18192( 3) - 03-Dec-2025 13:40:58 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18192 Version: 3 Check-in Time: 03-Dec-2025 13:40:58 STScI Edit Number: 0 Title Dual Fe Ka peaks in MCG-03-34-64 - a close merger pair in the local Universe? ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. T. Jane Turner Eureka Scientific Inc. Y CoI: Steven B. Kraemer Catholic University of America N CoI: Dr. James N. Reeves Catholic University of America N CoI: Dr. Valentina Braito Catholic University of America N CoI: Dr. Anna Trindade Falcao NASA Goddard Space Flight Center / ORAU N CoI: Dr. Henrique R. Schmitt Naval Research Laboratory N CoI: Dr. Lea Marie Feuillet Catholic University of America N ------------------------------------------------------------------------------------ Abstract ACIS imaging of the nearby Seyfert MCG-03-34-64 has revealed two spatially-resolved peaks of luminous Fe Ka line emission, coincident with radio peaks, comprising a candidate dual AGN. If confirmed, this merger pair - at a separation of just 100 pc - would be the closest dual nuclei detected in multi waveband analysis to date. Establishment of close nuclear pairs offers critical model constraints for galaxy/AGN co-evolution. However, a single nucleus plus shocked gas provides an alternative model for the data. We request 200 ks of ACIS-S time (4x the existing exposure), supported by 2 orbits of HST STIS, to confirm the statistical significance and origin of the Fe Ka peaks and confidently parameterize this important system. ------------------------------------------------------------------------------------ Observations Description ------------------------ In order to map the spatially-resolved kinematics of the NLR emission-line gas, we request a STIS G430M spectrum of [O III] 5007|*| through the 0:200 - 5200 slit. With this, we will achieve a velocity resolution of |*| 60 km/, which is ideal for separating distinct kinematic components and measuring accurate velocity dispersions for each component. The slit will be oriented to cover the bright knots of [O III] present in the archival ACS narrow-band image, with a |*|20 deg tolerance. Based on the [OIII] image, the peak [OIII] fluxes are similar corresponding to a surface brightness of 2|*|10|*|13 erg s|*|1 cm|*|2 arcsec|*|2, while the wings have surface brightness 5|*|10|*|14 erg s|*|1 cm|*|2 arcsec|*|2 and the fainter regions have surface brightness 3|*|10|*|15 erg s|*|1 cm|*|2 arcsec|*|2. Using the STIS ETC, and the NGC 1068 18192( 3) - 03-Dec-2025 13:40:58 - [ 2] spectrum (to represent a Seyfert 2) normalized to the [O III] line with an integration of 40 minutes and the 0:200 |*| 5200 slit, we will achieve a SNR = 75, 33, 3.5 for the 3 regions defined by the 3 [O III] knots. Therefore, we require one orbit for the G430M spectrum. In order to constrain the ionization mechanisms for the optical emission-line gas, we request a G430L spectrum with the same slit and orientation used for the G430M. We base our exposure request on the need to obtain useful S/N for [Ne V] 3426|*|, which, based on the archival ESO-VLT X-Shooter spectra, has a flux 10% that of the integrated [O III] emission, corresponding to a surface brightness of |*| 4 |*| 10|*|13 erg s|*|1 cm|*|2 arcsec|*|2. Using the ETC, we determine that in a 40 minute exposure we will obtain a SNR |*| 7.5 at the average surface brightness, and SNR |*| 3 at 1:5 |*| 10|*|13 erg s|*|1 cm|*|2 arcsec|*|2. The [O II] 3727|*| , [Ne III] 3869|*| , and [O III] 5007 |*| lines are all su|*|ciently bright to map the ionization structure of the NLR with the proposed data, at a slightly lower S/N than that detailed for [O III], above. We require one orbit for the G430L spectrum. For each spectrum, we will obtain three sub exposures at slightly di|*|erent positions along the slit to facilitate the removal of cosmic rays and hot pixels on the CCD images. We will obtain these exposures near the top of the chip (the E1 position) to minimize CTE loss. ------------------------------------------------------------------------------------ 18192( 3) - 03-Dec-2025 13:40:58 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MCG-03-34-06 GALAXY, ACCRETION DISK, RA=13H22M24.4583S +/- 1", J2000 V = 14.9 4 SEYFERT DEC=-16D43'42.48" +/- 1" Reference Frame: ICRS Extended: YES 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 ------------------------------------------------------------------------------------------------------------------------------------ 18192( 3) - 03-Dec-2025 13:40:58 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.567 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18192( 3) - 03-Dec-2025 13:40:58 - [ 5] Visit: 01 Visit Requirements: ORIENT 50D TO 95 D; ORIENT 230D TO 275 D 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 MCG-03-34-0 STIS/CCD ACQ F28X50LP MIRROR 1 3 S (3 S) 64 ------------------------------------------------------------------------------------------------------------------------------------ 2 MCG-03-34-0 STIS/CCD ACCUM 52X0.2 G430L 4300 1 500 S PATTERN 1 2 64 see below (1670 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 MCG-03-34-0 STIS/CCD ACCUM 52X0.2 G430M 5093 1 500 S PATTERN 1 3 64 see below (2100 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 | ------------------------------------------------------------------------------------------------------------------------------------ MCG-03-34-064 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 1 none none 1 1 275.0 S MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 1 none none 2 1 275.0 S MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 2 none none 1 1 260.0 S MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 2 none none 2 1 260.0 S MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 3 none none 1 1 300.0 S MCG-03-34-064 2 STIS/CCD ACCUM 52X0.2 G430L 4300 3 none none 2 1 300.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 1 none none 1 2 350.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 1 none none 2 2 350.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 2 none none 1 2 350.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 2 none none 2 2 350.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 3 none none 1 2 350.0 S MCG-03-34-064 3 STIS/CCD ACCUM 52X0.2 G430M 5093 3 none none 2 2 350.0 S 18192( 3) - 03-Dec-2025 13:40:58 - [ 6] Summary Form for Proposal 18192 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 230D TO 275 D, ORIENT 50D TO 95 D, PATTERN 1 2, PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G430L, G430M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names MCG-03-34-064 ------------------------------------------------------------------------------------------------------------------------------------