COUP_var {astrodatR}

COUP: X-ray source variability

Description

This dataset consists of three time series representing (in)homogeneous Poisson processes. They are tables of arrival times of individual X-ray photons from magnetically flaring young stars in the Orion Nebula Cluster, obtained from the Chandra Orion Ultradeep Project (COUP; Getman et al. 2005). NASA's Chandra X-ray Observatory is described at http://en.wikipedia.org/wiki/Chandra_X-ray_Observatory. COUP detected 1616 X-ray sources, mostly flaring young stars. The first source, COUP 263, has 209 photon arrival times that appear to represent a constant X-ray intensity. The second source, COUP 551, has 678 photons and exhibits at least two flares. The third source, COUP 554, is much stronger with 14,258 photons; it exhibits very high-amplitude, nearly continuous flaring. The dataset has three columns: the source identifier, the photon arrival time, and the photon X-ray energy. Gaps in the data streams due to the satellite observatory orbit have been removed. Photon energy may also represent a time dependent process as flares typically have higher average energy X-rays than quiescent periods. The dataset is discussed at http://astrostatistics.psu.edu/datasets/Chandra_flares.html. This dataset is useful for statistical methods treating event data and inhomogeneous Poisson processes.

Usage

COUP_var

Format

A table containing 15,145 rows and 3 columns

Source

Getman et al. (2005)

References

Getman,K. V., Flaccomio, E., Broos, P. S., Grosso, N., Tsujimoto, M., Townsley, L., Garmire, G. P., Kastner, J., Li, J., Harnden, F. R., Jr., Wolk, S., Murray, S. S., Lada, C. J., Muench, A. A., McCaughrean, M. J., Meeus, G., Damiani, F., Micela, G., Sciortino, S., Bally, J., Hillenbrand, L. A., Herbst, W., Preibisch, T., Feigelson, E. D. (2005), Chandra Orion Ultradeep Project: Observations and source lists, Astrophysical Journal Supplements, 160, 319-352 http://adsabs.harvard.edu/abs/2005ApJS..160..319G