Current Research

The current stage of cosmological structure formation in the universe is the formation and growth of galaxy clusters. Major mergers between these massive clusters of galaxies are a primary growth mechanism of galaxy clusters, so studies of their dynamics can test the paradigm of hierarchical structure formation in the universe. Currently, for a set of galaxy clusters, I'm working with my collaborators to compare multi-wavelength observational data from X-ray, optical, and sub-mm datasets to predictions from hydrodynamical simulations in order to constrain merger dynamics, geometries, and initial parameters. We will then use these galaxy cluster merger population statistics to test the ΛCDM cosmological model.

Past Projects

A Search for the 3.5 keV Line from the Milky Way's Dark Matter Halo with HaloSat

We use HaloSat observations of the Milky Way's Galactic dark matter halo to search for a 3.5 keV X-ray emission line associated with the decay of a 7.1 keV sterile neutrino dark matter candidate. Reporting a non-detection, we place upper limits on the 3.5 keV line flux and the corresponding 7.1 keV sterile neutrino mixing angle.

Global X-Ray Properties of the Vela and Puppis A Supernova Remnants

We report on the first soft X-ray (0.4-7 keV) observation of the entire Vela SNR and Puppis A SNR region with a single pointing at moderate spectral resolution. Using HaloSat observations, we provide estimates of the temperatures and total X-ray luminosities of Vela and Puppis A.

Publications

(full list available on ADS, or see my CV)

  1. E.M. Silich, K. Jahoda, L. Angelini, P. Kaaret, A. Zajczyk, D.M. LaRocca, R. Ringuette, and J. Richardson, “A Search for the 3.5 keV Line from the Milky Way’s Dark Matter Halo with HaloSat”, 2021, The Astrophysical Journal, 916, 2.

  2. E.M. Silich, P. Kaaret, A. Zajczyk, D.M. LaRocca, J. Bluem, R. Ringuette, K. Jahoda, and K.D. Kuntz, “Global X-Ray Properties of the Vela and Puppis A Supernova Remnants”, 2020, The Astronomical Journal, 160, 1.

  3. P. Kaaret, A. Zajczyk, D.M. LaRocca, R. Ringuette, J. Bluem, W. Fuelberth, H. Gulick, K. Jahoda, T.E. Johnson, D.L. Kirchner, D. Koutroumpa, K.D. Kuntz, R. McCurdy, D.M. Miles, W.T. Robison, and E.M. Silich, “HaloSat - A CubeSat to Study the Hot Galactic Halo”, 2019, The Astrophysical Journal, 884, 2.

  4. A. Zajczyk, P. Kaaret, D. LaRocca, W. Fuelberth, H.C. Gulick, K. Jahoda, D.L. Kirchner, R. McCurdy, W.T. Robison, and E. Silich, “On-ground calibration of the HaloSat science instrument”, J. Astron. Telesc. Instrum. Syst. 6(4), 044005 (2020), doi: 10.1117/1.JATIS.6.4.044005.

Outreach

Galaxy Clusters Collide: The Most Energetic Events since the Big Bang

Stargazing lecture (public-level) for Caltech Astro + Q&A panel