! +====================+ ! | PED OUTPUT PRODUCT | ! +====================+ ! ! /home/casa/e.elling/text/props/fall95/hstphase2/6832.prop ! Generated by PREPROCESSOR, version 6.0e ! Date: Thu Feb 8 16:53:03 MST 1996 Proposal_Information Title: Imaging of a Protogalaxy at z=2.7 Discovered by its Young Stellar Population Proposal_Category: GO Scientific_Category: COSMOLOGY Cycle: 6 Investigators PI_Name: Howard Yee PI_Institution: University of Toronto CoI_Name: Erica Ellingson CoI_Institution: University of Colorado Contact: Y CoI_Name: Ray Carlberg CoI_Institution: University of Toronto Contact: CoI_Name: David Schade CoI_Institution: University of Toronto Contact: CoI_Name: Jill Bechtold CoI_Institution: Steward Observatory Contact: Abstract: A protogalaxy candidate at z=2.7 has been discovered serendipitously by the CNOC cluster redshift survey. The candidate is a very bright (V=20.5 mag, absolute mag --28), resolved (2''*4''), disk-like galaxy with a strong absorption line spectrum indicative of young O, B, and A stars. The most likely interpretation of this object is that it is an early- type galaxy observed within 0.5 Gyr since its initial burst of star formation which produced most of its stellar mass. We propose to obtain HST images in 3 filters (F814W, F555W, and F300W) to study its structure and morphology in detail. These data will enable us to confirm our interpretation that the continuum arises from young stars, and to investigate the dynamical and evolutionary state of the protogalaxy and the uniformity of the star forming prcoess. The high resolution images will allow us to set stringent limits on the size of the bulge, the existence of a hidden quasar and gravitational lensing, if any. The nature, spatial distribution, and age of the stars can be studied using spatially resolved colors from these images. We estimate that the F555W-F814W color will allow us to discriminate age since star formation to an accuracy of ~0.1 Gyr. The F300W filter images the galaxy below the Ly limit, providing important proof of the stellar origin of the continuum and additional constraints on the existence of on-going star formation. Furthermore, these observations will also allow us to study the possible existence of a group or cluster associated with this object. Questions Observing_Description: The observation will consist of WFPC2 imaging using 3 filters (F814W, F555W, and F300W) on the field around the protogalaxy, with the protogalaxy on the PC quadrant. In a relative short ground-based exposure, the protogalaxy can be seen to the 24 mag/square arcsec isophot. The galaxy basically has a flat spectrum in the AB system between V and I. We expect that obtaining a S/N of 3 per pixel at 24 mag/sq arcsec will be sufficient for us to examine the structure of the object in detail. Using the tables and formulae in the WFPC2 handbook, we obtain integration times of ~ 200 and 440 mins for the F555W and F814W filters. Hence the request of 4 and 9 orbits for these filters, respectively. For the F300W filter, we wish to be able to detect objects with an AB magnitude of 27 covering about 1 sq arc at S/N~5. This requires about 120 min, hence the request of 3 orbits. The I band image and ground-based spectroscopy of the PG will allow us to correct for the red leak in the F300W filter. Real_Time_Justification: Calibration_Justification: Additional_Comments: Fixed_Targets Target_Number: 1 Target_Name: MS1512+37-GAL Alternate_Names: 1512-cB58 Description: GALAXY, High Redshift Galaxy Position: RA=15H 12M 25.7S +/- 0.2S, DEC= 36D 47' 31.1" +/-3" Equinox: 1950.0 RV_or_Z: Z=2.72 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: V=20.88, V-R=0.72 Comments: galaxy 6 arcsec NW of cluster cD galaxy Visits Visit_Number: 1 Visit_Requirements: ORIENT 135D TO 165D On_Hold_Comments: Visit_Comments: Exposure_Number: 1 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: DITHER-TYPE=LINE, CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: Comments: Exposure_Number: 2 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: DITHER-TYPE=LINE, CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: Comments: Exposure_Number: 3 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Exposure_Number: 4 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Exposure_Number: 5 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Visit_Number: 2 Visit_Requirements: SAME ORIENT AS 1 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F814W Wavelength: Optional_Parameters: DITHER-TYPE=LINE, CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: Comments: Exposure_Number: 2 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F555W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Exposure_Number: 3 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F555W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Exposure_Number: 4 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F300W Wavelength: Optional_Parameters: CR-TOLERANCE=0.2, DITHER-TYPE=LINE, CR-SPLIT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 45M Special_Requirements: Comments: Exposure_Number: 5 Target_Name: MS1512+37-GAL Config: WFPC2 Opmode: IMAGE Aperture: PC1 Sp_Element: F300W Wavelength: Optional_Parameters: DITHER-TYPE=LINE, CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: Comments: Data_Distribution ! Defaults indicated; change if desired Medium: 8MM Blocking_Factor: 10 Ship_To: E. Ellingson, CASA CB 389, U. Colorado, Boulder CO 80309 Ship_Via: UPS Recipient_Email: e.elling@casa.colorado.edu ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator