EVIDENCE OF ACCRETION-GENERATED X-RAYS IN THE YOUNG ...

for X-ray production in young stars. The focus of this dissertation is to explore some
of the aspects of X-ray production in young stars. Specifically, we will use examples
of erupting young stars as a testbed for one possible X-ray generation mechanism:
accretion of circumstellar material. In §1, I present an overview of star formation. In
§2, I describe the types of objects that are used as the focus of my X-ray analysis and
present what is known and not well understood regarding these particular objects.
IalsodiscusshowtheseobjectsarerelatedtotheformationofstarslikeourSun.
In §3, I begin by presenting an overview of previous work regarding X-ray studies of
young stars and the types of information that have been gleaned. Afterward, I focus
on the tools of X-ray astronomy, namely the Chandra X-ray Observatory (CXO) and
its instruments and capabilities. I also discuss the software tools that I used to reduce
and model the data. §4 concerns my own X-ray work done with CXO observations of
the young, erupting star V1647 Ori during the optical eruptions that were observed
to begin in 2003 and 2008, while §5 deals with X-ray observations of another young,
erupting star, EX Lupi, during its optical eruption of 2008. Finally, in §6 Idiscussthe
overall results of the X-ray studies of V1647 Ori and EX Lupi and their implications.
I conclude with a brief summary of the questions that the work of this dissertation
has helped answer regarding X-ray production in young stars and what questions still
remain unanswered.
1.1 An Overview of Star Formation
In order for star formation to occur, several ingredients must be present. First, the
building blocks of the future star have to be present, i.e., a large cloud of gas and dust
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