Home Galactic Star Clusters Across Cosmic Time. (arXiv:1812.01615v1 )

Star Clusters Across Cosmic Time. (arXiv:1812.01615v1 [astro-ph.GA])


Authors: Mark R. Krumholz, Christopher F. McKee, Joss Bland-Hawthorn

Star clusters stand at the intersection of much of modern astrophysics: the
interstellar medium, gravitational dynamics, stellar evolution, and cosmology.
Here we review observations and theoretical models for the formation,
evolution, and eventual disruption of star clusters. Current literature
suggests a picture of this life cycle with several phases: (1) Clusters form in
hierarchically-structured, accreting molecular clouds that convert gas into
stars at a low rate per dynamical time until feedback disperses the gas. (2)
The densest parts of the hierarchy resist gas removal long enough to reach high
star formation efficiency, becoming dynamically-relaxed and well-mixed. These
remain bound after gas removal. (3) In the first $sim 100$ Myr after gas
removal, clusters disperse moderately fast, through a combination of mass loss
and tidal shocks by dense molecular structures in the star-forming environment.
(4) After $sim 100$ Myr, clusters lose mass via two-body relaxation and shocks
by giant molecular clouds, processes that preferentially affect low-mass
clusters and cause a turnover in the cluster mass function to appear on $sim
1-10$ Gyr timescales. (5) Even after dispersal, some clusters remain coherent
and thus detectable in chemical or action space for multiple galactic orbits.
In the next decade a new generation of space- and AO-assisted ground-based
telescopes will enable us to test and refine this picture.


Source link


Please enter your comment!
Please enter your name here

Enter Captcha Here : *

Reload Image

Must Read

Why everyone is talking about energy storage | MNN

Ever since governments started getting serious about developing renewable energy, naysayers have been arguing that it's a pipe dream — after all, the...

Give charities free ad space on your smartphone’s lock screen with Screen Donor

This app gives free ad space to deserving charities and NGOs on one of our tech-centric culture's most commonly seen screens - our...

Tropicana 100% Juice 3-Flavor Fruit Blend Variety Pack, 10 Fl Oz, Bottles, (Pack of 24)

Price: (as of - Details) Now you can enjoy the refreshing taste of Tropicana’s Fruit Medley, Pineapple Peach Mango and Strawberry Orange Juice...

Cell phones and screens are keeping your kid awake

For children and teens, using cell phones, tablets and computers at night is associated with losing sleep time and sleep quality, new research...