Untangling the Near-IR Spectral Features in the Protoplanetary Environment of KH 15D

Abstract

We report on Gemini/GNIRS observations of the binary T Tauri system V582 Mon (KH 15D) at three orbital phases. These spectra allow us to untangle five components of the system: the photosphere and magnetosphere of star B, the jet, scattering properties of the ring material, and excess near-IR radiation previously attributed to a possible self-luminous planet. We confirm an early-K subgiant classification for star B and show that the magnetospheric He I emission line is variable, possibly indicating increased mass accretion at certain times. As expected, the H${}_2$ emission features associated with the inner part of the jet show no variation with orbital phase. We show that the reflectance spectrum for the scattered light has a distinctive blue slope and spectral features consistent with scattering and absorption by a mixture of water and methane ice grains in the 1-50 $\mu$m size range. This suggests that the methane frost line is closer than $\sim$5 AU in this system, requiring that the grains be shielded from direct radiation. After correcting for features from the scattered light, jet, magnetosphere, and photosphere, we confirm the presence of leftover near-IR light from an additional source, detectable near minimum brightness. A spectral emission feature matching the model spectrum of a 10 M${}_J$, 1 Myr old planet is found in the excess flux, but other expected features from this model are not seen. Our observations, therefore, tentatively support the picture that a luminous planet is present within the system, although they cannot yet be considered definitive.

arXiv commentAccepted by ApJ

References in corpus (24)

• Astropy: A Community Python Package for Astronomy
• Spectral and Photometric Diagnostics of Giant Planet Formation Scenarios
• Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres
• Structures in the protoplanetary disk of HD142527 seen in polarized scattered light
• Ice Lines, Planetesimal Composition and Solid Surface Density in the Solar Nebula
• The Circumbinary Ring of KH 15D
• The 0.5-2.22-micron Scattered Light Spectrum of the Disk Around TW Hya: Detection of a Partially Filled Disk Gap at 80 AU
• Saturn's icy satellites and rings investigated by Cassini - VIMS. III. Radial compositional variability
• HD100546 Multi-Epoch Scattered-Light Observations
• Eclipses by a Circumstellar Dust Feature in the Pre-Main Sequence Star KH15D
• Redshifted Absorption at He I 10830 as a Probe of the Accretion Geometry of T Tauri Stars
• Comet 17P/Holmes in Outburst: The Near Infrared Spectrum
• The Orbit and Occultations of KH 15D
• Moderate resolution near-infrared spectroscopy of cool stars: a new K-band library
• Locating the Trailing Edge of the Circumbinary Ring in the KH 15D System
• The Disappearing Act of KH 15D: Photometric Results from 1995 to 2004
• Spectropolarimetry and Modeling of the Eclipsing T Tauri Star KH 15D
• Water ice at the surface of HD 100546 disk
• Spectroscopy of Molecular Hydrogen Emission from KH 15D
• A Flare Observed in Coronal, Transition Region and Helium I 10830 Å Emissions
• H${}_2$ Emission Nebulosity Associated with KH 15D
• Multi-Wavelength Photometry of the T Tauri Binary V582 Mon (KH 15D): A New Epoch of Occultations
• Seeing Through the Ring: Near-Infrared Photometry of V582 Mon (KH 15D)
• Extending the Model of KH 15D: Estimating the Effects of Forward Scattering and Curvature of the Occulting Ring Edge

Cited by in corpus (6)

• Alignment of a circumbinary disc around an eccentric binary with application to KH 15D
• Constraining the Circumbinary Disk Tilt in the KH 15D system
• Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit and Discovery of a CO Outflow
• First observed interaction of the circumstellar envelope of an S-star with the environment of Sgr A*
• Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration Against Spectral Types and V-K Color
• Signatures of Hot Molecular Hydrogen Absorption from Protoplanetary Disks: I. Non-thermal Populations