THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION

A. Juhasz (Lead / Corresponding author), C. P. Dullemond, R. Van Boekel, J. Bouwman, P. Abraham, J. A. Acosta-Pulido, Th. Henning, A. Kospal, A. Sicilia-Aguilar, A. Jones, A. Moor, L. Mosoni, Zs Regaly, Gy Szokoly, N. Sipos

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

EX Lup is the prototype of the EXor class of eruptive young stars. These objects show optical outbursts which are thought to be related to runaway accretion onto the star. In a previous study we observed in situ crystal formation in the disk of EX Lup during its latest outburst in 2008, making the object an ideal laboratory to investigate circumstellar crystal formation and transport. This outburst was monitored by a campaign of ground-based and Spitzer Space Telescope observations. Here we modeled the spectral energy distribution (SED) of EX Lup in the outburst from optical to millimeter wavelengths with a two-dimensional radiative transfer code. Our results showed that the shape of the SED at optical wavelengths was more consistent with a single-temperature blackbody than a temperature distribution. We also found that this single-temperature component emitted 80%-100% of the total accretion luminosity. We concluded that a thermal instability, the most widely accepted model of EXor outbursts, was likely not the triggering mechanism of the 2008 outburst of EX Lup. Our mid-infrared Spitzer spectra revealed that the strength of all crystalline bands between 8 and 30 mu m increased right after the end of the outburst. Six months later, however, the crystallinity in the 10 mu m silicate feature complex decreased. Our modeling of the mid-infrared spectral evolution of EX Lup showed that, although vertical mixing should be stronger during the outburst than in the quiescent phase, fast radial transport of crystals (e.g., by stellar/disk wind) was required to reproduce the observed mid-infrared spectra.
Original languageEnglish
Article number118
JournalAstrophysical Journal
Volume744
Issue number2
DOIs
Publication statusPublished - 12 Dec 2012

Fingerprint

outburst
spectral energy distribution
crystals
stars
Space Infrared Telescope Facility
thermal instability
wavelengths
radiative transfer
silicates
crystallinity
temperature distribution
infrared spectra
crystal
luminosity
prototypes
temperature
accretion
wavelength
vertical mixing
energy

Keywords

  • accretion, accretion disks astrochemistry circumstellar matter infrared: stars protoplanetary disks stars: formation stars: individual(EX Lup) T-TAURI-STARS PROTOPLANETARY ACCRETION DISKS MULTIBAND IMAGING PHOTOMETER HERBIG AE/BE STARS FU-ORIONIS OBJECTS RADIATIVE-TRANSFER ABSOLUTE CALIBRATION CIRCUMSTELLAR DISKS AMORPHOUS SILICATES MAGNETIZED STAR

Cite this

Juhasz, A., Dullemond, C. P., Van Boekel, R., Bouwman, J., Abraham, P., Acosta-Pulido, J. A., ... Sipos, N. (2012). THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION. Astrophysical Journal, 744(2), [118]. https://doi.org/10.1088/0004-637X/744/2/118
Juhasz, A. ; Dullemond, C. P. ; Van Boekel, R. ; Bouwman, J. ; Abraham, P. ; Acosta-Pulido, J. A. ; Henning, Th. ; Kospal, A. ; Sicilia-Aguilar, A. ; Jones, A. ; Moor, A. ; Mosoni, L. ; Regaly, Zs ; Szokoly, Gy ; Sipos, N. / THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION. In: Astrophysical Journal. 2012 ; Vol. 744, No. 2.
@article{7f2ab13d162b46e3a12f54400e733c70,
title = "THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION",
abstract = "EX Lup is the prototype of the EXor class of eruptive young stars. These objects show optical outbursts which are thought to be related to runaway accretion onto the star. In a previous study we observed in situ crystal formation in the disk of EX Lup during its latest outburst in 2008, making the object an ideal laboratory to investigate circumstellar crystal formation and transport. This outburst was monitored by a campaign of ground-based and Spitzer Space Telescope observations. Here we modeled the spectral energy distribution (SED) of EX Lup in the outburst from optical to millimeter wavelengths with a two-dimensional radiative transfer code. Our results showed that the shape of the SED at optical wavelengths was more consistent with a single-temperature blackbody than a temperature distribution. We also found that this single-temperature component emitted 80{\%}-100{\%} of the total accretion luminosity. We concluded that a thermal instability, the most widely accepted model of EXor outbursts, was likely not the triggering mechanism of the 2008 outburst of EX Lup. Our mid-infrared Spitzer spectra revealed that the strength of all crystalline bands between 8 and 30 mu m increased right after the end of the outburst. Six months later, however, the crystallinity in the 10 mu m silicate feature complex decreased. Our modeling of the mid-infrared spectral evolution of EX Lup showed that, although vertical mixing should be stronger during the outburst than in the quiescent phase, fast radial transport of crystals (e.g., by stellar/disk wind) was required to reproduce the observed mid-infrared spectra.",
keywords = "accretion, accretion disks astrochemistry circumstellar matter infrared: stars protoplanetary disks stars: formation stars: individual(EX Lup) T-TAURI-STARS PROTOPLANETARY ACCRETION DISKS MULTIBAND IMAGING PHOTOMETER HERBIG AE/BE STARS FU-ORIONIS OBJECTS RADIATIVE-TRANSFER ABSOLUTE CALIBRATION CIRCUMSTELLAR DISKS AMORPHOUS SILICATES MAGNETIZED STAR",
author = "A. Juhasz and Dullemond, {C. P.} and {Van Boekel}, R. and J. Bouwman and P. Abraham and Acosta-Pulido, {J. A.} and Th. Henning and A. Kospal and A. Sicilia-Aguilar and A. Jones and A. Moor and L. Mosoni and Zs Regaly and Gy Szokoly and N. Sipos",
year = "2012",
month = "12",
day = "12",
doi = "10.1088/0004-637X/744/2/118",
language = "English",
volume = "744",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "American Astronomical Society",
number = "2",

}

Juhasz, A, Dullemond, CP, Van Boekel, R, Bouwman, J, Abraham, P, Acosta-Pulido, JA, Henning, T, Kospal, A, Sicilia-Aguilar, A, Jones, A, Moor, A, Mosoni, L, Regaly, Z, Szokoly, G & Sipos, N 2012, 'THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION', Astrophysical Journal, vol. 744, no. 2, 118. https://doi.org/10.1088/0004-637X/744/2/118

THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION. / Juhasz, A. (Lead / Corresponding author); Dullemond, C. P.; Van Boekel, R.; Bouwman, J.; Abraham, P.; Acosta-Pulido, J. A.; Henning, Th.; Kospal, A.; Sicilia-Aguilar, A.; Jones, A.; Moor, A.; Mosoni, L.; Regaly, Zs; Szokoly, Gy; Sipos, N.

In: Astrophysical Journal, Vol. 744, No. 2, 118, 12.12.2012.

Research output: Contribution to journalArticle

TY - JOUR

T1 - THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION

AU - Juhasz, A.

AU - Dullemond, C. P.

AU - Van Boekel, R.

AU - Bouwman, J.

AU - Abraham, P.

AU - Acosta-Pulido, J. A.

AU - Henning, Th.

AU - Kospal, A.

AU - Sicilia-Aguilar, A.

AU - Jones, A.

AU - Moor, A.

AU - Mosoni, L.

AU - Regaly, Zs

AU - Szokoly, Gy

AU - Sipos, N.

PY - 2012/12/12

Y1 - 2012/12/12

N2 - EX Lup is the prototype of the EXor class of eruptive young stars. These objects show optical outbursts which are thought to be related to runaway accretion onto the star. In a previous study we observed in situ crystal formation in the disk of EX Lup during its latest outburst in 2008, making the object an ideal laboratory to investigate circumstellar crystal formation and transport. This outburst was monitored by a campaign of ground-based and Spitzer Space Telescope observations. Here we modeled the spectral energy distribution (SED) of EX Lup in the outburst from optical to millimeter wavelengths with a two-dimensional radiative transfer code. Our results showed that the shape of the SED at optical wavelengths was more consistent with a single-temperature blackbody than a temperature distribution. We also found that this single-temperature component emitted 80%-100% of the total accretion luminosity. We concluded that a thermal instability, the most widely accepted model of EXor outbursts, was likely not the triggering mechanism of the 2008 outburst of EX Lup. Our mid-infrared Spitzer spectra revealed that the strength of all crystalline bands between 8 and 30 mu m increased right after the end of the outburst. Six months later, however, the crystallinity in the 10 mu m silicate feature complex decreased. Our modeling of the mid-infrared spectral evolution of EX Lup showed that, although vertical mixing should be stronger during the outburst than in the quiescent phase, fast radial transport of crystals (e.g., by stellar/disk wind) was required to reproduce the observed mid-infrared spectra.

AB - EX Lup is the prototype of the EXor class of eruptive young stars. These objects show optical outbursts which are thought to be related to runaway accretion onto the star. In a previous study we observed in situ crystal formation in the disk of EX Lup during its latest outburst in 2008, making the object an ideal laboratory to investigate circumstellar crystal formation and transport. This outburst was monitored by a campaign of ground-based and Spitzer Space Telescope observations. Here we modeled the spectral energy distribution (SED) of EX Lup in the outburst from optical to millimeter wavelengths with a two-dimensional radiative transfer code. Our results showed that the shape of the SED at optical wavelengths was more consistent with a single-temperature blackbody than a temperature distribution. We also found that this single-temperature component emitted 80%-100% of the total accretion luminosity. We concluded that a thermal instability, the most widely accepted model of EXor outbursts, was likely not the triggering mechanism of the 2008 outburst of EX Lup. Our mid-infrared Spitzer spectra revealed that the strength of all crystalline bands between 8 and 30 mu m increased right after the end of the outburst. Six months later, however, the crystallinity in the 10 mu m silicate feature complex decreased. Our modeling of the mid-infrared spectral evolution of EX Lup showed that, although vertical mixing should be stronger during the outburst than in the quiescent phase, fast radial transport of crystals (e.g., by stellar/disk wind) was required to reproduce the observed mid-infrared spectra.

KW - accretion, accretion disks astrochemistry circumstellar matter infrared: stars protoplanetary disks stars: formation stars: individual(EX Lup) T-TAURI-STARS PROTOPLANETARY ACCRETION DISKS MULTIBAND IMAGING PHOTOMETER HERBIG AE/BE STARS FU-ORIONIS OBJECTS

U2 - 10.1088/0004-637X/744/2/118

DO - 10.1088/0004-637X/744/2/118

M3 - Article

VL - 744

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 118

ER -

Juhasz A, Dullemond CP, Van Boekel R, Bouwman J, Abraham P, Acosta-Pulido JA et al. THE 2008 OUTBURST OF EX Lup-SILICATE CRYSTALS IN MOTION. Astrophysical Journal. 2012 Dec 12;744(2). 118. https://doi.org/10.1088/0004-637X/744/2/118