The Variable Source Content of the The Variable Source Content of the 2XMM Catalogue The Variable Source Content of the 2XMM Catalogue Sean Farrell Natalie Webb, Didier Barret, David Villa-Pascual, Joana Rodrigues Centre d’Etude Spatiale des Rayonnements Toulouse, France Andrew Gosling University of Oulu Oulu, Finland

Overview Overview The 2XMM catalogue – a brief introduction Determining the nature of the variable sources Statistical breakdown Preliminary population studies Some highlights Conclusions

The 2XMM Catalogue The 2XMM Serendipitous Source Catalogue Largest X-ray catalogue ever produced, containing: 246,897 source detections 38,320 detections with light curves / spectra 2,307 detections flagged as variable 191,870 unique sources 2,001 unique variable sources

Determining the Nature Determining the nature of the variable sources Manually inspected images, lightcurves & spectra for all 2,001 discrete variable sources Spurious sources identified from images Performed a search in SIMBAD around coordinates of real sources Attempted to determine nature of previously identified sources through SIMBAD and literature search Optical loading OOT event Wings of bright src

Statistics Serendipitous Targets TOTAL Planets (Saturn) - < 1%   Serendipitous Targets TOTAL Planets (Saturn) - < 1% AXPs/SGRs Pulsars Neutron Stars ULX SNR 1% GRB 3% SSS Extended Emission X-ray binaries 2% 14% 4% CVs 28% AGN 24% 5% Unknown 21% Stars 23% Spurious 47% 41% 100%

Breakdown of spurious sources Statistics Breakdown of spurious sources All spurious sources flagged as “good” due to optical loading from a very bright star in the field Remaining spurious sources picked up by pipeline Source Quality SUM_FLAG % Good < 1% Source parameters may be affected 1 0% Possibly spurious 2 In area where spurious detections may occur 3 50% In area where spurious detections may occur and possibly spurious 4 100%

Population Studies All 2XMM Sources LMC SMC Gal cluster Taurus MC Orion Neb

Population Studies Variable 2XMM Sources LMC SMC Gal cluster Taurus MC Orion Neb

Population Studies

Population Studies AGN Unknown XRBs CVs SSS Stars

Population Studies Compact Objects

Highlights 2.2 hr period Pow / brem spectrum Faint XRB or CV? BB / nsatmos spectrum Quiescent NS XRB? 2.1 hr period Pow / brem spectrum AM Her CV?

Highlights 1.2 hr period Brem spectrum CV? 1.6 hr period Pow / brem spectrum XRB or CV? 627 s period Cut-off pow spectrum Long-period pulsar

Highlights 237 s 237 s period Power law spectrum >8 NIR counterparts, 1 very blue Another long-period pulsar? 237 s

Conclusions Conclusions ~41% variable sources spurious, vast majority picked up by pipeline ~38% real sources unknown, ~37% stars, remaining sources mostly compact objects (AGN, CVs, XRBs) New populations of faint sources emerging, providing insight into X-ray emission over wider range of luminosities 2XMM catalogue is a powerful resource for population studies of all kinds of objects

Thanks for your attention Questions? Thanks for your attention Gratuitous poster plug… Soft X-ray Sources in the 2XMM Catalogue Rodrigues, Farrell, Webb & Barret Poster D.10