Predoc List

Gabriella Alvarez
Gabriella Alvarez, High Energy Astrophysics
Vanderbilt University
Advisor: Scott Randall

Gabriella is a graduate student from Vanderbilt University where she works with Dr. Kelly Holley-Bockelmann on simulations of the Milky Way's nuclear star cluster and central supermassive black hole Sag A* to develop gravitational wave strain metrics for the International Pulsar Timing Array (IPTA). At the CfA, Gabriella is studying the outskirts of galaxy cluster environments as well as intercluster filaments with CHANDRA data as well as eventually data from XMM-NEWTON and SUZAKU in order to better characterize the physical properties of these environments, as the mass of galaxy clusters help to constrain cosmology. Studying the extended diffuse emission of cluster outskirts and intercluster filaments may also provide clues to an answer for the "missing baryon" problem.

Yue Cao
Yue Cao, Radio and Geoastronomy
Advisor: Qizhou Zhang

Yue Cao is a PhD student from Nanjing University under Professor Keping Qiu's supervision. He is interested in studying the physical properties of molecular cloud structures (dense cores, filaments, etc.) and their relations with star formation. By using continuum data of single dish telescopes (e.g. Herschel, JCMT), Yue has generated a complete catalog of massive dense cores in the prominent Cyg X star-forming region (Cao et al. 2019) and reproduced a mass function similar to the canonical IMF (in prep.). Yue is currently working on the fragmentation of massive dense cores and the gas kinematics of massive filaments using interferometer data. In the near future, Yue plans to devote himself to star formation processes on even smaller scales (<0.01 pc or 2000 AU) with the help of SMA & ALMA and probably to disks.

Jordan Eagle, High Energy Astrophysics
Advisor: Daniel Castro

Jordan Eagle is a PhD student from Clemson University working under the advisory of Dr. Marco Ajello in the high energy astrophysics division. Specifically, Jordan researches candidate cosmic ray accelerators like supernova remnants and pulsar wind nebulae (PWNe) where a thorough multiwavelength analysis is performed on all objects of interest to determine emission mechanisms, particle populations present, and more. At the CfA, Jordan focuses on identifying and characterizing gamma-ray emitting pulsar wind nebulae to develop the first comprehensive PWNe catalog using the Fermi-LAT. Jordan aims to make a complete picture of each catalog object across the electromagnetic spectrum with data from Fermi, Chandra, XMM-Newton, NUSTAR, and optical instruments such as Gemini. Furthermore, Jordan will investigate known gamma-ray pulsars for new PWN candidates. The resulting comprehensive catalog will provide, for the first time, a detailed description of the properties of PWN across the light spectrum which will ultimately allow us to disentangle the PWN spectrum from its host SNR and to understand the emission mechanisms and particle populations at work.

Taylor Jacovich
Taylor Jacovich, High Energy Astrophysics
Advisor: Daniel Patnaude

Taylor is currently a PhD candidate at the George Washington University where he works with Dr. Alexander van der Horst on the broadband modeling of gamma-ray burst afterglows. In particular, His work focuses on modifying current hydrodynamic fitting routines to account for emission mechanisms beyond synchrotron effects. While at CfA, Taylor is working with Dr. Daniel Patnaude to produce physical models of supernovae and their remnants beginning from the pre-main sequence phase in order to better understand the resulting objects through the evolution of their progenitor objects.

Kristina Monsch, High Energy Astrophysics
Advisor: Jeremy Drake

Kristina is a PhD student at the Ludwig-Maximilians-University in Munich, Germany, where she works together with Barbara Ercolano and Thomas Preibisch on studying how the migration process of giant planets is affected by the dispersal of the surrounding circumstellar disc due to X-ray photoevaporation driven by the host star. In particular, she studies if signatures of this process are imprinted in the observed semi-major axis distribution of exo-giants. At CfA, she is working together with Jeremy Drake on characterising the time-evolution of the X-ray activity of young pre-main sequence stars, which is a crucial ingredient in order to be able to directly compare the outcome of theoretical models with observational data.

Benjamin Roulston
Benjamin Roulston, High Energy Astrophysics
Advisor: Paul Green

Benjamin is a PhD student at Boston University under the supervision of JJ Hermes. Ben's work at the CfA focuses on studying stellar variability with the Time Domain Spectroscopic Survey (TDSS) in the SDSS-IV. One project involves measuring radial velocity variability of dwarf carbon (dC) stars and using MCMC methods to fit separation distributions and constrain the binary fraction of these peculiar stars. While another project focuses on using the large sample of variable (periodic and non-periodic) stars in TDSS that have both light curves and spectra to provide spectral characterization of stellar variables. The ultimate goal is to develop a machine learning tool that uses both light curves and spectra to classify variable stars.

Arnab Sarkar, High Energy Astrophysics
Advisor: Scott Randall

I am a Ph.D. student at the University of Kentucky working under the advisory of Dr. Yuanyuan Su. I mainly study the intracluster medium (ICM) properties in the galaxy cluster outskirts, where the ICM connects to the large-scale cosmic web. In the standard CDM cosmological structure formation model, galaxy clusters continue to grow and evolve through mergers and the accretion of matter, mainly along cosmic filaments, in their outer regions. Therefore, probing the outskirts of galaxy clusters is crucial to study cosmology and the growth of large-scale structures. Here at CfA, under Dr. Scott Randall's supervision, I look for correlations between global cluster properties and sub-self-similar entropy values (SSSEV) in the cluster outskirts, which will provide a better understanding of how SSSEV varies with cluster mass and dynamical state.

Crisel Suarez
Crisel Suarez Bustamante, High Energy Astrophysics
Advisor: Christopher Moore

Crisel Suarez is a graduate student at Vanderbilt University where she is currently pursuing her Ph.D in Physics. She is interested in studying the physical properties of the solar corona by comparing different types of observations to numerical models. Her research focuses on analyzing solar flare observations from the Miniature X-ray Solar Spectrometer (MinXSS) Cubesats and using the hydrodynamic numerical simulations (HYDRAD) to better understand the emission, temperature and elemental abundances of the solar corona during flares. While at the CfA, Crisel is working with Dr. Christopher Moore to better understand the signature of Quasi-Periodic Pulsations (QPP) in solar flares by using a data constrained successive reconnection model.

Santiago Ubach Ramirez, High Energy Astrophysics
Advisor: James Steiner

Santi is a PhD student at Autonomous University of Barcelona (UAB) under the supervision of Dr. Gaug and Dr. Font in the high energy astrophysics group. Specially, Santi is focused on the detection of Quasi-Periodic Oscillations (QPOs) in the Very High Energy (VHE) regime inside the MAGIC collaboration to try to understand the origin of these QPOs. Such QPOs appear in stellar-mass Black Hole Binary (BHB) systems but also in Active Galactic Nucleus (AGN). At CfA and under the supervision of Dr. James Steiner, will study the Dynamic Accretion onto Stellar-Mass Black Holes, measuring the spin of black hole systems, modeling QPOs in black hole systems and relating QPO changes to spectral evolution of the BH system, modeling the geometrical and spectral characteristics during a black hole outburst, and using the premier Magellan telescopes to measure orbital characteristics and determine the masses of quiescent black hole systems. Outside of research, he enjoys reading science fiction and training for an Ironman, watching Japanese animations, and working as a field hockey coach. You can also find him playing field hockey or working extra hours.

Chao Wang, Radio and Geoastronomy
Peking University
Advisor: Qizhou Zhang

Chao is a PhD student from Peking University under Professor Ke Wang's supervision. He is interested in the properties and evolution of the turbulence and magnetic field in high-mass star formation regions. With the high resolution (both in spatial and spectral) data from VLA, SMA and ALMA, Chao’s research has revealed the dynamic properties in more than 20 high-mass star formation regions and the existence of the subsonic turbulence after excluding the channel effect. At the CfA, he studies the gas evolution of several massive cores with the ALMA polarization data as well as the study of the role of the magnetic field in different scales together with turbulence.

Xiaoyan Xie, High Energy Astrophysics
Advisor: Katharine Reeves

Xiaoyan is a PhD candidate at Yunnan Observatories, Chinese Academy of Sciences, under the supervision of Prof. Jun Lin. She has been performing numerical simulations to investigate various types of disturbances that occur during the solar eruptions, including the Moreton wave and EUV (extreme ultraviolet) wave. While at the CfA, she will employ numerical simulations on the basis of the catastrophe model of the solar eruption to study the waves in detail and predict observable signals in several wavebands. The subtopics are looking into the reflected waves in more realistic coronal environments by including optical thin radiative cooling and anisotropic thermal conduction in the simulations; investigating features of the model-based shock to obtain the observational consequences of the CME-driven shock in different bands and get statistics properties; and studying waves and perturbations driven by small structures in the large scale reconnecting current sheet. These studies will help us understand the coronal properties and the magnetic configuration during the solar eruptions. Outside of science, Xiaoyan enjoys running.