Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3065c Report Date: 09-May-96:17:53 Version: ********** Check-in Date: ********** 1.Proposal Title: HIGH SIGNAL-TO-NOISE QSO LINE PROFILES ------------------------------------------------------------------------------------ 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 strengths and profiles of emission lines in the UV in a bright, low-redshift QSO. We will present a high signal-to-noise spectrum which is essentially unaffected by the HST optical problems. These observations will be combined with optical observations of similar quality and lead to improved models of the structure of the broad-line region of QSOs. ------------------------------------------------------------------------------------ 8. Scientific Key Words: UV SPECTROSCOPY, QUASAR, EMISSION LINE PROFILE, LYMAN ALPHA ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.95 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3065c PI: E. margaret Burbidge Proposal Title: HIGH SIGNAL-TO-NOISE QSO LINE PROFILES ------------------------------------------------------------------------------------ 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 Page 3 ------------------------------------------------------------------------------------ 2. Scientific Justification. The broad emission lines present in QSO spectra are probably produced by clouds of gas moving at velocities around 10000 km/s at distances of order one to ten parsecs from the source of continuum radiation. The emission-line profiles produced by these clouds depend on both the dynamics of the clouds and the emission properties of the individual clouds. Several models for the broad- emission-line region have been developed that predict shapes for line profiles which are in reasonable agreement with observations. These models include: radiatively accelerated clouds (Blumenthal and Mathews, 1979), clouds accelerated by quasar winds (Weymann et al., 1982), and cloud motion along parabolic orbits (Kwan and Carroll, 1982). Because the overall line shapes do not provide a definitive test of the possible dynamical models, more subtle systematic properties of the emission-line profiles must be considered. Systematic QSO emission-line profile differences (Mathews and Wampler, 1985) and redshift differences (Gaskell, 1982 and Wilkes, 1984, 1986) have been observed. The interpretation of these data in terms of the dynamics and internal obscuration and geometry of the broad-emission-line region is limited by the quality of the observations and the statistical nature of the problem. These data already provide direct evidence for an inhomogeneous, multi-component broad emission line region. With further observations, the quality of the data will improve. We propose to observe the bright, low-redshift QSO CSO 251 with one of the high resolution UV gratings of the FOS. These observations will demonstrate the capabilities of the FOS and HST to produce high-signal-to-noise spectra of QSOs. Additionally, when we combine the UV spectral observations with the FOS described in this proposal with optical observations we will be able to study in detail profile differences and redshift differences of interesting emission-line pairs. Observations of this low redshift QSO will allow a comparison of Ly alpha, with H beta, [OIII] lambda 5007, and H alpha in the optical. The UV data obtained with this program will be at much higher resolution and signal-to-noise ratio than previous UV data on Seyferts and QSOs (taken with the IUE); the Lyman alpha profile should be unaffected by the absorption which affects this line in high redshift QSOs; and we will be able to measure the profiles of all lines in the same object, unlike previous studies of QSO line profiles. The [O III] line is probably near the systemic redshift of the QSO and provides a reference for the redshift difference studies. Observations of H alpha in the IR by Espey et al. (1989) show a median redshift difference of 1000 km/s between H alpha and C IV lambda 1549. Ly alpha is usually near the C IV redshift. This difference might be the result of a BELR that contains a low-ionization region that is optically thick and a separate optically thin high-ionization region (for example Mathews 1986). The Ly alpha emission-line profile compared to H beta can be used to estimate the Ly alpha / H beta ratio in each region. One prediction of this model is that at velocities where the optically thin component dominates, the Ly alpha / H beta ratio should be near the recombination value i.e. very large. Normalized emission line pairs can be divided to compare line flux ratios as a function of velocity (Shuder, 1982, 1984). From simple arguments based on H alpha and H beta profiles, Shuder was able to show that velocity must inrease inwards in the broad -line region. Detailed comparisons of several lines, including those from both the fully and partially ionized zones, combined with predictions from photoionization models should allow us to reach much more detailed conclusions. Blumenthal, G. R., and Mathews, W. G. 1979, Ap. J., 233, 479. Espey, B. R., Carswell, R. F., Bailey, J. A., Smith, M. G., and Ward, M. J. 1989, Ap. J., 342, 666. Gaskell, C. M. 1982, Ap. J., 263, 79. Kwan, J., and Carroll, T. J. 1982, Ap. J., 261, 25. Mathews, W. G. 1986, Ap. J., 305, 187. Mathews, W. G., and Wampler, E. J. 1985, P.A.S.P., 97, 966. Shuder, J. M. 1982, Ap. J., 259, 48. Shuder, J. M. 1984, Ap. J., 280, 491. Weymann, R. J., Scott, J. S., Schiano, A. V. R., and Christiansen, W. A. 1982, Ap. J., 262, 497. Wilkes, B. J. 1984, M.N.R.A.S., 207, 73. Wilkes, B. J. 1986, M.N.R.A.S., 218, 331. Page 4 ------------------------------------------------------------------------------------ 3. Description of proposed observations. This proposal contains 1 object which will be observed with G130H grating and FOS blue detector. S/N will be 30 per diode, enabling us to measure accurate line profiles. A short observation with the 4.3 arc second square aperture will be used to measure absolute fluxes. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The main point of this program is to demonstrate the capability of the HST and FOS to take high signal-to-noise spectra of objects with broad emission lines. We will use these data to model the structure of the broad-line region of QSOs. For comparison with models, ratios of line from different regions must be measured in the same object. Adequate signal-to-noise and resolution cannot be obtained either by observing low-redshift objects with the IUE or the rest optical lines of high-redshift lines in the IR. High resolution and high signal- to-noise studies in the optical region alone do not include enough lines formed in different portions of the emission-line region for a detailed analysis. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The signal-to-noise calculation assumed transmission through the 1.0 arc second diameter of 27% and a total HST+FOS efficiency (for all other components) of 0.01% at Lyman alpha with G130H and the blue detector. ------------------------------------------------------------------------------------ 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. We will measure line strength ratios and profile differences for UV and optical lines. The measurements will be compared to predictions of photoinization models and simple kinematic 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 to measure provide an estimate of the absolute flux to test the HST flux calibration and to provide additional scientific input. ------------------------------------------------------------------------------------ 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 = 3065c [ 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 CSO251 QUASAR RA = 10H 13M 03.173S +/- 2000 Z=0.0786 1 V=15.0 +/- 0.5 TON1187 1.0", DEC = 35D 51' 23.13" +/- 1.0", PLATE-ID = 01R3 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3065c [ 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 CSO251 FOS/BL ACQ/ 4.3 MIRROR TYPE=UP 1 0.6S 1 1 ONBOARD ACQ FOR PEAK 1.5 SPATIAL SCAN GROUP 1-4 WITHIN 60D CYCLE 0 / 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 1.5 CSO251 FOS/BL ACQ/ 4.3 MIRROR BRIGHT=700000 1 11S 1 1 ONBOARD ACQ FOR 2- BINARY 4 GROUP 1-4 WITHIN 60D CYCLE 0 / 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ ^ ACQ ^ ^ 1 11S 1 ^ ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ ^ ACCUM ^ G130H 1300 STEP- 1 100S 3 ^ PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ ^ ACCUM 1.0 ^ ^ STEP- 1 6900S 30 ^ PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 3065c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 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 3065c [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACQ/BINARY ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters TYPE=UP BRIGHT STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Proposal for EROS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.95 ------------------------------------------------------------------------------------------------------------------------------------ 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 ^ G130H ------------------------------------------------------------------------------------------------------------------------------------ Target Names CSO251 TON1187 ------------------------------------------------------------------------------------------------------------------------------------