8085( 4) - 12/08/99 07:43 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8085 Version: 4 Check-in Date: 03-Dec-1998 09:20:52 1.Proposal Title: Imaging of High Redshift Starburst galaxies in the light of Lyman alpha ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO/DD 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Steven Beckwith Space Telescope Science Institute CoI: David J. Thompson N 8085( 4) - 12/08/99 07:43 - [ 2] ------------------------------------------------------------------------------------ 5. Abstract The PI is the designated director for STScI but has no experience with HST. The purpose of this proposal is to gain experience with the facility by carrying out a modest observational program that is unique and will not conflict with any community programs. The proposed science is divided into priority 1 and priority 2, for 6 + 4 orbits. This division will allow allocation in parts, if the pressure on DDT is large and the total of 10 orbits unusually difficult to schedule. The priority 1 science is rather predictable and, hence, conservative, consisting of the brightest of the objects under study. The priority 2 science is somewhat riskier, because it is more difficult to estimate object brightnesses in the filters to be used on HST. Both priority 1 and priority 2 observations allow for a large degree of serendipity, because the fields are likely to have more starburst galaxies at the observed redshifts that may show up in Lyman alpha. Exploration of the high redshift u niverse and discovery of the most distant objects is still in its infancy. Only recently have the tools been available to detect normal galaxies at redshifts larger than one when the first galaxies were created (Pescarelle et al. 1996; Hu & McMahon 1996; Cowie & Hu 1998; Steidel et al. 1996). It seems likely that young galaxies will have a variety of different signatures (Franceschini et al. 1998; Guideroni et al. 1997), so that it will be necessary to use several diverse techniques to uncover all of them: searches at optical, infrared, x-ray, and radio wavelengths, for example. It is already known that many of the optically selected galaxies using the "dropout" technique are reddened by dust (Pettini et al. 1997). We carried out two surveys for infrared emission-line galaxies by imaging through narrow (Resolving power ~ 100) and broad band filters between 1 and 2.5 microns and identifying objects that appeared brighter in the narrow filters. Our first survey was designed to uncover emission lines at th e redshifts of quasars within each survey field, in case there is substantial clustering marked by quasars (Thompson et al. 1996). In an area of 276 square minutes of arc, only one emission-line galaxy was discovered (Beckwith et al. 1998). The surface density of such objects implied by these results is similar to that inferred from other surveys (Cowie et al. 1994; Graham & Dey 1996; Malkan et al. 1996; Bechtold et al. 1997) and suggests that the infrared emission-line galaxies constitute at most a modest population of young galaxies at high redshift. Using the same instruments, we undertook a second infrared survey for emission-line galaxies targeted at the redshifts of damped Lyman alpha absorption lines or metal absorption line in the spectra of quasars. Damped Lyman alpha absorbers are thought to contain as much baryonic matter as seen in all spiral galaxies today (Wolfe et al. 1986) and may, therefore, mark sites of vigorous star formation. Metal lines are usually associated with damped Lyman alph a systems, and they give us access to lower redshifts than Lyman alpha alone. Several other groups (Lowenthal et al. 1991; Macchetto et al. 1993; Wolfe et al. 1992; Moller & Warren 1993; Djorgovski et al. 1996; Francis et al. 1998) carried out similar surveys at optical wavelengths looking for Lyman alpha emission-line galaxies in these regions. They discovered only five such emission-line galaxies, but Wolfe (1993) showed that the implied volume density was significantly higher than in the general field. Eighteen candidates for emission line galaxies were discovered in this second survey in an area of only 150 square minutes of arc (Mannucci et al. 1998). The emission- lines correspond to H alpha at redshifts of 0.89 (6 objects) and 2.4 (10 objects), and [OII] at a redshift of 2.3 (2 objects). The presence of emission lines is inferred from the photometric magnitudes in narrow and broad band interference filters. A spectrum of one candidate confirms the emission line. Most of the objects are a few seco nds of arc in extent suggesting th a t they are galaxies at the redshifts of the damped Lyman alpha absorbers. Two of these objects, Q1623+268A & Q1623+268B, were serendipitously observed by HST in an independent program to study quasars with absorption lines (by Steidel; we retrieved these images from the HST archive). The HST images resolve the objects showing they are spiral galaxies. It is only with the HST images that a morphological identification can be made. (nB: I can make these images available as TIFF or GIF files, but I do not know how to do this via the web page for DDT). Because our first survey targeted at the redshifts of quasars themselves uncovered only one emission- line galaxy in a larger volume, the results imply substantial clustering of young galaxies or formation within filaments or sheets whose locations are indicated by the redshifts of strong Lyman alpha line absorption along the lines of sight to more distant quasars. Our eighteen emission- line objects are unique in highlighti ng these sheets from an infrared-s elected sample. The proposed HST observations have two goals. The first is to resolve the objects that have not been observed with HST to determine the types of underlying galaxies. Our ground-based observations in the infrared and R band (WIYN telescope) are sufficient to show that most of these objects are between 1 and 3 seconds of arc across, large enough to be galaxies at high redshifts but too small to study the distribution of light from the ground. The two extent HST images of Q1623+268 A & B show clearly how HST uncovers the nature of these galaxies. The second goal is to measure the amount of Lyman alpha emission to compare the morphology of the regions producing Lyman alpha to the continuum. Such a comparison is important to understand what fraction of a young galaxy's light is produced in the starburst population, what fraction in the old population, and what fraction might be associated with an active nucleus. We can get this information by imaging each ga laxy through two filters centered o n or near Lyman alpha with different widths. The technique is similar to the infrared technique used to discover these objects. Although the HST filters were not specifically designed for this task, there is sufficient choice to make it possible with various wide and medium width filters. In the event that Lyman alpha is weak or absent, we can average the data to create a higher signal to noise ratio image. The integration times have been chosen to give S/N ratios of between 10 and 50, depending on the (unknown) brightness of the galaxies in the selected bands. The infrared and R band magnitudes suggest AB magnitudes of order 24 to 25 for each object. Bechtold, J., Yee, H. K. C., Elston, R., & Ellingson, E. 1997, { it Ap. J. Letters}, { bf 477}, L29 Beckwith, S. V. W., Thompson, D. J., Mannucci, F., & Djorgovski, S. G. 1998, { it Ap. J.}, in press Cowie, L. L., & Hu, E. M., 1998, { it A. J.}, in press (astro- ph/9801003) Cowie, L. L., Songaila, A., Hu, E. M., Egam i, , Huang, J.-S., Pickles, A. J., Ridgway, S. E., & Wainscoat, R. J. 1994, { it Ap. J. Letters}, { bf 432}, L83 Djorgovski, S. G., Pahre, M. A., Bechtold J., & Elston, R., 1996, { it Nature}, { bf 382}, 234 Franceschini, A., Silva, L., Granato, G. L., Bressan, A., Danese, L., 1998, { it Ap. J. Lett}, in press Francis, P. J., Woodgate, B. E., and Danks, A. C. 1998, (astroph/9801300) Graham, J. R., & Dey, A. 1996, { it Ap. J.}, { bf 471}, 720 Guideroni, B., Bouchet, F. R., Puget, J.-L., Lagache, G., & Hivon, E., 1997, { it Nature}, { bf 390}, 257 Hu, E. M., McMahon, R. G., 1996, { it Nature}, { bf 382}, 231 Lowenthal, J. D., Hogan, C. J., Green, R. F., Caulet, A., Woodgate, B. E., Brown, L., and Foltz, C. B. 1991, { it Ap. J. Letters}, { bf 377}, L73 Macchetto, F., Lipari, S., Giavalisco, M., Turshek, D. A., & Sparks, W. B. 1993, { it Ap. J.} { bf 404}, 511 Malkan, M. A., Teplitz, H., & McLean, I. S. 1996, { it Ap. J. Letters}, { bf 468}, L9 Mannucci, F., Thompson, D. J., Beckwith, S.V.W., & Wil liger 1998, { it Ap. J. Letters}, i n press. Moller, P., & Warren, S. J., 1993, { it A. & A.}, { bf 270}, 43 Pascarelle, S. M., Windhorst, R. A., & Odewahn, S. C. 1996, { it Nature}, { bf 383}, 45 Pettini, M., Steidel, C. C., Adelberger, K. L, Kellogg, M., Dickinson, M., & Giavalisco, M. 1998, astro-ph/9708117 Steidel, C. C., Giavalisco, M., Pettini, M., Dickinson, M., & Adelberger, K. L. 1996, { it Ap. J.}, { bf 462}, 17 Thompson, D. J, Mannucci, F., & Beckwith, S. V. W. 1996, { it A. J.}, { bf 112}, 1794 Wolfe, A. M. 1993, { it Ap. J.}, { bf 402}, 411 Wolfe, A. M., Turnshek, D. A., Lanzetta, K. M., & Oke, J. B. 1992, { it Ap. J.}, { bf 385}, 151 Wolfe, A. M., Turnshek, D. A., Smith, H. E., & Cohen, R. E. 1986, { it Ap. J. Supp.}, { bf 61}, 249 ------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 3] Observations Description ------------------------ All observations will be with WFPC2. The following table gives the coordinates of the fields to position the pyramid center, the position angle for observation (PA_V3), the filters and integration times. I assume we will break the long integrations into several segments with dithering between each segment. Sub- pixel dithering is desired to enhance the spatial resolution. Real Time Justification ----------------------- It will be useful to have a specified rotation angle to orient the WFPC footprint on the sky. By specifying an exact position angle for the camera, it will be possible to observe several objects simultaneously in each field. There is some leeway in the exact position angle specified for some of these observations; because of the potential complexities involved, I would like to specify these boundaries after consultation with STScI staff. I assume that LOW_SKY should be specified in most cases to minimize the background for these background-limited images. I am FAXing a separate sheet to Peg Stanley with my calculations of the details to clarify the observations. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 Q0201+365 GALAXY RA=2H 4M 56.27S +/- .5", DEC=36D J2000 V = 20.0+/-0.1 48' 17.1" +/- .5" 2 Q2038-012 GALAXY RA=20H 40M 53.21S +/- .1", DEC=- J2000 V = 20.0+/-0.1 1D 7' 33.3" +/- .1" 3 Q2348-011 GALAXY RA=23H 50M 57.28S +/- .5", DEC=- J2000 V = 20.0+/-0.1 0D 52' 3.0" +/- .5" 4 Q1623+268 GALAXY RA=16H 25M 53.93S +/- .5", J2000 V = 20.0+/-0.1 DEC=26D 46' 51.9" +/- .5" 5 Q0100+130 GALAXY RA=1H 3M 11.85S +/- .5", DEC=13D J2000 V = 20.0+/-0.1 17' 1.5" +/- .5" 8085( 4) - 12/08/99 07:43 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 160D TO 200D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 Q0201+365 WFPC2 IMAGE WFALL F450W 1 2500 S ------------------------------------------------------------------------------------------------------------------------------------ 20 Q0201+365 WFPC2 IMAGE WFALL F814W 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 160D TO 185D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 Q2038-012 WFPC2 IMAGE PC1 F450W 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 Q2038-012 WFPC2 IMAGE PC1 F814W 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 15D TO 55D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 Q2348-011 WFPC2 IMAGE PC1 F450W 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 Q2348-011 WFPC2 IMAGE PC1 F814W 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 215D TO 235D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 Q1623+268 WFPC2 IMAGE WFALL F450W 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 Q1623+268 WFPC2 IMAGE WFALL F814W 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 9] Visit: 05 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 Q0100+130 WFPC2 IMAGE WF3 F450W 1 2400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 Q0100+130 WFPC2 IMAGE WF3 F814W 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 8085( 4) - 12/08/99 07:43 - [ 10] Summary Form for Proposal 8085 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFALL PC1 WF3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/DD ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 160D TO 200D ORIENT 160D TO 185D ORIENT 15D TO 55D ORIENT 215D TO 235D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F450W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names Q0201+365 Q2038-012 Q2348-011 Q1623+268 Q0100+130 ------------------------------------------------------------------------------------------------------------------------------------