5833( 6) - 09/07/95 10:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5833 Version: 6 Check-in Date: ********** 1.Proposal Title: The nature of the Lyman alpha emission from galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Galaxies & Clusters GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: James Lequeux Observatoire de Paris CoI: Angeles Diaz-Beltran Universidad Autonoma de Madrid N CoI: Michael Fall Space Telescope Science Institute N CoI: Daniel Kunth Institut d'Astrophysique de Paris N CoI: Miguel Mas-Hesse Laboratorio de Astrofisica Espacial y N Fisica Fundamental , Madrid CoI: Elena Terlevich Institute of Astronomy; University of N Cambridge CoI: Roberto Terlevich Royal Greenwich Observatory N ------------------------------------------------------------------------------------ 6. Abstract Lyman alpha photons are produced in abundance in HII regions but their escape from galaxies is problematic. This is an important problem as the observed Lyman alpha emission is often used as a tracer of massive star formation in distant galaxies and in searches for protogalaxies. We have recently obtained a GHRS spectrum of the HII galaxy Haro 2 around Lyman alpha and OI 1302Angstrom . We found a neutral galactic wind which produces Lyman alpha and OI absorptions and expands at 150 kms. We also see Lyman alpha in emission but redshifted by 140 kms with respect to the HII region. Either this line peeps out through a hole in the neutral wind, or much more probably the high-velocity photons escape because there is little matter at this velocity, in any case after considerable scattering in the neutral hydrogen. This unique observation opens new insights into the emission of Lyman alpha by galaxies. We now propose to study the profile and measure the relative velocity of the (known) Lyman alpha emission in other HII galaxies with respect to that of the neutral gas in front of the HII region and to that of the HII region itself, using the same method as for Haro 2. Our sample contains 3 galaxies. The comparison between these results should yield a definitive understanding of how Lyman alpha radiation leaves galaxies. ------------------------------------------------------------------------------------ 5833( 6) - 09/07/95 10:49 - [ 2] Observations Description ------------------------ All the galaxies we are proposing have been observed with IUE, and their redshifts were high enough to separate the intrinsic Lyman alpha emission line from the geocoronal Lyman alpha. From the flux we have measured in the continuum we can easily compute the exposure time needed to reach a S/N=10 for the brighter objects in the 1215A range . Such a S/N in the continuum is necessary in order to be able to detect STRUCTURES such as the broad absorption in the blue wing of the Lyman alpha line in Haro 2 spectrum. A similar S/N of 10 is demanded to measure the position and the width of the OI position as explained above. We can achieve such a S/N by binning over 4 diodes without loosing much resolution since the objects are much more extended than the LSA. Our targets have IUE fluxes around 4E-14 erg/sec/cm**2/Angstrom at 1300Angstrom and have redshifts large enough to allow for a small correction going from IUE aperture to LSA aperture. We assume a correction factor of about 2 to estimate their continuum flux in the LSA, although it is clear that this procedure remains uncertain. Using Haro 2 as a reference target, as well as the figures given in the GHRS Instrument Handbook (for the efficiency of G160M and taking into account the dark noise) we come with the following results:, S/N=10 after binning over 4 diodes will be obtained in 1.8 H at 1216Angstrom, S/N=10 after binning over 4 diodes will be obtained in 1.4 H at 1300Angstrom. Due to guide star and target acquisitions and the necessary overheads these exposure times translate into 5 orbits per target. Real Time Justification ----------------------- Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5833( 6) - 09/07/95 10:49 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ESO003426- GALAXY RA = 00H 36M 52.28S +/- 0.2", J2000 V = B=14.27 +/- 0.21 B-V = 0.0 +/- 0.2 F- 3349 DEC = -33D 33' 18.19" +/- 0.2" +6156 CONT(1285)= 2.0 +/- 0.5 E-14 Comments: THIS IS THE EXPECTED FLUX IN THE LSA APERTURE 2 ESO203431- GALAXY RA = 20H 37M 41.87S +/- 0.2", J2000 V = B=14.22 +/- 0.21 B-V = 0.0 +/- 0.2 F- 3539 DEC = -35D 29' 06.4" +/- 0.2" +5900 CONT(1285)= 2.0 +/- 0.5 E-14 Comments: THIS IS THE EXPECTED FLUX IN THE LSA APERTURE 3 IRAS08339+65 GALAXY RA = 08H 38M 23.20S +/- 0.2", J2000 V = B=14.16 +/- 0.3 B-V = 0.0 +/- 0.2 F- 17 DEC = 65D 07' 15.0" +/- 0.2" +5608 CONT(1285)= 2.0 +/- 0.5 E-14 Comments: THIS IS THE EXPECTED FLUX IN THE LSA APERTURE 5833( 6) - 09/07/95 10:49 - [ 4] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 ESO003426- HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN, 1 125S ONBOARD ACQ FOR 2-3 3349 SEARCH-SIZE=5, LOCATE=EXTENDED Comments: STEP-TIME = 5 s ------------------------------------------------------------------------------------------------------------------------------------ 2 ESO003426- HRS ACCUM 2.0 G160M 1241 STEP-PATT=DEF, 6 1193.4S 3349 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 3 ESO003426- HRS ACCUM 2.0 G160M 1330 STEP-PATT=DEF, 4 1176S 3349 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 5833( 6) - 09/07/95 10:49 - [ 5] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 4 ESO203431- HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN, 1 125S ONBOARD ACQ FOR 5-6 3539 SEARCH-SIZE=5, LOCATE=EXTENDED Comments: STEP-TIME = 5 s ------------------------------------------------------------------------------------------------------------------------------------ 5 ESO203431- HRS ACCUM 2.0 G160M 1240 STEP-PATT=DEF, 6 1204.2S 3539 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 6 ESO203431- HRS ACCUM 2.0 G160M 1330 STEP-PATT=DEF, 4 1200S 3539 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 5833( 6) - 09/07/95 10:49 - [ 6] Visit: 03 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 ------------------------------------------------------------------------------------------------------------------------------------ 7 IRAS08339+6 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN, 1 125S ONBOARD ACQ FOR 8-9 517 SEARCH-SIZE=5, LOCATE=EXTENDED Comments: STEP-TIME = 5 s ------------------------------------------------------------------------------------------------------------------------------------ 8 IRAS08339+6 HRS ACCUM 2.0 G160M 1239 STEP-PATT=DEF, 6 1350S 517 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 9 IRAS08339+6 HRS ACCUM 2.0 G160M 1327 STEP-PATT=DEF, 4 1200S 517 COMB=FOUR, DOPPLER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 5833( 6) - 09/07/95 10:49 - [ 7] Summary Form for Proposal 5833 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=5 LOCATE=EXTENDED DOPPLER=DEF COMB=FOUR STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Galaxies & Clusters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2-3 ONBOARD ACQ FOR 5-6 ONBOARD ACQ FOR 8-9 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names ESO003426-3349 ESO203431-3539 IRAS08339+6517 ------------------------------------------------------------------------------------------------------------------------------------