14047( 2) - 26-Feb-2015 16:29:03 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14047 Version: 2 Check-in Time: 26-Feb-2015 16:29:03 STScI Edit Number: 0 Title Confirming the AGN in a Low-Metallicity Dwarf Galaxy with the HSA and HST ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Amy E. Reines University of Michigan Y CoI: Dr. Adam Travis Deller Stichting Astronomisch Onderzoek in N Nederland (ASTRON) ------------------------------------------------------------------------------------ Abstract The incidence and properties of present-day dwarf galaxies hosting massive black holes (BHs) can provide important constraints on the origin of high-redshift BH seeds. Reines et al. (2014) have recently identified a candidate AGN in the low-metallicity dwarf galaxy pair Mrk 709. The case for an accreting massive BH is strong (co-spatial central VLA and Chandra point sources), but not watertight. Moreover, very little is known about the environment in which the BH is growing. The primary goal of our proposal is to confirm (or refute) the presence of this candidate AGN by using the HSA (VLBA+VLA+GBT) to detect a compact, high brightness temperature radio core. We also aim to characterize the host galaxy using HST optical and near-IR observations. In particular, we will determine if the AGN lives in a bulge and investigate the star formation in the immediate vicinity of the BH. Confirming the AGN and probing any potential impact on its host galaxy is only possible using deep, high-resolution observations with the HSA and HST. The results from these observations will have important implications for the birth and growth of the first high-redshift BHs. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain optical and near-IR observations of Mrk 709 with WFC3. The galaxy will be imaged in 3 filters: IR F110W, UVIS F680N, and UVIS F621M. For each filter, we will obtain 4 dithered exposures to facilitate cosmic-ray rejection, avoid bad pixels, and improve the PSF sampling. According to the WFC3/IR exposure time calculator, we need ~ 7 minutes in F110W to reach a 10-sigma surface-brightness sensitivity of mu_r ~ 23 mag arcsec^2 in a given pixel, which will allow us to adequately decouple bulge and disk components on small scales. We will use the timing sequence STEP25 with NSAMP=9 (~100 s per exposure) and use the IRSUB512 subarray to avoid buffer dumps. Our target galaxy is quite compact so using a subarray will not compromise our science or limit our sky subtraction. Requisite exposure times in F680N (redshifted H-alpha filter) and F621M (~r-band continuum) are based on the SDSS spectrum of Mrk 709 S. In this 3" aperture, we measure an H-alpha flux of 8.0 x 10^-14 erg/s/cm^2 and a continuum flux density of F6200 = 4.5 x 10^-16 erg/s/cm^2/A. To reach a signal-to-noise ratio of ~20-25 per pixel, the WFC3/UVIS exposure time calculator suggests we 14047( 2) - 26-Feb-2015 16:29:03 - [ 2] need ~25 and ~30 minutes in F680N and F621M, respectively. We will use the 2k x 2k subarray with chip 2 to avoid buffer dumps and reduce readout overhead. We will also use a post-flash to avoid poor charge transfer efficiency. ------------------------------------------------------------------------------------ 14047( 2) - 26-Feb-2015 16:29:03 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MRK709 GALAXY, DWARF COMPACT, RA=09H49M18.0300S, J2000 Z = R (Cousins) = 15.65 mag STARBURST DEC=+16D52'44.20" 0.052 Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 14047( 2) - 26-Feb-2015 16:29:03 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 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 ------------------------------------------------------------------------------------------------------------------------------------ 14047( 2) - 26-Feb-2015 16:29:03 - [ 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 MRK709 WFC3/UVI ACCUM UVIS2-2K2 F680N FLASH=7 1 586 S PATTERN 1 1 S C-SUB (2344 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 MRK709 WFC3/UVI ACCUM UVIS2-2K2 F621M FLASH=6 1 403 S PATTERN 1 2 S C-SUB (1612 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 MRK709 WFC3/IR MULTIAC IRSUB512 F110W SAMP-SEQ=STEP25, NSAMP=9 1 DEF PATTERN 2 3 CUM (422.074 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 | ------------------------------------------------------------------------------------------------------------------------------------ MRK709 1 WFC3/UVI ACCUM UVIS2-2K F680N 1 none none none 1 N/A S 2C-SUB MRK709 1 WFC3/UVI ACCUM UVIS2-2K F680N 2 none none none 1 N/A S 2C-SUB MRK709 1 WFC3/UVI ACCUM UVIS2-2K F680N 3 none none none 1 N/A S 2C-SUB MRK709 1 WFC3/UVI ACCUM UVIS2-2K F680N 4 none none none 1 N/A S 2C-SUB MRK709 2 WFC3/UVI ACCUM UVIS2-2K F621M 1 none none none 2 N/A S 2C-SUB MRK709 2 WFC3/UVI ACCUM UVIS2-2K F621M 2 none none none 2 N/A S 2C-SUB MRK709 2 WFC3/UVI ACCUM UVIS2-2K F621M 3 none none none 2 N/A S 2C-SUB MRK709 2 WFC3/UVI ACCUM UVIS2-2K F621M 4 none none none 2 N/A S 2C-SUB MRK709 3 WFC3/IR MULTIAC IRSUB512 F110W 1 none none none 2 N/A CUM MRK709 3 WFC3/IR MULTIAC IRSUB512 F110W 2 none none none 2 N/A CUM MRK709 3 WFC3/IR MULTIAC IRSUB512 F110W 3 none none none 2 N/A CUM MRK709 3 WFC3/IR MULTIAC IRSUB512 F110W 4 none none none 2 N/A CUM 14047( 2) - 26-Feb-2015 16:29:03 - [ 6] Summary Form for Proposal 14047 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IRSUB512, UVIS2-2K2C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=6, FLASH=7, NSAMP=9, SAMP-SEQ=STEP25 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1, PATTERN 1 2, PATTERN 2 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F621M, F680N ------------------------------------------------------------------------------------------------------------------------------------ Target Names MRK709 ------------------------------------------------------------------------------------------------------------------------------------