Welcome

I am a graduate student at Caltech's Astronomy Department. I work with Prof Richard Ellis and Prof Evan Kirby. My areas of interest are galaxy formation and evolution – in particular, the physical properties and chemical compositions of gravitationally-lensed galaxies. Most of my research uses Keck telescope observations.

 

 

email address: nichal [at] astro [dot] caltech [dot] edu

Metallicity gredients in z~2 galaxies

ApJ,820,84 (2016)

A study of 15 gravitationally-lensed star-forming galaxies at z ~ 2 with Keck's AO-assisted IFU spectograph. Our data indicate a diverse range of kinematic and metal gradient behavior. A high fraction of flat metal gredients suggests outflows or other strong feedback processes.

Covering fractions of z~4-5 galaxies

ApJ,831,152 (2016)

We use low-ionization absorption lines to estimate covering fractions in 7 gravitationally-lensed sources at z ~ 4-5. Accounting for reddening according to a dust-in-cloud model, we estimate an absolute escape fraction of ~19 ± 6%.

Stellar Metallicity Evolution

ApJ,856,15 (2018)

Does the stellar mass–stellar metallicity relation evolve with redshift? In this paper we detect an evolution of the stellar MZR from z=0.4 to z=0, which can be explained by an evolution of the stellar MZR with galaxy formation redshift. In future, we will extend the work to higher redshift galaxies and measure their alpha enhancement as well.

Education

California Institute of Technology

2013 to present

Doctor of Philosophy (in progress)

 

The University of Chicago

2009 to 2013

B.A. in Physics with Specialization in Astrophysics with Honors

B.S. in Mathematics