We propose to obtain HST polarimetry of the jets of the quasars 1150+497 and PKS 1136-135. Our goal is to solve the riddle of their high-energy emission mechanism, and tackle issues such as particle acceleration and jet dynamics. Our targets are the optically brightest quasar jets, and they span the range of luminosities and beaming parameters seen in these objects. Recent observations with Spitzer, HST and Chandra have shed new light on the spectral morphology of quasar jets, throwing wide open the question of the nature of their optical and X-ray emission. Three mechanisms are possible, including synchrotron emission as well as two Comptonization processes. Polarimetry can uniquely determine which of these mechanisms operates in the optical. We will compare the optical polarimetry to in-hand radio polarimetry as well as in-hand and new Spitzer, HST and Chandra imaging to gain new insights on the structure of these jets, as well as particle acceleration mechanisms and jet dynamics.

In this proposal, our aim is to obtain polarimetry of the jets of the quasars of PKS 1136-135 and 1150+497. We are doing these observations with NICMOS/NIC2/POLL for 1150+497 and with WFPC2/WF/F555W/POLQ for PKS1136-135. The different instruments and hence observing bands have been chosen to meet the needs of their respective spectral energy distributions. Observations of PKS 1136-135 have been broken down into 2 visits per polarizer because of the number of orbits (7 per polarizer). We are requiring all observations of a given object to have the same ORIENT. This cuts down on rotations, which are an unnecessary complicating factor, particularly when the polarizers are in. We are restricting ORIENTs so that the jet is not near a diffraction spike. Observations of a background field have been included for 1150+497. We are doing this with a POS TARG, hence the warning. All background observations for 1150+497 are being done in a single orbit (orbit 4 within visit 03). AGN/QUASARS 12 false 0.0 0.0 false false false false false false SUPPORTED GALAXY JET QSO QUASAR RADIO GALAXY This object was generated by the targetselector and retrieved from the NED database. J2000 11 39 10.7000 -13 50 44.00 J2000 GALAXY JET QSO QUASAR RADIO GALAXY This object was generated by the targetselector and retrieved from the NED database. J2000 11 53 24.5000 +49 31 8.80 J2000 NIC2 Imaging No Yes WFPC2 Imaging Yes F555W WFPC2 Imaging Yes F555W WFPC2 Imaging Yes F555W POS-TARG DITHER 0.3535 LINE false false 4 45.0 WFPC2-LINE 2 false POS-TARG DITHER 0.3535 LINE false false 3 45.0 WFPC2-LINE 3 false POS-TARG DITHER 0.170 LINE false false 3 47.23 ACS-WFC-DITHER-LINE 4 false POS-TARG DITHER 0.170 LINE false false 2 47.23 ACS-WFC-DITHER-LINE 5 false Timing link suitability includes constraints ([Sequence (01 02 03) within 14.0 days] [02 After 01 by 0.1 to 14.0 days] [03 After 01 by 0.1 to 14.0 days]) Same orient constraint links visits (01 02 03) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1150+497 OBSERVATIONS (Tic-Visit :proposal-id 11138 :visit-id "01" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:49:35.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 210736 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2804 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2722 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2722 :al-overhead-at-end 0 :internal-dur-at-end 269 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3183 :pcs-gap 0 ) false 3 0 Timing link suitability includes constraints ([Sequence (01 02 03) within 14.0 days] [02 After 01 by 0.1 to 14.0 days]) Same orient constraint links visits (01 02 03) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1150+497 OBSERVATIONS visit 2 (Tic-Visit :proposal-id 11138 :visit-id "02" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 210736 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2804 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2722 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2722 :al-overhead-at-end 0 :internal-dur-at-end 269 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3183 :pcs-gap 0 ) false 3 0 Timing link suitability includes constraints ([Sequence (01 02 03) within 14.0 days] [03 After 01 by 0.1 to 14.0 days]) Same orient constraint links visits (01 02 03) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1150+497 OBSERVATIONS visit 3 (Tic-Visit :proposal-id 11138 :visit-id "03" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:52:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 772720 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2850 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2961 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2961 :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 3183 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "03" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2960 :al-overhead-at-end 0 :internal-dur-at-end 346 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3183 :pcs-gap 0 ) false 4 0 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [51 After 50 by 0.1 to 14.0 days] [60 After 50 by 0.1 to 14.0 days] [61 After 50 by 0.1 to 14.0 days] [70 After 50 by 0.1 to 14.0 days] [71 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATIONS visit 1 1204462402000 348.628005981 (Tic-Visit :proposal-id 11138 :visit-id "50" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:29.0" :trans-errors '(:WARNINGS 11 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "50" :obset-id "50" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "50" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "50" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "50" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "50" :orbit-number 4 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "50" :orbit-number 5 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 5 3 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [51 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATIONS visit 1 1204548747000 348.6280059812227 (Tic-Visit :proposal-id 11138 :visit-id "51" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:36.0" :trans-errors '(:WARNINGS 8 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "51" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "51" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "51" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "51" :orbit-number 4 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 4 2 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [60 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATION VISIT 2 1204635042000 348.6280059812227 (Tic-Visit :proposal-id 11138 :visit-id "60" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:37.0" :trans-errors '(:WARNINGS 11 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "60" :obset-id "60" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "60" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "60" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "60" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "60" :orbit-number 4 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "60" :orbit-number 5 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 5 3 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [61 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATION VISIT 2 1204807668000 348.6280059812227 (Tic-Visit :proposal-id 11138 :visit-id "61" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:39.0" :trans-errors '(:WARNINGS 8 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "61" :obset-id "61" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "61" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "61" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "61" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "61" :orbit-number 4 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 4 2 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [70 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATION VISIT 3 1205055087000 348.6280059812227 (Tic-Visit :proposal-id 11138 :visit-id "70" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:40.0" :trans-errors '(:WARNINGS 11 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "70" :obset-id "70" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "70" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "70" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "70" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "70" :orbit-number 4 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "70" :orbit-number 5 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 5 3 Timing link suitability includes constraints ([Sequence (50 51 60 61 70 71) within 14.0 days] [71 After 50 by 0.1 to 14.0 days]) Same orient constraint links visits (50 51 60 61 70 71) The scheduling data was generated by CASM 17.5. CASM was run in Phase II mode. 1136-135 OBSERVATION VISIT 3 1205665076000 348.6280059812227 (Tic-Visit :proposal-id 11138 :visit-id "71" :proposal-version -1 :trans-version "20090915" :date "20-Nov-2009 09:41:42.0" :trans-errors '(:WARNINGS 8 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11138 :visit-id "71" :obset-id "71" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11138 :visit-id "71" :orbit-number 1 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "71" :orbit-number 2 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "71" :orbit-number 3 :pcs-time 355 :si-vis-utilization 3060 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11138 :visit-id "71" :orbit-number 4 :pcs-time 355 :si-vis-utilization 1440 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 4 2