Diagram displaying general view of SS433. (credit: ESO.)
When I was a first-year student, my preceptor told me that the best way to get a research position with a professor was to simply ask. Naturally I didn’t think it would be that easy, but in the fall of 2020, I did exactly that. I inquired about any open research positions with my major advisor Professor Dipankar Maitra, and surely enough, he had a project that I was able to join.
This project focuses on the enigmatic astronomical object, SS433. SS433 is an X-ray binary system, as well as the first discovered microquasar. To briefly describe the system, there is a compact object (i.e. a black hole) and a main-sequence (companion/donor) star that orbit each other. The compact object pulls matter from the donor star and the matter falls onto the compact object’s accretion disk (see image). Additionally, two high energy jets shoot out of the compact object in either direction. These jets precess around an axis, which creates a corkscrew pattern.
Now you may be wondering, why does the title of this blog post say “Black Hole or Neutron Star”? Well, that’s because astronomers still aren’t sure which one it is. Black holes and neutron stars are both incredibly dense objects with strong gravitational fields, and with the current data, there is no definitive answer. From it’s date of discovery nearly 50 years ago, SS433 has been a mysterious system with many questions left unanswered. In my research, my primary goal is to study the system and attempt to uncover the elemental makeup of the environment around the compact object.
For the first few months of this project, I spent time learning about the system: the geometry, the general mechanics, and the history of the discovery. After I understood these concepts, I moved on to data analysis. Since SS433 is an X-ray binary, data was obtained from NASA’s Chandra X-ray Observatory by Professor Maitra in 2018. In my project, the goal is to analyze the spectra obtained through these observations, and to model the emission lines using statistical methods. As this is an ongoing project, and I only just got to the data analysis, I do not have any results to share at this time. By the end of the semester I will have created several models for the spectra and will hopefully be able to draw conclusions at that time. For this analysis, I have learned how to use new software, notably the Interactive Spectral Interpretation System (ISIS) which is a powerful alternative to the more popular XSPEC software. In the bigger picture, astronomers are trying to understand the underlying mechanisms of this system. If new discoveries were to come forth, this knowledge could potentially lead to future discoveries, as well as a better understanding of other systems and the Universe as a whole.
This project has been a rewarding experience in several ways. I’ve developed my coding skills, refined my research skills through reading academic papers, and learned the basics of X-ray spectroscopy. It goes without saying that SS433 is an incredibly interesting and unique object, and I thoroughly enjoyed being able to dedicate an entire semester to studying it. It has been gratifying to see my own progress, and to apply concepts I have learned in my classes to a real-world project. Though SS433 was discovered nearly 50 years ago, it continues to excite astronomers from around the world. I can’t wait to see what the future holds for this fascinating object.
Nina Christenson, Class of 2023, Physics major/Mathematics minor