14486( 3) - 23-Feb-2016 20:13:18 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14486 Version: 3 Check-in Time: 23-Feb-2016 20:13:18 STScI Edit Number: 0 Title Catching a Changing Look Quasar as it retreats to the Shadows for the Second Time ------------------------------------------------------------------------------------ Type Cycle GO/DD 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Bernd Husemann European Southern Observatory - Germany Y CoI: Dr. Grant R. Tremblay Yale University N CoI: Dr. Tanya Urrutia Leibniz-Institut fur Astrophysik Potsdam N CoI: Dr. Scott Croom Anglo-Australian Observatory N CoI: Prof. Andreas Eckart Universitat zu Koln N ------------------------------------------------------------------------------------ Abstract We propose an urgent, exciting, and short observation of Mrk 1018, the first changing look quasar ever discovered to unambiguously undergo a full cyclical transformation, flickering from Type 2 (narrow lined), to Type 1 (broad lined), and back to Type 2 once more. The source first transitioned from a Seyfert 1.9 to a Seyfert 1 nucleus in 1984, and remained broad-lined for 29 years. Last week, in analyzing our new VLT/MUSE IFU data, we were astonished to discover that the source has transitioned *back* to a Seyfert 1.9, sometime between 2013 and now. This is the first time a quasar has unambiguously gone "there and back again", and its second retreat to the shadows is not yet complete: the AGN has dimmed by a factor of 50-100 in *both* X-ray and optical since 2013, showing no signs of slowing. This extreme variability is due either to dramatic intermittency in the accretion rate, or because eclipsing clouds, which vacated our line of sight to reveal the broad line region in 1984, are occulting the broad line region once more. *Both* Chandra and HST are urgently needed to discriminate between these two hypotheses. A DDT is necessary because this event may be a very short-lived "flicker" (lasting mere months, rather than another year). With our Chandra DDT approved yesterday, we now require UV-through-NIR photometry with HST to (1) construct a clean pan-chromatic SED of the nucleus during this flicker event, (2) use Ly-a and UV continuum to constrain accretion models, and (3) map the circumnuclear environment on 80 pc scales, while the AGN is very dim. This is a short-lived chance to place simultaneous *temporal* and *physical* constraints on the Type 1 lifetime in a QSO. ------------------------------------------------------------------------------------ Observations Description ------------------------ Standard two-orbit COS/FUV G140L observation of Markarian 1018, using the Primary Science Aperture. 150 sec ACQ/IMAGE observation to center on the UV photocentroid (the point source associated with the AGN). Four science exposures, spread over two orbits, are used to cycle through all four FP-POS positions. ------------------------------------------------------------------------------------ 14486( 3) - 23-Feb-2016 20:13:18 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MRK1018 GALAXY, BLR, QUASAR, RA=02H06M15.9888S +/- 0.25", J2000 Z = V = 15.0 +/- 0.5 maximum continuum flux SEYFERT DEC=-00D17'29.18" +/- 0.25" 0.043 of 1.2e-14erg/s/cm2/A at 1350A from IUE and HST/FOS spectroscopy during bright phase. Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the NED database. ------------------------------------------------------------------------------------------------------------------------------------ 14486( 3) - 23-Feb-2016 20:13:18 - [ 3] Visit: 01 (FUV-COS Mrk1018) Visit Requirements: PCS MODE FINE; BEFORE 29-FEB-2016:10:30:36 On Hold Comments: Additional Comments: UV spectroscopy of Lya and FUV continuum with COS of Mrk 1018 at the nucleus. 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 MRK1018 COS/NUV ACQ/IMA PSA MIRRORB 1 250 S (250 GE S) Comments: The exposure time for the acquisition is based on the assumption that the flux of the AGN nucleus has dropped by up to a factor 100 compared to the bright type 1 phase. We therefore set the exposure times so that the nucleus should be detected. If the source would be as bright as a few years ago the detector count limit would be exceeded by a factor of 3. However, recent ground-based u-band imaging obtained a week ago confirms that the u-band flux has dropped by several magnitudes compared to the original brightness between 1984 and 2012. ------------------------------------------------------------------------------------------------------------------------------------ 2 MRK1018 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=935, FLASH=YES, 1 2140 S G FP-POS=1, SEGMENT=A see below (935 S) Comments: ETC run is attached to verify the maximum count/rates expected if the source would be as bright as in the archival IUE and HST/FOS spectra. However, we suspect that the source has dropped by a factor of ~50-100 in the FUV. Buffer times and count rates should be perfectly fine in any case. ------------------------------------------------------------------------------------------------------------------------------------ 3 MRK1018 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=935, FLASH=YES, 1 2140 S G FP-POS=2, SEGMENT=A see below (935 S) Comments: ETC run is attached to verify the maximum count/rates expected if the source would be as bright as in the archival IUE and HST/FOS spectra. However, we suspect that the source has dropped by a factor of ~50-100 in the FUV. Buffer times and count rates should be perfectly fine in any case. ------------------------------------------------------------------------------------------------------------------------------------ 14486( 3) - 23-Feb-2016 20:13:18 - [ 4] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 MRK1018 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1370, FLASH=YES, 1 1370 S G FP-POS=3, SEGMENT=A see below (1370 S) Comments: ETC run is attached to verify the maximum count/rates expected if the source would be as bright as in the archival IUE and HST/FOS spectra. However, we suspect that the source has dropped by a factor of ~50-100 in the FUV. Buffer times and count rates should be perfectly fine in any case. ------------------------------------------------------------------------------------------------------------------------------------ 5 MRK1018 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1370, FLASH=YES, 1 1350 S G FP-POS=4, SEGMENT=A see below (1370 S) Comments: ETC run is attached to verify the maximum count/rates expected if the source would be as bright as in the archival IUE and HST/FOS spectra. However, we suspect that the source has dropped by a factor of ~50-100 in the FUV. Buffer times and count rates should be perfectly fine in any case. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ MRK1018 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE MRK1018 2 COS/FUV TIME-TA PSA G140L 1105 none none none none 1 935.0 S G MRK1018 3 COS/FUV TIME-TA PSA G140L 1105 none none none none 1 935.0 S G MRK1018 4 COS/FUV TIME-TA PSA G140L 1105 none none none none 2 1370.0 S G MRK1018 5 COS/FUV TIME-TA PSA G140L 1105 none none none none 2 1370.0 S G 14486( 3) - 23-Feb-2016 20:13:18 - [ 5] Summary Form for Proposal 14486 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1370, BUFFER-TIME=935, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, SEGMENT=A ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 29-FEB-2016:10:30:36, PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names MRK1018 ------------------------------------------------------------------------------------------------------------------------------------