#  ITC Pizza Lunch 

 



####  calendar\_today Date and Time 

 **March 28, 2018** 

 11:00AM - 12:00PM EDT 

####  pin\_drop Location 

 **Phillips**  



 

 



 

Sort    Anna Rosen (ITC)  
  
Title: Gone with the wind: Where is the missing stellar wind energy  
from massive star clusters?  
  
Abstract: Star clusters larger than ∼103 M⊙ contain multiple hot stars  
that launch fast stellar winds. The integrated kinetic energy carried  
by these winds is comparable to that delivered by supernova  
explosions, suggesting that at early times winds could be an important  
form of feedback on the surrounding cold material from which the star  
cluster formed. However, the interaction of these winds with the  
surrounding clumpy, turbulent, cold gas is complex and poorly  
understood. Here, we investigate this problem via an accounting  
exercise: we use empirically determined properties of four  
well-studied massive star clusters to determine where the energy  
injected by stellar winds ultimately ends up. We consider a range of  
kinetic energy loss channels, including radiative cooling, mechanical  
work on the cold interstellar medium, thermal conduction, heating of  
dust via collisions by the hot gas, and bulk advection of thermal  
energy by the hot gas. We show that, for at least some of the  
clusters, none of these channels can account for more than a small  
fraction of the injected energy. We suggest that turbulent mixing at  
the hot–cold interface or physical leakage of the hot gas from the HII  
region can efficiently remove the kinetic energy injected by the  
massive stars in young star clusters. Even for the clusters where we  
are able to account for all the injected kinetic energy, we show that  
our accounting sets strong constraints on the importance of stellar  
winds as a mechanism for feedback on the cold interstellar medium.  
  
----------------------------------------------------------------  
  
Atish Kamble (CfA)  
  
Title: "Radio Supernovae Illuminating the Environments of Massive Stars"  
  
Abstract: In a supernova explosion, the rapidly expanding shock wave  
races ahead of the radioactive ejecta and emits synchrotron radiation  
predominantly in radio waves. This radio emission naturally carries  
the stamp of the environment, that has been sculpted by the progenitor  
through winds, eruptions, binary interactions etc., and thus traces  
the final centuries in the life of the progenitor that are otherwise  
inaccessible to observations or current theories. Investigation of  
radio supernovae is, therefore, a powerful tool to probe the  
progenitors' mass-loss history and its identity as I will show through  
examples from diverse supernova classes. 

 





 

 



 

 See also:- [ 2017-18 ](/academic-year/2017-18)
- [ Pizza Lunch ](/event-type/pizza-lunch)
 
 

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