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Title: Spectroscopic Evolution of Disintegrating Planetesimals: Minute to Month Variability in the Circumstellar Gas Associated with WD 1145+017

Abstract

With the recent discovery of transiting planetary material around WD 1145+017, a critical target has been identified that links the evolution of planetary systems with debris disks and their accretion onto the star. We present a series of observations, five epochs over a year, taken with Keck and the VLT, which for the first time show variability of circumstellar absorption in the gas disk surrounding WD 1145+017 on timescales of minutes to months. Circumstellar absorption is measured in more than 250 lines of 14 ions among 10 different elements associated with planetary composition, e.g., O, Mg, Ca, Ti, Cr, Mn, Fe, and Ni. Broad circumstellar gas absorption with a velocity spread of 225 km s{sup −1} is detected, but over the course of a year blueshifted absorption disappears, while redshifted absorption systematically increases. A correlation of equivalent width and oscillator strength indicates that the gas is not highly optically thick (median τ ≈ 2). We discuss simple models of an eccentric disk coupled with magnetospheric accretion to explain the basic observed characteristics of these high-resolution and high signal-to-noise observations. Variability is detected on timescales of minutes in the two most recent observations, showing a loss of redshifted absorption for tensmore » of minutes, coincident with major transit events and consistent with gas hidden behind opaque transiting material. This system currently presents a unique opportunity to learn how the gas causing the spectroscopic, circumstellar absorption is associated with the ongoing accretion evidenced by photospheric contamination, as well as the transiting planetary material detected in photometric observations.« less

Authors:
; ;  [1];  [2];  [3];  [4]
  1. Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459 (United States)
  2. Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)
  3. Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH (United Kingdom)
  4. Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
Publication Date:
OSTI Identifier:
22661147
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 839; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ABUNDANCE; ASTEROIDS; CORRELATIONS; EVOLUTION; LOSSES; NOISE; OSCILLATOR STRENGTHS; OSCILLATORS; PLANETS; RED SHIFT; RESOLUTION; VELOCITY; WHITE DWARF STARS

Citation Formats

Redfield, Seth, Cauley, P. Wilson, Duvvuri, Girish M., Farihi, Jay, Parsons, Steven G., and Gänsicke, Boris T., E-mail: sredfield@wesleyan.edu. Spectroscopic Evolution of Disintegrating Planetesimals: Minute to Month Variability in the Circumstellar Gas Associated with WD 1145+017. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA68A0.
Redfield, Seth, Cauley, P. Wilson, Duvvuri, Girish M., Farihi, Jay, Parsons, Steven G., & Gänsicke, Boris T., E-mail: sredfield@wesleyan.edu. Spectroscopic Evolution of Disintegrating Planetesimals: Minute to Month Variability in the Circumstellar Gas Associated with WD 1145+017. United States. doi:10.3847/1538-4357/AA68A0.
Redfield, Seth, Cauley, P. Wilson, Duvvuri, Girish M., Farihi, Jay, Parsons, Steven G., and Gänsicke, Boris T., E-mail: sredfield@wesleyan.edu. Mon . "Spectroscopic Evolution of Disintegrating Planetesimals: Minute to Month Variability in the Circumstellar Gas Associated with WD 1145+017". United States. doi:10.3847/1538-4357/AA68A0.
@article{osti_22661147,
title = {Spectroscopic Evolution of Disintegrating Planetesimals: Minute to Month Variability in the Circumstellar Gas Associated with WD 1145+017},
author = {Redfield, Seth and Cauley, P. Wilson and Duvvuri, Girish M. and Farihi, Jay and Parsons, Steven G. and Gänsicke, Boris T., E-mail: sredfield@wesleyan.edu},
abstractNote = {With the recent discovery of transiting planetary material around WD 1145+017, a critical target has been identified that links the evolution of planetary systems with debris disks and their accretion onto the star. We present a series of observations, five epochs over a year, taken with Keck and the VLT, which for the first time show variability of circumstellar absorption in the gas disk surrounding WD 1145+017 on timescales of minutes to months. Circumstellar absorption is measured in more than 250 lines of 14 ions among 10 different elements associated with planetary composition, e.g., O, Mg, Ca, Ti, Cr, Mn, Fe, and Ni. Broad circumstellar gas absorption with a velocity spread of 225 km s{sup −1} is detected, but over the course of a year blueshifted absorption disappears, while redshifted absorption systematically increases. A correlation of equivalent width and oscillator strength indicates that the gas is not highly optically thick (median τ ≈ 2). We discuss simple models of an eccentric disk coupled with magnetospheric accretion to explain the basic observed characteristics of these high-resolution and high signal-to-noise observations. Variability is detected on timescales of minutes in the two most recent observations, showing a loss of redshifted absorption for tens of minutes, coincident with major transit events and consistent with gas hidden behind opaque transiting material. This system currently presents a unique opportunity to learn how the gas causing the spectroscopic, circumstellar absorption is associated with the ongoing accretion evidenced by photospheric contamination, as well as the transiting planetary material detected in photometric observations.},
doi = {10.3847/1538-4357/AA68A0},
journal = {Astrophysical Journal},
number = 1,
volume = 839,
place = {United States},
year = {Mon Apr 10 00:00:00 EDT 2017},
month = {Mon Apr 10 00:00:00 EDT 2017}
}
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