6827( 4) - 04/30/98 08:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6827 Version: 4 Check-in Date: 30-Apr-1998 08:45:03 1.Proposal Title: THE ENIGMATIC SOFT GAMMA-RAY REPEATERS ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 6 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: SHRINIVAS KULKARNI California Institute of Technology CoI: M. H. van Kerkwijk California Institute of Technology N CoI: R. Danner Max-Planck Institut fuer N Extraterrestrische Physik CoI: T. Murakami Institute for Space Astronautics and N Sciences ------------------------------------------------------------------------------------ 5. Abstract We prospose to try to identify an optical/UV counterpart of the Soft Gamma-ray Repeater (SGR) 0525-66, the most enigmatic of a class of sources, which, for reasons unknown, repeatedly show high-energy bursts. One SGR, 1806-20, has been identified with a plerionic supernova remnant, with a persistent X-ray source as well as a very luminous star coincident with the peak. For SGR 0525-60, the 5-March-1979 burst, the brightest burst ever observed, has led to a localisation to the northern part of the supernova remnant N49 in the LMC. Neither plerionic radio emission, nor a bright companion have been found, but there is a persistent X-ray source inside the error box. It is very unlikely find such a bright source in the 0.09 square arcmin error box by chance, but even so we recently found evidence for another, variable source right next to the persistent one. From SGR 1806-20, we infer that SGR events are associated not only with bursts of photons but also with strong burst of particles. For any reasonable ratio of the energy in particles to that in gamma- rays, the March 1979 event of SGR 0525-66 alone would suffice to power a small plerionic nebula. This nebula can account for the presistent X-ray source, and should also be detectable in the optical/UV. However, HST is needed to resolve it from the underlying emission of N49. With HST, we might even find that the plerion has the shape of a bow shock, due to the high transversal speed of the underlying power source. ------------------------------------------------------------------------------------ 6827( 4) - 04/30/98 08:46 - [ 2] Observations Description ------------------------ We intend to observe the error box of the ROSAT X-ray sources with the Planetary Camera of WFPC2. We chose the F547M filter to have as little overlap as possible with the emission lines from N49 (see the spectra by Vancura et al.\ (1992). Based on the analysis of the WFPC1 image in the F517N, we expect that in 180 minutes in F547M (two orbits in CVZ), we will be able to go down a factor sqrt6*12 deeper because of the wider filter and longer integration time (notice that the observations will be background limited, due to the signal from the supernova remnant). This means we can go down to 0.5 MuJy. For the blue region, it is not possible to chose a filter that is as free from lines. To compensate for that and for the lower sensitivity, we need to integrate about three times longer. The observations will all be slit in 1000 s exposures. These will be taken at slightly different positions, so that following the prescription of Freudling (1995; see also ST-ECF News Letter 22), we will be able to partly recover the resolution lost by undersampling, as well as get rid of cosmic ray hits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 6827( 4) - 04/30/98 08:46 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 N49-052601- UNIDENTIFIED, GAMMA RAY RA=05H 26M 00.7S +/- 1.0S, DEC=- 2000 V = 24 660435 EMITTER 66D 04' 35" +/- 10" B-V = 0 Comments: We are trying to find the SGR companion and do not know its flux in advance. We have put a best guess. 6827( 4) - 04/30/98 08:46 - [ 4] Visit: 01 Visit Priority: Visit Requirements: CVZ ORIENTATION 295D TO 310D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 N49-052601- WFPC2 IMAGE PC1-FIX F547M CLOCKS=YES 2 100 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 2 N49-052601- WFPC2 IMAGE PC1-FIX F547M DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1000 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 3 N49-052601- WFPC2 IMAGE PC1-FIX F380W CLOCKS=YES 2 100 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 4 N49-052601- WFPC2 IMAGE PC1-FIX F380W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1000 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 5 N49-052601- WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES ,CR-SPLIT=0.5652173 1 463 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 7 N49-052601- WFPC2 IMAGE PC1-FIX F300W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1300 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 8 N49-052601- WFPC2 IMAGE PC1-FIX F300W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1100 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 6827( 4) - 04/30/98 08:46 - [ 5] Visit: 02 Visit Priority: Visit Requirements: CVZ ORIENTATION 295D TO 310D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 N49-052601- WFPC2 IMAGE PC1-FIX F547M CLOCKS=YES 2 100 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 2 N49-052601- WFPC2 IMAGE PC1-FIX F547M DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1000 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 3 N49-052601- WFPC2 IMAGE PC1-FIX F380W CLOCKS=YES 2 100 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 4 N49-052601- WFPC2 IMAGE PC1-FIX F380W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1000 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 5 N49-052601- WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES ,CR-SPLIT=0.5652173 1 463 S 660435 ------------------------------------------------------------------------------------------------------------------------------------ 7 N49-052601- WFPC2 IMAGE PC1-FIX F300W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1300 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 8 N49-052601- WFPC2 IMAGE PC1-FIX F300W DITHER-TYPE=BOX ,CR-SPLIT=NO , 1 1100 S 660435 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 6827( 4) - 04/30/98 08:46 - [ 6] Summary Form for Proposal 6827 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES CR-SPLIT=NO DITHER-TYPE=BOX CR-SPLIT=0.5652173 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ ORIENTATION 295D TO 310D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F547M F380W F300W ------------------------------------------------------------------------------------------------------------------------------------ Target Names N49-052601-660435 ------------------------------------------------------------------------------------------------------------------------------------