Through Dust And Light: Constraining The Distance To The GBHT 4U 1630-47 Through High Resolution MM And X-RAY Observations

Accurately determining the distance to Galactic blackhole X-ray binaries is criticalfor understanding their intrinsic luminosities, accretion physics, and jet properties.However, for sources which are highly obscured by dust, traditional distance estimationmethods often fail. In this thesis, we present a novel imaging-based methodologywhich utilizes high-resolution millimeter observations from the Atacama PathfinderExperiment APEX combined with X-ray data from Chandra to constrain the distanceto the galactic blackhole transient (GBHT) 4U 1630-47 through the modelingof its dust scattering halo (DSH).We identify 15 molecular clouds from the 12CO data and generate synthetic DSHimages for all possible near/far configurations of these clouds across a grid of candidatesource distances and subsequently fit the images both radially and azimuthally.Our analysis favors a source distance of 11.5 kpc, with strong constraints on severalmolecular clouds. We perform Monte Carlo analysis to quantify uncertainties andfind a robust peak in best-fit distances at 11.5 kpc. While 13.6 kpc also yieldedgood statistical fits, it is ultimately discarded due to observational inconsistencies.This thesis demonstrates the power of combining high-resolution mm observationswith X-ray imaging to resolve kinematic distance ambiguities and constrain thesource distance. The methodology developed here builds upon the foundation laidin Kalemci, Maccarone & Tomsick (2018), and is also presented in E. Kalemci (2025).