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Hubble Space Telescope
COS Instrument Science Reports

2016

ISR 2016-15: Third COS FUV Lifetime Calibration Program: Flatfield and Flux Calibrations

The derivation of the L-flats and sensitivities at LP3 differed from their LP1 and LP2 counterparts in a few key ways, which we describe in this report. Firstly, we quantified a cut-off in spatial frequency that we assigned to the L-flats. Secondly, we derived a new method for simultaneously fitting both the L-flats, pixel-to-pixel flats (P-flats), and sensitvities which we compared to our previous method of separately fitting L-flats and sensitivities. These new methods produce comparable results, but provide us with an external test on the robustness of each approach individually.
J. Debes 04 Oct 2016

ISR 2016-14: Cycle 22 COS/NUV Fold Distribution

We summarize the Cycle 22 COS/NUV Fold Distribution for the Cosmic Origins Spectrograph's (COS) MAMA detector on the Hubble Space Telescope. The detector micro-channel plate's health state is determined and the results are presented.
T. Wheeler 22 Sep 2016

ISR 2016-13: Cycle 22 COS/FUV Spectroscopic Sensitivity Monitor

We summarize the Cycle 22 COS/FUV spectroscopic sensitivity monitor that ran from November 2014 to October 2015. We give an overview of the program and a summary of the analysis of the data.
G. DeRosa 22 Sep 2016

ISR 2016-12: Cycle 22 COS NUV Internal/External Wavelength Scale Monitor

We report on the results of the monitoring of the COS NUV wavlength scale zero-points during Cycle 22. Select cenwaves for all NUV gratings were monitoring in this program with a structure that remained unchanged since Cycle 21.
P. Sonnentrucker 22 Sep 2016

ISR 2016-11: Cycle 22 COS NUV Dark Monitor Summary

Here we summarize the Cycle 22 NUV Dark Monitoring Program for COS covering dates November 2014 to October 2015. We give an overview of the calibration plan and summary for this calibration program.
M. Fix 22 Sep 2016

ISR 2016-10: Cycle 22 COS/NUV Spectroscopic Sensitivity Monitor

Results from the cycle 22 NUV TDS program show the reflectivity of the G225M and G285M gratings, which are coated in bare-aluminum, declines at a rate of -3 to -2.5%/year and -10.6 to -11.8%/year, respectively. The G185M and G230L gratings, which are coated in MgF2 over aluminum, show a decline of -0.3 to +0.6%/year and -0.4 to +0.9%/year, respectively.
J. Taylor 22 Sep 2016

ISR 2016-09: Cycle 22 COS Target Acquisition Monitor

COS program 13972 was designed to verify that COS Target Acquisitions (TA) were performing nominally during Cycle 22, and to check if any of the TA patchable constants present in the COS flight software (FSW) need updating. COS exposures obtained in HST program 14035 (HST Cycle 22 Focal Plane Calibration [SI-FGS Alignment]) were also used in this analysis. This program verified that all three TA modes were behaving nominally in Cycle 22, and determined that no SIAF, subarray, or FSW parameter updates were required at this time.
COS 22 Sep 2016

ISR 2016-08: Cycle 22 Characterization of HV Change Effect on the COS/FUV Sensitivity

Program 13971 was a special calibration program executed in Cycle 22 in order to characterize the effect of the COS FUV detector high voltage on the sensitivity. Previous changes to the high voltage settings led us to believe that an increase in the high voltage values caused an increase in sensitivity in addition to the expected increase in gain. This program was designed to measure that effect and determine whether it is a function of incident wavelength and/or position on the detector.
D. Sahnow 22 Sep 2016

ISR 2016-07: Cycle 22 COS FUV Detector Gain Maps

Program 13970 used the onboard deuterium lamp to illuminate the LP2 and LP3 regions of the COS FUV detector at the time of the Lifetime 3 move. The pulse height information obtained was used to create gain maps in order to monitor the detector gain sag and to determine when high voltage changes and Lifetime Position changes were needed.
D. Sahnow 21 Sep 2016

ISR 2016-06: Cycle 22 COS FUV Internal/External Wavelength Scale Monitor

We report on the results of the monitoring of the COS FUV wavlength scale zero-points during Cycle 22. Only the G130M/1096 and G140L/1105-1280 configurations were monitored in this program. Monitoring of the standard G130M and G160M modes was part of the calibration phase associated with the move of COS FUV operations to LP3 and will be presented in a separate ISR.
P. Sonnentrucker 21 Sep 2016

ISR 2016-05: Cycle 22 COS FUV Dark Monitor Summary

Here we summarize the Cycle 22 FUV Dark Monitoring Program for COS covering dates November 2014 to October 2015. We give an overview of the calibration plan and summary for this calibration program.
M. Fix 22 Sep 2016

ISR 2016-04: Summary of COS Cycle 23 Calibration Plan

We summarize the calibration activities for the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope during Cycle 23 which ran from November 2015 through October 2016. We give an overview of the COS calibration plan, COS usage statistics and we briefly describe major changes with respect to the previous cycle. High-level executive summaries for each calibration program comprising Cycle 23 are also given here. Results of the analysis attached to each program are published in separate ISRs.
P. Sonnentrucker 22 Sep 2016

ISR 2016-03: Summary of the COS Cycle 22 Calibration Program

We summarize the calibration activities for the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope during Cycle 22 which ran from November 2014 through October 2015. We give an overview of the COS calibration plan, COS usage statistics and we briefly describe major changes with respect to the previous cycle. High-level executive summaries for each calibration program comprising Cycle 22 are also given here. Results of the analysis attached to each program are published in separate ISRs.
P. Sonnentrucker 21 Sep 2016

ISR 2016-02: Characterizing the COS OSM1 Drift in the Dispersion Direction

In this ISR, we analyze the OSM drift on finer time-scales than the TAGFLASH intervals to determine if the current CalCOS correction is sufficient.
J. White 25 Aug 2016

ISR 2016-01: Optimization of Lifetime Position 3 of the COS/FUV Detector

In this ISR, we describe the process for selecting the LP3 location, and the subsequent requirements for the new extraction algorithm supporting science at LP3.
J. Roman-Duval 25 Feb 2016

2015

ISR 2015-05: Verification of COS/FUV Bright Object Aperture (BOA) Operations at Lifetime Position 3

We report the results of the COS/FUV calibration program LCAL4, designed to verify operations and performance of the bright object aperture (BOA) at the third lifetime position (LP3).
A. Fox 10 Dec 2015

ISR 2015-04: Does Not Exist

An ISR with this number does not exist
04 Oct 2016

ISR 2015-06: Summary of the COS Cycle 21 Calibration Program

We summarize the Cycle 21 calibration program for the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, covering the time period from November 2013 through October 2014. We give an overview of the Calibration plan and status summaries for each of the individual proposals comprising the C21 Calibration program.
H. Sana 25 Sep 2015

ISR 2015-03: Changes to the COS Extraction Algorithm for Lifetime Position 3

The COS FUV Detector Lifetime Position 3 (LP3) has been placed only 2.5” below the original lifetime position (LP1). This is sufficiently close to gain-sagged regions at LP1 that a revised extraction algorithm is needed to ensure good spectral quality. We provide an overview of this new “TWOZONE” extraction algorithm, discuss its strengths and limitations, describe new output columns in the X1D files that show the boundaries of the new extraction regions, and provide some advice on how to manually tune the algorithm for specialized applications.
C. Proffitt 25 Sep 2015

ISR 2015-02: Summary of the COS Cycle 20 Calibration Program

We summarize the Cycle 20 calibration program for the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, covering the time period from November 2012 through October 2013. We give an overview of the Calibration plan and status summaries for each of the individual proposals comprising the C20 Calibration program.
J. Roman-Duval 11 Jun 2015

ISR 2015-01: The COS/FUV Focus Sweep Program at Lifetime Position 3 (LENA2/13635)

We present the results from the focus sweeps performed in July 2014 in preparation for the move to lifetime position 3 with the G130M, G160M, and G140L gratings using the bright stars Feige 48 and AzV75 as targets.
A. Fox 20 May 2015

2014

ISR 2013-13: COS/FUV Characterization of Optical Effects at Potential Lifetime Positions

In this document we provide a summary of the analysis performed on data obtained as part of program 12678, "COS/FUV Characterization of Optical Effects". Changes to throughput, resolution and gain as a function of position were evaluated and compared to raytrace models.
D. Sahnow 24 Apr 2015

ISR 2014-01: Summary of the Cycle 19 COS Calibration Program

We summarize the Cycle 19 calibration program for the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, covering the time period from November 2011 through October 2012. We give an overview of the Calibration Plan and status summaries for each of the individual proposals comprising the C19 Calibration program.
J. Roman-Duval 16 Jul 2014

ISR 2013-09: Updated Absolute Flux Calibration of the COS FUV Modes

We present newly derived point source absolute flux calibrations for the COS FUV modes at both the original and second lifetime positions.
D. Massa 14 Mar 2014

2013

ISR 2013-16: Summary of Results from the First Move to a New COS FUV Lifetime Position

We summarize the results of the enabling and calibration activities involved in the first COS FUV move to a new lifetime position, which occurred on July 23, 2012.
R. Osten 08 Oct 2013

ISR 2013-08: Characterization of the COS FUV Detectors

This document describes the results derived from the COS calibration Program 12676, "COS/FUV Characterization of Detector Effects".
D. Massa 01 Oct 2013

ISR 2013-06: COS FUV Dispersion Solution Verification at the New Lifetime Position

In this report, we describe the analysis we performed to verify the dispersion solutions of the M gratings using data collected in 12805 and of the L grating using data obtained in enabling program 12796 (FENA3:“Second COS FUV Lifetime Position: Focus Sweep Enabling Program”; Oliveira et al. 2013).
P. Sonnentrucker 10 Jun 2013

ISR 2013-07: COS/FUV Spatial and Spectral Resolution at the new Lifetime Position

In this ISR we characterize the spatial and spectral resolution at the second COS FUV lifetime position.
J. Roman-Duval 10 Jun 2013

ISR 2013-05: Second COS FUV Lifetime Position: Verification of FUV Bright Object Aperture (BOA) Operations (FCAL4)

The document describes the analysis of data taken as part of the second lifetime calibration program 12807. This program was designed to characterize the BOA spectroscopic performance at the second lifetime position.
J. H. Debes 22 May 2013

ISR 2013-04: Summary of COS Cycle 18 Calibration Programs

This document summarizes the status of the calibration programs for COS during Cycle 18.
G. Kriss 26 Apr 2013

ISR 2013-03: Second COS FUV Lifetime Position: Verification of Aperture and FUV Spectrum Placement (FENA2)

This document describes the analysis of the data obtained for proposal 12795 which determined the exact updates for the Science Instrument Aperture File (SIAF) and for the COS aperture block positioning needed to implement routine science operations at COS FUV Lifetime Position 2.
C. Proffitt 08 Apr 2013

ISR 2013-02: COS/FUV Mapping of Stray PtNe Lamp Light Through the FCA

This ISR reviews the causes of the shutdown program 12096 and how program 12677 was crafted to avoid a similar shutdown. The document presents results from program 12677 and their impact on future lifetime position is discussed.
C. Oliveira 07 Feb 2013

ISR 2013-01: Second COS FUV Lifetime Position Results from the Focus Sweep Enabling Program, FENA3 (12796)

This document describes the results from the second lifetime position focus sweep with COS/FUV G130M, G160M, and G140L gratings as part of the programs executed to enable COS/FUV science at the second lifetime position.
C. Oliveira 06 Feb 2013

2012

ISR 2012-02: Summary of COS Cycle 17 Calibration Program

This document summarizes the status of the calibration programs for COS during Cycle 17.
R.Osten 29 Nov 2012

ISR 2012-01: COS FUV Focus Determination for the G140L Grating

Describes the procedures for determining the COS FUV fine-focus for the G140L grating.
P. Ghavamian 03 Oct 2012

2011

ISR 2010_11: COS FUV Detector Dark Rates During SMOV and Cycle 17

This ISR describes the behavior and characteristics of the COS FUV detector dark rate during SMOV and Cycle 17.
D. Sahnow 07 Oct 2011

ISR 2011-05: Gain sag in the FUV detector of the Cosmic Origins Spectrograph

SPIE paper describing the characteristics and mitigation strategies of gain sag in the FUV detector.
David J. Sahnow, Cristina Oliveira, Alessandra Aloisi, Philip E. Hodge, Derck Massa, Rachel Osten, Charles Proffitt, Azalee Bostroem, Jason B. McPhate, Stéphane Béland, Steven N. Osterman and Steven V. Penton, "Gain sag in the FUV detector of the Cosmic Origins Spectrograph", Proc. SPIE 8145, 81450Q (2011); http://dx.doi.org/10.1117/12.893989
Copyright 2011 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

D. Sahnow 26 Sep 2011

ISR 2011-04: Details of COS TAGFLASH Execution

Describes the characteristics of COS TAGFLASH exposures.
T. Keyes 07 Sep 2011

ISR 2011-03: COS FUV Gridwire Flat Field Template

Results of the FUV Gridwire Flat Field Development and Testing.
J. Ely 05 Aug 2011

ISR 2011-02: Updated Results from the COS Spectroscopic Sensitivity Monitoring Program

Updated Results from the COS Spectroscopic Sensitivity Monitoring Program.
R. Osten 28 Jun 2011

ISR 2010_12: COS NUV Detector Dark Rates During SMOV and Cycle 17

This ISR describes the behavior and characteristics of the COS NUV detector dark rate during SMOV and Cycle 17.
D. Sahnow 12 Jul 2011

ISR 2010_13: SMOV: COS FUV and NUV On-Orbit Structural and Thermal Stability

This ISR provides a description and analysis of the structural and thermal stability of the COS instrument.
T. Ed Smith 12 Jul 2011

ISR 2011-01: Improved Medium Resolution Line Spread Function for the COS FUV Spectrum

We have developed an improved line spread function (LSF) for the medium resolution far- ultraviolet gratings (G130M and G160M) of the Cosmic Origins Spectrograph (COS) by taking into account scattering in the far wings due to microroughness on the HST primary mirror.
G. Kriss 18 Mar 2011

2010

ISR 2010-10: SMOV: COS NUV Imaging Performance

Presenting data analysis to describe NUV Imaging Performance for COS after SM4. Revised 10/6/2010
P. Goudfrooij 11 Mar 2010

ISR 2010-08: SMOV: COS NUV External Spectroscopic Performance

Describes the external spectroscopic performance of the COS NUV detector
S. Béland 30 Sep 2010

ISR 2010-09: COS FUV External Spectroscopic Performance

A description of the External Spectroscopic Performance of the FUV Channel on COS
P. Ghavamian 30 Sep 2010

ISR 2010-15: Early Results from the COS Spectroscopic Sensitivity Monitoring Programs

We report initial results from the Cosmic Origins Spectrograph spectroscopic sensitivity monitoring calibration programs.
R. Osten 02 Aug 2010

ISR 2010-14: COS Target Acquisition Guidelines, Recommendations, and Interpretation

This ISR provides an overview of COS TA and updates, expands, and supersedes information in the COS IHB(v2)
T. Keyes 15 Jun 2010

ISR 2010-07: SMOV: COS FUV Focus Determination

The procedures for determining the COS FUV fine-focus are described
D. Lennon 04 Mar 2010

ISR 2010-05: SMOV: COS NUV Wavelength Calibration

Update to the NUV wavelength calibration from SMOV
C. Oliveira 19 Feb 2010

ISR 2010-06: SMOV: COS FUV Wavelength Calibration

Update to the FUV wavelength calibration from SMOV data
C. Oliveira 19 Feb 2010

ISR 2010-04: SMOV: COS NUV On-orbit Optical Alignment

SMOV NUV optical alignment process description
G. Hartig 12 Feb 2010

ISR 2010-01: SMOV Absolute Flux Calibration of the COS NUV Modes

Describes the processes used to determine the absolute flux calibration of COS NUV point source spectra
D. Massa 28 Jan 2010

ISR 2010-02: SMOV Absolute Flux Calibration of the COS FUV Modes

Describes the processes used to determine the absolute flux calibration of COS FUV point source spectra
D. Massa 28 Jan 2010

ISR 2010-03: COS Near-UV Flat Fields and High S/N Determination from SMOV Data

Describes the process of determining and results of the COS NUV high S/N flat field reference files from data taken during SMOV4
T. Ake 04 Feb 2010

2009

ISR 2009-01(v1): Preliminary Characterization of the Post-Launch Line Spread Function of COS

Description of the COS Line Spread Function (LSF) as determined by post-launch testing.
P. Ghavamian 01 Oct 2009

2008

COS ISR 08-01: Phase II Update and Guidelines for Cycle 17 Users of COS

Summary of recommended practice and suggestions for observers preparing their Phase II COS program submissions for Cycle 17.
D. Soderblom 06 Jun 2008

2002

COS ISR 02-01: COS Bright Object Protection

COS Bright Object Protection
C. Leitherer 07 Mar 2006

1999

COS ISR 99-01: COS Design Reference Mission and Ground System Volume Requirements

COS Design Reference Mission and Ground System Volume Requirements
Charles (Tony) Keyes 07 Mar 2006