Women in the High-Energy Universe: Aneta Siemiginowska

Aneta Siemiginowska is an astrophysicist at the Chandra X-ray Center. In addition to her responsibilities for Chandra’s Science Data System group, she is actively involved is exploring the Universe, particularly its black holes and galaxies.

For as long as I can remember, I wanted to learn about stars. The winter sky displayed the entire Universe right in front of me and I wanted to learn and understand the sky and the space. I do not think I understood what it meant to become an astronomer when I was a six year old, but each time somebody asked me what do I want to be when I grew up I answered, "I want to be an astronomer".

I was lucky to be a post-doctoral fellow (aka, a "post doc") at the Harvard-Smithsonian Center for Astrophysics during very exciting times, just a few years before the launch of the Chandra X-ray Observatory. For my post-doc I worked on X-ray observations and data analysis from ROSAT and ASCA telescopes, and later become a member of the Chandra team. I am now an astrophysicist working in the Science Data System group at the Chandra X-ray Center. In addition to my science research I have responsibility for the development of science algorithms used in analysis of Chandra data.

Preparations for the Chandra launch involved calibration of the instruments and detectors on the ground. My colleagues and I spent several weeks at a time working long hours supporting the 24-hour operations at the calibration facilities. We had to analyze the new instrument data on the spot before our daily reviews and status updates. It was a very different type of work than the one we do every day. The pressure and excitement made us all forget about the outside world during these several weeks of calibrations. I can only compare the intensity of this time to the preparation of proposals for new observations, when the entire focus and attention is set on one goal. The competition for observing time is high, but getting my own observations is always exciting. My own data can bring discoveries!

The Chandra X-ray Observatory brought many discoveries to the entire field. I also had a few of my own. One morning I woke up with the realization that a bright streak in my newly observed quasar was not an instrumental effect, but a relativistic jet over three hundred kiloparsecs – or nearly one million light years -- long! It was really a great feeling to be the first human to see this jet and know about it. Of course the data analysis and the subsequent articles describing the science were not trivial and took a lot of effort. However, my discovery made me realize that even in the 21st century we can still be the first to see and learn, or to have a new idea. There are still many unanswered questions about the Universe and our small contributions to the answers are important.

My research concerns active galaxies and quasars, their evolution and impact on large-scale environments. Signatures of the power released by an accreting supermassive black hole are visible across the entire observable Universe. It is just amazing that a tiny center of a galaxy can generate so much energy and impacts structures located far away. At this time we probably understand the general process by which a black hole's gravitational energy is released in the form of radiation or the mechanical jet power displayed by quasars. We also understand the general physics of the radiation processes responsible for the observed spectra. We have observational evidence that the energy generated by a black hole is released and transferred to the interstellar and intergalactic medium on many scales. This energy affects the evolution of galaxies at all redshifts. However, the detailed physics of many processes involved in the observed phenomena are not well understood. There are many questions that modern astronomers are trying to answer using new observations and theories. Being an astronomer means working on many puzzles, solving new problems every day and making progress on our understanding of the Universe.

- Aneta Siemiginowska