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Hot Cores and the CMF

Adam Ginsburg

Assistant Professor
Department of Astronomy
University of Florida, Gainesville

with the ALMA-IMF team (incl. Timea Csengeri, Melisse Bonfand, Thomas Nony), postdoc Allison Towner, and students Desmond Jeff, Theo Richardson, Alyssa Bulatek, Nazar Budaiev, and Savannah Gramze
Slides available at https://keflavich.github.io/talks/starstogalaxies2022_hotcores.html

Meet my group

49 Theo Richardson:
YSO radiative transfer modeling 		54 Nazar Budaiev: Protostars & cores in Sgr B2
55 Desmond Jeff:
Hot Cores in Sgr B2 DS 		66 Allison Towner (postdoc): SiO in ALMA-IMF (at low velocities)
157 Savannah Gramze:
Overshooting and crashing gas along the Galactic bar 		160 Alyssa Bulatek:
Lines as tracers of physical processes in The Brick

Summary

  • Hot cores are where high-mass, forming young stars feed back onto their environments
  • They suppress fragmentation by heating the gas

How does the observed CMF transform to the IMF?




Offner+ 2014 PPVI review

ALMA-IMF: $\sim800$ cores

www.almaimf.com/data.html
Pouteau+ 2022 W43-MM2/3

ALMA-IMF:
The CMF is shallow (top-heavy) in HMSFRs

Pouteau+ 2022 W43-MM2/3 CMF
Motte+ 2018 W43-MM1 CMF: α≳-1

Top-heavier IMFs are seen in high-mass clusters,
CMFs in protoclusters

Hosek+ 2018
https://tinyurl.com/IMF-figure
Hot cores in ALMA-IMF: From rare objects to a population ($\sim50$)
Cores with line forests
TD>50 K
TG ≳100K
Brouillet+, resubmitted
Bonfand+ (last talk): CH3OCHO HC catalog ($T\gtrsim100$ K)
Many lines of CH3OCHO toward W51-E2

Hot cores are generally the most massive cores

Hot cores are mostly small ($\lesssim5000$ AU)

The characteristic fragmentation scale is larger near HCs
Jeans Mass MJ ∝ T3/2 ρ−1/2
Ginsburg+ 2017

HCs don't fragment in our data

No clear cases of another core existing with the radius (as seen in CH3OCHO) of a hot core in ALMA-IMF data (2000 AU resolution).
Limited fragmentation at higher resolution.

HCs don't fragment in our data

No clear cases of another core existing with the radius (as seen in CH3OCHO) of a hot core in ALMA-IMF data (2000 AU resolution).
Limited fragmentation at higher resolution.
Hot cores in the Galactic center
Desmond Jeff:
Ten hot cores in Sgr B2 DS
TG ~ 200-500 K
M ~ 200 - 2900 M⊙

Hot cores in the CMZ are a bit hotter and more massive

Summary

  • Hot cores are where high-mass, forming young stars feed back onto their environments
  • They suppress fragmentation by heating the gas