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Title: 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-infrared (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{sub 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 μ m size range. This suggests that the methane frost line is closer than ∼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 emissionmore » feature matching the model spectrum of a 10 M {sub 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.« less

Authors:
; ; ;  [1];  [2]
  1. Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States)
  2. Gemini Observatory (North), Hilo, HI 96720 (United States)
Publication Date:
OSTI Identifier:
22663984
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 834; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; AUGER ELECTRON SPECTROSCOPY; BINARY STARS; CLASSIFICATION; DETECTION; EMISSION; HYDROGEN; INFRARED RADIATION; MASS; METHANE; PHOTOSPHERE; PLANETS; PROTOPLANETS; SATELLITES; SCATTERING; SPECTRA; STARS; VISIBLE RADIATION

Citation Formats

Arulanantham, Nicole A., Herbst, William, Gilmore, Martha S., Cauley, P. Wilson, and Leggett, S. K., E-mail: nicole.arulanantham@colorado.edu. UNTANGLING THE NEAR-IR SPECTRAL FEATURES IN THE PROTOPLANETARY ENVIRONMENT OF KH 15D. United States: N. p., 2017. Web. doi:10.3847/1538-4357/834/2/119.
Arulanantham, Nicole A., Herbst, William, Gilmore, Martha S., Cauley, P. Wilson, & Leggett, S. K., E-mail: nicole.arulanantham@colorado.edu. UNTANGLING THE NEAR-IR SPECTRAL FEATURES IN THE PROTOPLANETARY ENVIRONMENT OF KH 15D. United States. doi:10.3847/1538-4357/834/2/119.
Arulanantham, Nicole A., Herbst, William, Gilmore, Martha S., Cauley, P. Wilson, and Leggett, S. K., E-mail: nicole.arulanantham@colorado.edu. Tue . "UNTANGLING THE NEAR-IR SPECTRAL FEATURES IN THE PROTOPLANETARY ENVIRONMENT OF KH 15D". United States. doi:10.3847/1538-4357/834/2/119.
@article{osti_22663984,
title = {UNTANGLING THE NEAR-IR SPECTRAL FEATURES IN THE PROTOPLANETARY ENVIRONMENT OF KH 15D},
author = {Arulanantham, Nicole A. and Herbst, William and Gilmore, Martha S. and Cauley, P. Wilson and Leggett, S. K., E-mail: nicole.arulanantham@colorado.edu},
abstractNote = {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-infrared (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{sub 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 μ m size range. This suggests that the methane frost line is closer than ∼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 {sub 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.},
doi = {10.3847/1538-4357/834/2/119},
journal = {Astrophysical Journal},
number = 2,
volume = 834,
place = {United States},
year = {Tue Jan 10 00:00:00 EST 2017},
month = {Tue Jan 10 00:00:00 EST 2017}
}