9353( 4) - 12/10/02 06:45 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9353 Version: 4 Check-in Date: 10-Dec-2002 06:44:04 1.Proposal Title: Direct imaging of the progenitors of massive, core-collapse supernovae ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Stephen Smartt University of Cambridge CoI: Dr Gerry Gilmore Institute of Astronomy N CoI: Dr Simon Hodgkin Institute of Astronomy N CoI: Dr Neil Trentham Institute of Astronomy N CoI: Dr Chris Tout Institute of Astronomy N CoI: Mr Enrico Ramirez-Ruiz Institute of Astronomy N CoI: Mr Justyn Maund Institute of Astronomy Y ------------------------------------------------------------------------------------ 5. Abstract Modern supernovae searches in the nearby Universe are discovering vast numbers of SNe which have massive star progenitors (Types II, Ib and Ic). The extensive HST (and ground-based) image archives of galaxies within ~20 Mpc enables their individual bright stellar content to be resolved. As massive, evolved stars are the most luminous single objects in a galaxy, the progenitors of core-collapse SNe should be directly detectable on pre-explosion images. Within the last year we have set direct mass limits on the progenitors of two SNe Type II-P by analysing pre- explosion archive images and follow up HST exposures. We have now identified six other recent, nearby SNe which have WFPC2 archive exposures of the site taken before explosion. Additionally, our Cycle 10 SNAP program will double the WFPC2 image archive of nearby galaxies which significantly increases the chances of having multi-colour photometry of pre-explosion sites for future SNe. In this Cycle, we request time on two fronts. Firstly we require imaging of the six SNe with existing pre-explosion data in order to perform exact astrometry of the SNe positions to around 0.05''. Secondly, as a follow on from our two successful Cycle 10 programs, we request ToO status for any nearby core-collapse SN which explodes during Cycle 11 and which has pre-explosion HST images. The goal of this proposal is to directly identify the progenitor stars of core-collapse SNe. ------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 2] Observations Description ------------------------ The six SNe with confirmed pre-explosion data: As discussed above, there are six core-collapse events with WFPC2 exposures in the archive taken before explosion, and these are listed in Table 1. Three of them are Ib/Ic events and the other three are Type II. We have identified the regions on the WFPC2 FOV where these SNe are likely to lie, but there is a ~2'' error circle on the these positions due to the absolute pointing position of HST and the accuracy of each SN position. Either WFPC2 or ACS imaging of the SNe now is the only way to accurately determine the explosion position on the these archive frames (as in Smartt et al. 2001a). We favour using ACS WFC due to its better throughput in the VRI- bands and the higher resolution over the whole field it will provide. The pixel grid astrometry used to match the images in Fig. 1 produced excellent results when using higher resolution data (from the PC1 chip of WFPC2) as the reference frame, and the WFC of ACS can be used similarly. The pre- explosion image for 2001B is only 70s but there are resolved objects detected within 2'' of the position on the CCD. For the others, in the worse case they have exposures of similar quality used in our study of 1999gi, and hence at the very least we can set the same type of luminosity and mass limits as in Smartt et al. (2001a). begintable captionDetails of the six nearby SN since 1990 which have pre-explosion images in the WFPC2 archive. SN2001ci also has data, but it is probably reddened by ~4-5 magnitudes, so we ignore that one. begintabularlllll SN & Galaxy & Type & V_ rad (kms^-1) & Pre-explosion data , 2001B & IC391 & Ib & 1557 & F555W (70s) , 2000ew & NGC3810 & Ic & 993 & F606W (160s) , 2000ds & NGC2768 & Ib/c & 1407 & F555W (1560s), F814W (2420s) , 1999ev & NGC4274 & II & 926 & F555W (296s) , 1999br & NGC4900 & II & 967 & F606W (160s) , 1999an & IC755 & II & 1507 & F606W (160s), endtabular endtable As the pre-explosion exposures are made up of a V-band exposure (either F555W or F606W), and in one case an additional I-band (F814W) image, we request repeat F555W exposures to pinpoint the SN. One orbit will allow 700s exposures in three filters. This includes a 6-min overhead for guide-star acquisition and 6.5-min overhead per filter for a CR-split exposure. We request ACS filters F555W, F625W and F775W as 3-colours will allow a reddening to be determined for the surrounding stellar population. This is of extreme importance to determining the progenitor mass or mass limit (as discussed in Smartt et al. 2001b). We will also make use of any reddening measurements in observations of the SNe themselves (e.g. Baron et al. 2000), but this provides an extra check as we showed in Smartt et al. (2001a). A 700s exposure in F555W will reach 27^m (5Sigma). The expected magnitudes of the SNe are a little difficult to predict given the uncertainty in the observational epoch and the sparse data that exists on quite late-time SNe fluxes. Our best estimates (comparing with other late-time events) put them in the range 22-27^m around December 2002. noindent SN19993J:, Aldering et al. (1994) suggest the progenitor of SN 1993J was a K0Ia star but had excess UB-band flux. This has been interpreted as a sign of either a hot companion or that the progenitor was part of a small, young association. The UV- flux of the SN will now be minimal and by high-resolution imaging of the site with the HRC on ACS we will be able to tell if there is any residual UV-flux from the contaminant object. We will discriminate between a point- source (binary companion) or extended OB association. The contaminant was estimated to have an M_ V~-5 by Aldering et al., and a spectral type of around early-B (with A_V=0.5^m). We request deep exposures in the UV filters F220W and F330W (where the SN flux itself is expected to be non-existent) and short exposures F435W and F555W for a consistency check on the colours and position. Using the expected parameters of Aldering et al. we require exposure times of 4800s (F220W), 600s (F330W), 200s (F435W), 180s (F555W) to get a S/N of 20 in each filter. If we do see a single source consistent with the HRC PSF then this will put very strong constraints on the binary progenitor models of 1993J. 9353( 4) - 12/10/02 06:45 - [ 3] noindent Future SN:, If during the duration of Cycle 11 a bright supernova is discovered for which an archive pre-explosion image exists, then we will request a set of observations tailored to best match the pre-explosion material, and maximise our chances of identifying the progenitor. We loosely request a ToO observation as we clearly cannot name our targets, but our observations can be scheduled several weeks in advance so we need not disturb the telescope schedule. We certainly do not need a rapid turn around of HST, but we request 2 orbits per new supernova in Cycle 11 as soon as they can be fitted into the schedule without disruption. We will take a series of short and long exposures so that we get a non-saturated measurement of the PSF centre of the SN, and good signal-to- noise of the surrounding fainter stars in the galaxy. The main problem is of course the dynamic range of WFPC2 or ACS, and the fact that the supernova will saturate in exposures of the neighbouring stars. The PSF centres of the stars are required to pixel-map the post- explosion data to the pre- explosion data. Again we favour ACS because of its higher resolution, and better dynamic range capabilities. For each event we will choose between the WFC and the HRC on the basis of the number of astrometric calibration stars that would be available in the small field of the HRC. The guiding of HST is easily good enough that drifts between exposures are generally less than 0.02''. During the 2 orbits we will 1. match the pre- explosion data 2. make sure we have exposures that both measure the unsaturated PSF of the SN and also give good S/N on the surrounding fainter stellar population 3. make sure we have photometry in at least 3-bands, again for reddening determinations. We could of course wait until Cycle 12 and attempt late-time recovery of the SNe, however we request these early observations in order to identify the progenitor, as soon as possible. This will give added impetus to the supernova monitoring community, and indeed our own campaign to monitor the targets through the Liverpool Robotic Telescope, the ING on La Palma, ESO, AAO and SAAO. Drawing connections between the progenitor and the explosion and evolution of the supernova is the key to constructing a unified picture of the origin of the core-collapse SNe types. As there are many SNe that can be monitored each year, we wish to identify those with progenitor information so that they can be prioritised. This has been missed somewhat with the 6 SNe listed in Table 1 and we wish to extend our fast response programme started in Cycle 10. We have shown we can get results very quickly, with the observations for 1999gi taken in March 2001, and an ApJ Letter accepted in June. The quick detection of a progenitor will allow a SN to be studied in great detail, and such an opportunity would be missed if we were to wait until the next Cycle. Also note we are not attempting a monitoring campaign, or rapid turn around observations - this is being successfully done by the SINS group. Our proposal is totally geared towards exploiting the archive and identifying progenitors, as shown in the above two examples. We will only request observations if we already have a WFPC2/WFPC archive image which contains the SN position in the FOV. How many total orbits we require will be determined by the discovery rate and the coincidence probability. This has been estimated in Smartt et al. (2001b) and we briefly summarise the arguments here. The SN rates from Cappellaro et al. (1999) suggest the rate of core- collapse SN in typical Sbc-Sd spirals is 1.00+/-0.31 SN (100yr)^-1 (10^10L_odot^B)^-1. Within ~20 Mpc there will be at least ~400 spirals with HST WFPC2 images in the archive by the end of Cycle 10, and this will continue to rise due to other projects observing the same targets for different primary science goals. Hence assuming these archived galaxies have a mean luminosity of 10^10L_odot^B, we expect ~4.0 +/- 1 core-collapse SNe per year to be discovered in this sample. The completion rate of discovery of SNe in these galaxies by the combined efforts of various teams around the world has increased rapidly and is now close to 100\ SN on the WFPC2 FOV, we expect ~2.0 +/- 1 per year. Hence we request 3(targets)*2(orbits per target) = 6 orbits for Cycle 11. This is a rather modest investment in time in order to fully exploit the wealth and unique historical value of the HST 9353( 4) - 12/10/02 06:45 - [ 4] archive. Real Time Justification ----------------------- noindent Future SN:, We request that if future SN are discovered with already existing material in the archive then we are allocated time at a suitable date in the future. As explained in the previous sections we do not need rapid turn around at all, hence it is not a ``true TOO'' and can easily be scheduled into routine telescope observations at several weeks notice. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 5] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2001B EXT-STAR, SUPERNOVA RA=04H 57M 19.24S +/- 2", J2000 V = 23+/-2 TYPE IB, SUPERNOVA, DEC=78D 11' 16.5" +/- 2" GALAXY, SPIRAL Coordinate Source: Other_Source: CFA/Asiago catalogues 2 SN2000EW EXT-STAR, SUPERNOVA, RA=11H 40M 58.52S +/- 2", J2000 V = 23+/-2 GALAXY, SPIRAL DEC=11D 27' 55.9" +/- 2" Coordinate Source: Other_Source: CFA/Asiago catalogues 3 SN2000DS EXT-STAR, SUPERNOVA, RA=09H 11M 36.24S +/- 2", J2000 V = 23+/-2 GALAXY, SPIRAL DEC=60D 1' 42.2" +/- 2" Coordinate Source: Other_Source: CFA/Asiago catalogues 4 SN1999EV EXT-STAR, SUPERNOVA, RA=12H 19M 48.33S +/- 2", J2000 V = 23+/-2 GALAXY, SPIRAL DEC=29D 37' 22.2" +/- 2" Coordinate Source: Other_Source: CFA/Asiago catalogues 5 SN1999BR EXT-STAR, SUPERNOVA, RA=13H 0M 41.80S +/- 2", DEC=02D J2000 V = 23+/-2 SUPERNOVA TYPE II, 29' 45.8" +/- 2" GALAXY, SPIRAL Coordinate Source: Other_Source: CFA/Asiago catalogues 6 SN1999AN EXT-STAR, SUPERNOVA, RA=12H 1M 10.57S +/- 2", DEC=14D J2000 V = 23+/-2 SUPERNOVA TYPE II, 6' 12.3" +/- 2" GALAXY, SPIRAL Coordinate Source: Other_Source: CFA/Asiago catalogues 7 SN1993J EXT-STAR, SUPERNOVA, RA=09H 55M 25.0S +/- 2", DEC=69D J2000 V = 23+/-2 GALAXY, SPIRAL 1' 13.0" +/- 2" Coordinate Source: Other_Source: CFA/Asiago catalogues 9353( 4) - 12/10/02 06:45 - [ 6] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 8 SN2002XX EXT-STAR, SUPERNOVA OTHER: FUTURE SUPERNOVA V = 15+/-2 ------------------------------------------------------------------------------------------------------------------------------------ 9 SN2002XY EXT-STAR, SUPERNOVA OTHER: FUTURE SUPERNOVA V = 15+/-2 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2003XZ EXT-STAR, SUPERNOVA OTHER: FUTURE SUPERNOVA V = 15+/-2 ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 7] Visit: 01 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2001B ACS/WF ACCUM WFC1 F555W CR-SPLIT=2 1 700 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN2001B ACS/WF ACCUM WFC1 F435W CR-SPLIT=2 1 800 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN2001B ACS/WF ACCUM WFC1 F814W CR-SPLIT=2 1 700 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 8] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 01-May-2002 AND 01-Feb-2003 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2000DS ACS/WF ACCUM WFC1 F555W CR-SPLIT=2 1 700 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN2000DS ACS/WF ACCUM WFC1 F814W CR-SPLIT=2 1 700 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN2000DS ACS/WF ACCUM WFC1 F435W 1 680 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 9] Visit: 03 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999EV ACS/WF ACCUM WFC1 F555W CR-SPLIT=2,SIZEAXIS2=2046 1 450 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999EV ACS/WF ACCUM WFC1 F814W CR-SPLIT=2,SIZEAXIS2=2046 1 450 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999EV ACS/WF ACCUM WFC1 F435W CR-SPLIT=2,SIZEAXIS2=2046 1 400 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 10] Visit: 04 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2000EW ACS/WF ACCUM WFC1 F555W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN2000EW ACS/WF ACCUM WFC1 F814W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN2000EW ACS/WF ACCUM WFC1 F435W CR-SPLIT=2,SIZEAXIS2=2046 1 400 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 11] Visit: 05 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999AN ACS/WF ACCUM WFC1 F555W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999AN ACS/WF ACCUM WFC1 F814W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999AN ACS/WF ACCUM WFC1 F435W CR-SPLIT=2,SIZEAXIS2=2046 1 400 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 12] Visit: 06 Visit Priority: Visit Requirements: BETWEEN 01-May-2002 AND 01-Feb-2003 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999BR ACS/WF ACCUM WFC1 F555W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999BR ACS/WF ACCUM WFC1 F814W CR-SPLIT=2,SIZEAXIS2=2046 1 430 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999BR ACS/WF ACCUM WFC1 F435W CR-SPLIT=2,SIZEAXIS2=2046 1 400 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 13] Visit: 07 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1993J ACS/HR ACCUM HRC F250W CR-SPLIT=3 1 2100 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1993J ACS/HR ACCUM HRC F330W CR-SPLIT=2 1 1200 S C ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1993J ACS/HR ACCUM HRC F435W CR-SPLIT=2 1 1000 S C ------------------------------------------------------------------------------------------------------------------------------------ 40 SN1993J ACS/HR ACCUM HRC F555W CR-SPLIT=2 1 1120 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 14] Visit: 08 Visit Priority: Visit Requirements: ON HOLD On Hold Comments: Target of opportunity 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2002XX ACS/WF ACCUM WFC1 F555W 1 500 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 15] Visit: 09 Visit Priority: Visit Requirements: ON HOLD On Hold Comments: Target of opportunity 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2002XY ACS/WF ACCUM WFC1 F555W 1 500 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 16] Visit: 10 Visit Priority: Visit Requirements: ON HOLD On Hold Comments: Target of opportunity 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 SN2003XZ ACS/WF ACCUM WFC1 F555W 1 500 S C ------------------------------------------------------------------------------------------------------------------------------------ 9353( 4) - 12/10/02 06:45 - [ 17] Summary Form for Proposal 9353 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1 HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 SIZEAXIS2=2046 CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-May-2002 AND 01-Feb-2003 ON HOLD ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F435W F814W F250W F330W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2001B SN2000DS SN1999EV SN2000EW SN1999AN SN1999BR SN1993J SN2002XX SN2002XY SN2003XZ ------------------------------------------------------------------------------------------------------------------------------------