This revised version decreases the exposure time to 230 s in order to constrain
the saturation to 40 adjacent pixels. We then take 3 exposures per dither point,
with CR-SPLIT = NO. ----- Attempting Submission 1 (Fri Oct 05 04:02:58 GMT 2007) -----
Phase II Proposal 11344 (OJ287.apt) successfully submitted.
----- Attempting Submission 2 (Wed Oct 10 16:21:53 GMT 2007) -----
Phase II Proposal 11344 (OJ287.apt) successfully submitted.
----- Attempting Submission 3 (Wed Oct 10 23:14:29 GMT 2007) -----
Phase II Proposal 11344 (OJ287.apt) successfully submitted.
----- Attempting Submission 4 (Thu Oct 11 04:53:40 GMT 2007) -----
Phase II Proposal 11344 (OJ287.apt) successfully submitted.
----- Attempting Submission 5 (Tue Oct 16 19:57:17 GMT 2007) -----
Velocity Gradients in the Jets of BL Lac ObjectsWe propose to observe the arcsec-scale jets of 2 BL Lac objects with highly relativistic jets (bulk Lorentz factor of 16) on parsec scales in order to determine whether a velocity gradient exists between the axis and edge of the jet and along the length of the jet. Models both for the morphology of jets in BL Lac objects and for the launching of the jet predict such gradients. If radio-selected BL Lac objects are end-on FR 1 sources, there should be strong X-ray emission from inverse Compton scattering of CMB photons along the highly beamed fast spine of the jet. The imaging observations with Chandra, HST, SST, and the VLA will therefore verify whether such a spine exists and on what length scale it decelerates to nonrelativistic speeds.We will use WFPC2/WFC with filter F606W to observe the BL Lac object OJ287 (the target accepted in Phase I) during two orbits in order to detect and measure the flux of knots in the extended jet. On VLA radio images, the jet extends 10 arcsec to the west of the nucleus, with knots at about 5 and 9 arcsec and possibly some closer. The nucleus has a magnitude of about 14 (highly variable, range of 13-15 mag.) in R-band. We expect the jet knots to have a magnitude of roughly 25, so we will need to use drizzle and Tiny Tim PSF subtraction in order to detect the knots with certainty and to either measure or place interesting upper limits on their angular sizes. Our observations will be long exposures in a boxed dither pattern. We require an orientation of the telescope so that the diffraction spikes are not along the jet, which lies at a position angle of 270D relative to the nucleus.12false0.0falsefalsefalsefalsefalsefalseSUPPORTEDGALAXYBL LACJETKNOTThis object was generated by the targetselector and retrieved from the NED database. The dec given by NED was adjusted slightly to be accurate to within 0.1 arcsec. The main object is highly variable in flux.R-band: 14.0+/-10851+202J200000 00 0.0000+00 00 0.00J2000POS-TARGDITHER0.559017LINE0.559017falsefalse143.130096426.56505WFPC2-BOX1falsetrue/private/tmp/OPVisit34318.xml
(Tic-Visit
:proposal-id 11344
:visit-id "01"
:proposal-version -1
:trans-version "20070709"
:date "16-Oct-2007 15:54:25.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 2
:saa-model "26"
:si-bright-earth-limb-angle 20.0
:data-volume 537792
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 11344
:visit-id "01"
:obset-id "01"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 11344
:visit-id "01"
:orbit-number 1
:pcs-time 355
:si-vis-utilization 2720
:al-overhead-at-end 160
:internal-dur-at-end 0
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3147
:pcs-gap 0
)
(Tic-Orbit
:proposal-id 11344
:visit-id "01"
:orbit-number 2
:pcs-time 355
:si-vis-utilization 2700
: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 3147
:pcs-gap 0
)
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