Two Rings and a Marginally Resolved, 5 AU, Disk Around LkCa 15 Identified Via Near Infrared Sparse Aperture Masking Interferometry

Abstract

Sparse aperture masking interferometry (SAM) is a high resolution observing technique that allows for imaging at and beyond a telescope's diffraction limit. The technique is ideal for searching for stellar companions at small separations from their host star; however, previous analysis of SAM observations of young stars surrounded by dusty disks have had difficulties disentangling planet and extended disk emission. We analyse VLT/SPHERE-IRDIS SAM observations of the transition disk LkCa\,15, model the extended disk emission, probe for planets at small separations, and improve contrast limits for planets. We fit geometrical models directly to the interferometric observables and recover previously observed extended disk emission. We use dynamic nested sampling to estimate uncertainties on our model parameters and to calculate evidences to perform model comparison. We compare our extended disk emission models against point source models to robustly conclude that the system is dominated by extended emission within 50 au. We report detections of two previously observed asymmetric rings at $\sim$17 au and $\sim$45 au. The peak brightness location of each model ring is consistent with the previous observations. We also, for the first time with imaging, robustly recover an elliptical Gaussian inner disk, previously inferred via SED fitting. This inner disk has a FWHM of ~5 au and a similar inclination and orientation as the outer rings. Finally, we recover no clear evidence for candidate planets. By modelling the extended disk emission, we are able to place a lower limit on the near infrared companion contrast of at least 1000.

arXiv commentAccepted for publication in ApJ

References in corpus (44)

• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Resolved Images of Large Cavities in Protoplanetary Transition Disks
• SPHERE: the exoplanet imager for the Very Large Telescope
• The Disk Substructures at High Angular Resolution Project (DSHARP): II. Characteristics of Annular Substructures
• Ring shaped dust accumulation in transition disks
• LkCa 15: A Young Exoplanet Caught at Formation?
• Dynamic nested sampling: an improved algorithm for parameter estimation and evidence calculation
• Photometric characterization of exoplanets using angular and spectral differential imaging
• Observational Signatures of Planets in Protoplanetary Disks I: Gaps Opened by Single and Multiple Young Planets in Disks
• Accreting Protoplanets in the LkCa 15 Transition Disk
• On the Diversity of the Taurus Transitional Disks: UX Tau A & Lk Ca 15
• Unveiling the Structure of Pre-Transitional Disks
• Gas Flow Across Gaps in Protoplanetary Disks
• Resolved gas cavities in transitional disks inferred from CO isotopologues with ALMA
• Observational Signatures of Planets in Protoplanetary Disks II: Spiral Arms Observed in Scattered Light Imaging Can be Induced by Planets
• Dust depleted inner disks in a large sample of transition disks through long-baseline ALMA observations
• Resolving the inner dust disks surrounding LkCa 15 and MWC 480 at mm wavelengths
• GALARIO: a GPU Accelerated Library for Analysing Radio Interferometer Observations
• Michelson Interferometry with the Keck I Telescope
• No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals
• Optical imaging polarimetry of the LkCa 15 protoplanetary disk with SPHERE ZIMPOL
• SPHERE IRDIS and IFS astrometric strategy and calibration
• Sparse aperture masking at the VLT I. Faint companion detection limits for the two debris disk stars HD 92945 and HD 141569
• Resolving the planet-hosting inner regions of the LkCa 15 disk
• Testing particle trapping in transition disks with ALMA
• Annular substructures in the transition disks around LkCa 15 and J1610
• Resolving the gap and AU-scale asymmetries in the pre-transitional disk of V1247 Orionis
• The power of Bayesian evidence in astronomy
• The architecture of the LkCa 15 transitional disk revealed by high-contrast imaging
• Direct Detection of the Brown Dwarf GJ 802B with Adaptive Optics Masking Interferometry
• Inner disk structure of the classical T Tauri star LkCa 15
• Full 2D radiative transfer modelling of transitional disk LkCa 15
• OIFITS 2: the 2nd version of the Data Exchange Standard for Optical (Visible/IR) Interferometry
• Spectro-astrometry of the pre-transitional star LkCa 15 does not reveal an accreting planet but extended H$\alpha$ emission
• An image-plane algorithm for JWST's non-redundant aperture mask data
• Sparse Aperture Masking Observations of the FL Cha Pre-transitional Disk
• Sparse Aperture Masking (SAM) at NAOS/CONICA on the VLT
• The GRAVITY Young Stellar Object Survey. VI. Mapping the variable inner disk of HD 163296 at sub-au scales
• The James Webb Space Telescope Aperture Masking Interferometer
• Near-Infrared Imaging Polarimetry of LkCa 15: A Possible Warped Inner Disk
• An asymmetric dust ring around a very low mass star ZZ Tau IRS
• New Spatially Resolved Imaging of the SR 21 Transition Disk and Constraints on the Small-Grain Disk Geometry