0 ----- Attempting Submission 1 (Tue Jul 25 06:18:07 GMT 2017) ----- ----- Attempting Submission 2 (Fri Jul 13 18:53:02 GMT 2018) ----- High-Precision Proper Motions in the M87 Jet As the nearest galaxy with an optical jet, M87 affords an unparalleled opportunity to study extragalactic jet phenomena at the highest resolution. We have previously obtained HST images of the jet with unprecedented resolution which show detailed shock structures as well as numerous unresolved condensations over the first few arcseconds of the jet. Our previous HST monitoring observations have found superluminal motion at speeds up to 6c in many of these features, and showed the formation of new emission regions and rapid variability. The STIS/NUV instrument presents a unique opportunity to measure proper motions in the M87 jet with a single highly stable, high resolution detector across a 19 yr timebase. We will use these new data, together with existing STIS/NUV data, to map the velocity field of the jet with much higher accuracy than previously possible. This will allow us to measure the bulk deceleration of the jet, transverse motions, accelerations / decelerations of individual features, and numerous fainter jet features. We will use this to test models for the structure and kinematics of relativistic jet flows, synchrotron emission regions, and AGN in general. We will obtain STIS NUV F25QTZ images of the jet using a setup which closely duplicates our previous monitor observations. Sub-exposures will be dithered to improve PSF sampling by the 0.024" pixels and minimize detector artifacts. ACCUM mode is used for greatest consistency with past monitoring observations. We do not expect any bright object issues for either the M87 nucleus or jet. Bright object discussion for STIS NUV-MAMA: We made an identical observation (same mode and filter, program 14810) in May 2017, and used these images to check the MAMA-NUV count rate. The brightest compact feature (highest counts/pixel) was the nucleus which had F(lambda)=5.0e-16 erg cm-2 s-1 A-1. With these inputs the ETC gives the brightest pixel as 19 counts/sec (STIS.im.1014493). This is well below the limit of 100 counts/sec. The actual observed maximum counts in the image was only 6 counts/sec, due to pixelation and de-focus effects. The M87 jet has been previously seen to produce a bright flare with an e-folding (factor 3) rise time ~1 year. In May 2017 the same flaring component had only F(lambda)=7.4e-17 erg cm-2 s-1 A-1. Based on this flare timescale and observed flux, the maximum count rate in May 2018 would be <8 counts/sec. Finally we note the flaring component in fact faded between 2016 and 2017, at a rate of 20% loss per year, which suggests it will be far below the limit in 2018. AGN/QUASARS 6 false false false false false false 0.0 0.0 false SUPPORTED GALAXY ELLIPTICAL JET RADIO GALAXY J2000 J2000 WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F814W STIS/NUV-MAMA Imaging No No F25QTZ The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. STIS NUV-MAMA ORIENT chosen to match prior epochs of monitoring observations. POS TARG used to place middle of jet near center of detector. Dithering used to improve PSF sampling and remove any detector artifacts. ACCUM used for greatest consistency with prior observations. A BETWEEN timing constraint is used to place this observation roughly one year after our previous epoch. 1528852774000 105.0 (Tic-Visit :proposal-id 15358 :visit-id "01" :proposal-version -1 :trans-version "20170613" :date "25-Jul-2017 02:15:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 278320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15358 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15358 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2653 :al-overhead-at-end 0 :internal-dur-at-end 450 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2987 :pcs-gap 0 ) true 1 0 See OBSERVING DESCRIPTION for discussion of Bright Object issues. The scheduling data was generated by CASM 26.0. CASM was run in Phase II mode. /private/var/folders/dv/kllm6qvx1m3bq_0v7lp6wwtc000702/T/OPVisit3741832217901360284.xml STIS NUV-MAMA ORIENT chosen to match prior epochs of monitoring observations. POS TARG used to place middle of jet near center of detector. Dithering used to improve PSF sampling and remove any detector artifacts. ACCUM used for greatest consistency with prior observations. A BETWEEN timing constraint is used to place this observation roughly one year after our previous epoch. (Tic-Visit :proposal-id 15358 :visit-id "02" :proposal-version -1 :trans-version "20180409" :date "13-Jul-2018 13:06:06.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 278320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15358 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15358 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2653 :al-overhead-at-end 0 :internal-dur-at-end 450 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2987 :pcs-gap 0 ) true 1 0 See OBSERVING DESCRIPTION for discussion of Bright Object issues.