The 2008 outburst of EX Lup-Silicate crystals in motion
EntityUAM. Departamento de Física Teórica
PublisherThe American Astronomical Society.
10.1088/0004-637X/744/2/118The Astrophysical Journal 744.2 (2012): 118
ISSN0004-637X (print); 1538-4357 (online)
Funded byThe research of A.K. is supported by the Netherlands Organization for Scientific Research. The research of Zs.R. is supported by the “Lendület” Young Researcher Program of the Hungarian Academy of Sciences.
SubjectsAccretion; Accretion disks; Astrochemistry; Circumstellar matter; Infrared: stars; Protoplanetary disks; Stars: formation; Stars: individual (EX Lup); Física
NoteThe Astrophysical Journal 744.2 (2012): 118 reproduced by permission of the AAS
Rights© 2012 The American Astronomical Society.
EXLup 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 EXLup 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 EXLup 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 EXLup. Our mid-infrared Spitzer spectra revealed that the strength of all crystalline bands between 8 and 30μm increased right after the end of the outburst. Six months later, however, the crystallinity in the 10μm silicate feature complex decreased. Our modeling of the mid-infrared spectral evolution of EXLup 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.
Google Scholar:Juhász, Attila - Dullemond, Cornelis P. - Van Boekel, Roy - Bouwman, Jeroen - Ábrahám, Péter - Acosta-Pulido, José Antonio - Kóspál, Ågnes - Sicilia-Aguilar, Aurora - Jones, Anthony P. - Moór, Attila - Mosoni, László - Regály, Zs - Szokoly, Gyula P. - Sipos, Nikoletta - Henning, Th.
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Goto, Miwa; Regály, Zs; Dullemond, Cornelis P.; Van Den Ancker, Mario E.; Brown, Joanna M.; Carmona, Andrés; Pontoppidan, Klaus M.; Ábrahám, Péter; Blake, Geoffrey A.; Fedele, Davide; Henning, Th H E; Juhász, Attila; Kóspál, Ågnes; Mosoni, László; Sicilia-Aguilar, Aurora; Terada, Hiroshi; Van Boekel, Roy; Van Dishoeck, Ewine F.; Usuda, Tomonori
Kóspál, Ågnes; Ábrahám, Péter; Goto, Miwa; Regály, Zs; Dullemond, Cornelis P.; Henning, Th H E; Juhász, Attila; Sicilia-Aguilar, Aurora; Van Den Ancker, Mario E.
Optical spectroscopy of EX Lupi during quiescence and outburst: Infall, wind, and dynamics in the accretion flow Sicilia-Aguilar, Aurora; Kóspál, Ågnes; Setiawan, Johny; Ábrahám, Péter; Dullemond, Cornelis; Eiroa, Carlos; Goto, Miwa; Henning, Th.; Juhász, Attila