10823( 3) - 03/08/07 09:34 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10823 Version: 3 Check-in Time: 08-Mar-2007 14:32:37 STScI Edit Number: 0 Title The spectrum of a magnetar in the blue and ultraviolet. ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 15 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Martin Durant University of Toronto CoI: Prof. Marten H. van Kerkwijk University of Toronto N ------------------------------------------------------------------------------------ Abstract Magnetars are natural laboratories for investigating the behaviour of matter at the very extremes of nature. The magnetar CXOU J010043.1-721134 was serendipitously discovered by WFPC2 imaging of the SMC. Because of the low reddening to this source compared to the other magnetars, this is a unique opportunity to measure the spectral shape in the blue and ultraviolet. We hope also to establish the feasibility of spectroscopic follow-up. We are asking for two orbits of ACS imaging. ------------------------------------------------------------------------------------ 10823( 3) - 03/08/07 09:34 - [ 2] Observations Description ------------------------ We will use two orbits with ACS to accurately measure CXOU J010043.1-721134's F606W magnitude (where the only detection has been made, mF606W = 24.2) and measure the source or set good limits across the optical/UV band, using filters F330W, F435W, and F814W. A Rayleigh-Jeans form spectrum (nuF_nu ~ nu^n, n = 3) is possible given the limits in F814W previously obtained. Since it is very unlikely that the spectrum rises faster than this (it would require a very strong and broad spectral line), we predict a magnitude of mF814W = 25. We can also predict what we might might find in F435W by supposing that CXOU J010043.1?721134 has the same intrinsic B-V color as 4U 0142+61. With B-V = 2.5 (Hulleman et al., 2004) and using our new estimated reddening for 4U 0142+61 (AV = 3.5, Durant & van Kerkwijk, 2006, submitted), we find (B-V )_0 = 1.4 and thus we would predict mF435W = 25.7. For U we have no predictions, and hence for this initial study we will go as deep as possible in a single orbit. In the optical, with the WFC, a given SNR is reached much quicker than with the HRC. Only the HRC is sensitive in U, however, so we will use the WFC for one orbit and the HRC for the second. According to the ACS ETC for the WFC, 200s is required to reach SNR=20 at V=24.2 in F606W. Good measurements (SNR=10) will be reached in F435W in 530s down to 25.3mag and in F814W in 860s down to 25.0mag, respectively. These all assume CR-SPLIT=2, GAIN=2 and average conditions. In total, these three filters will take 52min to observe, or one orbit exactly, including overheads. We will use the WFC1-1K sub-array to reduce the read-out time and release more time for exposures (and eliminate the buffer dump overhead). In the second orbit, we will use the HRC to get as deep an image in F330W as possible. After accounting for overheads, 2550s remains, which reaches a detection limit (SNR=3) of U=25.3 for GAIN=2, CR-SPLIT=2. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10823( 3) - 03/08/07 09:34 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOUJ010043. STAR, NEUTRON STAR, RA=01H00M43.1090S +/- 0.25", J2000 V = 24.2+/-0.2 1-721134 PULSAR, X-RAY TRANSIENT DEC=-72D11'33.77" +/- 0.25" m606-m814 < -0.3 Reference Frame: ICRS 10823( 3) - 03/08/07 09:34 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-LINE Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.3535 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 45.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 10823( 3) - 03/08/07 09:34 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 20.0D TO 70.0 D; ORIENT 200.0D TO 250.0 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOUJ010043 WFPC2 IMAGE WF3 F336W CLOCKS=YES 1 2600 S PATTERN 1 1 .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 2 CXOUJ010043 WFPC2 IMAGE WF3 F439W CLOCKS=YES 1 1000 S .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 CXOUJ010043 WFPC2 IMAGE WF3 F439W CLOCKS=YES 1 1200 S SAME POS AS 5 .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 4 CXOUJ010043 WFPC2 IMAGE WF3 F439W CLOCKS=YES 1 1000 S POS TARG 0.5, 0.5 .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 5 CXOUJ010043 WFPC2 IMAGE WF3 F814W CLOCKS=YES 1 1200 S POS TARG 0.5, 0.5 .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 6 CXOUJ010043 WFPC2 IMAGE WF3 F814W CLOCKS=YES 1 1400 S POS TARG 0.25, 0.25 .1-721134 see below ------------------------------------------------------------------------------------------------------------------------------------ 7 CXOUJ010043 WFPC2 IMAGE WF3 F606W CLOCKS=YES,CR-SPLIT=NO 1 400 S POS TARG 0.25, 0.25 .1-721134 ------------------------------------------------------------------------------------------------------------------------------------ 8 CXOUJ010043 WFPC2 IMAGE WF3 F606W CLOCKS=YES,CR-SPLIT=NO 1 400 S .1-721134 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 1 none none 1 1 1400.0 S 34 CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 1 none none 2 1 N/A 34 CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 2 none none 1 2 N/A 34 CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 2 none none 2 2 1400.0 S 34 CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 3 none none 1 3 1400.0 S 34 10823( 3) - 03/08/07 09:34 - [ 6] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ CXOUJ010043.1-7211 1 WFPC2 IMAGE WF3 F336W 3 none none 2 3 N/A 34 CXOUJ010043.1-7211 2 WFPC2 IMAGE WF3 F439W none none none 1 4 500.0 S 34 CXOUJ010043.1-7211 2 WFPC2 IMAGE WF3 F439W none none none 2 4 500.0 S 34 CXOUJ010043.1-7211 3 WFPC2 IMAGE WF3 F439W none none none 1 4 500.0 S 34 CXOUJ010043.1-7211 3 WFPC2 IMAGE WF3 F439W none none none 2 4 800.0 S 34 CXOUJ010043.1-7211 4 WFPC2 IMAGE WF3 F439W none none none 1 5 700.0 S 34 CXOUJ010043.1-7211 4 WFPC2 IMAGE WF3 F439W none none none 2 5 400.0 S 34 CXOUJ010043.1-7211 5 WFPC2 IMAGE WF3 F814W none none none 1 5 500.0 S 34 CXOUJ010043.1-7211 5 WFPC2 IMAGE WF3 F814W none none none 2 5 700.0 S 34 CXOUJ010043.1-7211 6 WFPC2 IMAGE WF3 F814W none none none 1 6 700.0 S 34 CXOUJ010043.1-7211 6 WFPC2 IMAGE WF3 F814W none none none 2 6 700.0 S 34 CXOUJ010043.1-7211 7 WFPC2 IMAGE WF3 F606W none none none none 6 N/A 34 CXOUJ010043.1-7211 8 WFPC2 IMAGE WF3 F606W none none none none 6 N/A 34 10823( 3) - 03/08/07 09:34 - [ 7] Summary Form for Proposal 10823 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WF3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 20.0D TO 70.0 D; ORIENT 200.0D TO 250.0 D; PATTERN 1 1; SAME POS AS 5; POS TARG 0.5, 0.5; POS TARG 0.25, 0.25; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F439W F814W F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CXOUJ010043.1-721134 ------------------------------------------------------------------------------------------------------------------------------------