16661( 5) - 17-Aug-2021 17:55:00 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16661 Version: 5 Check-in Time: 17-Aug-2021 17:55:00 STScI Edit Number: 3 Title Dwarf Galaxies with Radio-Selected Massive Black Holes ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Amy E. Reines Montana State University - Bozeman Y CoI: Dr. Mallory Molina Montana State University - Bozeman N CoI: Prof. Jeremy Darling University of Colorado at Boulder N ------------------------------------------------------------------------------------ Abstract Studies of massive black holes (BHs) in nearby dwarf galaxies can provide important constraints on the birth and growth of the first seed BHs in the early Universe. Using high-resolution observations from the Very Large Array, Reines et al. (2020) discovered a set of compact radio sources in nearby dwarf galaxies with luminosities indicative of accreting massive BHs. Moreover, some of these radio sources are not in the centers of the galaxies with offsets on the order of ~1 kpc. As part of a pilot study, we propose HST/WFC3 observations of 3 dwarf galaxies hosting radio-selected (''wandering'') massive BHs that also have guaranteed X-ray observations with Chandra. We propose narrow-band H-alpha imaging and wide-band optical continuum imaging to 1) determine spatially-resolved star formation rates and colors, 2) search for faint, small optical counterparts of the BHs, and 3) determine detailed morphologies of the dwarf host galaxies. The proposed observations are crucial to asses possible contributions from star-formation-related emission at X-ray and radio wavelengths, and characterize the properties of this new class of BH-hosting dwarf galaxies. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain HST/WFC3 UVIS observations in three filters, including narrow-band H-alpha imaging (F680N) and wide-band continuum imaging at 4300 Ang (F438W) and 8000 Ang (F814W). We choose the F438W and F814W filters to bracket the wavelength of H-alpha (for continuum subtraction) and to avoid strong emission lines such as [OIII] 5007 and the [OII] 3727, 3729 doublet. We have three target galaxies and can achieve our science goals with two HST orbits per galaxy for a total of 6 orbits. From prior experience, exposure times are based on detecting a 5 Myr-old, ~3x10^4 Msun star cluster at the distance of our target galaxies (z ~ 0.02-0.03) with a signal-to-noise ratio of S/N=10. Starburst99 models of an instantaneous burst indicate that the corresponding H-alpha flux is ~10^-16 erg/s/cm^2 with an underlying continuum flux density of ~3 x 10^-19 erg/s/cm^2/Ang. Assuming the cluster is a point source, the WFC3/UVIS exposure time calculator suggests we need ~35 minutes in F680N. The required times in F814W and F438W are ~13 and ~ 11 minutes, respectively. Note that we have also allowed for 1 magnitude of visual extinction (AV = 1 mag) in these calculations. We will break the total time into four dithered exposures to 16661( 5) - 17-Aug-2021 17:55:00 - [ 2] improve the PSF sampling and avoid bad pixels, as well as include a post flash to avoid poor charge efficiency. We will use the 2k x 2k subarray (to avoid buffer dumps) with the more efficient chip 2. Our galaxies are quite compact so using a subarray will not compromise our science or limit our sky subtraction. A similar observing strategy has been successfully employed in previous work (Kimbro et al. 2021). To summarize, we can achieve our science goals with 2 orbits per galaxy. We will spend one orbit on narrow-band H-alpha imaging (F680N) and one orbit on wide-band continuum imaging (F438W and F814W). Our observing strategy provides the requisite time on source in each filter, as well as sufficient time for acquisition and instrument overheads (including guide-star acquisition, readout and dithering). ------------------------------------------------------------------------------------ 16661( 5) - 17-Aug-2021 17:55:00 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 J1136+1252 GALAXY, DWARF COMPACT, RA=11H36M48.5256S, J2000 Z = V = 17.2 INTERACTING GALAXY, DEC=+12D52'39.90" 0.034 RADIO GALAXY Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 J1200-0341 GALAXY, DWARF COMPACT, RA=12H00M58.3008S, J2000 Z = V = 16.8 INTERACTING GALAXY, DEC=-03D41'18.46" 0.026 RADIO GALAXY Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 J1253-0312 GALAXY, DWARF COMPACT, RA=12H53M5.9688S, J2000 Z = V = 15.5 INTERACTING GALAXY, DEC=-03D12'58.75" 0.022 RADIO GALAXY Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16661( 5) - 17-Aug-2021 17:55:00 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16661( 5) - 17-Aug-2021 17:55:00 - [ 5] 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 J1136+1252 WFC3/UVI ACCUM UVIS2-2K2 F680N FLASH=9 1 797 S GS ACQ SCENARIO BASE1BE; S C-SUB (2391 S) PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 J1136+1252 WFC3/UVI ACCUM UVIS2-2K2 F438W FLASH=16 1 270 S (810 PATTERN 3 2 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J1136+1252 WFC3/UVI ACCUM UVIS2-2K2 F814W FLASH=6 1 332 S (996 PATTERN 3 3 S C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1136+1252 1 WFC3/UVI ACCUM UVIS2-2K F680N 1 none none none 1 N/A S 2C-SUB J1136+1252 1 WFC3/UVI ACCUM UVIS2-2K F680N 2 none none none 1 N/A S 2C-SUB J1136+1252 1 WFC3/UVI ACCUM UVIS2-2K F680N 3 none none none 1 N/A S 2C-SUB J1136+1252 2 WFC3/UVI ACCUM UVIS2-2K F438W 1 none none none 2 N/A S 2C-SUB J1136+1252 2 WFC3/UVI ACCUM UVIS2-2K F438W 2 none none none 2 N/A S 2C-SUB J1136+1252 2 WFC3/UVI ACCUM UVIS2-2K F438W 3 none none none 2 N/A S 2C-SUB J1136+1252 3 WFC3/UVI ACCUM UVIS2-2K F814W 1 none none none 2 N/A S 2C-SUB J1136+1252 3 WFC3/UVI ACCUM UVIS2-2K F814W 2 none none none 2 N/A S 2C-SUB J1136+1252 3 WFC3/UVI ACCUM UVIS2-2K F814W 3 none none none 2 N/A S 2C-SUB 16661( 5) - 17-Aug-2021 17:55:00 - [ 6] Visit: 02 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 J1200-0341 WFC3/UVI ACCUM UVIS2-2K2 F680N FLASH=9 1 795 S GS ACQ SCENARIO BASE1BE; S C-SUB (2385 S) PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 J1200-0341 WFC3/UVI ACCUM UVIS2-2K2 F438W FLASH=16 1 270 S (810 PATTERN 3 2 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J1200-0341 WFC3/UVI ACCUM UVIS2-2K2 F814W FLASH=6 1 330 S (990 PATTERN 3 3 S C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1200-0341 1 WFC3/UVI ACCUM UVIS2-2K F680N 1 none none none 1 N/A S 2C-SUB J1200-0341 1 WFC3/UVI ACCUM UVIS2-2K F680N 2 none none none 1 N/A S 2C-SUB J1200-0341 1 WFC3/UVI ACCUM UVIS2-2K F680N 3 none none none 1 N/A S 2C-SUB J1200-0341 2 WFC3/UVI ACCUM UVIS2-2K F438W 1 none none none 2 N/A S 2C-SUB J1200-0341 2 WFC3/UVI ACCUM UVIS2-2K F438W 2 none none none 2 N/A S 2C-SUB J1200-0341 2 WFC3/UVI ACCUM UVIS2-2K F438W 3 none none none 2 N/A S 2C-SUB J1200-0341 3 WFC3/UVI ACCUM UVIS2-2K F814W 1 none none none 2 N/A S 2C-SUB J1200-0341 3 WFC3/UVI ACCUM UVIS2-2K F814W 2 none none none 2 N/A S 2C-SUB J1200-0341 3 WFC3/UVI ACCUM UVIS2-2K F814W 3 none none none 2 N/A S 2C-SUB 16661( 5) - 17-Aug-2021 17:55:00 - [ 7] Visit: 03 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 J1253-0312 WFC3/UVI ACCUM UVIS2-2K2 F680N FLASH=10 1 794 S PATTERN 3 1 S C-SUB (2382 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J1253-0312 WFC3/UVI ACCUM UVIS2-2K2 F438W FLASH=17 1 270 S (810 PATTERN 3 2 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J1253-0312 WFC3/UVI ACCUM UVIS2-2K2 F814W FLASH=7 1 329 S (987 PATTERN 3 3 S C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1253-0312 1 WFC3/UVI ACCUM UVIS2-2K F680N 1 none none none 1 N/A S 2C-SUB J1253-0312 1 WFC3/UVI ACCUM UVIS2-2K F680N 2 none none none 1 N/A S 2C-SUB J1253-0312 1 WFC3/UVI ACCUM UVIS2-2K F680N 3 none none none 1 N/A S 2C-SUB J1253-0312 2 WFC3/UVI ACCUM UVIS2-2K F438W 1 none none none 2 N/A S 2C-SUB J1253-0312 2 WFC3/UVI ACCUM UVIS2-2K F438W 2 none none none 2 N/A S 2C-SUB J1253-0312 2 WFC3/UVI ACCUM UVIS2-2K F438W 3 none none none 2 N/A S 2C-SUB J1253-0312 3 WFC3/UVI ACCUM UVIS2-2K F814W 1 none none none 2 N/A S 2C-SUB J1253-0312 3 WFC3/UVI ACCUM UVIS2-2K F814W 2 none none none 2 N/A S 2C-SUB J1253-0312 3 WFC3/UVI ACCUM UVIS2-2K F814W 3 none none none 2 N/A S 2C-SUB 16661( 5) - 17-Aug-2021 17:55:00 - [ 8] Summary Form for Proposal 16661 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-2K2C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, FLASH=16, FLASH=17, FLASH=6, FLASH=7, FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1BE, PATTERN 3 1, PATTERN 3 2, PATTERN 3 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F438W, F680N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names J1136+1252, J1200-0341, J1253-0312 ------------------------------------------------------------------------------------------------------------------------------------