]]>A tremendous amount of information is contained within the temporal variations of various measurable quantities, such as the energy distributions of the incident photons, the overall intensity of the source, and the spatial coherence of the variations. While the detection and interpretation of periodic variations is well studied, the same cannot be said for non-periodic behavior in a multi-dimensional domain. Methods to deal with such problems are still primitive, and any attempts at sophisticated analyses are carried out on a case-by-case basis. Some of the issues we seek to focus on are methods to deal with are:
* Stochastic variability
* Chaotic Quasi-periodic variability
* Irregular data gaps/unevenly sampled data
* Multi-dimensional analysis
* Transient classificationOur goal is to present some basic questions that require sophisticated temporal analysis in order for progress to be made. We plan to bring together astronomers and statisticians who are working in many different subfields so that an exchange of ideas can occur to motivate the development of sophisticated and generally applicable algorithms to astronomical time series data. We will review the problems and issues with current methodology from an algorithmic and statistical perspective and then look for improvements or for new methods and techniques.
Abstracts are due Sep 17.
Meeting Justification
We propose to highlight the growing use of ‘non-parametric’ techniques to distill meaningful science from today’s astronomical data. Challenges range from Kuiper objects to cosmology. We have chosen just a few ‘teaching’ examples from this lively interdisciplinary area.
Meeting Notes
This ‘Astro-Statistics’ special session is proposed in concert with an ‘Astro-Informatics’ Special Session, organized by Kirk Bourne. In this proposed ‘Non-Parametrics for the Non-Specialist’ session, we are highlighting just a few of the new, outstanding, applications. Many are coming to fruition just now, in this age of large data-sets, complex instruments, and subtleties of distilling accurate science from indirect measurements. We chose to highlight: complex models (cosmology, black hole mass distributions); and complex data, such as image (spatial); and timing analyses (e.g. transients such as the distribution of Kuiper objecs) from surveys. We invited a mixture of newer and seasoned speakers; and ones that will make good ‘teaching examples’. At the same time, we left out many new areas. Hence we are planning a lively, associated, poster session. The format will be: An Intro by one of the seasoned statisticians; followed by ‘examples’ talks by two astronomers and a physicist. Following, another of the senior statisticians will discuss the principles. Finally, a senior astrophysicist will summarize challenges for the future. We plan to leave time for one-minute poster advertisements highlighting other areas. Expected participants include: Eric Feigelson, Brandon Kelly, Meyer Pesenson, Stanislav (George) Djorgovski, Tom Loredo, Alanna Connors, Pavlos Protopapas, Katrin Heitmann, Chad Schaefer, Xiao Li Meng.
]]>When it comes to survey, the first thing comes in my mind is the census packet although I only saw it once (an easy way to disguise my age but this is true) but the questionaire layouts are so carefully and extensively done so as to give me a strong impression. Such survey is designed prior to collecting data so that after collection, data can be analyzed according to statistical methodology suitable to the design of the survey. Strategies for response quantification is also included (yes/no for 0/1, responses in 0 to 10 scale, bracketing salaries, age groups, and such, handling missing data) for elaborated statistical analysis to avoid subjective data transformation and arbitrary outlier eliminations.
In contrast, survey in astronomy means designing a mesh, not questionaires, unable to be transcribed into statistical models. This mesh has multiple layers like telescope, detector, and source detection algorithm, and eventually produces a catalog. Designing statistical methodology is not a part of it that draws interpretable conclusion. Collecting what goes through that mesh is astronomical survey. Analyzing the catalog does not necessarily involve sophisticated statistics but often times adopts chi-sq fittings and cast aways of unpleasant/uninteresting data points.
As other conflicts in jargon, –a simplest example is Ho: I used to know it as Hubble constant but now, it is recognized first as a notation for a null hypothesis — survey has been one of them and like the measurement error, some clarification about the term, survey is expected to be given by knowledgeable astrostatisticians to draw more statisticians involvement in grand survey projects soon to come. Luckily, the first opportunity will be given soon at the Special Session: Meaning from Surveys and Population Studies: BYOQ during the 213 AAS meeting, at Long Beach, California on Jan. 5th, 2009.
]]>The meeting website is at: http://www.confcon.com/head2008/.The abstract submission deadline is January 25, 2008 (now past, but late abstracts are not unheard of among astronomers).
If you are attending the meeting, and plan to present posters or talks that deal with astrostatistical methods or techniques, we welcome you to participate in this session. When you submit an abstract, be sure to indicate a category of “Other” and in the comments field state that it belongs with the AstroStatistics special session.If you have questions, please contact Aneta or me. There is also a page for this session on the astrostat google groups site.
Update (1/22): The abstract submission page currently says that only one abstract is allowed per person. We have been informed that this is incorrect, and that people can submit two abstracts, one for the special session and one as a regular contribution. Note that posters will be up only one day, and those associated with a special session will be put up the day of the session.
Update (1/26): A detailed program is not yet available, but here is a description of the session:
Astrostatistics: Methods and Techniques
This session will provide a forum for the discussion and presentation of statistical challenges in high energy astrophysics, highlighting the great deal of progress that has been made in methods and techniques over the past decade. The one hour session will cover the current and future directions in Astrostatistics, and will include a discussion of MCMC methods in the context of specific applications (such as propagating calibration errors, defining the significance of image features, etc.); a discussion of standardized methods for computing detection limits, upper limits, and confidence intervals for weak sources; and hypothesis testing and its limitations (including the significance testing of emission lines).
Update (2/19): We have been allocated the mid-day slot of March 31. The session will run from 12:30pm till 1:30pm2pm. The tentative program is as follows:
- Remarks on current and future trends in AstroStatistics, by Eric Feigelson
- Poster haiku
- F-Test theory and usage, by David van Dyk
- Discussion on MCMC techniques, led by Andy Ptak
Update (2/26): The final program is out, and the AstroStat session is scheduled for 12:30pm-2pm at the Museum/Bunker Hill Room.
Update (4/1): The talks and posters associated with the AstroStat special session are now online at
http://hea-www.harvard.edu/AstroStat/HEAD2008/. Additional comments and descriptions will be archived there.