6440( 6) - 06/03/97 22:17 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6440 Version: 6 Check-in Date: 03-Jun-1997 22:16:14 1.Proposal Title: Resolving the Radio Hotspots in Nearby Starburst Galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES & CLUSTERS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Duncan Forbes UNIVERSITY OF BIRMINGHAM CoI: Martin Ward Oxford University N ------------------------------------------------------------------------------------ 6. Abstract We propose to image the central regions of the starburst galaxy NGC 253 using narrow and broad--band filters. With such data a variety of topics relating to the starburst can be addressed. Our primary goal is to understand the nature of the numerous discrete radio sources seen in high--resolution radio mapping of these galaxies. Considerable controversy exists over whether these radio sources are HII regions or SNRs. A number of these in M82 have recently been resolved with sizes of 50 to 300 mas. We aim to resolve many of these radio sources in the PC chip and use narrow--band imaging in the emission lines of HAlpha, SII6717+6731 and SIII9532 as a diagnostic to discriminate between HII regions and SNRs. These data will also give important information on the physical properties of the SNRs. In addition, the WFC chips will trace the warm gas associated with the large--scale superwind present in all three galaxies on small physical scales. Finally, the broad--band imaging allows us to derive color--magnitude and color-color diagrams of the central regions, from which we can measure the integrated stellar properties, identify super--star clusters and estimate the dust extinction on small scales. ------------------------------------------------------------------------------------ 6440( 6) - 06/03/97 22:17 - [ 2] Observations Description ------------------------ We request WFPC2 imaging of the nearby starburst galaxy NGC 253 (it has high-- resolution radio maps available) centered in the PC. NGC 253 has been imaged in F656N, F675W, F336W, F555W, F814W in cycle 4 by Trauger (\\#5211). We will obtain this data from the archive and combine it with new images in F673N, F675W (needed to ensure the same roll angle as F673N), F953N, F850LP and F450W. Exposure times are based on examination of the F502N (30m) and F664N (15m) WFPC1 observations of NGC 253 by Ford using archive data. His F664N images show bright knots and nebulosity but have low counts. All three galaxies have a nuclear HAlpha flux similar to that of NGC 253, i.e. 4 * 10^-12 erg s^-1 cm^-2 with strong equivalent widths 10 -- 100 Angstrom (e.g. Waller et al. 1988, AJ, 95, 1057). Trauger obtained 40m exposure of NGC 253 in the F656N filter, but this data is not available in the archive until late Sept. 1995. We propose to obtain; F673N (40m), F953N (42m), F675W (11m), F850LP (11m), F450W (10m). , All images will be CR split. Calibration of the broad--band filters will be carried out using ground-- based magnitudes from the literature taken in standard filters (for which transformations to WFPC2 filters are available). Narrow-- band filters will be calibrated using the known relative spectral response of the narrow--band (line) and broad--band (continuum) filters. NOTE: F631N has been substituted for F673N. F622W has been substituted for F675W. Both changes were requested by the PI in order to avoid duplication problems. - RAL - 1 April, 1997 NOTE: Further substitutions were made by PI with CS's approval. The 2x1200s exposures at ATD-GAIN=7 in F631N became 2x1200s exposures at ATD-GAIN=7 in F502N. The 2x300s exposures at ATD-GAIN=15 in F622W became 2x300s exposures at ATD-GAIN=15 in F631N. The 1x300s and 1x160s at ATD-GAIN=15 in F300W became 1x300s and 1x160s at ATD-GAIN=15 in F631N. The order of the exposures in F850LP and the first two exposures in F631N were changed to minimize overhead time lost to filter wheel changes and to group all the F631N exposures together. - Ray Lucas - 3 June, 1997 Real Time Justification ----------------------- None. None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6440( 6) - 06/03/97 22:17 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC253-NUC GALAXY,STARBURST RA=00H47M33.1S+/-1",DEC=- 2000 V=+249 B-V = 1.26+/-0.1 25D17'18"+/-1" SURF(V) = 18.9+/-0.2 6440( 6) - 06/03/97 22:17 - [ 4] Visit: 01 Visit Requirements: ORIENT 273.2732D TO 313.2732D On Hold Comments: Additional Comments: This ORIENT is meant to reproduce the same roll angle of Trauger in cycle 5 (ID number 5211) for his F656N observation. I have specified +/-20 D about his roll angle (293.2732D), but if not possible then any roll angle will do. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC253-NUC WFPC2 IMAGE PC1-FIX F502N ATD-GAIN=7,CR-SPLIT=NO 1 1200 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC253-NUC WFPC2 IMAGE PC1-FIX F502N ATD-GAIN=7,CR-SPLIT=NO 1 1200 S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC253-NUC WFPC2 IMAGE PC1-FIX F953N ATD-GAIN=7,CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC253-NUC WFPC2 IMAGE PC1-FIX F953N ATD-GAIN=7,CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC253-NUC WFPC2 IMAGE PC1-FIX F850LP ATD-GAIN=15,CR-SPLIT=NO 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC253-NUC WFPC2 IMAGE PC1-FIX F850LP ATD-GAIN=15,CR-SPLIT=NO 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC253-NUC WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15,CR-SPLIT=NO 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC253-NUC WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15,CR-SPLIT=NO 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC253-NUC WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15,CR-SPLIT=NO 1 300 S ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC253-NUC WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15,CR-SPLIT=NO 1 160 S ------------------------------------------------------------------------------------------------------------------------------------ 6440( 6) - 06/03/97 22:17 - [ 5] Summary Form for Proposal 6440 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=7 CR-SPLIT=NO ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 273.2732D TO 313.2732D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F502N F953N F850LP F631N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC253-NUC ------------------------------------------------------------------------------------------------------------------------------------