Theory Group


Cosmic Reionization

Early Universe

First Stars & Galaxies

Fundamental Physics

Structure Formation

Extragalactic Astrophysics

Clusters of Galaxies

Theoretical & Computational Astrophysics

Galactic Evolution

ISM and Star Formation

Milky Way Evolution

Planetary Sciences


Planet Formation

Stellar Astrophysics


Gamma-ray Bursts

Neutron Stars & Magnetars


White Dwarfs

Theory Group : Galactic Evolution : ISM and Star Formation

Sample publications:

Volker Bromm, John Scalo, Paul Shapiro

ADS | astro-ph

Volker Bromm  



Research Interests

Formation of the first stars and quasars; high-redshift supernovae and metal enrichment; supermassive black hole formation; gamma-ray bursts; reionization of the intergalactic medium; present-day star formation; computational astrophysics.

Group Areas

Theory, First Stars & Galaxies, Structure Formation, Theoretical & Computational Astrophysics, ISM and Star Formation

ADS | astro-ph

John Scalo  



Research Interests

Star formation; interstellar medium; turbulence; galaxy evolution; complex systems; astrobiology.

Group Areas

Planetary Systems, Atmospheres & Life, Theory, Astrobiology, Planet Formation, ISM and Star Formation, Milky Way Evolution, Star Formation & Protoplanetary Disks

ADS | astro-ph

Paul Shapiro  



Research Interests

Theoretical astrophysics: cosmology, galaxy formation, the interstellar medium, the intergalactic medium, interstellar dust grains, astrophysical hydrodynamics.

Group Areas

Theory, Cosmic Reionization, Early Universe, First Stars & Galaxies, Structure Formation, Clusters of Galaxies, ISM and Star Formation, Milky Way Evolution

Observed vs. "accreted" Fe (panel A) and Mg (panel B) abundances for the sample of metal-poor stars (red circles). The case where all stars pass through a dense cloud once is also presented (green open circles). The three most Fe-poor stars are indicated (crossed circles, diamond). For HE 1327−2326, both the 1D non-LTE and 3D LTE Fe values are shown. All stars have accreted fewer metals than what is observed, thus demonstrating the validity of the basic assumption underlying stellar archaeology. The minimum Fe and Mg abundance ranges, calculated under the assumption of a top-heavy Pop III IMF, are given (yellow region). The approximate Mg abundance arising from a PISN event in an atomic cooling halo is indicated (dashed line, panel B), as well as the Fe and Mg levels of enrichment from a 25M⊙ mixing and fallback SN (dotted lines, blue regions). We highlight those stars (gray regions) that can be used to place constraints on the Pop III IMF, where accretion does not affect whether they lie above or below the theoretical "bedrock abundances", predicted for a top-heavy IMF. Since all observed Mg abundances within the IMF-sensitive (gray) region to date fall above this bedrock range, we conclude that a top-heavy IMF is favored for the first stars.


The minimum stellar metallicity observable in the Galaxy astro-ph