16836( 2) - 12-Oct-2021 18:33:42 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16836 Version: 2 Check-in Time: 12-Oct-2021 18:33:42 STScI Edit Number: 0 Title The Massive Relic Galaxy NGC 5872 ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. David Buote University of California - Irvine Y CoI: Dr. Aaron J. Barth University of California - Irvine N ------------------------------------------------------------------------------------ Abstract A potentially powerful approach to study early galaxy formation is through massive relic galaxies (MRGs) which are local analogs of the high-redshift "red nuggets" thought to represent progenitors of today's early-type galaxies. When a luminous hot halo is present, X-ray observations of the diffuse hot gas of MRGs provide the most viable means to measure the gravitating mass profile, and X-rays afford a powerful direct approach to study cooling and AGN feedback. Here we propose a joint Chandra -HST observation of NGC 5872, a very massive MRG, to map its inner mass profile (<~R_e), especially by measuring the stellar mass-to-light ratio, and to examine the magnitude of AGN feedback through image analysis and the radial profile of the ratio of the cooling and free-fall times. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our HST observations are designed to measure the surface brightness profile of galaxy NGC 5872 accurately. The data will be used together with Chandra observations to model the galaxy's mass distribution including stellar mass, hot gas, and dark matter. We will use WFC3 with both UVIS and IR cameras. Our IR F160W exposures will include four dithered RAPID mode exposures to obtain high dynamic range imaging of the galaxy's central region, with the IRSUB512 subarray. Then, four dithered full-frame IR exposures will be obtained using the WFC3-IR-DITHER-BOX-UVIS pattern in order to obtain deeper imaging out to large radius. Finally, we will obtain two UVIS F814W images using the UVIS-GAP-LINE pattern to dither across the CCD gap. The F814W data will provide higher angular resolution of the galaxy's nuclear region than the IR data, which will enable measurement of the galaxy's stellar profile at the smallest radii and also enable detection of dust lanes or a dust disk if present. This exposure plan efficiently fills a single orbit with no time lost to buffer dump overheads. ------------------------------------------------------------------------------------ 16836( 2) - 12-Oct-2021 18:33:42 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5872 GALAXY, ELLIPTICAL RA=15H10M55.6580S, J2000 Z = V = 13.31 +/- 0.74 H=9.521 +/- 0.018 DEC=-11D28'48.53" 0.024556 mag, I=11.30 +/- 0.11 Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 16836( 2) - 12-Oct-2021 18:33:42 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 2.414 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.759 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 6 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-UVIS Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 23.02 Line_Spacing 35.212 Coordinate_Frame POS-TARG Pattern_Orient 0.713 Angle_Between_Sides 89.287 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 8 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16836( 2) - 12-Oct-2021 18:33:42 - [ 4] Visit: 01 Visit Requirements: 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5872 WFC3/IR MULTIAC IRSUB512 F160W NSAMP=14, SAMP-SEQ=RAPID 1 DEF (47.77 PATTERN 8 1 CUM S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5872 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=STEP50 1 DEF PATTERN 6 2 CUM (1396.932 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5872 WFC3/UVI ACCUM UVIS1 F814W CR-SPLIT=NO, FLASH=15 1 268 S (536 PATTERN 4 3 S S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC5872 1 WFC3/IR MULTIAC IRSUB512 F160W 1 none none none 1 N/A CUM NGC5872 1 WFC3/IR MULTIAC IRSUB512 F160W 2 none none none 1 N/A CUM NGC5872 1 WFC3/IR MULTIAC IRSUB512 F160W 3 none none none 1 N/A CUM NGC5872 1 WFC3/IR MULTIAC IRSUB512 F160W 4 none none none 1 N/A CUM NGC5872 2 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM NGC5872 2 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM NGC5872 2 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM NGC5872 2 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A CUM NGC5872 3 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 N/A S NGC5872 3 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 N/A S 16836( 2) - 12-Oct-2021 18:33:42 - [ 5] Summary Form for Proposal 16836 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, IRSUB512, UVIS1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO, FLASH=15, NSAMP=12, NSAMP=14, SAMP-SEQ=RAPID, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 4 3, PATTERN 6 2, PATTERN 8 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC5872 ------------------------------------------------------------------------------------------------------------------------------------