| Proposal Number | Subject Category | PI Name | Chandra Time | Title |
|---|---|---|---|---|
| 27700354 | ACTIVE GALAXIES AND QUASARS | Joseph Hora | 100 ks | A Joint Mid-IR and X-ray Investigation of the Physics Driving Sgr A*'s Flares |
Subject Category: ACTIVE GALAXIES AND QUASARS
Proposal Number: 27700354
Title: A Joint Mid-IR and X-ray Investigation of the Physics Driving Sgr A*'s Flares
PI Name: Joseph Hora
Abstract: The Galactic Center offers the closest opportunity for studying accretion onto a supermassive black hole. Flares from Sgr A* are detected across the electromagnetic spectrum and may originate in the accretion flow or the jet. Recent models indicate that this variability can be produced by a tilted inner disk, gravitational lensing of bright spots in the disk by the black hole, or particle acceleration in reconnection events. These models produce different flare characteristics, and better characterization of flares’ spectral energy distributions will enable us to distinguish between emission models. Meanwhile, the circumnuclear environment of Sgr A* contains dozens of IR sources and structures that are critical to understanding both the accretion-feeding processes and the nature of the nuclear star cluster and nearby dusty gas features. Only JWST's MIRI has the high angular resolution and mid-IR sensitivity to probe this complex and dynamic region. MIRI can detect changes in the mid-IR spectral index, which is an important diagnostic of physical conditions in the flare. The X-ray flux will constrain the energy distribution of non-thermal particles in the flare. Thus, we propose MIRI MRS IFU time-series together with Chandra X-ray monitoring of Sgr A* (and its surroundings) to determine the nature of its flare emission and to test models of the accretion and radiation processes near our closest supermassive black hole.