0 Assigned ID: 6659 ----- Attempting Submission 1 (Thu Apr 10 20:12:13 GMT 2025) ----- 0 ----- Attempting Submission 1 (Wed Aug 13 09:50:22 GMT 2025) ----- Extreme-UV to Near-UV Spectroscopic Exploration of the Lensed Quasar PG 1115+080 Emerging evidence indicates that traditional models of black hole accretion are incomplete - quasar accretion disks appear systematically larger than predicted, a discrepancy that challenges our understanding of disk structure, black hole growth, and the use of quasars as standard candles. Gravitational microlensing has been proven successful in studying quasar interiors that remain unresolvable by conventional imaging techniques. The gravitationally lensed quasar PG 1115+080 offers an ideal natural experiment; its fold-caustic configuration produces a close image pair that, through microlensing effects, serves as a "zoom" on the smallest emission regions. We propose a small HST/STIS program designed to obtain continuous spectroscopy from the extreme ultraviolet (UV) to the near UV. This extensive spectral coverage will probe the innermost emission regions of the quasar - capturing the hottest accretion disk zones near the Lyman limit and linking them to the extended near UV continuum. Our observations will cover a wealth of emission features, including prominent broad lines and several little-explored lines in the extreme/far UV, thereby offering new insights into the ionization structure and gas kinematics of the broad-line region. By measuring the wavelength-dependent microlensing magnification of the continuum, we will determine the disk size as a function of wavelength - a critical test of thin-disk theory. These observations are especially timely, as HST/STIS is currently the only facility capable of accessing the extreme and far UV regimes. Without it, this spectral window, and the physics it probes, will remain out of reach. Target & Goal: Resolved STIS spectroscopy of PG 1115+080 to extract separate spectra of images A1 and A2. Orient: We require an ORIENT that puts A1 and A2 along the slit with > 0.40 arcsec separation. Acquisition. One STIS/CCD ACQ (POINT) at the start of each visit. Scheduling. Visits limited to short contiguous blocks (2-5 orbits) to avoid MAMA SAA conflicts. FUV-/NUV-MAMA Spectroscopy: Time-Tag; Buffer-Time: 4/5 x ETC. CCD Spectroscopy - G430L & G750L: Accum; we add fringe flats immediately after the red science with no grating move. The proposing team has extensive experience in microlensing studies of quasar interiors and has served as both PIs and co-Is on numerous observational proposals (HST, GTC, WHT). PI Fian is an expert in gravitational microlensing and observational studies of strongly lensed quasars. Over the years, she has led multiple observing programs aimed at using microlensing as a tool to probe the innermost emitting regions of quasars - unlocking key insights into accretion disk structures and broad-line region kinematics. Her expertise qualifies her to lead the proposed HST program, ensuring that the observations will yield robust results on the structure of quasar interiors. Co-PI Chelouche is at the forefront of innovative techniques for probing active galactic nuclei (AGN) interiors. At the Wise Observatory, he has developed a unique monitoring system that unravels the structure and physics of quasar continuum-emitting regions. His recent work - published in Nature Astronomy - demonstrates the capability of these methods to resolve fine spatial details within AGN, providing a strong foundation for the present proposal. Co-I Kaspi is a world-renowned expert on the structure and kinematics of AGN broad-line regions and the leading author of one of the most influential studies in the field (Kaspi et al. 2000). He excels in optical data acquisition, reduction, and time-series analysis. Additionally, he oversees operations at the Wise Observatory, which will provide complementary data overlapping with HST's observations. Co-I Munoz is a leading observational expert in gravitational lensing and microlensing. He has pioneered high-cadence monitoring campaigns of lensed quasars - including PG 1115+080 - using HST and ground-based facilities. His innovative techniques exploit microlensing-induced flux anomalies to derive quasar accretion disk sizes and constrain stellar mass fractions in the vicinity of lensed quasar images, making him ideally suited to collaborate on this project. Co-I Zitrin is a world-class expert in gravitational lensing and mass modeling. In this proposal, he will assist to construct and refine the macro-lens model of PG 1115+080. Co-I Bowen is the collaboration'ss expert in HST performance, data reduction, and analysis. In particular, he has led numerous spectroscopic campaigns using HST's STIS and COS since the early years of the telescope's operation. Supermassive Black Holes and Active Galaxies 6 false true false false false false SUPPORTED GALAXY GRAVITATIONAL LENS QSO QUASAR NO This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 STIS/FUV-MAMA Spectroscopic No No G140L 1425 STIS/NUV-MAMA Spectroscopic No No G230L 2376 STIS/CCD Spectroscopic No No G430L 4300 STIS/CCD Spectroscopic No No G750L 7751 /System/Volumes/Data/solaris/user1/crodriguez/work/hst/OP-cache/18083-v01.xml Timing link suitability includes constraints ([02 After 01 by at most 3.0 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18083 :visit-id "01" :proposal-version -1 :trans-version "20250624" :date "05-Sep-2025 15:06:32.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 870128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18083 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18083 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "01" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 361 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "01" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 2298 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "01" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "01" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 5 0 /System/Volumes/Data/solaris/user1/crodriguez/work/hst/OP-cache/18083-v02.xml Timing link suitability includes constraints ([02 After 01 by at most 3.0 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18083 :visit-id "02" :proposal-version -1 :trans-version "20250624" :date "05-Sep-2025 15:06:32.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18083 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18083 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "02" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 119 :internal-dur-at-end 599 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 2 0 /System/Volumes/Data/solaris/user1/crodriguez/work/hst/OP-cache/18083-v03.xml Timing link suitability includes constraints ([04 After 03 by at most 3.0 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18083 :visit-id "03" :proposal-version -1 :trans-version "20250624" :date "05-Sep-2025 15:06:26.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 870128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18083 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18083 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "03" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 361 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "03" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 2298 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "03" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "03" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 5 0 /System/Volumes/Data/solaris/user1/crodriguez/work/hst/OP-cache/18083-v04.xml Timing link suitability includes constraints ([04 After 03 by at most 3.0 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18083 :visit-id "04" :proposal-version -1 :trans-version "20250624" :date "05-Sep-2025 15:06:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 166048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18083 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18083 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18083 :visit-id "04" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2597 :al-overhead-at-end 119 :internal-dur-at-end 599 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 2 0