13102( 4) - 17-Aug-2012 20:02:08 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13102 Version: 4 Check-in Time: 17-Aug-2012 20:02:08 STScI Edit Number: 2 Title Zooming in on the Starburst at the Core of the Phoenix Cluster ------------------------------------------------------------------------------------ Type Cycle GO/DD 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Michael McDonald Massachusetts Institute of Technology Y CoI: Prof. Sylvain Veilleux University of Maryland N CoI: Dr. Marshall Bautz Massachusetts Institute of Technology N CoI: Dr. Bradford Benson University of Chicago N ------------------------------------------------------------------------------------ Abstract In a recently published letter to Nature, we report the discovery of the most X-ray luminous galaxy cluster in the known Universe, within which the intracluster medium is cooling at an unprecedented rate. In the core of this cluster, the brightest cluster galaxy is forming stars at an unmatched rate of 740 Msun/yr, which is highly unusual for this class of galaxy which are typically referred to as "red and dead". We suspect that the extreme cooling and star formation rates are intimately linked: the cooling intracluster gas is most likely providing fuel for the starburst. We request 2 orbits of near-UV and optical broadband WFC3-UVIS imaging in order to morphologically classify this starburst as a result of i) cooling, infalling gas (filamentary UV emission); ii) a recent merger (tidal tails with both UV and optical emission); or iii) a starburst- or AGN-driven wind (wide opening angle). These data will also allow us to determine the stellar populations of both the starburst and the underlying, older stellar populations, and will provide a much sharper view of the central AGN, allowing us to more carefully extract the contribution to the extended UV emission from young stars. Our early results have already received substantial attention from the international press, and we expect that a dramatically improved picture of the heart of this cluster would stir up as much, if not more, interest from the public. ------------------------------------------------------------------------------------ Observations Description ------------------------ Straightforward broad-band imaging in 2x near-UV filters (F225W, F336W) and 3x optical filters (F475W, F625W, F814W). We use a 2-pt dither pattern, since our exposures are <1000s and we are concerned with maximizing S/N. Since our target is relatively small, we opt to use a single quadrant (80"x80") in order to reduce read-out time. Real Time Justification ----------------------- Calibration Justification ------------------------- 13102( 4) - 17-Aug-2012 20:02:08 - [ 2] Additional Comments ------------------- ------------------------------------------------------------------------------------ 13102( 4) - 17-Aug-2012 20:02:08 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PHOENIX-A GALAXY, COOLING FLOW, RA=23H44M43.9368S +/- 0.5", J2000 V = 17.3 +/- 0.3 ELLIPTICAL, EMISSION DEC=-42D43'12.80" +/- 0.5" LINE NEBULA, SEYFERT, STARBURST Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13102( 4) - 17-Aug-2012 20:02:08 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13102( 4) - 17-Aug-2012 20:02:08 - [ 5] Visit: 01 Visit Requirements: BEFORE 01-DEC-2012 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PHOENIX-A WFC3/UVI ACCUM UVIS1-2K2 F225W 1 608 S POS TARG 8.02, -12.03; S A-SUB PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 PHOENIX-A WFC3/UVI ACCUM UVIS1-2K2 F336W 1 608 S POS TARG 8.02, -12.03; S A-SUB PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PHOENIX-A 1 WFC3/UVI ACCUM UVIS1-2K F225W 1 none none none 1 N/A S 2A-SUB PHOENIX-A 1 WFC3/UVI ACCUM UVIS1-2K F225W 2 none none none 1 N/A S 2A-SUB PHOENIX-A 2 WFC3/UVI ACCUM UVIS1-2K F336W 1 none none none 1 N/A S 2A-SUB PHOENIX-A 2 WFC3/UVI ACCUM UVIS1-2K F336W 2 none none none 1 N/A S 2A-SUB 13102( 4) - 17-Aug-2012 20:02:08 - [ 6] Visit: 02 Visit Requirements: BEFORE 01-DEC-2012 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PHOENIX-A WFC3/UVI ACCUM UVIS1-2K2 F475W 1 344 S POS TARG 8.02, -12.03; S A-SUB PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 PHOENIX-A WFC3/UVI ACCUM UVIS1-2K2 F625W 1 344 S POS TARG 8.02, -12.03; S A-SUB PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 PHOENIX-A WFC3/UVI ACCUM UVIS1-2K2 F814W 1 344 S POS TARG 8.02, -12.03; S A-SUB PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PHOENIX-A 1 WFC3/UVI ACCUM UVIS1-2K F475W 1 none none none 1 N/A S 2A-SUB PHOENIX-A 1 WFC3/UVI ACCUM UVIS1-2K F475W 2 none none none 1 N/A S 2A-SUB PHOENIX-A 2 WFC3/UVI ACCUM UVIS1-2K F625W 1 none none none 1 N/A S 2A-SUB PHOENIX-A 2 WFC3/UVI ACCUM UVIS1-2K F625W 2 none none none 1 N/A S 2A-SUB PHOENIX-A 3 WFC3/UVI ACCUM UVIS1-2K F814W 1 none none none 1 N/A S 2A-SUB PHOENIX-A 3 WFC3/UVI ACCUM UVIS1-2K F814W 2 none none none 1 N/A S 2A-SUB 13102( 4) - 17-Aug-2012 20:02:08 - [ 7] Summary Form for Proposal 13102 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1-2K2A-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 01-DEC-2012, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, POS TARG 8.02, -12.03 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F225W, F336W, F475W, F625W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names PHOENIX-A ------------------------------------------------------------------------------------------------------------------------------------