X-Ray+Transient+Surveys


 * X-ray Transient Surveys Workshop Summary **


 * Organizers**: Daryl Haggard, Gregory R. Sivakoff

Modern X-ray observatories yield unique insight into the astrophysical time domain – each X-ray photon can be assigned an arrival time, an energy, and a sky position, enabling sensitive, energy-dependent light curves and time-resolved spectra down to millisecond timescales. Combined with multiple views of the same patch of sky (e.g. in the Chandra and XMM deep fields) that enable variability studies over longer baselines, the spectral timing capacity of X-ray observatories stretch over 10 orders of magnitude at spatial resolutions of arcseconds and 13 orders of magnitude at spatial resolutions of a degree. A wealth of high energy time domain data already exist, indicating variability on timescales ranging from microseconds to years in a wide variety of objects: (1) numerous classes of AGN; (2) high-energy phenomena at the galactic center; (3) galactic X-ray binaries; (4) extra-galactic X-ray binaries; (5) Supernovae; (6) GRBs; (7) stellar flares; (8) as-yet unknown X-ray variables. This workshop will focus on the potential of strategic X-ray surveys to explore this broad range of source types and astrophysical phenomena.

Guiding Questions

1. In recent years, optical and radio transient science have increasingly gained attention among the general astronomical community. At the same time, X-ray transient surveys seem to be ceding ground, both financially and scientifically. What are the most compelling science cases for current and future X-ray transient studies? What efforts does the X-ray transient community need to undertake to best lobby for the importance of X-ray transient studies (past and present) to the general astronomical community?

2. The Rossi X-ray Timing Explorer has been a tremendous boon to X-ray transient studies; however, it will cease operation at the end of this year. While some of its scientific capacities can be shifted to current instruments like Swift and MAXI, other capacities are unique to RXTE among currently flown instruments. What steps do we need to take to transition from the era of RXTE to the era without it? What important lessons have we learned from RXTE? How will new planned or soon to be launched instruments support X-ray transient surveys? What inventive ways can we develop to utilize new instruments that may not be originally designed for X-ray transient studies?

3. The scientific output of X-ray transient surveys can be greatly increased through multi-wavelentgh observations. How do we best coordinate multi-wavelength observations, especially for X-ray transient surveys? Do we need to develop an X-ray Transient Network or are existing infrastructures like The Gamma-ray Circular Network and the Astronomers Telegram sufficient? What cadences are needed to achieve various science priorities at different wavelengths? Are there opportunities for citizen science with X-ray transient surveys?

Here are PPT slides from the workshop, followed by our **brief** summary: