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The origin of tail-like structures around protoplanetary disks

Vorobyov, Eduard I. ; Skliarevskii, Alexandr M. ; Elbakyan, Vardan G. LU ; Takami, Michihiro ; Liu, Hauyu Baobab ; Liu, Sheng Yuan and Akiyama, Eiji (2020) In Astronomy and Astrophysics 635.
Abstract

Aims. We study the origin of tail-like structures recently detected around the disk of SU Aurigae and several FU Orionis-type stars. Methods. Dynamic protostellar disks featuring ejections of gaseous clumps and quiescent protoplanetary disks experiencing a close encounter with an intruder star were modeled using the numerical hydrodynamics code FEOSAD. Both the gas and dust dynamics were taken into account, including dust growth and mutual friction between the gas and dust components. Only plane-of-the-disk encounters were considered. Results. Ejected clumps produce a unique type of tail that is characterized by a bow-shock shape. Such tails originate from the supersonic motion of ejected clumps through the dense envelope that often... (More)

Aims. We study the origin of tail-like structures recently detected around the disk of SU Aurigae and several FU Orionis-type stars. Methods. Dynamic protostellar disks featuring ejections of gaseous clumps and quiescent protoplanetary disks experiencing a close encounter with an intruder star were modeled using the numerical hydrodynamics code FEOSAD. Both the gas and dust dynamics were taken into account, including dust growth and mutual friction between the gas and dust components. Only plane-of-the-disk encounters were considered. Results. Ejected clumps produce a unique type of tail that is characterized by a bow-shock shape. Such tails originate from the supersonic motion of ejected clumps through the dense envelope that often surrounds young gravitationally unstable protostellar disks. The ejected clumps either sit at the head of the tail-like structure or disperse if their mass is insufficient to withstand the head wind of the envelope. On the other hand, close encounters with quiescent protoplanetary disks produce three types of the tail-like structure; we define these as pre-collisional, post-collisional, and spiral tails. These tails can in principle be distinguished from one another by particular features of the gas and dust flow in and around them. We find that the brown-dwarf-mass intruders do not capture circumintruder disks during the encounter, while the subsolar-mass intruders can acquire appreciable circumintruder disks with elevated dust-to-gas ratios, which can ease their observational detection. However, this is true only for prograde collisions; the retrograde intruders fail to collect appreciable amounts of gas or dust from the disk of the target. The mass of gas in the tail varies in the range 0.85-11.8 MJup, while the total mass of dust lies in the 1.75-30.1 M⊙ range, with the spiral tails featuring the highest masses. The predicted mass of dust in the model tail-like structures is therefore higher than what was inferred for similar structures in SU Aur, FU Ori, and Z CMa, making their observational detection feasible. Conclusions. Tail-like structures around protostellar and protoplanetary disks can be used to infer interesting phenomena such as clump ejection or close encounters. In particular, the bow-shock morphology of the tails could point to clump ejections as a possible formation mechanism. Further numerical and observational studies are needed to better understand the detectability and properties of the tails.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Hydrodynamics, Protoplanetary disks, Stars: protostars
in
Astronomy and Astrophysics
volume
635
article number
A196
publisher
EDP Sciences
external identifiers
  • scopus:85082868632
ISSN
0004-6361
DOI
10.1051/0004-6361/201936990
language
English
LU publication?
yes
id
d7181c8d-d894-4a2d-b406-2e8567344225
date added to LUP
2020-04-21 17:54:15
date last changed
2022-12-08 07:54:56
@article{d7181c8d-d894-4a2d-b406-2e8567344225,
  abstract     = {{<p>Aims. We study the origin of tail-like structures recently detected around the disk of SU Aurigae and several FU Orionis-type stars. Methods. Dynamic protostellar disks featuring ejections of gaseous clumps and quiescent protoplanetary disks experiencing a close encounter with an intruder star were modeled using the numerical hydrodynamics code FEOSAD. Both the gas and dust dynamics were taken into account, including dust growth and mutual friction between the gas and dust components. Only plane-of-the-disk encounters were considered. Results. Ejected clumps produce a unique type of tail that is characterized by a bow-shock shape. Such tails originate from the supersonic motion of ejected clumps through the dense envelope that often surrounds young gravitationally unstable protostellar disks. The ejected clumps either sit at the head of the tail-like structure or disperse if their mass is insufficient to withstand the head wind of the envelope. On the other hand, close encounters with quiescent protoplanetary disks produce three types of the tail-like structure; we define these as pre-collisional, post-collisional, and spiral tails. These tails can in principle be distinguished from one another by particular features of the gas and dust flow in and around them. We find that the brown-dwarf-mass intruders do not capture circumintruder disks during the encounter, while the subsolar-mass intruders can acquire appreciable circumintruder disks with elevated dust-to-gas ratios, which can ease their observational detection. However, this is true only for prograde collisions; the retrograde intruders fail to collect appreciable amounts of gas or dust from the disk of the target. The mass of gas in the tail varies in the range 0.85-11.8 M<sub>Jup</sub>, while the total mass of dust lies in the 1.75-30.1 M<sub>⊙</sub> range, with the spiral tails featuring the highest masses. The predicted mass of dust in the model tail-like structures is therefore higher than what was inferred for similar structures in SU Aur, FU Ori, and Z CMa, making their observational detection feasible. Conclusions. Tail-like structures around protostellar and protoplanetary disks can be used to infer interesting phenomena such as clump ejection or close encounters. In particular, the bow-shock morphology of the tails could point to clump ejections as a possible formation mechanism. Further numerical and observational studies are needed to better understand the detectability and properties of the tails.</p>}},
  author       = {{Vorobyov, Eduard I. and Skliarevskii, Alexandr M. and Elbakyan, Vardan G. and Takami, Michihiro and Liu, Hauyu Baobab and Liu, Sheng Yuan and Akiyama, Eiji}},
  issn         = {{0004-6361}},
  keywords     = {{Hydrodynamics; Protoplanetary disks; Stars: protostars}},
  language     = {{eng}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{The origin of tail-like structures around protoplanetary disks}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/201936990}},
  doi          = {{10.1051/0004-6361/201936990}},
  volume       = {{635}},
  year         = {{2020}},
}