Chemical Signatures of the FU Ori Outbursts

Abstract

The FU Ori-type young stellar objects are characterized by a sudden increase in luminosity by 1$-$2 orders of magnitude, followed by slow return to the pre-outburst state on timescales of $\sim$10$-$100 yr. The outburst strongly affects the entire disk, changing its thermal structure and radiation field. In this paper, using a detailed physical-chemical model we study the impact of the FU Ori outburst on the disk chemical inventory. Our main goal is to identify gas-phase molecular tracers of the outburst activity that could be observed after the outburst with modern telescopes such as ALMA and NOEMA. We find that the majority of molecules experience a considerable increase in the total disk gas-phase abundances due to the outburst, mainly due to the sublimation of their ices. Their return to the pre-outburst chemical state takes different amounts of time, from nearly instantaneous to very long. Among the former ones we identify CO, NH${}_3$, C${}_2$H${}_6$, C${}_3$H${}_4$, etc. Their abundance evolution tightly follows the luminosity curve. For CO the abundance increase does not exceed an order of magnitude, while for other tracers the abundances increase by 2$-$5 orders of magnitude. Other molecules like H${}_2$CO and NH${}_2$OH have longer retention timescales, remaining in the gas phase for $\sim 10-10^3$ yr after the end of the outburst. Thus H${}_2$CO could be used as an indicator of the previous outbursts in the post-outburst FU Ori systems. We investigate the corresponding time-dependent chemistry in detail and present the most favorable transitions and ALMA configurations for future observations.

arXiv commentaccepted for publication in ApJ

References in corpus (48)

• Spectral Energy Distributions of T Tauri Stars With Passive Circumstellar Disks
• An atomic and molecular database for analysis of submillimetre line observations
• Protoplanetary Disks and Their Evolution
• Gas- and dust evolution in protoplanetary disks
• The 2014 KIDA network for interstellar chemistry
• A Parametric Modeling Approach to Measuring the Gas Masses of Circumstellar Disks
• LIME - a flexible, non-LTE line excitation and radiation transfer method for millimeter and far-infrared wavelengths
• Imaging the water-snow line during a protostellar outburst
• The chemical history of molecules in circumstellar disks. I. Ices
• Organic molecules in protoplanetary disks around TTauri and HerbigAe stars
• Resolving the Luminosity Problem in Low-Mass Star Formation
• Chemical evolution of turbulent protoplanetary disks and the Solar nebula
• Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
• Episodic formation of cometary material in the outburst of a solar-like young star
• Organic Molecules and Water in the Inner Disks of T Tauri Stars
• A recent accretion burst in the low-mass protostar IRAS 15398-3359: ALMA imaging of its related chemistry
• Cometary ices in forming protoplanetary disc midplanes
• Protoplanetary Disk Structure With Grain Evolution: the ANDES Model
• Volatile snowlines in embedded disks around low-mass protostars
• First Detection of Near-Infrared Line Emission from Organics in Young Circumstellar Disks
• Evolution of dust and ice features around FU Orionis objects
• An X-ray Outburst from the Rapidly Accreting Young Star That Illuminates McNeil's Nebula
• The 2008 outburst of EX Lup - silicate crystals in motion
• The ALMA early science view of FUor/EXor objects - V: continuum disc masses and sizes
• Impact of grain evolution on the chemical structure of protoplanetary disks
• CO2 Ice toward Low-luminosity, Embedded Protostars: Evidence for Episodic Mass Accretion via Chemical History
• Fundamental aspects of episodic accretion chemistry explored with single-point models
• Chemical Evolution in VeLLOs
• The chemistry of episodic accretion in embedded objects. 2D radiation thermo-chemical models of the post-burst phase
• Increased H${}_2$CO production in the outer disk around HD 163296
• High spatial resolution imaging of SO and H2CO in AB Auriga: the first SO image in a transitional disk
• The effect of episodic accretion on the phase transition of CO and CO_2 in low-mass star formation
• Gas mass tracers in protoplanetary disks: CO is still the best
• A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects
• Probing Episodic Accretion in Very Low Luminosity Objects
• The Early ALMA View of the FU Ori Outburst System
• X-raying the Beating Heart of a Newborn Star: Rotational Modulation of High-energy Radiation from V1647 Ori
• Disentangling the Environment of the FU Orionis Candidate HBC 722 with Herschel
• Mass transport from the envelope to the disk of V346 Nor: a case study for the luminosity problem in an FUor-type young eruptive star
• V346 Normae: First post-outburst observations of an FU Orionis star
• The chemistry of planet-forming regions is not interstellar
• Brightness variations of the FUor-type eruptive star V346 Nor
• X-ray Emission from the FU Orionis Star V1735 Cygni
• FU Orionis outbursts, preferential recondensation of water ice, and the formation of giant planets
• Spectrally Resolved Mid-Infrared Molecular Emission from Protoplanetary Disks and the Chemical Fingerprint of Planetesimal Formation
• X-ray emission from an FU Ori star in early outburst: HBC 722
• Chandra Reveals Variable Multi-Component X-ray Emission from FU Orionis
• X-ray Production by V1647 Ori During Optical Outbursts

Cited by in corpus (29)

• The ice composition in the disk around V883 Ori revealed by its stellar outburst
• JWST/MIRI Spectroscopy of the Disk of the Young Eruptive Star EX Lup in Quiescence
• Luminosity outburst chemistry in protoplanetary discs: going beyond standard tracers
• Gravitoviscous protoplanetary disks with a dust component. I. The importance of the inner sub-au region
• Massive compact disks around FU Orionis-type young eruptive stars revealed by ALMA
• Gravitoviscous protoplanetary disks with a dust component. II. Spatial distribution and growth of dust in a clumpy disk
• Evolution of dust in protoplanetary disks of eruptive stars
• Collisional evolution of dust and water ice in protoplanetary discs during and after an accretion outburst
• MINDS. A multi-instrument investigation into the molecule-rich JWST-MIRI spectrum of the DF Tau binary system
• Burned to ashes: How the thermal decomposition of refractory organics in the inner protoplanetary disc impacts the gas-phase C/O ratio
• Primordial Dusty Rings and Episodic Outbursts in Protoplanetary Discs
• The Molecular Composition of Shadowed Protosolar Disk Midplanes beyond the Water Snowline
• Gaia21bty: An EXor lightcurve exhibiting an FUor spectrum
• Machine learning-accelerated chemistry modeling of protoplanetary disks
• A Chemical Map of the Outbursting V883 Ori system: Vertical and Radial Structures
• Using HCO${}^{+}$ isotopologues as tracers of gas depletion in protoplanetary disk gaps
• Magnetic disk winds in protoplanetary disks: Description of the model and impact on global disk evolution
• Modeling snowline locations in protostars: The impact of the structure of protostellar cloud cores
• Constraining the Chemical Signatures and the Outburst Mechanism of the Class 0 Protostar HOPS 383
• ALMA and VLA Observations of EX Lupi in its Quiescent State
• Time-resolved protoplanetary disk physics in DQ Tau with JWST
• Time-dependent response of protoplanetary disk temperature to an FU Ori-type luminosity outburst
• Gaia20bdk -- a new FUor in Sh 2-301 Star Forming Region
• Molecular inventory of a young eruptive star's environment -- Case study of the classical FU Orionis star V1057 Cyg
• Dancing on the Grain: Variety of CO and its isotopologue fluxes as a result of surface chemistry and T Tauri disk properties
• The hot corino-like chemistry of four FUor-like protostars
• Chemical modelling of FU Ori protoplanetary disks
• Ancillary science with Ariel: Feasibility and scientific potential of young stellar object observations
• Protoplanetary Disk Chemistry