Brian Siana

Associate Professor of Physics and Astronomy  

Pierce Hall 2144A
brian.siana [at] ucr.edu
Department of Physics and Astronomy
University of California, Riverside
900 University Ave
Riverside, CA 92521


I am primarily interested in understanding galaxy formation in the early universe and its effects on the intergalactic medium.  I use the Hubble and Spitzer Space Telescopes and the ground-based W. M. Keck Observatory to understand star formation processes in the early universe, determine a more accurate census of star formation, and estimate its effects on the intergalactic medium.  In particular, my latest research is focused on understanding how faint, dwarf galaxies ionized the hydrogen in the intergalactic medium in the first billion years (the so-called “reionization” of the universe).


  • MOSDEF – A 48.5 night Keck/MOSFIRE spectroscopic survey of 1500 galaxies at 1<z<3.5
  • Ultraviolet Frontier – A 96 orbit Hubble near-UV imaging survey of lensing clusters: Abell 1689 and the Hubble Frontier Fields

Graduate Student Advising

Kaveh Vasei – Lyman continuum escape fraction and the ionizing background.
Najmeh Emami – Characterizing “bursty” star formation in dwarf galaxies.
Timothy Gburek – The mass-metallicity relation in low mass galaxies at high-redshift.

Former students:

Anahita Alavi- Luminosity functions and dust extinction of lensed, high-redshift dwarf galaxies.

William (Bill) Freeman – Galaxy scale outflows.


PHYS 018 – Energy and the Environment

PHYS 040A – Introductory Mechanics (for engineers and physical sciences)

PHYS 111 – Stellar Astrophysics (upper level physics majors)

PHYS 203 – Statistics and Data Analysis Techniques (for graduate students or advanced undergraduates)