17523( 6) - 17-Jun-2024 18:24:01 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17523 Version: 6 Check-in Time: 17-Jun-2024 18:24:01 STScI Edit Number: 3 Title Determining the broad line region continuum contribution in NGC 7469 ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Edward M. Cackett Wayne State University Y CoI: Dr. Aaron J. Barth University of California - Irvine N CoI: Dr. Michael R. Goad University of Leicester N CoI: Prof. Kirk T. Korista Western Michigan University N CoI: Ethan Partington Wayne State University N CoI: Dr. Rick Edelson Eureka Scientific Inc. N CoI: Prof. Keith Horne University of St. Andrews N CoI: Dr. Juan V. Hernandez Santisteban University of St. Andrews N ------------------------------------------------------------------------------------ Abstract In the last decade, significant progress in understanding the sizescale and structure of the inner regions of Active Galactic Nuclei has been brought about by high cadence continuum reverberation mapping campaigns. Measuring time lags between light curves at different wavelengths probes sizescales not possible through imaging. Results from these campaigns are now seriously challenging the scenario where X-rays drive variability in a standard optically thick, geometrically thin accretion disk at UV/optical wavelengths. Observational evidence suggests the presence of significant continuum emission from the broad line region (BLR). An 8-month multiwavelength continuum reverberation mapping campaign of the nearby bright Seyfert 1 NGC 7469 is on-going, utilizing NICER, Swift and ground-based monitoring. The UV and optical filter bands used for photometric monitoring include significant contamination by reprocessed emission from the broad-line region, including broad emission lines, Balmer continuum, and Fe II emission. To properly interpret the measured photometric lags therefore requires a careful assessment of the strength of each of these spectral components through the UV and optical. This can only be achieved with HST/STIS spectra covering from 1150 - 10000 Angstrom. ------------------------------------------------------------------------------------ Observations Description ------------------------ Here we will obtain a simultaneous UV/optical spectrum of the AGN NGC 7469. These data are taken to support on-going multiwavelength monitoring of this source with NICER, Swift and ground-based data. That campaign is taking place from began in 2023 May 10 and will continue until 2024 Jan 12. As described in the Phase I proposal, we request that the HST observations take place before 2024 Jan 12. To maximize scheduling flexibility, we do not require any specific orientation or slit position angle. However, since this AGN is highly variable on timescales of days to weeks, it is critically important that the entire program be carried out in a single visit, so that we can obtain an accurate overall spectral shape for the AGN. The scientific goal of these observations is to determine the contribution of 17523( 6) - 17-Jun-2024 18:24:01 - [ 2] broad emission lines, Balmer continuum and Fe II emission to the various broadband filters used in the Swift and ground-based photometric monitoring. To achieve this a contemporaneous broadband spectrum will be obtained with HST using STIS and the G140L, G230L, G430L and G750L gratings. Two orbits have been approved in Phase I, and we will use the first orbit for target acquisition and the G140L exposures. The second orbit will be used for G230L, G430L and G750L. The AGN nucleus is very compact, and thus we will use the ACQTYPE=POINT for the STIS acquisition. We will use the 0.2 arcsec slit width for all spectroscopic exposures. For the CCD exposures, the E1 aperture position will be used to minimize CTE losses. With each grating, we will obtain dithered exposures using the STIS-ALONG-SLIT pattern to remove the effect of bad pixels and cosmic-ray hits in the CCD data and to maximize S/N in the MAMA data following Section 12.5.1 of the STIS Instrument Handbook. We will use the STIS/MAMA in ACCUM mode to maximize the on source integration time, and since the variability timescales are such that we do not expect any detectable variability during a single exposure. The total CCD exposure is less than 30 minutes (including overheads) and thus it is allowable to have both STIS MAMA and CCD exposures in the same orbit. We will use GAIN=4 for the CCD exposures to ensure that the peaks of the Halpha and [OIII] lines are well below the saturation level, based on STIS ETC calculations and a standard type I quasar spectrum. For G750L we will obtain fringe flats at the end of the orbit. Following Table 11.1 of the STIS Instrument Handbook, the 52X0.1 slit will be used for the G750L fringe flats. We choose not to use the 52X0.2E2 aperture position for the G750L observation of the AGN because this will negatively impact the throughput and measurement of the spectral shape when combined with the other grating settings. ------------------------------------------------------------------------------------ 17523( 6) - 17-Jun-2024 18:24:01 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-7469 GALAXY, ACCRETION DISK, RA=23H03M15.6740S, J2000 Z = V = 12.34 4E-14 erg/cm^2/s/A at 1500A BLR, SEYFERT DEC=+08D52'25.28" 0.166 from archival HST/FOS observations Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17523( 6) - 17-Jun-2024 18:24:01 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.2 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.2 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 17523( 6) - 17-Jun-2024 18:24:01 - [ 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 NGC-7469 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 1 S (1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-7469 STIS/FUV ACCUM 52X0.2 G140L 1425 1 676 S PATTERN 3 2 -MAMA (2028 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-7469 STIS/NUV ACCUM 52X0.2 G230L 2376 1 307 S PATTERN 3 3 -MAMA see below (924 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-7469 STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=NO, GAIN=4 1 90 S PATTERN 2 4 see below (364 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-7469 STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=NO, GAIN=4 1 40 S PATTERN 2 5 see below (164 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 DEF (0 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-7469 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A NGC-7469 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 1 N/A -MAMA NGC-7469 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 1 N/A -MAMA NGC-7469 2 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 1 N/A -MAMA NGC-7469 3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 none none none 2 308.0 S -MAMA NGC-7469 3 STIS/NUV ACCUM 52X0.2 G230L 2376 2 none none none 2 308.0 S -MAMA NGC-7469 3 STIS/NUV ACCUM 52X0.2 G230L 2376 3 none none none 2 308.0 S -MAMA NGC-7469 4 STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 none none none 2 91.0 S NGC-7469 4 STIS/CCD ACCUM 52X0.2E1 G430L 4300 2 none none none 2 91.0 S NGC-7469 4 STIS/CCD ACCUM 52X0.2E1 G430L 4300 3 none none none 2 91.0 S NGC-7469 4 STIS/CCD ACCUM 52X0.2E1 G430L 4300 4 none none none 2 91.0 S 17523( 6) - 17-Jun-2024 18:24:01 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-7469 5 STIS/CCD ACCUM 52X0.2E1 G750L 7751 1 none none none 2 41.0 S NGC-7469 5 STIS/CCD ACCUM 52X0.2E1 G750L 7751 2 none none none 2 41.0 S NGC-7469 5 STIS/CCD ACCUM 52X0.2E1 G750L 7751 3 none none none 2 41.0 S NGC-7469 5 STIS/CCD ACCUM 52X0.2E1 G750L 7751 4 none none none 2 41.0 S CCDFLAT 6 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 2 N/A CCDFLAT 6 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 2 N/A 17523( 6) - 17-Jun-2024 18:24:01 - [ 7] Summary Form for Proposal 17523 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.1, 52X0.2, 52X0.2E1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, CR-SPLIT=NO, GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 4, PATTERN 2 5, PATTERN 3 2, PATTERN 3 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, G430L, G750L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names CCDFLAT, NGC-7469 ------------------------------------------------------------------------------------------------------------------------------------