HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4515

 

PERIOD COVERED: UT December 27, 2007 (DOY 361)

 

OBSERVATIONS SCHEDULED

 

 

NIC1/NIC2/NIC3 11330

 

NICMOS Cycle 16 Extended Dark

 

This takes a series of Darks in parallel to other instruments.

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA calibration - CR Persistence Part 6

 

A new procedure proposed to alleviate the CR-persistence problem of

NICMOS. Dark frames will be obtained immediately upon exiting the SAA

contour 23, and every time a NICMOS exposure is scheduled within 50

minutes of coming out of the SAA. The darks will be obtained in parallel

in all three NICMOS Cameras. The POST-SAA darks will be non- standard

reference files available to users with a USEAFTER date/time mark. The

keyword 'USEAFTER=date/time' will also be added to the header of each

POST-SAA DARK frame. The keyword must be populated with the time, in

addition to the date, because HST crosses the SAA ~8 times per day so

each POST-SAA DARK will need to have the appropriate time specified, for

users to identify the ones they need. Both the raw and processed images

will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS

science/calibration observations started within 50 minutes of leaving an

SAA will need such maps to remove the CR persistence from the science i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

 

NIC3 11064

 

CYCLE 15 NICMOS SPECTROPHOTOMETRY CALIBRATION PROGRAM

 

Now that the spectrophotometric capabilities of the NICMOS grism have

been established, cycle 15 observations are needed to refine the

sensitivity estimates, to check for sensitivity loss with time, to

improve the accuracy of the linearity correction, to improve the

secondary flux standards by re-observation, and to expand the G206 data

set now that the sky subtraction technique has been shown to produce

useful fluxes for some of the fainter secondary standards. These faint

secondary IR standards will be a significant step towards establishing

flux standards for JWST, as well as for SNAP, Spitzer, and SOFIA. 1.Re-

observe the 3 primary WDs GD71, G191B2b, & GD153 twice each, once at the

beginning and once near the end of the 18 month cycle. To date, we have

only 2 observation of each star, while the corresponding STIS data set

for these primary standards ranges from 6 to 23 obs. No observations

exist for GD71 or GD153 with G206, so that the current G206 sensitivity

is defined solely by G191B2B. Purposes: Refine sensitivities, measure

sens losses. Orbits: 2 for each of 6 visits = 12 2. Re-observe WD1057 &

WD1657 plus another P041C lamp-on visit to improve the scatter in the

non-lin measurements per Fig. 8 of NIC ISR 2006-02. The WD stars require

2 orbits each, while the lamp-on test is done in one. The very faintest

and most crucial standard WD1657 has 2 good visits already, so to

substantially improve the S/N, two visits of two orbits are needed.

Include G206 for P041C in the lamp-off baseline part of that orbit.

Orbits: WD1057-2, WD1657-4, P041C-1 --> 7 3. Re-observe 9 secondary

standards to improve S/N of the faint ones and to include G206 for all

9. BD+17 {3 obs} is not repeated in this cycle. Four are bright enough

to do in one orbit: VB8, 2M0036+18, P330E, and P177D. Orbits:2*5+4=14

Grand Total orbits over 18 month cycle 15 is 12+6+14=32 {Roelof will

submit the P041C lamp-on visit in a separate program.}

 

WFPC2 11124

 

The Origin of QSO Absorption Lines from QSOs

 

We propose using WFPC2 to image the fields of 10 redshift z ~ 0.7

foreground {FG} QSOs which lie within ~29-151 kpc of the sightlines to

high-z background {BG} QSOs. A surprisingly high fraction of the BG QSO

spectra show strong MgII {2796,2803} absorption lines at precisely the

same redshifts as the FG QSOs. The high resolution capabilities of WFPC2

are needed to understand the origin of these absorption systems, in two

ways. First, we wish to explore the FG QSO environment as close as

possible to the position of the BG QSO, to search for interloping group

or cluster galaxies which might be responsible for the absorption, or

irregularly shaped post-merger debris between the FG and BG QSO which

may indicate the presence of large amount of disrupted gas along a

sightline. Similarly, high resolution images are needed to search for

signs of tidal interactions between any galaxies which might be found

close to the FG QSO. Such features might provide evidence of young

merging events causing the start of QSO duty cycles and producing

outflows from the central AGN. Such winds may be responsible for the

observed absorption lines. Second, we seek to measure the intrinsic

parameters of the FG QSO host galaxy, such as luminosity and morphology,

to correlate with the properties of the MgII absorption lines. We wish

to observe each field through the F814W filter, close to the rest-frame

B-band of the FG QSO. These blue data can reveal enhanced star formation

regions close to the nucleus of the host galaxy, which may be indicative

of galaxy mergers with the FG QSO host. The FG QSO environment offers

quite a different set of phenomena which might be responsible for MgII

absorption, providing an important comparison to studies of MgII

absorption from regular field galaxies.

 

WFPC2 11202

 

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

 

The structure, formation and evolution of early-type galaxies is still

largely an open problem in cosmology: how does the Universe evolve from

large linear scales dominated by dark matter to the highly non-linear

scales of galaxies, where baryons and dark matter both play important,

interacting, roles? To understand the complex physical processes

involved in their formation scenario, and why they have the tight

scaling relations that we observe today {e.g. the Fundamental Plane}, it

is critically important not only to understand their stellar structure,

but also their dark-matter distribution from the smallest to the largest

scales. Over the last three years the SLACS collaboration has developed

a toolbox to tackle these issues in a unique and encompassing way by

combining new non-parametric strong lensing techniques, stellar

dynamics, and most recently weak gravitational lensing, with

high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic

data of early-type lens systems. This allows us to break degeneracies

that are inherent to each of these techniques separately and probe the

mass structure of early-type galaxies from 0.1 to 100 effective radii.

The large dynamic range to which lensing is sensitive allows us both to

probe the clumpy substructure of these galaxies, as well as their

low-density outer haloes. These methods have convincingly been

demonstrated, by our team, using smaller pilot-samples of SLACS lens

systems with HST data. In this proposal, we request observing time with

WFPC2 and NICMOS to observe 53 strong lens systems from SLACS, to obtain

complete multi-color imaging for each system. This would bring the total

number of SLACS lens systems to 87 with completed HST imaging and

effectively doubles the known number of galaxy-scale strong lenses. The

deep HST images enable us to fully exploit our new techniques, beat down

low-number statistics, and probe the structure and evolution of

early-type galaxies, not only with a uniform data-set an order of

magnitude larger than what is available now, but also with a fully

coherent and self-consistent methodological approach!

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS:

11123 - REAcq2,3,2) failed to RGA Hold (Gyro Control)

           REAcq(2,3,2) scheduled at 361/16:02:00 - 16:10:05 failed to RGA Hold due

           to a Search Radius Limit Exceeded Error on FGS-2. ESB 1805

           (T2G_MOVING)TARGET_DETECTED) was received at 361/16:02:39 post-OBAD2.

           One ESB "a05" (FGS Coarse Track failed-Search Radius Limit Exceeded) was

           received at 361/16:07:34. Pre-acquisition OBAD1 attitude correction

           value not available due to LOS. Pre-acq OBAD2 had (RSS) value of 44.61

           arcseconds. Post-acq OBAD/MAP had (RSS) value of 194.34 arcseconds. At

           361/16:14:07 Equation F3SOB flagged indicating Stuck-on-Bottom. (OPS

           REQUEST 17597-9) FHST Stuck-on-Bottom Macro was executed at

           361/16:18:49. F3SOB was back in bounds at 361/16:19:12.

 

           Subsequent REAcq(2,3,2)scheduled at 361/17:38:42 was successful.

 

COMPLETED OPS REQUEST:

17597-9 - FHST Stuck-on-Bottom Macro Execution

 

COMPLETED OPS NOTES: (None)

 

                       SCHEDULED      SUCCESSFUL

FGS GSacq               07                  07          

FGS REacq               08                  07                

OBAD with Maneuver 30                  30               

 

SIGNIFICANT EVENTS: (None)