The document summarizes research on the first luminous objects in the early universe, including the first stars and their deaths in supernovae. Massive first stars between 80-250 solar masses died in pair-instability supernovae or pulsational pair-instability supernovae, enriching the interstellar medium with metals. Later population II and III stars formed in the first galaxies around redshift 10-20, which were influenced by feedback from earlier stellar populations. Observations of supernovae, gamma rays, and gravitational waves may reveal more about the first stars and galaxies.

1. The Cosmic Dawn:
Physics of the First Luminous Objects
Ke-Jung (Ken) Chen
Johnston Graduate Fellow, University of Minnesota

2. The First Stars

3. The First Stars
Abel, et al. Science (2002) Bromm, et al. Nature (2009)
Mass Scale ~ 100-1000 M⊙

4. The Death of Massive Stars
Woosley, Heger, & Weaver (2002)
MS Mass He Core Supernova Mechanism
10 ≤ M ≤ 85 2 ≤ M ≤ 32 Fe core collapse to a
neutron star or black hole
(GRB Talks: Aloy, Matsumoto, Mizuta)
(CCSNe Talk by Suwa )
80 ≤ M ≤ 150 35 ≤ M ≤ 60 Pulsational pair instability
followed by core (PPSN)
150 ≤ M ≤ 250 60 ≤ M ≤ 133 Pair instability supernova
(PSN)
250 ≤ M 133 ≤ M Black holes
Mass Unit: solar mass ⊙

5. Pair-Instability Supernova (PSN)

6. Supernovae (Energetic Explosions)

7. Luminous Supernovae

8. How to Model 3D Supernovae
1D Models
80 - 150 M⊙ Stars (Woosley+ 2007, priv. comm.)
150 - 250 M⊙ Stars (Heger & Woosley 2002, 2010)
CASTRO (DOE SciDAC Computational Astrophysics Team)
Massive Parallel, Adaptive Mesh Refinement (AMR), Multi-D,
Radiation, Hydro, +( Nuclear Burning, Mapping, Rotation, GR, ... )
(Almgren+ 2010, Zheng+ 2011 2012, Chen+ 2011 2012)
Supercomputers
Itasca Franklin Hopper Jaguar

9. Explosion of a 110 M⊙ Star
(Chen+ Nature 2013)

10. Explosion of a 200 M⊙ Star

11. More Explosions !
(Chen+ 2012)
BSG 150 BSG 200 BSG 250
No Bang !!
form a black hole
RSG 150 RSG 200 RSG 250

12. Mixing of Elements

13. Results
Mass Core E Ni
Model 52 erg] [M⊙] Instab. Mixing
[M⊙] [M⊙] [10
B150 150 67 1.29 0.07 Burning weak
B200 200 95 4.14 6.57 Burning weak
B250 250 109 7.23 28.05 Burning weak
R150 150 59 1.19 0.10 Rev. Strong
R200 200 86 3.43 4.66 Rev. Strong
R250 250 156 ... ... ... ...
Ni is only slightly mixed out .
The Gamma-Ray emission for PSNe is unlikely.

14. Conclusions
Fate Very Bright Sources Observation
80 ~ 150 M⊙ PPSN YES Pop I, II, III Multi-SN
150 ~ 250 M⊙ PSN YES Pop I(?), II, III Large Ni
250+ M⊙ BH(?) No No GW
Mixing can be important ! 13

15. Formation of the First Galaxies
?
z ~ 10
👍
time
z ~ 20
👍👍

16. Characters of the First Galaxies
Bromm, & Yoshida (2011)
• Mass scale ~ 108 M⊙
• Redshift ~ 10
• Self-bound system.
• Affected from the previous stellar feedback
• Hosted the Pop III and Pop II stars

17. Modeling the Galaxy Formation
Gadget-2 ( Springel 2005)
1. Star formation
2. Radiative transfer
3. Diffusion mixing
4. Chemical cooling
Bromm+ 2002,2003 Johnson+ 2007
Greif+ 2009, 2010 Jeon+ 2012
Possible radiative feedbacks
1. Ionizing photons
2. SN shock reheating
3. X-Ray Binaries
Chemical enrichment
1. SN feedback

18. Impact of the First Stars and Supernovae

19. Conclusions
• All possible radiative feedback
1. Ionizing photons
2. SN shock reheating
3. X-Ray Binaries
• Chemical enrichment
1. SN feedback
2. Pop III to Pop II transition
The impact of the first stars holds the key to the later
galaxy formation!!

20. The cosmic dawn may be observed by

21. Many thanks for your attention
My work has been kindly supported by: