it is located in the disk, but its precise motion is not determined. The origin of the asymmetry in the disk is complex and may be related to asymmetric shell ejections.

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Study of the sub-AU disk of the Herbig B[e] star HD 85567 with near-infrared interferometry

Cited by 7 publications

References 33 publications

Resolving the inner disk of UX Orionis

Resolving the inner disk of UX Orionis

Polycyclic Aromatic Hydrocarbons in Protoplanetary Disks around Herbig Ae/Be and T Tauri Stars

A disk asymmetry in motion around the B[e] star MWC158

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