Thieves in the neighborhood:
Michael Küffmeier (Marie Skłodowska-Curie global fellow)
Mass transfer from a disk to its companion
Sigurd Jensen, Jaime Pineda (all MPE), Rajika Kuruwita (HITS), Troels Haugbølle (NBI)
Mind (late) infall:
A source of rejuvenation and misalignment
Wow!
Credit: ALMA (ESO/NAOJ/NRAO)
Credit:
DSHARP team
10 au
50 au
The classical picture
Greene 2001
star formation
planet formation
Is this the full picture?
Credit: ALMA (ESO/NAOJ/NRAO)
Ginski et al. 2021
Yen et al. 2019
Garufi et al. 2021
Pineda et al. 2020
50 au
see also:
BHB1 (Alves et al. 2020), GM Aur (Huang et al. 2021), IRS 63 (Segura-Cox in prep.), AB Aur (Grady et al. 1999 / Fukagawa et al. 2004), ...
Per-emb-50
Valdivia-Mena et al. 2022
Model star formation in its birth environment
isothermal magnetohydrodynamical (MHD), adaptive mesh refinement (AMR) simulations with RAMSES; maximum resolution 25 AU; 3000 solar masses; sink particles
x
y
1 pc
(same setup as R. Kuruwita presented this morning)
Late infall is common for stars*
*unless they remain tiny
On average, stars with final masses of more than 1 solar mass accrete more than 50 % of their mass after 500 kyr
15 to 20 % of stars more massive than 1 solar mass accrete 50 % of their mass after 1 Myr
Origin of accreting gas
For solar mass stars ~50 % of final mass from beyond prestellar core! (Pelkonen et al. 2021)
Possibility of replenishing and refreshing the mass and chemical budget
Class II
Class I
Class 0
YSOs can appear younger than they really are
How old is the protostar?
Class II
Class I
Class 0
YSOs can appear younger than they really are
How old is the protostar?
A poor analogy to a conference
Session start
Coffee break!
Class II
Class I
Class 0
Streamers (and shadows?) as signs of infall
Formation of misaligned configuration
Observable as shadows in outer disk
Küffmeier, Dullemond, Reissl & Goicovic 2021
Ginski et al. 2021
300 au
Accretion of a binary system
zoom-in with maximum resolution of 3 AU; isothermal; ideal MHD; no radiative transfer
You are missing
non-ideal MHD
radiative transfer
resolution
dust
...
1000 au
Accretion of a binary system
zoom-in with maximum resolution of 3 AU; isothermal; ideal MHD; no radiative transfer
1000 au
Accretion of a binary system
Caveat: zoom-in with only maximum resolution of 3 AU; isothermal; ideal MHD; no radiative transfer (more to be done, but intriguing)
about 30 % of accreting mass goes through the star's own disk
almost 10 % of accreting mass of companion goes through the primary star's disk
Summary
Pineda ... Küffmeier et al. 'Protostars and Planets VII'
.
.
Segura-Cox et al. in prep.
Star & disk can be replenished by infall of initially unbound material
YSOs can be rejuvenated
Mass can be "stolen" from a disk by a companion (TBC)
The connection to the larger scales
Küffmeier et al. 2017 / 2022 in prep.
Gas from beyond the prestellar core can fall onto the star-disk system
Simulate cloudlet infall onto disk
AREPO, pure hydrodynamical
R_{\rm i,d}=50\, \rm au
\Sigma(r) = 170 \left(\frac{\rm g}{\rm cm}\right)^{2} \left( \frac{r}{1 \rm au} \right)^{-3/2}
M_{\rm cloudlet}(R_{\rm cloudlet}) = 0.01 {\rm M}_{\odot} \left( \frac{R_{\rm cloudlet}}{5000 \rm au}\right)^{2.3}
R_{\rm cloudlet} = 887\, \rm au
isothermal gas
vary infalling angle
\alpha = 0^{\circ} (35^{\circ}, 60^{\circ}, 90^{\circ})
b = 1774\, \rm au
vary rotation (prograde, retrograde)
Küffmeier, Dullemond, Reißl, Goicovic et al. 2021
M_{*}=2.5\, \mathrm{M}_{\odot}
Outer disk forms around inner disk
Küffmeier et al. 2021
Prograde vs. retrograde infall
Retrograde infall causes:
- counter-rotating inner and outer disk
- shrinking of inner disk
- enhanced accretion
- larger and deeper gap between disks
see also Vorobyov+ 2016
Küffmeier et al. 2021
Inner disk orientation
M_{\rm i, disk}=4 \ M_{\rm cloudlet}
M_{\rm cloudlet} = 1.87 \times 10^{-4} \ \mathrm{M}_{\odot}
M_{\rm i,disk} = 24 M_{\rm cloudlet}
M_{\rm i,disk}=4 \ M_{\rm cloudlet}
M_{\rm i,disk} = 0.4 \ M_{\rm
cloudlet}
Küffmeier et al. 2021
Copy of HHSF_workshop2022
By kuffmeier
