8112( 7) - 11/01/99 13:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8112 Version: 7 Check-in Date: 01-Nov-1999 13:57:24 1.Proposal Title: Probing the Galactic Halo and Beyond with Young Supernovae ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: George Sonneborn NASA Goddard Space Flight Center CoI: Dr. Peter Garnavich Harvard College Observatory N CoI: Dr. Kenneth Sembach The Johns Hopkins University N CoI: Dr. C. S. Jason Pun NASA/Goddard Space Flight Center N CoI: Dr. Rosina C. Iping University of Guam N ------------------------------------------------------------------------------------ 5. Abstract We propose a Target of Opportunity program to obtain STIS echelle spectra of a bright new supernova (V<14) to characterize the ionization state, gas-phase abundances, depletion on dust grains, metallicity, and gas kinematics in the Galactic halo, the ISM and halo of the SN's host galaxy, and, if the properties of the sightline are favorable, in the intervening intergalactic medium. The principal spectral region for this study is the far ultraviolet (1200-1700A), which provides a comprehensive set of lines to study the hot, warm, and cool phases of the ISM. Near- UV spectra will provide Zn II and Cr II line profiles with which to assess gas-phase depletion. New core-collapse supernovae, with their strong, nearly featureless UV continua, provide outstanding opportunities to obtain high-quality absorption line spectra of the gas on the line of sight to the SN, but only if the observations are executed within ~2 weeks of outburst. Our team has the experience and extensive ground-based support to rapidly assess the suitability of each newly-discovered supernova for this program and provide all the necessary data to efficiently implement the proposed observations, as demonstrated by our successful STIS low resolution UV spectra of SN 1998S in Cycle 7. ------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 2] Observations Description ------------------------ We have designed a simple observing program that can be implemented quickly once a bright supernova (V<14) has been discovered and determined to be suitable for our program, a process which takes about a day. Because visits using the STIS MAMA detectors must be quantized in units of 5-6 orbits, this sets a logical limit to the length of any exposures which need to be scheduled and executed on short notice. We plan one 5-orbit visit to use E140M and a second 5-orbit visit to use E140M and E230M/2269. The second E140M exposure provides a check on possible absorption line variability, the signature of significant circumstellar gas being swept up or ionized by the supernova shock front between Visits 1 and 2. We use the 0.2x0.2 slit to simplify target acquisition and maximize throughput. The highest priority is to schedule the E140M visit as soon as possible because the rapid UV flux decrease is faster at shorter wavelengths. The second visit should be scheduled within 5 days of Visit 1. The total time requested is 10 orbits (2 MAMA visits). Our ability to obtain confirmation and early optical spectra of any newly discovered bright (V<14) supernova, northern or southern hemisphere, within a day of discovery makes our program's chances of success very high. Our high resolution observations will be coordinated with the SINS program, which seeks STIS low resolution UV spectra to study the SN itself. The expected S/N of the proposed observations has been evaluated for the 16 March STIS G140L and G230L spectra of SN 1998S, 12 days after discovery and 11 days after TOO program activation. Figure 2 shows that if our proposed program had been executed then, we would have achieved S/N = 15-19 (t=12500 sec) over most of the E140M spectral range and S/N = 20-40 for E230M (2269: t=7500 sec) at full spectral resolution (~ 10kms). These exposure times fit in two 5-orbit visits and include all acquisition and instrument overhead. Figure 2 also shows that with the same exposure times we could achieve S/N>10 over the E140M bandpass and S/N=15-35 for E230M for two limiting cases: 1) the SN is one magnitude fainter in the UV than SN 1998S (and still achieve 10kms resolution) and 2) the SN has extinction DeltaE(B-V)=+0.2 mag greater than SN 1998S. In the latter case we would bin the spectra by 2X to achieve a spectral resolution of ~20kms. Real Time Justification ----------------------- Target of opportunity: The need for a prompt response by HST is illustrated by the HST/STIS low resolution spectra obtained for SN 1998S by the SINS program last spring (see Fig. 1). As described in the scientific justification section, the important lines lie at the shorter UV wavelengths, which are the first to fade as a new SN ages. For SN 1998S, we estimate that we could have achieved good S/N at full spectral resolution if the proposed observing program had been executed as late as 20 March 1998 (16 days after discovery). MAMA detector safety. The STIS spectra of SN 1998S show that this SN is essentially unreddened. We can therefore predict the maximum UV flux of a new SN based on its V magnitude and age. Other SNe have been observed in the UV (IUE) at earlier epochs (e.g. SN 1987A at 1 day and 1993J at 1.5 days). Unless the new SN occurs in a Local Group galaxy, the MAMA bright limits will not be reached for the medium resolution echelle modes. In the rare event that the new SN has V<10 (F_1400>2* 10^-12\ergcmsA), we would switch to the E140H and E230H gratings and adjust exposure times accordingly. The availability of observations at other facilities when the proposed HST TOO observations are made are not necessary for the success of the proposed program. However, we expect the following observations to enhance and complement this program. FUSE: Two of us (GS and KS) plan FUSE GTO observations of newly discovered SNe, which will be planned and activated in the same manner as this program. It is possible that FUSE observations may be made earlier than with HST since the FUSE TOO response time is expected to be ~48 hours. Ground based observations: CfA/Mt. Lemmon, Apache Point, CTIO, etc. provide photometry and spectra of new supernovae as they are discovered, as well as spectra contemporaneous with the HST observations. Co-I Garnavich coordinates these observations for the Harvard supernova group, including the HST SINS team. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 3] Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 101 SN1999EM EXT-STAR, SUPERNOVA RA=04H 41M 27.06S +/- 0.03S, J2000 V = 13.7 TYPE II DEC=-02D 51' 45.68" +/- 0.7" U = 12.6 E(B-V) = 0.2+/-0.07 Comments: Magnitudes are epoch 31 Oct 1999. SN is brightening and is still blue. 8112( 7) - 11/01/99 13:58 - [ 5] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 100 SN1999XX STAR, SUPERNOVA, V = 12 SUPERNOVA TYPE II B = 12 Comments: Target of Opportunity. Precise coordinates to be specified within 1-2 days after discovery. ------------------------------------------------------------------------------------------------------------------------------------ 200 SN1999YY STAR, SUPERNOVA, V = 9 SUPERNOVA TYPE II B = 9 Comments: Target of Opportunity. Precise coordinates to be specified within 1-2 days after discovery. ------------------------------------------------------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 6] Visit: 01 Visit Priority: Visit Requirements: SEQ 01, 02 WITHIN 5 D VISIBILITY INTERVAL 53M On Hold Comments: Additional Comments: FUV echelle E140M observations. To be executed before VISIT 02. Target of Opportunity Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999EM STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P Comments: Acquisition of the target. Exposure time based on V=12, B-V=0.00 ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999EM STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO,PATTERN=ALONG-SLIT, 1 60 S CD P NUM-POS=2,STEP-SIZE=0.5, PATTERN-DIRECTION=PLUS Comments: Determine HST pointing position ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2000 S UV-MAM A Comments: Exposure 1 of 5 ------------------------------------------------------------------------------------------------------------------------------------ 40 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2840 S UV-MAM A Comments: Exposure 2 of 5. ------------------------------------------------------------------------------------------------------------------------------------ 50 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2840 S UV-MAM A Comments: Exposure 3 of 5. ------------------------------------------------------------------------------------------------------------------------------------ 60 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2840 S UV-MAM A Comments: Exposure 4 of 5. ------------------------------------------------------------------------------------------------------------------------------------ 70 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2840 S UV-MAM A Comments: Exposure 5 of 5. ------------------------------------------------------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 7] Visit: 02 Visit Priority: Visit Requirements: AFTER 01 SEQ 01, 02 WITHIN 5 D On Hold Comments: Additional Comments: NUV echelle E230M observations. VISIT 02 is to be executed after VISIT 01. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999EM STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P Comments: Target acquisition. ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999EM STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO,PATTERN=ALONG-SLIT, 1 60 S CD P NUM-POS=2,STEP-SIZE=0.5, PATTERN-DIRECTION=PLUS Comments: Determine HST pointing position. ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999EM STIS/N ACCUM 0.2X0.2 E230M 2269 1 2050 S UV-MAM A Comments: NUV short wavelength exposure 1 of 3. ------------------------------------------------------------------------------------------------------------------------------------ 40 SN1999EM STIS/N ACCUM 0.2X0.2 E230M 2269 1 2900 S UV-MAM A Comments: NUV short wavelength exposure 2 of 3. ------------------------------------------------------------------------------------------------------------------------------------ 50 SN1999EM STIS/N ACCUM 0.2X0.2 E230M 2269 1 2900 S UV-MAM A Comments: NUV short wavelength exposure 3 of 3. ------------------------------------------------------------------------------------------------------------------------------------ 60 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2550 S UV-MAM A Comments: FUV long wavelength exposure 1 of 2. ------------------------------------------------------------------------------------------------------------------------------------ 70 SN1999EM STIS/F ACCUM 0.2X0.2 E140M 1425 1 2900 S UV-MAM A Comments: FUV long wavelength exposure 2 of 2. ------------------------------------------------------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 8] Visit: 05 Visit Priority: Visit Requirements: ON HOLD SEQ 05, 06 WITHIN 10 D On Hold Comments: Target of Opportunity Additional Comments: For really bright (V < 10) supernova. FUV echelle E140H and NUV echelle E230H observations. VISIT 05 is to be executed before VISIT 06. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999YY STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 30-80 CD P Comments: Target acquisition. ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999YY STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO,PATTERN=ALONG-SLIT, 1 60 S CD P NUM-POS=2,STEP-SIZE=0.5, PATTERN-DIRECTION=PLUS Comments: Determine HST pointing position. ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1234 1 1900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1416 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1598 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2013 1 2000 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 70 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2513 1 1500 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 80 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2762 1 1400 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 9] Visit: 06 Visit Priority: Visit Requirements: AFTER 05 SEQ 05, 06 WITHIN 10 D On Hold Comments: Additional Comments: For really bright (V < 10) supernova. FUV echelle E140H and NUV echelle E230H observations. VISIT 06 is to be executed after VISIT 05. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 SN1999YY STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 30-80 CD P Comments: Target acquisition. ------------------------------------------------------------------------------------------------------------------------------------ 20 SN1999YY STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO,PATTERN=ALONG-SLIT, 1 60 S CD P NUM-POS=2,STEP-SIZE=0.5, PATTERN-DIRECTION=PLUS Comments: Determine HST pointing position. ------------------------------------------------------------------------------------------------------------------------------------ 30 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1234 1 1900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1416 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 SN1999YY STIS/F ACCUM 0.2X0.2 E140H 1598 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2013 1 2000 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 70 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2513 1 1500 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 80 SN1999YY STIS/N ACCUM 0.2X0.2 E230H 2762 1 1400 S MIN DUR 95% MAX DUR 100% UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8112( 7) - 11/01/99 13:58 - [ 10] Summary Form for Proposal 8112 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT PATTERN-DIRECTION=PLUS STEP-SIZE=0.5 NUM-POS=2 PATTERN=ALONG-SLIT ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 01, 02 WITHIN 5 D VISIBILITY INTERVAL 53M AFTER 01 SEQ 01, 02 WITHIN 5 D ON HOLD SEQ 05, 06 WITHIN 10 D ONBOARD ACQ FOR 30-80 MIN DUR 95% MAX DUR 100% AFTER 05 SEQ 05, 06 WITHIN 10 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M E230M E140H E230H ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN1999EM SN1999YY ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2269 1234 1416 1598 2013 2513 2762 ------------------------------------------------------------------------------------------------------------------------------------