Accepted Cycle 25 Theory Proposals

Proposal Number	Subject Category	PI Name	Title
25200179	STARS AND WD	Asif ud-Doula	X-ray emission from fast rotating magnetic massive stars
25200432	STARS AND WD	Amy Gall	Updating Fe L-shell wavelengths for stellar coronal studies
25500012	SN, SNR AND ISOLATED NS	Emmanouil Chatzopoulos	X-ray Emission from Circumstellar Interaction in Superluminous Supernovae
25500311	SN, SNR AND ISOLATED NS	Vikram Dwarkadas	Shock Interaction and X-ray Emission in Stripped Envelope Supernovae Interacting with a Dense Circumstellar Medium
25700278	ACTIVE GALAXIES AND QUASARS	Jason Dexter	Non-thermal Radiation GRMHD Simulations of Sgr A* Flares
25800086	CLUSTERS OF GALAXIES	Elena Rasia	ICM metal history, metal transport mechanism, link to stellar population
25800103	CLUSTERS OF GALAXIES	John ZuHone	The Most Powerful Explosion in the Universe? Simulating AGN Feedback and Gas Motions in the Ophiuchus Cluster

Subject Category: STARS AND WD

Proposal Number: 25200179

Title: X-ray emission from fast rotating magnetic massive stars

PI Name: Asif ud-Doula

Magnetic massive stars are prominent sources of X-ray emission due to magnetically confined wind shocks. Direct comparison between Chandra/XMM observations and X-rays from Analytic Dynamical Magnetosphere (XADM) model (with a reduced 10\% duty-cycle factor) show the agreement is best for slowly rotating stars. Stars with an order magnitude higher X-ray emission are mostly all rapidly rotating B-stars. The proposal here aims to develop a new scaling law that will extend XADM formalism to explain anomalous X-ray emission from these rapidly rotating magnetic massive stars. This will utilize extensive set of MHD simulations of magnetic massive star winds that include rotation as a free parameter.

Subject Category: STARS AND WD

Proposal Number: 25200432

Title: Updating Fe L-shell wavelengths for stellar coronal studies

PI Name: Amy Gall

The Fe-L spectral region is diagnostically rich, providing line ratios sensitive to temperature, density, and abundance. In stellar coronae, Fe-L lines can be used to understand the corona density distribution among stellar populations and probe the density distribution as a function of temperature for individual stars, greatly improving our understanding of stellar coronae and possibly our Sun. Currently, these lines are largely underutilized due to the complexity of the calculations required to produce reliable models. We aim to change this by providing a set of accurate Fe-L measurements to test theories and improve models. Final wavelengths will be made available to the community through publication of line lists and by including results directly into AtomDB.

Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 25500012

Title: X-ray Emission from Circumstellar Interaction in Superluminous Supernovae

PI Name: Emmanouil Chatzopoulos

The goal of this proposal is to model the X-ray radiative properties of superluminous supernovae and luminous transient phenomena that are powered by SN ejecta - circumstellar matter interaction (CSI). The first part of this project will focus on adapting the capabilities of an existing Monte Carlo radiation transport code to include non-thermal sources of X-rays. Accordingly, the CSI model parameter space will be explored to determine the conditions that enable early detections by the CXO. Our results will also be used to characterize the environments around the extreme progenitors of SLSNe and their eruptive mass-loss histories, and ultimately help determine the prevalence of the CSI model in events that do not display hydrogen signatures in their optical spectra: hydrogen-poor SLSN-I.

Subject Category: SN, SNR AND ISOLATED NS

Proposal Number: 25500311

Title: Shock Interaction and X-ray Emission in Stripped Envelope Supernovae Interacting with a Dense Circumstellar Medium

PI Name: Vikram Dwarkadas

Some stripped envelope supernovae (SESNe) show signs of circumstellar interaction, including increasing X-ray emission, and time varying Halpha emission, months to years after explosion. These suggest interaction with a dense medium, that may have been expelled by the progenitor star or a companion in the years before core-collapse. Understanding the hydrodynamics of the interaction of the SN shock wave with this medium is key to evaluating the emission signatures from the SN. We propose to study the interaction using analytic calculations as well as numerical simulations, followed by computation of the X-ray emission using non-equilibrium ionization calculations. Our results will be applied to understanding young SESNe interacting with a dense medium, and interpreting the X-ray emission.

Subject Category: ACTIVE GALAXIES AND QUASARS

Proposal Number: 25700278

Title: Non-thermal Radiation GRMHD Simulations of Sgr A* Flares

PI Name: Jason Dexter

Chandra has extensively measured the empirical properties of large amplitude X-ray flares from the Galactic center black hole, Sgr A*. A promising physical scenario has emerged for the flares being produced by magnetic reconnection during eruption events in a strongly magnetized accretion flow. We propose to carry out the first numerical simulations of this mechanism which include both the non-thermal acceleration of electrons to high energies and their radiative cooling including in the X-ray band. We will directly measure X-ray light curves and spectra for comparison to Chandra data, providing new insight into the physical origin of Sgr A* flares and their connection to the global structure of the accretion flow.

Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 25800086

Title: ICM metal history, metal transport mechanism, link to stellar population

PI Name: Elena Rasia

The metal abundance of the intra-cluster medium represents a fossil record of the cumulative metal production by stellar populations across cosmic times. Its radial distribution in cool-core clusters has an established shape, whose deep understanding is, nonetheless, obscured by long-standing puzzles: what is the origin of the metal peak and its connection with the brightest central galaxy? What are the most-important metals-transport mechanisms? What is the cause of the cluster-to-cluster scatter in the outskirts and of the mismatch between the effective iron yields of groups and clusters? Our program will solve all these mysteries by analyzing various samples of highly-resolved simulated clusters which reproduce the observed features of metal abundance and gas and stellar fractions.

Subject Category: CLUSTERS OF GALAXIES

Proposal Number: 25800103

Title: The Most Powerful Explosion in the Universe? Simulating AGN Feedback and Gas Motions in the Ophiuchus Cluster

PI Name: John ZuHone

The bright and nearby Ophiuchus cluster shows evidence of gas sloshing and an offset between between the peak of the X-ray emission and the BCG. Chandra observations have revealed a sharp and concave surface brightness edge at a radius of 120 kpc, which radio observations show is filled with steep-spectrum synchrotron emission, indicating that it may be a AGN cavity. The pV work required to inflate it is ~5e61 erg, making it the most powerful AGN explosion observed. How such a large cavity could be created, without disrupting the cool core entirely, is a mystery. We propose to carry out MHD simulations of the Ophiuchus cluster with AGN feedback to test if such a cavity can be created, and investigate whether or not an offset AGN explosion can set off the sloshing of the cool core.