TIPSCOS Status: SMOV update III

STScI/CU COS Team17 September 2009

COS Highlights Science enabled on 14 SeptemberScience enabled on 14 September All COS SMOV observations (except one dark) planned to be completed by All COS SMOV observations (except one dark) planned to be completed by

end of 264 SMS (27 Sep 2009)end of 264 SMS (27 Sep 2009) Many COS Cycle 17 calibration programs have begun; all are now activated in Many COS Cycle 17 calibration programs have begun; all are now activated in

LRPLRP FUV focus updated after second focus sweepFUV focus updated after second focus sweep NUV Internal Flat FieldsNUV Internal Flat Fields

– No change from ground structure; on-orbit combined with ground for better S/N; updated No change from ground structure; on-orbit combined with ground for better S/N; updated reference file delivered including vignetting functionreference file delivered including vignetting function

NUV/FUV Internal/External WavecalsNUV/FUV Internal/External Wavecals– FUV spectrum templates, dispersion relations, and extraction boxes delivered to pipelineFUV spectrum templates, dispersion relations, and extraction boxes delivered to pipeline– NUV extraction boxes delivered to pipeline; new dispersion relations and template spectra NUV extraction boxes delivered to pipeline; new dispersion relations and template spectra

reference files in preparation (est 9/30 delivery)reference files in preparation (est 9/30 delivery)

COS Highlights (continued) SensitivitySensitivity

– Initial on-orbit PSA reference files in processing for deliveryInitial on-orbit PSA reference files in processing for delivery

Target AcquisitionTarget Acquisition– Imaging plate-scales, WCA/PSA/BOA offsets, subarrays all updatedImaging plate-scales, WCA/PSA/BOA offsets, subarrays all updated– Spectroscopic plate-scale, BOA parameter updates expected Spectroscopic plate-scale, BOA parameter updates expected – All TA modes working well All TA modes working well – New recommendations for BOA imaging mode S/NNew recommendations for BOA imaging mode S/N

Structural / Thermal StabilityStructural / Thermal Stability– 5-orbit CVZ-like exposures for NUV/FUV spectroscopy, NUV imaging5-orbit CVZ-like exposures for NUV/FUV spectroscopy, NUV imaging– Highest S/N NUV COS data; presently in analysisHighest S/N NUV COS data; presently in analysis

FUV External Flats; FUV High S/N recently obtainedFUV External Flats; FUV High S/N recently obtained

--- courtesy Kevin Fance, COS IDT

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Target Acquisition Updates• S/N Recommendation for ACQ/IMAGE

– PSA MIRRORA and MIRRORB: S/N=40 (no change)

– BOA MIRRORA and MIRRORB : S/N=60 (change from 40)

• FUV Dispersed-Light Acquisition subarrays updated after optical alignment– avoid airglow contamination for ACQ/SEARCH, ACQ/PEAKXD, and ACQ/PEAKD

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Left: COS G130M spectrum compared with the STIS E140H spectrum convolved with a gaussian of R=15,000 (dotted)

Right : COS G130M spectrum compared with the STIS E140H spectrum convolved with a gaussian of R=7,000 (dotted)

• Sk155 is an O9 star in SMC with STIS E140H observations using 0.2X0.09 aperture giving R~114,000• ISM lines are both narrow features and broad saturated lines with sharp edges

FUV Spectral Resolution

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Comparison of COS LSF model at 1309 A with (dotted line) andwithout (solid) OTA mid-frequency WFE.

OTA WFE effect on the COS FUV LSF

• Effective resolving power (from FWHM) changes fromR ~ 20,000 to

R ~ 16,000(~20% effect)

• Line depth (LSF amplitude) decreases (~30% effect)

• LSF develops broad wings out to ~4 FWHM (~9 sigma)

• Models were calculated for G130M at 1309Å (G.Hartig, STScI), including:

a) COS optics, using Code V model (T.Delker, Ball)

b) COS/FUV detector blur kernel, empirically matched to TV06 data (T.Delker, Ball)

c) OTA low-frequency errors (spherical and astigmatism, in Code V model)

d) OTA mid-frequency errors

• When d) is left out, these models fit the data from TV06.

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COS G130M spectrum of previous region (solid) compared with the STIS E140H spectrum convolved with a gaussian of R=20,000 (dotted line) and with the LSF model containing OTA WFE effects (full line).

Note the good agreement with the LSF model containing OTA WFE effects which fits weak and strong features and correctly predicts cores of lines.

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Summary

• The COS G130M spectrum of Sk155 cannot be reproduced with a simple gaussian LSF

• The filling in of the saturated cores of the ISM lines is indicative of broad wings on the LSF

• An LSF with broad wings from a model that includes known COS and OTA properties gives an excellent fit to the COS G130M spectrum.

• The apparent finding of a different COS/FUV LSF on-orbit than during TV06 is expected from the fact that RAS/Cal did not include OTA mid-frequency WFE– Spectral resolution (~20%), line depth, and line shape are impacted.

• The broad LSF wings suggested by both the LSF model and the data are consistent with:– Prior expertise on HST with e.g. STIS

• Team in process of investigating further including examination of G160M, NUV, focus quality

Pulse Height Screening

N132D G130M/1318/FUVB (1310 s)--- courtesy Brian Keeney, COS IDT

The FUV B-segment “Friends”

Before Pulse Height Screening

N132D G130M/1318/FUVB (1310 s)

--- courtesy Brian Keeney, COS IDT

After Pulse Height Screening

N132D G130M/1318/FUVB (1310 s)

--- courtesy Brian Keeney, COS IDT

Danforth, Keeney, France, et al.

Backup Slides

COS/G130M

STIS/E140M

OVI z=0.18269

??

Science: Line Profiles

--- courtesy Winter, Keeney, Froning, Penton, Danforth, France, COS IDT