How old are you?
Michael Küffmeier (Marie Skłodowska-Curie global fellow)
Rejuvenation of disks by (late) infall
Sigurd Jensen, Jaime Pineda, Paola Caselli (all MPE), Troels Haugbølle (NBI)
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
magnetohydrodynamical (MHD), adaptive mesh refinement (AMR) simulations with RAMSES; maximum resolution 25 AU; 3000 solar masses
x
y
1 pc
Late infall is common for stars*
*unless they are tiny
On average, stars with final masses of more than 1 solar mass accrete more than 50 % of their mass after 500 kyr
Almost 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?
A poor analogy to this morning
Session start
My talk
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
Ginski et al. 2021
Küffmeier, Dullemond et al. 2021
see also Bate 2018
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
Late infall happens more often than assumed
For solar mass stars ~50 % of final mass from beyond prestellar core! (Pelkonen et al. 2021)
Can disks be rejuvenated?
Küffmeier et al. 2022 in prep
Possibility of replenishing and refreshing the mass and chemical budget
It's fun to work on cosmic rays,
instead of catching Covid waves.
Does cosmic-ray ionization play a crucial role in disk formation?
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
ESO_workshop2022
By kuffmeier
