X-ray sources in NSVS

1. X-ray sources in NSVS Tim McKay University of Michigan 04/03/04

2. The ROTSE-I Instrument • Optics: four Canon f/1.8 200mm lenses • Cameras: 4 20482 CCDs (14.4” pixels) • 16°x16° field of view • Rapid slewing mount • Five Linux control computers • A lot of software (Kehoe + Marshall)

3. The toaster…. ROTSE-I Operations • Completely automated, unattended, operation (8 Gbytes/night) • Usually, an all-sky patrol instrument • 4 patrols (2 pairs) of the entire sky nightly, 80s exposures • Paired images for background rejection • Unfiltered observations • All instantly interruptable by GCN for triggered responses: GRBs • Operated March 1998-Dec 2001 Inside the toaster…..

4. Everything to -30 regularly patrolled ROTSE Sky Patrols: keeping a nightly watch Large field of view allows full sky coverage (4) in 206 fields Everything with elevation >20° observed every night >90 fields and 20,000 square degrees a night

5. Initial ROTSE-I Patrol Analysis • Test analysis of 9 (out of 160) fields: 2000 square degrees • 5% of the entire sky, 1/17th of available ROTSE-I data • Four months of data (March to June 1999, 40-120 epochs) RSV1 fields Note wide range of latitudes

6. ROTSE-I data from April 1999-March 2000 Covers ~33,000 square degrees: 80% of the sky, best for 50%... 184,000 CCD images 257/365 nights Ntotal = 14.5 million 3.3 billion light curve points Unfiltered CCD data Calibration from 1500 Tycho stars / frame Northern Sky Variability Survey

8. Number density Photometric scatter Number of light curve points Number of ‘good’ points

10. A first quick-look based on a few days work…. Variability selection with modified Welch-Stetson algorithm Require 20 pairs of observations… Variability analysis

11. Variability Index Magnitude: roughly V…

12. All variables

13. Long Period Variables

20. Short Period Variables

25. Comparison to other all-sky surveys is particularly enlightening Two-Micron All Sky Survey provides J, H, and K data for all these objects Roughly the same epoch… ROSAT All-Sky Survey provides possible x-ray counterparts IRAS provides far-IR counterparts to many Other possibilities include FIRST, NVSS, SDSS, Tycho, USNOB….. Auxiliary data

26. These figures show the J-H vs. H-K color-color plots for RVS1 variables in four classes. Note that the color ranges confirm the classifications well. The splitting in the intermediate period population suggests that these colors can be used for further classification.

27. 2MASS period-color relations for Contact Binaries and Delta Scuti stars. These relatively tight relations suggest that decent distance estimates can be obtained for these objects.

28. RASS BSC and FSC include 124,000 objects RASS positions accurate to between 20 and 40” ROTSE-I positions to <5” Cross-match by position Compare to matches with randomized positions Check that matches are drawn from particular subsets of variable types Matching to RASS

29. Matches to real ROTSE positions Matches to randomized ROTSE positions RASS matching to 44” square…. 1424 111

30. RASS CPS distributions for all, and for those which match ROTSE-I variables…

37. Classify the NSVS variables Explore 2MASS information for classification and distance estimation Estimate x-ray flux from contact systems Work on contact binary space density Explore the long period variables, especially with 2MASS and IRAS infrared information Some goals