Biography

My work involves using X-ray observations to study supernova remnants (SNRs), using spatially resolved imaging and spectral analysis to study the properties of their ejecta along with any compact objects embedded within. I then compare these results to the theoretical predictions of supernova simulations and observational work in other wavelengths in order to learn more about the processes that occur during supernova explosions and as SNRs expand through their surrounding medium. I have analyzed data from Chandra, XMM-Newton, ROSAT, Suzaku, and XRISM X-ray telescopes.

As a graduate student at The Ohio State University, I investigated the asymmetries of bulk ejecta in multiple SNRs, performing spectral fitting using the X-ray analysis software Xspec and AtomDB. I quantified the ejecta asymmetries and compared them to each other and NS kick velocity, finding that NSs are preferentially kicked opposite to the bulk of ejecta. In the SNR Cassiopeia A, I analyzed the bulk motion of individual elements and found that the NS’s motion was most directly opposite the heaviest ejecta elements. In another project, I studied recombining plasma in the SNR W49B, creating spectral fits to 46 regions in the remnant in order to investigate the properties and presence of overionized plasma and constrain the origin of rapid cooling.

As a Future Faculty Leader Postdoctoral Fellow at the Center for Astrophysics, I performed a detailed analysis of the global X-ray emission in Kepler’s SNR, fitting the entire 0.5-8.0 keV spectrum in order to measure the mass ratios of various ejecta elements and link the SNR to specific Type Ia progenitor scenarios. In order to obtain accurate results, I incorporated the effects of Suzaku’s effective area calibration uncertainties and the effects of the unknown emitting volumes of different plasma components, both of which dominated over the photon Poisson uncertaintis and together resulted in ~15% uncertainties on my final mass ratio estimates. In a separate project, I measured the proper motion of the neutron star in the SNR Cassiopeia A, making use of the wealth of data taken using Chandra from 1999 to present. Even though there are few nearby point sources for which to perform astrometric calibration (necessary to measure the small <0.1 arcsec/year motion of the NS), the sheer number of observations can be used in order to reduce errors and obtain a more precise velocity measurement. Finally, I collaborated with Dr. Adrien Picquenot to use the General Morphological Component Analysis (GMCA) technique to study Kepler’s and Tycho SNRs. We identified the asymmetries of different elements, the plasma properties of different regions of the SNR, and disentangle different types of X-ray emitting material: i.e., swept-up CSM vs Fe-rich vs intermediate-mass ejecta dominant.

Currently, as an NPP Fellow at NASA GSFC, I am building upon my past research and beginning to incorporate XRISM data in my analysis of SNRs. I performed a similar global, full-X-ray-spectrum analysis of Tycho’s SNR to measure its mass ratios and constrain its origin. In the future, I plan to build up a large sample of SNRs analyzed using this method. I also am continuing the measure the velocities of NSs embedded in SNRs: comparing these velocities to SNR ejecta asymmetries and energetics to help further our knowledge of explosion physics and the mechanism(s) by which NSs are accelerated. I have already performed this analysis on the SNR G18.9-1.1, for which I was awarded Chandra observation time in Cycle 24, obtaining the first direct proper motion measurement of the NS embedded within. In my projects going forward, I will use the incredibly detailed spectra from microcalorimeters like XRISM to study the 3D distribution of and make precise measurements of ejecta metals and plasma properties in SNRs, making use of it and other telescopes’ data simultaneously.