I am a fourth year Graduate Student at Drexel University. My research area is optical AGN variability and accretion physics. However, attending workshops like this one and participating in a SAMSI ASTRO working group, has expanded my interest to other types of variable objects and time series signatures. I enjoy thinking critically about how these characterizations relate to physical properties of objects grouped in the same hyperplane of parameter space.
Our community of astronomers, statisticians and physical scientists are excitedly anticipating the era of time domain astronomy and, our new lens for probing the distant universe, gravitational wave detection. The SAMSI-ICTS workshop (Time Series Analysis for Synoptic Surveys and Gravitational Wave Astronomy) made a pioneering effort to bring together experts from seemingly different research fields in order to find common ground to exchange techniques and insights for analyzing time series data. The workshop was hosted by the International Centre for Theoretical Sciences (ICTS) in Bengaluru, India. ICTS and SAMSI worked together to arrange speakers to present interesting content, coordinate for meals, handle logistics for the workshop and manage transportation for outings to explore the city. Special thanks are owed to ICTS as they went above and beyond assisting with visas, travel, accommodations and in orchestrating the 4-day workshop.
The speakers presented on various topics, such as: variability statistics for classification in surveys; domain adaptation; noise modelling; and a whole slew of methodologies used to study the physics of transients, periodic and aperiodic variables and binary candidates for GW detection and localization. Speakers emphasized critical issues that needed improvements or further investigation. These issues were framed in the form of challenges to facilitate possible projects for collaboration. Talks were followed by panel discussions. Several participants suggested that future similar workshops should provide allotted time for hacking or coding in conjunction with the panel discussions. There was also an effort to document the challenges in an Authorea document, to serve as a discussion board afterward.
“SAMSI workshops and working groups have helped me understand how my thesis work fits into the larger scientific picture and how to gain a better understanding of what our science priorities are as a community of observational astronomers.”
All of the talks were video recorded, so visitors can view the talks, participants and abstracts of the presentations. In addition, photos and links to the webpage at SAMSI are also provided. SAMSI was a proud co-sponsor of this event and, in the future, they look forward to supporting research events like this in an international community setting. Sessions between panel discussions were organized into the following broad topics:
- Outliers and Background
- EM follow up of GW events
- Science of Transients, and
- Techniques for Time Domain Astronomy
A few talks that stood out to me included Rafael Martinez‘s (Associate Scientist at the Harvard-Smithsonian Center for Astrophysics) talk on “Building a Training Set for an Automatic LSST Lightcurve Classifier.” He talked about combining different classifiers, the problems with miscellaneous labels containing the largest number of objects and problems with period finding algorithms. Hyungsuk Tak, a SAMSI postdoc, also gave a very nice talk, “Robust and accurate inference via a mixture of Gaussian and terrors,” and he asked the question why do astronomers so often and automatically assume Gaussian distributed errors? He presented a very promising method he developed combining Gaussians and heavy tailed (t-distributed) error models and demonstrated that the accuracy of inferred parameters improved significantly. Another talk I enjoyed was Kuntal Misra‘s (Scientist of the Aryabhatta Research Institute Observational Sciences [ARIES] in Naintal, India). She talked about “Gamma Ray Bursts and Associated Supernovae”. She provided a comprehensive discussion of lightcurve and spectral features used to classify and characterize these objects.
From my perspective, as a fourth-year graduate student, I found the SAMSI workshops to be very eye-opening because they gave me so much context about sophisticated and efficient methodologies that work well with different data sets. They provided a briefing on the latest and greatest techniques being applied to astronomical data in a setting conducive to discussion, cross-discipline education, and collaboration. SAMSI workshops and working groups have helped me to understand how my thesis work fits into the larger scientific picture and to gain a better understanding of what our science priorities are as a community of observational astronomers.
I’m excited to see where these applications of machine learning take us? In the future, I’d like to see more applications of hierarchical clustering and other techniques that capture continuity between subpopulations within a broader class. These methods might help us transition into this massive (time series) data era to better understand our observations as dynamic systems but also in an evolutionary context.
This conference was not only great because of the science and stats. The location and the people who attended made it an unforgettable experience for me! Both ICTS locals and people invited through SAMSI were genuinely welcoming and kind folks. In the evenings after the workshop we all had dinner together, went for bike rides and played some ping pong. After the workshop, I was invited to join a group touring the central part of Bengaluru and the archaeological sites at Hampi. The days that followed were an adventure, and I sincerely appreciated the moments I shared with the great friends I made through this workshop!