The Mid-Infrared Evolution of the Fu Orionis Disk

Green, Joel D.; Jones, O. C.; Keller, L. D.; Poteet, C. A.; Yang, Yao-Lun; Fischer, William J.; Evans, Neal J.; Sargent, Benjamin; Rebull, L. M.

doi:10.3847/0004-637x/832/1/4

Cited by 13 publications

(14 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For a few au scale circumstellar disks, the characteristic variational time scale may be as short as a few years (e.g., dynamical timescale). On the other hand, there is not yet observational evidence for flux variability at >20 µm wavelengths (e.g., Green et al 2016). Finally, it is also possible that the JVLA, SMA, and ALMA observations have recovered all fluxes at the observed frequency bands without being affected by missing short spacing issues.…”

Section: Resultsmentioning

confidence: 99%

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

Liu

Vorobyov

Dong

et al. 2017

A&A

View full text Add to dashboard Cite

Aims. The aim of this work is to constrain properties of the disk around the archetype FU Orionis object, FU Ori, with as good as ∼25 au resolution. Methods. We resolved FU Ori at 29-37 GHz using the Karl G. Jansky Very Largy Array (JVLA) in the A-array configuration, which provided the highest possible angular resolution to date at this frequency band (∼0 ′′ .07). We also performed complementary JVLA 8-10 GHz observations, the Submillimeter Array (SMA) 224 GHz and 272 GHz observations, and compared with archival Atacama Large Millimeter Array (ALMA) 346 GHz observations to obtain the spectral energy distributions (SEDs). Results. Our 8-10 GHz observations do not find evidence for the presence of thermal radio jets, and constrain the radio jet/wind flux to at least 90 times lower than the expected value from the previously reported bolometric luminosity-radio luminosity correlation. The emission at frequencies higher than 29 GHz may be dominated by the two spatially unresolved sources, which are located immediately around FU Ori and its companion FU Ori S, respectively. Their deconvolved radii at 33 GHz are only a few au, which is two orders of magnitude smaller in linear scale than the gaseous disk revealed by the previous Subaru-HiCIAO 1.6 µm coronagraphic polarization imaging observations. We are struck by the fact that these two spatially compact sources contribute to over 50% of the observed fluxes at 224 GHz, 272 GHz, and 346 GHz. The 8-346 GHz SEDs of FU Ori and FU Ori S cannot be fit by constant spectral indices (over frequency), although we cannot rule out that it is due to the time variability of their (sub)millimeter fluxes. Conclusions. The more sophisticated models for SEDs considering the details of the observed spectral indices in the millimeter bands suggest that the >29 GHz emission is contributed by a combination of free-free emission from ionized gas, and thermal emission from optically thick and optically thin dust components. We hypothesize that dust in the innermost parts of the disks ( 0.1 au) has been sublimated, and thus the disks are no more well shielded against the ionizing photons. The estimated overall gas and dust mass based on SED modeling, can be as high as a fraction of a solar mass, which is adequate for developing disk gravitational instability. Our present explanation for the observational data is that the massive inflow of gas and dust due to disk gravitational instability or interaction with a companion/intruder, was piled up at the few au scale due to the development of a deadzone with negligible ionization. The piled up material subsequently triggered the thermal instability and the magnetorotational instability when the ionization fraction in the inner sub-au scale region exceeded a threshold value, leading to the high protostellar accretion rate.

show abstract

Section: Resultsmentioning

confidence: 99%

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

Liu

Vorobyov

Dong

et al. 2017

A&A

View full text Add to dashboard Cite

show abstract

“…Nevertheless, we found that once a good fit for the interferometric data was achieved, the infrared spectrum predicted from the model is also very close to the Spitzer and Herschel observations. Green et al 2006Green et al , 2013Green et al , 2016a, and the fluxes of the au scales structures around FU Ori taken with the VLTI/GRAVITY (i.e., the "Extended" column of Table 4). Black lines show our model of the combined fluxes of these two sources.…”

Section: Abstracted Geometric Model and Integrated Sedsmentioning

confidence: 99%

Diagnosing 0.1–10 au Scale Morphology of the FU Ori Disk Using ALMA and VLTI/GRAVITY

Liu

Mérand

Green

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

We report new Atacama Large Millimeter/submillimeter Array Band 3 (86-100 GHz; ∼80 mas angular resolution) and Band 4 (146-160 GHz; ∼50 mas angular resolution) observations of the dust continuum emission toward the archetypal and ongoing accretion burst young stellar object FU Ori, which simultaneously covered its companion, FU Ori S. In addition, we present near-infrared (2-2.45 μm) observations of FU Ori taken with the General Relativity Analysis via VLT InTerferometrY (GRAVITY; ∼1 mas angular resolution) instrument on the Very Large Telescope Interferometer (VLTI). We find that the emission in both FU Ori and FU Ori S at (sub)millimeter and near-infrared bands is dominated by structures inward of ∼10 au radii. We detected closure phases close to zero from FU Ori with VLTI/GRAVITY, which indicate the source is approximately centrally symmetric and therefore is likely viewed nearly face-on. Our simple model to fit the GRAVITY data shows that the inner 0.4 au radii of the FU Ori disk has a triangular spectral shape at 2-2.45 μm, which is consistent with the H 2 O and CO absorption features in a˙M 10 −4 M e yr −1 , viscously heated accretion disk. At larger (∼0.4-10 au) radii, our analysis shows that viscous heating may also explain the observed (sub)millimeter and centimeter spectral energy distribution when we assume a constant, ∼10 −4 M e yr −1 mass inflow rate in this region. This explains how the inner 0.4 au disk is replenished with mass at a modest rate, such that it neither depletes nor accumulates significant masses over its short dynamic timescale. Finally, we tentatively detect evidence of vertical dust settling in the inner 10 au of the FU Ori disk, but confirmation requires more complete spectral sampling in the centimeter bands.

show abstract

“…The second form appeals to the century scale (Hartmann & Kenyon 1996;Green et al 2016) heating from an FU Orionis scale accretion event, which would provide the required heating for the required time out to an orbital location between Venus' orbit and Mars'. The heating time scale and resulting radial planetesimal distribution would be consistent with Earth's composition (Hubbard & Ebel 2014) and with Mars' small size (Chambers 2014); and appeals to a process that we have proposed to promote the formation of Jupiter and Saturn-like gas giants (Hubbard 2017).…”

Section: Discussionmentioning

confidence: 99%

“…Hubbard & Ebel (2014) put forth a model to explain the Earth's abundance pattern through timedependent heating and cooling from an FU Orionis type event in the early Solar System (Hartmann & Kenyon 1996). FU Orionis type events are dramatic, long lived accretion events, associated with luminosity increases of 4 − 6 magnitudes and time scales of 50 − 100 yr (Hartmann & Kenyon 1996;Green et al 2016). FU Orionis events (or FUors) can raise the temperature at Earth's orbital position to about 1350 K (Hubbard & Ebel 2014), and drive the frost line out to about 40 au (Cieza et al 2016).…”

Section: Fu Orionis Type Eventsmentioning

confidence: 99%

Making Terrestrial Planets: High Temperatures, FU Orionis Outbursts, Earth, and Planetary System Architectures

Hubbard

2017

ApJL

View full text Add to dashboard Cite

Current protoplanetary dust coagulation theory does not predict dry silicate planetesimals, in tension with the Earth. While remedies to this predicament have been proposed, they have generally failed numerical studies, or are in tension with the Earth's (low, volatility dependent) volatile and moderately volatile elemental abundances. Expanding on the work of Boley et al. (2014), we examine the implications of molten grain collisions and find that they may provide a solution to the dry silicate planetesimal problem. Further, the source of the heating, be it the hot inner disk or an FU Orionis scale accretion event, would dictate the location of the resulting planetesimals, potentially controlling subsequent planetary system architectures. We hypothesize that systems which did undergo FU Orionis scale accretion events host planetary systems similar to our own, while ones that did not instead host very close in, tightly packed planets such as seen by Kepler.

show abstract

The Mid-Infrared Evolution of the Fu Orionis Disk

Cited by 13 publications

References 56 publications

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations

Diagnosing 0.1–10 au Scale Morphology of the FU Ori Disk Using ALMA and VLTI/GRAVITY

Making Terrestrial Planets: High Temperatures, FU Orionis Outbursts, Earth, and Planetary System Architectures

Contact Info

Product

Resources

About