Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2290c Report Date: 09-May-96:17:01 Version: ********** Check-in Date: ********** 1.Proposal Title: CHEMICAL ABUNDANCES IN LOCAL GROUP SUPERNOVA REMNANTS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID INTERSTELLAR MEDIUM GO Sub Category SN & SNR ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Michael A. Dopita MT. STROMLO AND SIDING SPRIN AUSTRALIA (011 61) 62-49 SENIOR FELLOW ------------------------------------------------------------------------------------ 7. Abstract There is an increasing body of data, based on abundance analyses of the interstellar medium, which suggests that Local Group disk galaxies have had a star-formation history which is quite different from the region of the Galaxy about the sun. For example, the solar region appears to have undergone a burst of high-mass star formation at the time of disk collapse, unlike Local Group systems of low metallicity. The evolved, radiative supernova remnants (SNR) can be used as a powerful probe of the chemical abundances in the Interstellar Medium (ISM). This proposal is to obtain FOS UV spectrophotometry of the brightest radiative SNR discovered by us in Local Group Galaxies. This data will complement our ground-based data in the optical to give abundances of a variety of elements with different nucleogenic origins. The data to be obtained in the LMC will complement the abundance analysis of the spectra of many supergiant stars, already performed, to give us a complete picture of the "cosmic" abundances of most ------------------------------------------------------------------------------------ 8. Scientific Key Words: ASTROPHYSICS:EVOLUTION,STELLAR POPULATION,ABUNDANCE, ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 8.00 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2290c PI: Dr. Michael A. Dopita Proposal Title: CHEMICAL ABUNDANCES IN LOCAL GROUP SUPERNOVA REMNANTS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr Ian R Tuohy MT. STROMLO AND SIDING SPRING AUSTRALIA OBSERVATORIES Prof Donald S Mathewson MT. STROMLO AND SIDING SPRING AUSTRALIA OBSERVATORIES Dr Stephen C Russell MT. STROMLO AND SIDING SPRING AUSTRALIA OBSERVATORIES Dr Piero Benvenuti SPACE TELESCOPE COORDINATING X FACILITY Dr John I Danziger EUROPEAN SOUTHERN OBSERVATORY X Dr Sandro D'Odorico EUROPEAN SOUTHERN OBSERVATORY X Dr Francesca Matteucci EUROPEAN SOUTHERN OBSERVATORY X Dr Roger Chevalier UNIVERSITY OF VIRGINIA USA Dr Michael A. Dopita MT. STROMLO AND SIDING SPRING AUSTRALIA OBSERVATORIES ------------------------------------------------------------------------------------ 3. Description of proposed observations. We are proposing to obtain FOS spectra (between 1500 and 2332 angstroms) of radiative SNR in several nearby galaxies. A signal to noise of 4 per angstrom in the continuum is sought. A total of eight SNR in four galaxies have been targetted. Of these, three are in each of the LMC and M33, and are broadly distributed across the face of their parent galaxy. Whilst available data leads us to expect that abundance gradients across the LMC are negligible, an appreciable abundance gradient exists in M33. Thus, in this case, we should be able to assess the variability in relative chemical yields as a function of position in the galaxy. For the massive precursor stars of these Type II SNR, it is possible that pre-supernova mass-loss allows a certain enrichment of the surrounding ISM in nitrogen. The data obtained in the LMC will allow us to check out this possibility. Furthermore, this data will be complemented by the fine analysis of the spectra of many Supergiant stars in these galaxies (Russell and Bessell 1988). The LMC SNR; N49 and a single SNR in M33 has been targetted by the GTO proposal #1048. This data is not of limited utility to our program, since the exposure times are too short to allow an accurate determination of the equivalent widths of lines against the two-photon continuum, which is a prime objective of our proposal. Nevertheless, we have avoided selecting these objects for this proposal. The remaining dwarf Magellanic galaxy; IC1613 and the late- type spirals NGC300 and M33 cover a metallicity range from about 1 : 30 solar (1 : 4 SMC) up to about 1: 2 solar. We therefore cover a wide range of chemical evolutionary stages, and therefore expect to be able to reach meaningful conclusions about the dependence of IMF and star formation history on the galaxian environment. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Although valiant attempts have been made to use IUE, this satellite lacks the sensitivity and resolution to carry through the sort of program we are proposing. The results that have been obtained are interesting, but not definitive. We have obtained exhausive spectrophotometry in the optical, but the interpretation of this data remains ambiguous until UV data for important coolants such as C, N, O and Si have been obtained. It is vital for a program that we measure the equivalent widths of the lines against the nebular continuum, which arises principally from the two-photon continuum of hydrogen. By this method, we propose to eliminate the considerable errors resulting from assumed reddening and uncertainties in the form of the extinction law for the particular galaxy (it is well-known that the form of the reddening law is strongly dependent on metallicity and on the local environment). Only the FOS on the HST has the sensitivity and dynamic range for this purpose. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Our program, covering five objects in three galaxies, is configured to sample the brightest radiative SNR, and to cover the widest possible range of metallicity. Our exposure times have been chosen so as to allow measurement of the nebular continuum to < 3% in bins of 100 angstroms. Since this nebular continuum is strongly dominated by the collisionally-enhanced two-photon continuum of Hydrogen (D'Odorico et.al. 1980), the equivialent widths of the emission lines can be used to derive the absolute intensity of these lines with respect to H-beta. This has the great advantage that neither the reddening curve, nor the absolute value of the reddening need be accurately known. In the 1200- 2000 band, the integrated flux in the continuum and in the emission lines is expected to be about equal. The continuum fluxes at 1650 have been computed on the basis of the observed H-beta flux, the observed extinction and using theoretical models. IC 1613 was assumed to have an SMC-like extinction law and the other galaxies an LMC-like law. Using the Newsletter sensitivity figures, the FOS counts / second / angstrom, N, the effextive no. of angstroms transmitted by the aperture used, Aap, and the flux at 1650, F1650,, are related by: log(N) = 13.59 +log(F1650) +log(Aap). This formula represents the basis of the exposure time calculations, which aim to give a mean signal / noise of 3 per angstrom, or 30 per 100 angstrom. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Since we require to measure a very faint continuum, these targets would benefit from dark time. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. The MSSSO investigators will have the prime responsibility for the analysis phase of the HST observations. It is anticipated that the reduction of the raw data will be performed at STScI, however, we have installed the IRAF system at MSSSO, so that local analysis is possible. Analysis of calibrated HST data will be undertaken at MSSSO where the hardware environment (network of Vax 11/780, MicroVax computers and Sun Workstations with a variety of image and spectral reduction packages) is more than adequate for this task. The chemical abundances will be derived at MSSSO, using theoretical modelling based on the code MAPPINGS developed by Dopita and his collaborators. For this purpose, the FOS data will be combined with optical data in the range 3300 - 10000 angstroms, to give a complete table of reddening-corrected line intensities with respect to H-beta. The interpretation and theoretical modelling of the results in terms of galactic evolution theory, and the subsequent preparation of papers will be the joint responsibility of the team. Communications are to be maintained by e-mail, telephone and by overseas travel as necessary. Page 4 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). The manpower, fiscal and hardware resources necessary to carry through the reduction and interpretation of the data will be supplied within the internal budget of MSSSO as necessary. Funding will also be available to support any short overseas visits that may be necessary to coordinate team members' activities. Similar facilities and arrangements will also be put in hand at ESA. ------------------------------------------------------------------------------------ 11. Address Information Name: MICHAEL A DOPITA Category: PI Institution: MT. STROMLO AND SIDING SPRING OBS Address: PRIVATE BAG WODEN P.O. City: CANBERRA State: Zip Code: 2606 Country: AUSTRALIA Telephone: (011 61) 62 49-0212 Telex (or e-mail): AA 62270 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2290c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 IC1613-S8 ISM; SNR IN IC1613 RA = 01H 02M 28.3S +/- 0.1S, 1950.0 V=250 EXT 1 SURF-LINE(4861) = 6.0 +/- 1.5 E-15 SA8 DEC = +01D 52' 36" +/- 1" 2 SURF-CONT(1650) = 9.0 +/- 4.0 E-17 3 SURF-CONT(5500) = 1.5 +/- 1.0 E-13 4 W-LINE(4861) = 1.0, SIZE = 4.5 ------------------------------------------------------------------------------------------------------------------------------------ 2 M33-DBB6 ISM; SNR IN M33 RA = 01H 30M 40.0S +/- 0.1S, 1950.0 V=250 EXT 1 SURF-LINE(4861) = 2.5 +/- 0.5 E-15 013040+30269 DEC = 30D 26' 55" +/- 1" 2 SURF-CONT(1650) = 5.0 +/- 2.0 E-17 3 SURF-CONT(5500) = 6.0 +/- 4.0 E-14 4 W-LINE(4861) = 1.0, SIZE = 4.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 LMC-N103B SUPERNOVA REMNANT IN RA = 05H 09M 13.0S +/- 0.1S, 1950.0 V=250 EXT 1 SURF-LINE(4861) = 3.0 +/- 1.0 E-15 LMC DEC = -68D 47' 15" +/- 1" 2 SURF-CONT(1650) = 5.4 +/- 2.5 E-17 3 SURF-CONT(5500) = 8.0 +/- 4.0 E-14 4 W-LINE(4861) = 1.0, SIZE = 4.5 ------------------------------------------------------------------------------------------------------------------------------------ 5 LMC-N63A SUPERNOVA REMNANT IN RA = 05H 35M 38.4S +/- 0.1S, 1950.0 V=250 EXT 1 SURF-LINE(4861) = 2.6 +/- 1.0 E-15 LMC DEC = -66D 03' 46.4" +/- 1" 2 SURF-CONT(1650) = 5.0 +/- 2.5 E-17 3 SURF-CONT(5500) = 6.0 +/- 3.0 E-14 4 W-LINE(4861) = 1.0, SIZE = 14.0 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2290c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE # FOS/RD ACQ/ 4.3 MIRROR TYPE=UP # 1S 17 3 # GETOBJ PEAK SEARCH-SIZE=4 SCAN-STEP=1 Comments: USED FOR PEAKUP ON MILDLY EXTENDED SNRS. FLUXNUM-3, ESTIMATED TOTAL FLUX FOR THE OBJECT (LINES +CONT). ------------------------------------------------------------------------------------------------------------------------------------ 3 DEFINE # FOS/BL ACCUM 1.0 G130H 1300 # 1S # 2 # FOS130 Comments: LATEST SENSITIVITY FIGURES USED FOR EXPOSURE AND S/N CALCS. ------------------------------------------------------------------------------------------------------------------------------------ 4 DEFINE # FOS/RD ACCUM 1.0 G190H 1900 # 1S # 2 # FOS190 Comments: LATEST SENSITIVITY FIGURES USED FOR EXPOSURE AND S/N CALCS. ------------------------------------------------------------------------------------------------------------------------------------ 5 DEFINE # FOS/RD ACCUM 1.0 PRISM 5007 # 1S # 1 # FOSCAL Comments: LATEST SENSITIVITY FIGURES USED FOR EXPOSURE AND S/N CALCS. ------------------------------------------------------------------------------------------------------------------------------------ 10 USE IC1613-S8 1 X30 2 SEQ 10 - 13 NO GAP GETOBJ ONBOARD ACQ FOR 11 - 13 CYCLE 1 DARK TIME / 10-53 ------------------------------------------------------------------------------------------------------------------------------------ 11 USE IC1613-S8 2 X1100 40 2 CYCLE 1 FOSCAL 2200S ------------------------------------------------------------------------------------------------------------------------------------ 12 USE IC1613-S8 2 X1100 5 2 CYCLE 1 FOS190 2200S ------------------------------------------------------------------------------------------------------------------------------------ 13 USE IC1613-S8 2 X2000 4 2 CYCLE 1 FOS130 3600S ------------------------------------------------------------------------------------------------------------------------------------ 20 USE M33-DBB6 1 X40 4 SEQ 20 - 23 NO GAP GETOBJ ONBOARD ACQ FOR 21 - 23 CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 21 USE M33-DBB6 2 X1200 30 4 CYCLE 1 FOSCAL 2400S ------------------------------------------------------------------------------------------------------------------------------------ 22 USE M33-DBB6 2 X1200 4 4 CYCLE 1 FOS190 2400S ------------------------------------------------------------------------------------------------------------------------------------ 23 USE M33-DBB6 2 X2000 4 4 CYCLE 1 FOS130 3000S ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2290c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 40 USE LMC-N103B 1 X10 2 SEQ 40 - 43 NO GAP GETOBJ ONBOARD ACQ FOR 41 - 43 CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 41 USE LMC-N103B 2 X1200 30 2 CYCLE 1 FOSCAL ------------------------------------------------------------------------------------------------------------------------------------ 42 USE LMC-N103B 2 X1200 4 2 CYCLE 1 FOS190 ------------------------------------------------------------------------------------------------------------------------------------ 43 USE LMC-N103B 2 X1700 4 2 CYCLE 1 FOS130 3000S ------------------------------------------------------------------------------------------------------------------------------------ 51 USE LMC-N63A 1 X2000 30 1 SEQ 51 - 53 NO GAP FOSCAL CYCLE 1 Comments: NO ACQ EXPOSURE NEEDED SINCE TARGET IS 20 ARCSEC ACROSS. ------------------------------------------------------------------------------------------------------------------------------------ 52 USE LMC-N63A 1 X2000 4 1 CYCLE 1 FOS190 ------------------------------------------------------------------------------------------------------------------------------------ 53 USE LMC-N63A 2 X1750 4 1 CYCLE 1 FOS130 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2290c [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters TYPE SEARCH-SIZE SCAN-STEP ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 8.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category SN & SNR ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 10 - 13 NO GAP; ONBOARD ACQ FOR 11 - 13; CYCLE 1; DARK TIME / 10-53 CYCLE 1 SEQ 20 - 23 NO GAP; ONBOARD ACQ FOR 21 - 23; SEQ 40 - 43 NO GAP; ONBOARD ACQ FOR 41 - 43; SEQ 51 - 53 NO GAP; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G130H G190H PRISM ------------------------------------------------------------------------------------------------------------------------------------ Target Names IC1613-S8 SA8 M33-DBB6 013040+30269 LMC-N103B LMC-N63A ------------------------------------------------------------------------------------------------------------------------------------