HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5124

 

PERIOD COVERED: 5am June 23 - 5am June 24, 2010 (DOY 174/09:00z-175/09:00z)

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS: (None)

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

              SCHEDULED  SUCCESSFUL

FGS GSAcq               6        6      

FGS REAcq               9        9      

OBAD with Maneuver 6        6       

 

SIGNIFICANT EVENTS: (None)

 

 

 

OBSERVATIONS SCHEDULED:

 

ACS/WFC 11655

 

Dynamics of the Galactic Bulge/bar

 

We request second-epoch ACS observations of four star fields in the

Galactic bar. These will allow us to measure proper motions for tens of

thousands of stars well below the turnoff, to construct a dynamical

model for the bulge/bar (in combination with data already in hand from

other HST fields, and from VLT spectroscopy), and hence to take a unique

look at the internal dynamical structure of the central regions of our

Galaxy. By relating the kinematics with stellar population we can

elucidate the formation history of the bulge and bar, and their relation

to the surrounding Galactic disk. This is a resubmission of an approved

Cycle 15 proposal that was hit by the ACS malfunction.

 

ACS/WFC 11996

 

CCD Daily Monitor (Part 3)

 

This program comprises basic tests for measuring the read noise and dark

current of the ACS WFC and for tracking the growth of hot pixels. The

recorded frames are used to create bias and dark reference images for

science data reduction and calibration. This program will be executed

four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To

facilitate scheduling, this program is split into three proposals. This

proposal covers 308 orbits (19.25 weeks) from 21 June 2010 to 1 November

2010.

 

COS/FUV 11541

 

COS-GTO: Cool, Warm, and Hot Gas in the Cosmic Web and in Galaxy Halos

 

COS G130M and G160M 20, 000 resolution observations will be obtained for

17 QSOs to study cool, warm and hot gas in the cosmic web and in galaxy

halos. 5 QSOs with z from 0.177 to 0.574 and sum z = 1.68 will be

observed with S/N = 40-50 per resolution element. 12 QSOs with z = 0.286

to 0.669 and sum z = 5.57 will be observed with S/N = 30-40. The

observations will allow a wide range of IGM studies including

determining the frequency of occurrence of the different types of

absorption systems detected, along with studies of the physical

conditions and elemental abundances in the different systems. Special

emphasis will be given to a study of the properties of highly ionized

IGM as traced by O VI, O V, O IV, N V, and C IV. The high S/N of the

observations will allow a search for broad Lyman alpha absorption and

weak metal line absorption that can be crucial for the evaluation of

physical conditions and elemental abundances. Supporting ground based

observations will allow studies of the association of the absorbers with

galaxy structures along the 17 lines of sight. The overall goal of the

program will be to obtain the information that will allow an assessment

of the baryonic content of the IGM as revealed by UV and EUV absorption

lines seen in the spectra of QSOs.

 

COS/NUV/FUV 11698

 

The Structure and Dynamics of Virgo's Multi-Phase Intracluster Medium

 

The dynamical flows of the intracluster medium (ICM) are largely

unknown. We propose to map the spatial and kinematic distribution of the

warm ICM of the nearby Virgo cluster using the Cosmic Origins

Spectrograph. 15 sightlines at a range of impact parameters within the

virial radius of the cluster (0.2 - 1.7 Mpc) will be probed for

Lyman-alpha absorption and the data compared to blind HI, dust and x-ray

surveys to create a multi-phase map of the cluster's ICM. Absorption

line sightlines are commonly 40-100 kpc from a galaxy, allowing the flow

of baryons between galaxies and the ICM to be assessed. The velocity

distribution of the absorbers will be directly compared to simulations

and used to constrain the turbulent motions of the ICM. This proposal

will result in the first map of a cluster's warm ICM and provide

important tests for our theoretical understanding of cluster formation

and the treatment of gas cooling in cosmological simulations.

 

STIS/CC 11693

 

Follow-up Observations of Debris Disks around Two Solar-Type Stars

 

Circumstellar debris disks offer direct views into the structure of

extrasolar planetary systems. Their constituent dust, seen in scattered

light and thermal emission, is created by the collisions of asteroidal

and cometary parent bodies. The distribution of this dust provides

information on the location of the parent bodies, and can be strongly

affected by planetary perturbations. Dynamical signatures of planets can

include asymmetries, warps, central clearings, and radial gaps in a

disk, and thus are key features to search for in resolved images.

Following up recent Spitzer measurements, we have now detected two new,

nearby debris disks in scattered light. Our initial ACS F606W

coronagraphic images show faint ringlike structures around the

solar-type stars HD 10647 (F9V) and HD 207129 (G0V); both are also

spatially resolved in Spitzer/MIPS 70 micron images. The HD 10647 disk,

seen close to edge-on, represents the first disk ever imaged in

scattered light around a star known to have a radial velocity planet.

The inclined ring around HD 207129 is the faintest disk ever imaged in

scattered light, and seems in the MIPS image to be asymmetric like the

eccentric ring around Fomalhaut. We propose to obtain deep ACS

coronagraphic images of these two disks. Our goals are to get definitive

measurements of the dust spatial distributions (including disk

asymmetries and sharpness of the ring edges), and measure the overall

F606W-F814W color of each disk in order to constrain the dust

properties. The results will be a definitive exploration of the Kuiper

belts of two nearby, Sun-like stars. NOTE: HD 207129 was deleted from

this program.

 

STIS/CC 11845

 

CCD Dark Monitor Part 2

 

Monitor the darks for the STIS CCD.

 

STIS/CC 11847

 

CCD Bias Monitor-Part 2

 

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,

and 1x1 at gain = 4, to build up high-S/N superbiases and track the

evolution of hot columns.

 

STIS/CCD/MA1/MA2 11860

 

MAMA Spectroscopic Sensitivity and Focus Monitor

 

The purpose of this proposal is to monitor the sensitivity of each MAMA

grating mode to detect any change due to contamination or other causes,

and to also monitor the STIS focus in a spectroscopic and an imaging

mode.

 

STIS/MA1/MA2 11857

 

STIS Cycle 17 MAMA Dark Monitor

 

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

 

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

 

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or

five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.

This will give more information on the brightness of the FUV MAMA dark

current as a function of the amount of time that the HV has been on, and

for the NUV MAMA will give a better measure of the short term

temperature dependence.

 

WFC3/IR/S/C 11929

 

IR Dark Current Monitor

 

Analyses of ground test data showed that dark current signals are more

reliably removed from science data using darks taken with the same

exposure sequences as the science data, than with a single dark current

image scaled by desired exposure time. Therefore, dark current images

must be collected using all sample sequences that will be used in

science observations. These observations will be used to monitor changes

in the dark current of the WFC3-IR channel on a day-to-day basis, and to

build calibration dark current ramps for each of the sample sequences to

be used by Gos in Cycle 17. For each sample sequence/array size

combination, a median ramp will be created and delivered to the

calibration database system (CDBS).

 

WFC3/UVIS/IR 11644

 

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into

the Formation of the Outer Solar System

 

The eight planets overwhelmingly dominate the solar system by mass, but

their small numbers, coupled with their stochastic pasts, make it

impossible to construct a unique formation history from the dynamical or

compositional characteristics of them alone. In contrast, the huge

numbers of small bodies scattered throughout and even beyond the

planets, while insignificant by mass, provide an almost unlimited number

of probes of the statistical conditions, history, and interactions in

the solar system. To date, attempts to understand the formation and

evolution of the Kuiper Belt have largely been dynamical simulations

where a hypothesized starting condition is evolved under the

gravitational influence of the early giant planets and an attempt is

made to reproduce the current observed populations. With little

compositional information known for the real Kuiper Belt, the test

particles in the simulation are free to have any formation location and

history as long as they end at the correct point. Allowing compositional

information to guide and constrain the formation, thermal, and

collisional histories of these objects would add an entire new dimension

to our understanding of the evolution of the outer solar system. While

ground based compositional studies have hit their flux limits already

with only a few objects sampled, we propose to exploit the new

capabilities of WFC3 to perform the first ever large-scale

dynamical-compositional study of Kuiper Belt Objects (KBOs) and their

progeny to study the chemical, dynamical, and collisional history of the

region of the giant planets. The sensitivity of the WFC3 observations

will allow us to go up to two magnitudes deeper than our ground based

studies, allowing us the capability of optimally selecting a target list

for a large survey rather than simply taking the few objects that can be

measured, as we have had to do to date. We have carefully constructed a

sample of 120 objects which provides both overall breadth, for a general

understanding of these objects, plus a large enough number of objects in

the individual dynamical subclass to allow detailed comparison between

and within these groups. These objects will likely define the core

Kuiper Belt compositional sample for years to come. While we have many

specific results anticipated to come from this survey, as with any

project where the field is rich, our current knowledge level is low, and

a new instrument suddenly appears which can exploit vastly larger

segments of the population, the potential for discovery -- both

anticipated and not -- is extraordinary.

 

WFC3/UVIS/IR 11909

 

UVIS Hot Pixel Anneal

 

The on-orbit radiation environment of WFC3 will continually generate new

hot pixels. This proposal performs the procedure required for repairing

those hot pixels in the UVIS CCDs. During an anneal, the two-stage

thermo-electric cooler (TEC) is turned off and the four-stage TEC is

used as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of

the CCD warmup, a majority of the hot pixels will be fixed; previous

instruments such as WFPC2 and ACS have seen repair rates of about 80%.

Internal UVIS exposures are taken before and after each anneal, to allow

an assessment of the procedure's effectiveness in WFC3, provide a check

of bias, global dark current, and hot pixel levels, as well as support

hysteresis (bowtie) monitoring and CDBS reference file generation. One

IR dark is taken after each anneal, to provide a check of the IR

detector.