! Proposal 6942, submission 3 ! PI: Massimo Stiavelli. ! Received Tue Aug 20 17:02:22 EDT 1996 ! From: shireen@stsci.edu Proposal_Information Title: WFPC2 Camera Electronics Proposal_Category: CAL/WF2 Scientific_Category: Cycle: 6 Investigators PI_Name: Massimo Stiavelli. PI_Institution: Space Telescope Science Institute CoI_Name: Stefano Casertano CoI_Institution: Space Telescope Science Institute CoI_Name: Harry Ferguson CoI_Institution: Space Telescope Science Institute Abstract: The aim of this proposal is to study several aspects of the WFPC2 camera electronics. In particular the linearity of the camera, the ratio of the two gains, the effect of CLOCKS, the effect of CTE on extended sources. These goals are achieved by observing a very extended non uniform target represented by the giant elliptical galaxy NGC 4472. Questions Observing_Description: The linearity test is carried out by taking exposures of NGC 4472, centered in WFALL, with a variety of exposure times. Since the galaxy is non uniform, the ratio of these exposures is directly related to the camera linearity. The exposures will be taken with GAIN=7. However, one exposure will also be taken with GAIN=15. Additional exposures will be taken with CLOCKS=YES and with a preflash. These observations complement those of the internal calibration proposal 6907. The two major advantages of these observations compared to the 6907 ones are the possibility of studying the effect of preflash (since the light distribution of the preflash is different from that of NGC 4472) and the possibility of measuring an absolute response curve, since NGC 4472, unlike the INTFLAT lamp, does not have variations in luminosity. NGC 4472 has been chosen as target galaxy because it is large enough to produce significant signal in all chips and bright enough to allow us to explore the highest counts without excessive integration times. Real_Time_Justification: Calibration_Justification: Additional_Comments: Fixed_Targets Target_Number: 1 Target_Name: NGC4472 Alternate_Names: Description: GALAXY,CALIBRATION Position: RA=187.4445063137D+/-0.0001D,DEC=8.000493131526D+/-0.0001D Equinox: J2000 RV_or_Z: V = 913 RA_PM: 0.0 Dec_PM: 0.0 Epoch: J2000 Annual_Parallax: 0.0 Flux: B = 9.8+/-0.1 Comments: Solar_System_Targets Generic_Targets Scan_Data Visits Visit_Number: 01 Visit_Requirements: On_Hold_Comments: Visit_Comments: Exposure_Number: 10 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F502N Wavelength: Optional_Parameters: ATD-GAIN=7,CLOCKS=NO,CR-SPLIT=no,READ=NO Number_of_Iterations: 1 Time_Per_Exposure: 20S Special_Requirements: Comments: Used to preflash the following exposure number 20. Should be follows immediately by exposure 20. Exposure_Number: 20 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=7,CR-SPLIT=no,CLOCKS=NO Number_of_Iterations: 1 Time_Per_Exposure: 200S Special_Requirements: SEQ 10-20 NON-INT Comments: It is a pre-flashed version of the 2nd exposure of the basic series. It should follow immediately after exposure number 10. Exposure_Number: 30 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=7,CR-SPLIT=no,CLOCKS=NO Number_of_Iterations: 1 Time_Per_Exposure: 200S Special_Requirements: Comments: 2nd exposure in the basic series. Exposure_Number: 40 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=7,CLOCKS=NO,CR-SPLIT=no Number_of_Iterations: 1 Time_Per_Exposure: 100S Special_Requirements: Comments: 3rd exposure in the basic series. Exposure_Number: 50 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=7,CLOCKS=NO,CR-SPLIT=no Number_of_Iterations: 1 Time_Per_Exposure: 50S Special_Requirements: Comments: 4th and shortest exposure in the basic series. Exposure_Number: 60 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=15,CLOCKS=NO,CR-SPLIT=no Number_of_Iterations: 1 Time_Per_Exposure: 200S Special_Requirements: Comments: Duplicates the 2nd exposure of the basic series. It explores the effect of changing gain. Should have the same counts as the 3rd if the camera is linear. Exposure_Number: 70 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: ATD-GAIN=7,CLOCKS=YES,CR-SPLIT=no Number_of_Iterations: 1 Time_Per_Exposure: 200S Special_Requirements: Comments: Duplicates the 2nd exposure of the basic series. It explores the effect of CLOCKS=YES option. Exposure_Number: 80 Target_Name: NGC4472 Config: WFPC2 Opmode: IMAGE Aperture: WFALL-FIX Sp_Element: F702W Wavelength: Optional_Parameters: CR-SPLIT=no,ATD-GAIN=7,CLOCKS=NO Number_of_Iterations: 1 Time_Per_Exposure: 350S Special_Requirements: SEQ 10-80 NON-INT Comments: Longest integration. Should slightly saturate near the center. This is done in purpose to have a number of values close to the maximum. Data_Distribution ! Defaults indicated; change if desired Medium: 8MM Blocking_Factor: 10 Ship_To: PI_Address Ship_Via: Recipient_Email: