HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #5152



PERIOD COVERED: 5am August 3 - 5am August 4, 2010 (DOY 215/09:00z-216/09:00z)



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:



FOR DOY 200

12346 - GSAcq(1,2,1) at 200/07:14:07z required three attempts to achieve

FL-DV on FGS1, receiving scan step limit exceeded twice. The acquisition

was successful.



COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 6 6

FGS REAcq 9 9

OBAD with Maneuver 4 4



SIGNIFICANT EVENTS: (None)





OBSERVATIONS SCHEDULED:



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.



ACS/WFC 12327



Calibration of the ACS CTE at Low Signal Levels



The empirical pixed-based CTE correction algorithm of Anderson & Bedin

(2010) provides excellent results for ACS/WFC pixel signals above ~10

DN, but it is not well calibrated for smaller signals because of the

lack of uncontaminated "warm-pixel" trails in standard long-exposure

dark frames. To improve the CTE model at signals below ~ 10 DN, short

dark frames are needed to obtain a statistically useful sample of clean,

warm pixel trails. This program obtains 9 dark frames for each of the

following exposure times: 33 s, 100 s, and 339 s. These short darks and

the 1000 s darks obtained from the CCD Daily Monitor will sample warm

and hot pixels over logarithmically increasing brightness.



ACS/WFC3 11882



CCD Hot Pixel Annealing



This program continues the monthly anneal that has taken place every

four weeks for the last three cycles. We now obtain WFC biases and darks

before and after the anneal in the same sequence as is done for the ACS

daily monitor (now done 4 times per week). So the anneal observation

supplements the monitor observation sets during the appropriate week.

Extended Pixel Edge Response (EPER) and First Pixel Response (FPR) data

will be obtained over a range of signal levels for the Wide Field

Channel (WFC). This program emulates the ACS pre-flight ground

calibration and post-launch SMOV testing (program 8948), so that results

from each epoch can be directly compared. The High Resolution Channel

(HRC) visits have been removed since it could not be repaired during

SM4.



This program also assesses the read noise, bias structure, and amplifier

cross-talk of ACS/WFC using the GAIN=1.4 A/D conversion setting. This

investigation serves as a precursor to a more comprehensive study of WFC

performance using GAIN=1.4.



COS/FUV 11625



Beyond the Classical Paradigm of Stellar Winds: Investigating Clumping,

Rotation and the Weak Wind Problem in SMC O Stars



SMC O stars provide an unrivaled opportunity to probe star formation,

evolution, and the feedback of massive stars in an environment similar

to the epoch of the peak in star formation history. Two recent

breakthroughs in the study of hot, massive stars have important

consequences for understanding the chemical enrichment and buildup of

stellar mass in the Universe. The first is the realization that rotation

plays a major role in influencing the evolution of massive stars and

their feedback on the surrounding environment. The second is a drastic

downward revision of the mass loss rates of massive stars coming from an

improved description of their winds. STIS spectroscopy of SMC O stars

combined with state-of-the-art NLTE analyses has shed new light on these

two topics. A majority of SMC O stars reveal CNO- cycle processed

material brought at their surface by rotational mixing. Secondly, the

FUV wind lines of early O stars provide strong indications of the

clumped nature of their wind. Moreover, we first drew attention to some

late-O dwarfs showing extremely weak wind signatures. Consequently, we

have derived mass loss rates from STIS spectroscopy that are

significantly lower than the current theoretical predictions used in

evolutionary models. Because of the limited size of the current sample

(and some clear bias toward stars with sharp-lined spectra), these

results must however be viewed as tentative. Thanks to the high

efficiency of COS in the FUV range, we propose now to obtain

high-resolution FUV spectra with COS of a larger sample of SMC O stars

to study systematically rotation and wind properties of massive stars at

low metallicity. The analysis of the FUV wind lines will be based on our

2D extension of CMFGEN to model axi-symmetric rotating winds.



COS/FUV/STIS/CCD/MA1 11592



Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A

Survey of Galactic Halo Stars at z>3 kpc



Cosmological simulation predicts that highly ionized gas plays an

important role in the formation and evolution of galaxies and their

interplay with the intergalactic medium. The NASA HST and FUSE missions

have revealed high-velocity CIV and OVI absorption along extragalactic

sightlines through the Galactic halo. These highly ionized high-velocity

clouds (HVCs) could cover 85% of the sky and have a detection rate

higher than the HI HVCs. Two competing, equally exciting, theories may

explain the origin of these highly ionized HVCs: 1) the "Galactic"

theory, where the HVCs are the result of feedback processes and trace

the disk-halo mass exchange, perhaps including the accretion of matter

condensing from an extended corona; 2) the "Local Group" theory, where

they are part of the local warm-hot intergalactic medium, representing

some of the missing baryonic matter of the Universe. Only direct

distance determinations can discriminate between these models. Our group

has found that some of these highly ionized HVCs have a Galactic origin,

based on STIS observations of one star at z<5.3 kpc. We propose an HST

FUV spectral survey to search for and characterize the high velocity NV,

CIV, and SiIV interstellar absorption toward 24 stars at much larger

distances than any previous searches (4<d<21 kpc, 3<|z|<13 kpc). COS

will provide atomic to highly ionized species (e.g.,OI, CII, CIV, SiIV)

that can be observed at sufficient resolution (R~22, 000) to not only

detect these highly ionized HVCs but also to model their properties and

understand their physics and origins. This survey is only possible

because of the high sensitivity of COS in the FUV spectral range.



NIC2/WFC3/IR 11548



Infrared Imaging of Protostars in the Orion A Cloud: The Role of

Environment in Star Formation



We propose NICMOS and WFC3/IR observations of a sample of 252 protostars

identified in the Orion A cloud with the Spitzer Space Telescope. These

observations will image the scattered light escaping the protostellar

envelopes, providing information on the shapes of outflow cavities, the

inclinations of the protostars, and the overall morphologies of the

envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron

spectra of 75 of the protostars. Combining these new data with existing

3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured

with the Spitzer Space Telescope, we will determine the physical

properties of the protostars such as envelope density, luminosity,

infall rate, and outflow cavity opening angle. By examining how these

properties vary with stellar density (i.e. clusters vs. groups vs.

isolation) and the properties of the surrounding molecular cloud; we can

directly measure how the surrounding environment influences protostellar

evolution, and consequently, the formation of stars and planetary

systems. Ultimately, this data will guide the development of a theory of

protostellar evolution.



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.



WFC3/ACS/IR 11563



Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to

<0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields



The first generations of galaxies were assembled around redshifts

z~7-10+, just 500-800 Myr after recombination, in the heart of the

reionization of the universe. We know very little about galaxies in this

period. Despite great effort with HST and other telescopes, less than

~15 galaxies have been reliably detected so far at z>7, contrasting with

the ~1000 galaxies detected to date at z~6, just 200-400 Myr later, near

the end of the reionization epoch. WFC3 IR can dramatically change this

situation, enabling derivation of the galaxy luminosity function and its

shape at z~7-8 to well below L*, measurement of the UV luminosity

density at z~7-8 and z~8-9, and estimates of the contribution of

galaxies to reionization at these epochs, as well as characterization of

their properties (sizes, structure, colors). A quantitative leap in our

understanding of early galaxies, and the timescales of their buildup,

requires a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can

achieve this with 192 WFC3 IR orbits on three disjoint fields

(minimizing cosmic variance): the HUDF and the two nearby deep fields of

the HUDF05. Our program uses three WFC3 IR filters, and leverages over

600 orbits of existing ACS data, to identify, with low contamination, a

large sample of over 100 objects at z~7-8, a very useful sample of ~23

at z~8-9, and limits at z~10. By careful placement of the WFC3 IR and

parallel ACS pointings, we also enhance the optical ACS imaging on the

HUDF and a HUDF05 field. We stress (1) the need to go deep, which is

paramount to define L*, the shape, and the slope alpha of the luminosity

function (LF) at these high redshifts; and (2) the far superior

performance of our strategy, compared with the use of strong lensing

clusters, in detecting significant samples of faint z~7-8 galaxies to

derive their luminosity function and UV ionizing flux. Our recent z~7.4

NICMOS results show that wide-area IR surveys, even of GOODS-like depth,

simply do not reach faint enough at z~7-9 to meet the LF and UV flux

objectives. In the spirit of the HDF and the HUDF, we will waive any

proprietary period, and will also deliver the reduced data to STScI. The

proposed data will provide a Legacy resource of great value for a wide

range of archival science investigations of galaxies at redshifts z~2-9.

The data are likely to remain the deepest IR/optical images until JWST

is launched, and will provide sources for spectroscopic followup by

JWST, ALMA and EVLA.



WFC3/ACS/UVIS 11877



HST Cycle 17 and Post-SM4 Optical Monitor



This program is the Cycle 17 implementation of the HST Optical

Monitoring Program.



The 36 orbits comprising this proposal will utilize ACS (Wide Field

Channel) and WFC3 (UVIS Channel) to observe stellar cluster members in

parallel with multiple exposures over an orbit. Phase retrieval

performed on the PSF in each image will be used to measure primarily

focus, with the ability to explore apparent coma, and astigmatism

changes in WFC3.



The goals of this program are to: 1) monitor the overall OTA focal

length for the purposes of maintaining focus within science tolerances

2) gain experience with the relative effectiveness of phase retrieval on

WFC3/UVIS PSFs 3) determine focus offset between the imagers and

identify any SI-specific focus behavior and dependencies



If need is determined, future visits will be modified to interleave

WFC3/IR channel and STIS/CCD focii measurements.



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 11594



A WFC3 Grism Survey for Lyman Limit Absorption at z=2



We propose to conduct a spectroscopic survey of Lyman limit absorbers at

redshifts 1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal

intends to complete an approved Cycle 15 SNAP program (10878), which was

cut short due to the ACS failure. We have selected 64 quasars at 2.3 < z

< 2.6 from the Sloan Digital Sky Survey Spectroscopic Quasar Sample, for

which no BAL signature is found at the QSO redshift and no strong metal

absorption lines are present at z > 2.3 along the lines of sight. The

survey has three main observational goals. First, we will determine the

redshift frequency dn/dz of the LLS over the column density range 16.0 <

log(NHI) < 20.3 cm^-2. Second, we will measure the column density

frequency distribution f(N) for the partial Lyman limit systems (PLLS)

over the column density range 16.0 < log(NHI) < 17.5 cm^-2. Third, we

will identify those sightlines which could provide a measurement of the

primordial D/H ratio. By carrying out this survey, we can also help

place meaningful constraints on two key quantities of cosmological

relevance. First, we will estimate the amount of metals in the LLS using

the f(N), and ground based observations of metal line transitions.

Second, by determining f(N) of the PLLS, we can constrain the amplitude

of the ionizing UV background at z~2 to a greater precision. This survey

is ideal for a snapshot observing program, because the on-object

integration times are all well below 30 minutes, and follow-up

observations from the ground require minimal telescope time due to the

QSO sample being bright.



WFC3/UVIS 11903



UVIS Photometric Zero Points



This proposal obtains the photometric zero points in 53 of the 62

UVIS/WFC3 filters: the 18 broad-band filters, 8 medium-band filters, 16

narrow-band filters, and 11 of the 20 quad filters (those being used in

cycle 17). The observations will be primary obtained by observing the

hot DA white dwarf standards GD153 and G191-B2B. A redder secondary

standard, P330E, will be observed in a subset of the filters to provide

color corrections. Repeat observations in 16 of the most widely used

cycle 17 filters will be obtained once per month for the first three

months, and then once every second month for the duration of cycle 17,

alternating and depending on target availability. These observations

will enable monitoring of the stability of the photometric system.

Photometric transformation equations will be calculated by comparing the

photometry of stars in two globular clusters, 47 Tuc and NGC 2419, to

previous measurements with other telescopes/instruments.



WFC3/UVIS 11905



WFC3 UVIS CCD Daily Monitor



The behavior of the WFC3 UVIS CCD will be monitored daily with a set of

full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals throughout the

cycle to support subarray science observations. The internals from this

proposal, along with those from the anneal procedure (Proposal 11909),

will be used to generate the necessary superbias and superdark reference

files for the calibration pipeline (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.