Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3066c Report Date: 09-May-96:17:53 Version: ********** Check-in Date: ********** 1.Proposal Title: EMISSION LINES IN HIGH REDSHIFT QSOS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID QUASARS & AGN EROS Sub Category QUASAR EMISSION ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone E. margaret Burbidge UC, SAN DIEGO USA (619) 534-4477 ------------------------------------------------------------------------------------ 7. Abstract We will use the FOS to measure the strength of the He I lambda 584 line in the UV in a QSO which has a good probability of having light at that wavelength. We will demonstrate the ability of the FOS to detect weak emission lines against a background of weak absorption lines in a faint object with the degraded performance due to the slit losses, decreased resolution, possible increased scattered light and greater than expected particle-induced background. From this line we will determine the relative abundance of Helium in the early universe. ------------------------------------------------------------------------------------ 8. Scientific Key Words: UV SPECTROSCOPY, QUASAR, EMISSION LINE PROFILE, ABUNDANCE EVOLUTION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 2.19 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3066c PI: E. margaret Burbidge Proposal Title: EMISSION LINES IN HIGH REDSHIFT QSOS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Edward Beaver UC, SAN DIEGO USA E. Margaret Burbidge UC, SAN DIEGO USA Bruce Margon WASHINGTON, UNIVERSITY OF USA J. Roger P. Angel ARIZONA, UNIVERSITY OF USA Frank Bartko MARTIN MARIETTA CORPORATION USA Arthur F. Davidsen JOHNS HOPKINS UNIVERSITY USA Richard J. Harms APPLIED RESEARCH CORPORATION USA Ralph Bohlin SPACE TELESCOPE SCIENCE USA INSTITUTE Holland C. Ford SPACE TELESCOPE SCIENCE USA INSTITUTE ------------------------------------------------------------------------------------ 2. Scientific Justification. Observations of CSO 38 will yield a determination of the cosmic abundance of helium at a look back time of more than 75% of the age of the universe and characterize the ability of the FOS to measure weak emission lines in faint objects. We will determine the helium abundance by comparing the strength of the He I lambda 584 recombination line with the strengths of other emission lines which we will measure from the ground. The He I lambda 584 emission line has never been measured, and measurements of this line and HeII lambda 304 are important HST goals. Additionally, we may be able to set constraints on the ionization level of the intergalactic medium of the early universe, a major indicator of the constituent parts of the early universe. Determining the initial cosmic helium abundance can in principle refine our estimate of the baryon number of the universe. CSO 38 is one of the best objects available to us with which we can perform this test, both scientifically and from a technical standpoint. The FOS ability to measure emission lines differs from the performance predicted before launch in several ways. These include light loss, loss of resolution, and greater than predicted background. The signal-to-noise per diode for a 5900s exposure will be approximately 35, assuming that the 1.0 arc sec diameter FOS aperture transmits 33% of the incident light. We have also included a short exposure with the 4.3 arc second aperture to obtain an accurate flux for the scientific analysis. This will also be useful for testing the predicted light loss through the 1.0 arc second aperture. This observation will demonstrate the ability of the HST to take high quality spectra of high-redshift emission-line objects. ------------------------------------------------------------------------------------ 3. Description of proposed observations. This proposal contains 1 object which will be observed with G160L and the red detector of the FOS. S/N will be 20 per diode allowing us to detect a weak emission line. A very short exposure will be used to measure the absolute flux. All exposures are cycle 0. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The main point of this program is demonstrate the ability of the HST and FOS to observe high-redshift objects and to determine the Helium abundace in the early universe. The important emission lines for this determination cannot be measured from the ground or with IUE in any known object. Page 3 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The signal-to-noise calculation assumed transmission through the 1.0 arc second diameter aperture of 33% at 2100 Angstroms, and a total HST+FOS efficiency due to all other components of 3.4% with G160L at 2114 Angstroms. The particle-induced background is assumed to be 0.01 c/s/d. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. The OV prerequisite programs for all observations are: Prop ID 2188, 2189, 1441, 1442, and 1443 The SV prerequisite program for all observations is: Prop ID 2195 ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. To characterize the performance of the HST + FOS, we will measure the flux in a weak emission line, superposed on absorption, in the total observation as well as in shorter segments of the total integration. We will compare the flux levels in portions to check the particle-induced background subtraction. We will do spectral deconvolution to determine the effect of the decreased spectral resolution of the FOS on our observations. The abundance determination will be performed by comparing the measured emission-line strength to optical lines and the predictions of published models. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. We will schedule ground-based observations at Lick Observatory as close to the HST observations in time as possible in order to check FOS fluxes and obtain the strengths of optical emission lines for comparison. ------------------------------------------------------------------------------------ 11. Address Information Name: E. MARGARET BURBIDGE Category: PI Institution: UNIVERSITY OF CALIFORNIA, SAN DIE Address: CASS DEPT., C-011 City: LA JOLLA State: CA Zip Code: 92093 Country: USA Telephone: (619) 534-4477 Telex (or e-mail): FAX: (619) 534-6316 ------------------------------------------------------------------------------------ Name: ROSS D. COHEN Category: CON Institution: UNIVERSITY OF CALIFORNIA, SAN DIE Address: CASS DEPT., C-011 City: LA JOLLA State: CA Zip Code: 92093 Country: USA Telephone: (619) 534-2664 Telex (or e-mail): FAX: (619) 534-6316 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3066c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 CSO38 QUASAR RA = 10H 11M 55.599S +/- 2000 Z=2.62 1 V=16.0 +/- 0.5 1.0", DEC = 29D 41' 41.50" +/- 1.0", PLATE-ID = 021H ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3066c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 CSO38 FOS/RD ACQ/ 4.3 MIRROR TYPE=UP 1 1.2S 1 1 ONBOARD ACQ FOR PEAK 1.5 SPATIAL SCAN GROUP 1-4 WITHIN 60D CYCLE 0 / 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 1.5 CSO38 FOS/RD ACQ/ 4.3 MIRROR BRIGHT=700000 1 22S 1 1 ONBOARD ACQ FOR 2- BINARY 4 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ ^ ACQ ^ ^ 1 22S 1 ^ ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ ^ ACCUM 4.3 G160L 1600 STEP- 1 100S 5 ^ PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ ^ ACCUM 1.0 G160L 1600 STEP- 1 5900S 35 ^ PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 3066c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 1 Exposure Logsheet lines: 1 FGS Scan: DWELL Dwell Only: dwell points/line: 2 Seconds per dwell: 0.00 Scan width (arc-secs): 7.0000 Scan length (arc-secs): 4.3000 Angle between sides (degrees) 90.00 Number of lines: 6 Scan rate (arc-sec/sec): 0.0000 PA of first scan line (degrees) 90.000 Scan frame (CEL or S/C): S/C Length Offset (arc-sec): 2.1500 Width Offset (arc-sec): 3.5000 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3066c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACQ/BINARY ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters TYPE=UP BRIGHT STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Proposal for EROS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 2.19 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QUASARS & AGN ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category QUASAR EMISSION ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 1.5; SPATIAL SCAN; GROUP 1-4 WITHIN 60D; CYCLE 0 / 1-4 ONBOARD ACQ FOR 2-4; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ^ G160L ------------------------------------------------------------------------------------------------------------------------------------ Target Names CSO38 ------------------------------------------------------------------------------------------------------------------------------------