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The Slow Slew Survey

The Slow Slew Survey. Richard Saxton / Pedro Rodriguez November 2006. Operations. Scan over the Galactic plane at 30 degs/hour Orbit 1242 - 16 legs covering 45 x ~0.5 degs with 15 arcmin overlap between legs ~200 sq degs

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The Slow Slew Survey

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  1. TheSlow Slew Survey Richard Saxton / Pedro Rodriguez November 2006

  2. Operations • Scan over the Galactic plane at 30 degs/hour • Orbit 1242 - 16 legs covering 45 x ~0.5 degs with 15 arcmin overlap between legs ~200 sq degs • Open loop slew for 1.5 hours, followed by closed-loop slew of 17 mins to set position to start of next leg. • Nominal • Manually intensive to plan • Drift was very small, typical offset was 2 arc mins • Gives effectively a 1ks pointed obs at the end of each slew leg • Closed slew data not available this time because of PN DLI SSC Potsdam Slow slew survey / Richard Saxton

  3. Exposure time PN exposure map – Pedro Rodriguez SSC Potsdam Slow slew survey / Richard Saxton

  4. Exposure time M2 – mean=21.5 s PN – mean=18.6 s M1 – mean=17.3 With overlap, PN mean exposure time ~35 s SSC Potsdam Slow slew survey / Richard Saxton

  5. Instrument modes: EPIC-pn • EPIC-pn operated in FF mode with Medium filter SSC Potsdam Slow slew survey / Richard Saxton

  6. Instrument modes: EPIC-MOS EPIC-MOS cameras operated in FF (3x3 pixel binning) mode with Medium filter Leg 9124200003 SSC Potsdam Slow slew survey / Richard Saxton

  7. MOS 3x3 mode New SAS mode PRIMEFULLWIN3X3 201 Intended 0.4 s frame time but 0.8 s in practice. 203 SAS for simplicity remaps raw pixels from the 203x201 back onto the original 610 x 602 grid randomising to avoid gaps. emchain emenergy:rejectbade3e4=NO emenergy:detectbadoffset=NO badpixfind=no Use events with #XMMEA_EM && PATTERN==0 SSC Potsdam Slow slew survey / Richard Saxton

  8. Instrument modes: RGS RGS operated with 1 CCD centred on Oxygen VII (~0.7 keV) SSC Potsdam Slow slew survey / Richard Saxton

  9. PSF IGR J17497-2821 – Andy Read SSC Potsdam Slow slew survey / Richard Saxton

  10. PSF Extension=12” in slew direction due to frame time of 400 ms – actually 24” extension because of 800 ms clocking. 1E 1746.7-3224 • PSF needs to be modeled fully for correct ARF • Experience with PN eFF mode (18” extension) shows that sources are still found but are falsely flagged as extended SSC Potsdam Slow slew survey / Richard Saxton

  11. PSF IGR J17497-2821 – Andy Read SSC Potsdam Slow slew survey / Richard Saxton

  12. Properties Mean background (c/arcmin2) from slew legs 5,7: INST 0.2-12 0.2-2 2-12 ----------------------------------------- PN 0.56 0.28 0.28 M1 0.10 0.062 0.041 M2 0.11 0.067 0.066 But extraction region bigger for MOS (1.5-2x depending on final frame time) Flux Limits INST 0.2-12 0.2-2 2-12 ------------------------------------------------------- PN 5x10-13 2.5x10-13 1.6x10-12 PN+MOS1/2 4x10-13 2x10-13 1.3x10-12 PN: Exposure time ~6x normal slew, limits MOS ~3x lower eff. Area (depending on spectrum, etc.) but 2-3x lower backgnd. MOS 3x3 Pattern 0 = Singles + 2/3 doubles + 4/9 (trips+quads) + Part of Patt 31 Q.E. to be calibrated…. 3x deeper than XMMSL1 SSC Potsdam Slow slew survey / Richard Saxton

  13. Source list Coords Count RateID PN M1 M2 RASS 17 47 55.84 -26 33 50.0 270.3 58.3 64.5 19.2 GX 3+01 17 38 58.07 -44 26 59.8 204.4 - - 61.9 V* V926 Sco 17 50 11.92 -37 03 02.6 89.3 - - 4.1 4U 1746-37 17 46 05.01 -29 30 53.3 39.4 - - 0.14 2E 1742.9-2929 17 49 37.93 -28 21 15.2 46.6 10.6 8.8 - IGR J17497-2821 17 47 25.85 -29 59 58.7 35.7 14.5 9.3 0.1 AX J1747.4-3000 17 47 25.95 -30 02 38.8 13.3 9.2 4.1 0.1 AX J1747.4-3003 17 46 20.91 -28 43 40.0 9.1 - - - 2E 1743.1-2842 17 43 54.73 -29 44 41.4 8.6 - - - GREAT ANNIHILATOR 17 50 03.98 -32 25 51.4 6.0 - - 0.08 2E 1746.7-3225 17 47 39.40 -35 48 23.0 4.0 0.9 1.0 0.25 HD 161529 17 47 35.02 -40 07 35.1 1.6 0.21 0.46 - HD 161471 17 48 35.74 -32 54 55.5 1.7 0.41 0.25 0.05 1RXS J174835.9-325513 17 46 01.74 -40 47 48.3 0.8 - - 0.05 HD 324323 17 49 07.22 -27 32 30.0 0.9 0.17 - - AX J1749.1-2733 SSC Potsdam Slow slew survey / Richard Saxton

  14. Source list stats Search on combined first 8 EPIC-pn slews (Pedro Rodriguez) – 72 sources in 86 deg2 (> 3 sigma) Position error = 3.6 arc sec (median) [Simbad optical positions] MOS positions also generally ok to a few arc secs 44/72 identified from SIMBAD, 33/72 Rosat sources 30-40% unknown sources, brightest=1.8 c/s (pn) [F=5E-12] • Standard edetect_chain issues: • Many false “Halo” sources around bright sources • eexpmap took ~ 0.5 hours / 1 deg image for 0.1s resolution • drove the processing schedule SSC Potsdam Slow slew survey / Richard Saxton

  15. Spectra 1E 1746.7-3224 – LMXB, NH=6E21 Pile-up a problem @ PN: 8 c/s MOS: 1 c/s for pointed FF mode x 6 for 0.4s frame time / ~3 for 3x3 big pixel x 1.5 - 2 (?) for slew movement of PSF across 4 big pixels during frame ≈ 3-4 c/s ≈ same pile-up flux limit for MOS / PN ! SSC Potsdam Slow slew survey / Richard Saxton

  16. Spectral: bright sources GX 3+01 – NH=1E22 SSC Potsdam Slow slew survey / Richard Saxton

  17. Summary • PN – no surprises • MOS – work to do with s/w, calibration and CCFs • Great for mapping large extended sources • Probe flux levels intermediate between XMMSL1 and dedicated short pointings • Covers 200 deg2 in 1 revolution • Position error is ~4 arcsecs – similar to pointed obs for low count sources SSC Potsdam Slow slew survey / Richard Saxton

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