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

Kluska, J.; Benisty, M.; Soulez, Ferréol; Berger, J.‐P.; Bouquin, J.-B. Le; Malbet, Fabien; Lazareff, B.; Thiébaut, Éric

doi:10.1051/0004-6361/201527924

Cited by 28 publications

(59 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One notable exception is MWC 158 (at graph coordinates (0.85, 0)); this object has been observed with PIONIER before and during the Herbig Large Program, over a time span of ≈2 years, and has been shown (Kluska et al 2016) to have a variable structure on ≈ 2 mas scale, possibly corresponding to the orbital motion of a bright condensation around the central star.…”

Section: Is the Azimuthal Modulation Aligned As We Expect?mentioning

confidence: 99%

Structure of Herbig AeBe disks at the milliarcsecond scale

Lazareff¹,

Berger²,

Kluska³

et al. 2017

A&A

Self Cite

126

143

View full text Add to dashboard Cite

Context. It is now generally accepted that the near-infrared excess of Herbig AeBe stars originates in the dust of a circumstellar disk. Aims. The aims of this article are to infer the radial and vertical structure of these disks at scales of order 1 au, and the properties of the dust grains. Methods. The program objects (51 in total) were observed with the H-band (1.6µm) PIONIER/VLTI interferometer. The largest baselines allowed us to resolve (at least partially) structures of a few tenths of an au at typical distances of a few hundred parsecs. Dedicated UBVRIJHK photometric measurements were also obtained. Spectral and 2D geometrical parameters are extracted via fits of a few simple models: ellipsoids and broadened rings with azimuthal modulation. Model bias is mitigated by parallel fits of physical disk models. Sample statistics were evaluated against similar statistics for the physical disk models to infer properties of the sample objects as a group. Results. We find that dust at the inner rim of the disk has a sublimation temperature T sub ≈ 1800K. A ring morphology is confirmed for approximately half the resolved objects; these rings are wide δ r/r ≥ 0.5. A wide ring favors a rim that, on the star-facing side, looks more like a knife edge than a doughnut. The data are also compatible with a the combination of a narrow ring and an inner disk of unspecified nature inside the dust sublimation radius. The disk inner part has a thickness z/r ≈ 0.2, flaring to z/r ≈ 0.5 in the outer part. We confirm the known luminosity-radius relation; a simple physical model is consistent with both the mean luminosity-radius relation and the ring relative width; however, a significant spread around the mean relation is present. In some of the objects we find a halo component, fully resolved at the shortest interferometer spacing, that is related to the HAeBe class.

show abstract

Section: Is the Azimuthal Modulation Aligned As We Expect?mentioning

confidence: 99%

Structure of Herbig AeBe disks at the milliarcsecond scale

Lazareff¹,

Berger²,

Kluska³

et al. 2017

A&A

Self Cite

126

143

View full text Add to dashboard Cite

show abstract

“…However, the image also reveals spiral features that seem to extend from the major axis of the disk. To assess the significance of the features seen in the image we used the bootstrap method, where we reconstructed images from 500 new data sets built by drawing baselines and triangles from the full data set (see Kluska et al 2016). Figure 11 shows the average image computed for all the bootstrap reconstructions together with contours corresponding to the pixel significance levels.…”

mentioning

confidence: 99%

A Multi-instrument and Multi-wavelength High Angular Resolution Study of MWC 614: Quantum Heated Particles Inside the Disk Cavity*

Kluska

Kraus

Davies

et al. 2018

ApJ

View full text Add to dashboard Cite

High angular resolution observations of young stellar objects are required to study the inner astronomical units of protoplanetary disks in which the majority of planets form. As they evolve, gaps open up in the inner disk regions and the disks are fully dispersed within ∼10 Myr. MWC614 is a pretransitional object with a ∼10 au radius gap. We present a set of high angular resolution observations of this object including SPHERE/ZIMPOL polarimetric and coronagraphic images in the visible, Keck/NIRC2 near-infrared (NIR) aperture masking observations, and Very Large Telescope Interferometer (AMBER, MIDI, and PIONIER) and Center for High Angular Resolution Astronomy (CLASSIC and CLIMB) long-baseline interferometry at infrared wavelengths. We find that all the observations are compatible with an inclined disk (i∼55°at a position angle of ∼20°-30°). The mid-infrared data set confirms that the disk inner rim is at 12.3±0.4 au from the central star. We determined an upper mass limit of 0.34 M e for a companion inside the cavity. Within the cavity, the NIR emission, usually associated with the dust sublimation region, is unusually extended (∼10 au, 30 times larger than the theoretical sublimation radius) and indicates a high dust temperature (T∼1800 K). As a possible result of companion-induced dust segregation, quantum heated dust grains could explain the extended NIR emission with this high temperature. Our observations confirm the peculiar state of this object where the inner disk has already been accreted onto the star, exposing small particles inside the cavity to direct stellar radiation.

show abstract

“…There are several clearing mechanisms proposed, like grain growth, photoevaporation, and dynamical clearing by a (sub-)stellar companion (Espaillat et al 2014). Kluska et al (2016) reported a moving asymmetry in the disc of HD 50138, which could be fitted with a circular trajectory with a radius of ∼2 au. However, they could not directly link the asymmetry to the presence of a companion, rather they hypothesized that it may be a spiral arm or other disc asymmetry.…”

Section: Geometric Modellingmentioning

confidence: 97%

“…Following previous near-IR interferometric studies that observed disc asymmetries (e.g., Kluska et al 2016;Koutoulaki et al 2018), we examined the MIDI data to find indications for binarity. The binary signal in the spectrally resolved correlated spectra and differential phases usually appears as a sinusoidal modulation.…”

Section: Binaritymentioning

confidence: 99%

Dust evolution in the circumstellar disc of the unclassified B[e] star HD 50138

Varga

Gerják

Ábrahám

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We studied the disc of the unclassified B[e] star HD 50138, in order to explore its structure, and to find indications for the evolutionary status of this system, whether it is a young Herbig Be or a post-main-sequence star. Using high spatial resolution interferometric measurements from MIDI instrument (N-band) on the Very Large Telescope Interferometer, we analysed the disc size, the time-variability of the disc's thermal emission, and the spectral shape of the 10 µm silicate feature. By fitting simple disc models, we determined the inclination and the mid-infrared size of the disc, confirming earlier results based on a lower number of observations. We searched for mid-infrared temporal variability of different regions of the disc, and concluded that its morphology is not experiencing significant changes over the observed epochs. We characterized the mid-infrared silicate feature by determining the feature amplitude and the 11.3/9.8 µm flux ratio. The latter parameter is a good indicator of the grain size. The shape of the feature suggests the presence of crystalline silicate grains in the disc. The interferometric data revealed a strong radial trend in the mineralogy: while the disc's innermost region seems to be dominated by forsterite grains, at intermediate radii both forsterite and enstatite may be present. The outer disc may predominantly contain amorphous silicate particles. A comparison of the observed spectral shape with that of a sample of intermediate-mass stars (supergiants, Herbig Ae/Be stars, unclassified B[e] stars) implied that the evolutionary state of HD 50138 cannot be unambiguously decided from mid-IR spectroscopy. nandes et al. 2011), however, high spatial resolution observations can provide an efficient classification tool for them (Miroshnichenko 2007). A notable feature of unclassified B[e] stars is their high mass loss rates, compared to normal mainsequence stars, which can not be explained by the windtheory for main-sequence B-type stars (de la Fuente et al. 2015). Originally unclassified B[e] stars were thought to be isolated objects, but recently de la Fuente et al. (2015) reported that these objects can be also found in clusters. They estimated the age of the stars in the range from 3.5 to 6.5 Myr, which is out of the range for both pre-and post-main sequence origin, as the former phase lasts for ∼ 0.1 Myr, and the main-sequence lifetime is 15 − 20 Myr for a 12 M star.

show abstract

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

Cited by 28 publications

References 39 publications

Structure of Herbig AeBe disks at the milliarcsecond scale

Structure of Herbig AeBe disks at the milliarcsecond scale

A Multi-instrument and Multi-wavelength High Angular Resolution Study of MWC 614: Quantum Heated Particles Inside the Disk Cavity*

Dust evolution in the circumstellar disc of the unclassified B[e] star HD 50138

Contact Info

Product

Resources

About