1 / 20

Investigation into the strong residuals seen near the Oxygen edge in MOS spectra of

Investigation into the strong residuals seen near the Oxygen edge in MOS spectra of bright continuum sources. Rate Dependent CTI effect ? Steve Sembay. Event 1. Readout direction. Event 2. Trap. Emission timescales for filled traps (Holland et al. 1993, NIMS, A326, 335).

nenet
Download Presentation

Investigation into the strong residuals seen near the Oxygen edge in MOS spectra of

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Investigation into the strong residuals seen near the Oxygen edge in MOS spectra of bright continuum sources. Rate Dependent CTI effect ? Steve Sembay

  2. Event 1 Readout direction Event 2 Trap

  3. Emission timescales for filled traps (Holland et al. 1993, NIMS, A326, 335) σn electron capture cross section Xn entropy factor υth electron thermal velocity Ncdensity of states in conduction band E energy level of trap T temperature

  4. Emission timescales for filled traps (Holland et al. 1993, NIMS, A326, 335) c.f. row transfer time of MOS = 15 µs

  5. Around O edge χ2 -> 3.90 – 2.13 with gain offset = 8.7±1.0 eV

  6. Around Si and Au edge: χ2 -> 1.025 – 0.998 Offset ~ 12.5 eV

  7. SW Obs. MOS v RGS Line Energy: N line ~ 432 eV J. Carter (Mallorca 06) Most MOS Large Window Mode

  8. Closed Cal Al line in small window mode

  9. Closed Cal Al line in small window mode

  10. Is there a “possible” gain shift at O: CTI dependent on rate? Method 1: Analyse spectra from different regions

  11. Sample of bright AGN/BL Lacs: The “Usual Suspects” 3C 273 0094 MKN 421 0165 MKN 421 0171 3C 273 0277 H1426+428 0278 PKS2155-304 0362 PKS2155-304 0450 ARK 120 0679 H1426+428 0852 PKS2155-304 1095 PKS2155-304 1266 3C 273 1299 MKN 421 1357

  12. MOS1 Count Rate v Offset In Boxes Before/After Cooling

  13. MOS2 Count Rate v Offset In Boxes Before/After Cooling

  14. Is there a “possible” gain shift at O: CTI dependent on rate? Method 2: Flag precursor events from event file

  15. Flag Bad Flag Bad Readout direction

  16. Flagged events

  17. |Summary: Observed offset is not affected by removal of precursor events in CCD RAWY direction This suggests offset is not caused by incorrect application of CTI measurement due to trap filling in CCD.

More Related