HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #5053



PERIOD COVERED: 5am March 15 - 5am March 16, 2010 (DOY 074/10:00z-075/10:00z)



OBSERVATIONS SCHEDULED



ACS/WFC 11995



CCD Daily Monitor (Part 2)



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 320 orbits (20 weeks) from 1 February 2010 to 20 June

2010.



ACS/WFC3 11882



CCD Hot Pixel Annealing



All the data for this program is acquired using internal targets (lamps)

only, so all of the exposures should be taken during Earth occultation

time (but not during SAA passages). 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.

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). The High Resolution Channel (HRC) visits have been

removed since it could not be repaired during SM4.



ACS/WFC3/STIS/CCD 11889



Photometric Cross-Calibration using Stellar Flux Standards



The purpose of this proposal is to: A) Verify the ACS HRC and WFC

photometric calibrations with a repeat visit to one of the three primary

WDs. B) Measure the change in sensitivity with time for bright stars

(which would include any small CTE contributions). C) Continue to

investigate the ~2% discrepancy between ACS flux calibration and that of

STIS (ACS ISR 2007-06). The goal is to measure any filter bandpass

shifts in ACS or rule out the possibility of shifts as the primary

contributors to the ACS/STIS discrepancy for cool stars.



COS/FUV 11895



FUV Detector Dark Monitor



The purpose of this proposal is to monitor the FUV detector dark rate by

taking long science exposures without illuminating the detector. The

detector dark rate and spatial distribution of counts will be compared

to pre-launch and SMOV data in order to verify the nominal operation of

the detector. Variations of count rate as a function of orbital position

will be analyzed to find dependence of dark rate on proximity to the

SAA. Dependence of dark rate as function of time will also be tracked.



COS/NUV 11894



NUV Detector Dark Monitor



The purpose of this proposal is to measure the NUV detector dark rate by

taking long science exposures with no light on the detector. The

detector dark rate and spatial distribution of counts will be compared

to pre-launch and SMOV data in order to verify the nominal operation of

the detector. Variations of count rate as a function of orbital position

will be analyzed to find dependence of dark rate on proximity to the

SAA. Dependence of dark rate as function of time will also be tracked.



COS/NUV/FUV 11728



The Impact of Starbursts on the Gaseous Halos of Galaxies



Perhaps the most important (yet uncertain) aspects of galaxy evolution

are the processes by which galaxies accrete gas and by which the

resulting star formation and black hole growth affects this accreting

gas. It is believed that both the form of the accretion and the nature

of the feedback change as a function of the galaxy mass. At low mass the

gas comes in cold and the feedback is provided by massive stars. At high

mass, the gas comes in hot, and the feedback is from an AGN. The

changeover occurs near the mass where the galaxy population transitions

from star-forming galaxies to red and dead ones. The population of red

and dead galaxies is building with cosmic time, and it is believed that

feedback plays an important role in this process: shutting down star

formation by heating and/or expelling the reservoir of cold halo gas. To

investigate these ideas, we propose to use COS far-UV spectra of

background QSOs to measure the properties of the halo gas in a sample of

galaxies near the transition mass that have undergone starbursts within

the past 100 Myr to 1 Gyr. The galactic wind associated with the

starburst is predicted to have affected the properties of the gaseous

halo. To test this, we will compare the properties of the halos of the

post-starburst galaxies to those of a control sample of galaxies matched

in mass and QSO impact parameter. Do the halos of the post-starburst

galaxies show a higher incidence rate of Ly-Alpha and metal

absorption-lines? Are the kinematics of the halo gas more disturbed in

the post-starbursts? Has the wind affected the ionization state and/or

the metallicity of the halo? These data will provide fresh new insights

into the role of feedback from massive stars on the evolution of

galaxies, and may also offer clues about the properties of the QSO metal

absorption-line systems at high-redshift .



NIC3/WFC3/IR 11149



Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman

Break Galaxies at 5.7<z<7 in the Subaru Deep Field



The epoch of reionization marks a major phase transition of the

Universe, during which the intergalactic space became transparent to UV

photons. Determining when this occurred and the physical processes

involved represents the latest frontier in observational cosmology. Over

the last few years, searches have intensified to identify the population

of high-redshift (z>6) galaxies that might be responsible for this

process, but the progress is hampered partly by the difficulty of

obtaining physical information (stellar mass, age, star formation

rate/history) for individual sources. This is because the number of z>6

galaxies that have both secure spectroscopic redshifts and high-quality

infrared photometry (especially with Spitzer/IRAC) is still fairly

small. Considering that only several photometric points are available

per source, and that many model SEDs are highly degenerate, it is

crucial to obtain as many observational constraints as possible for each

source to ensure the validity of SED modeling. To better understand the

physical properties of high-redshift galaxies, we propose here to

conduct HST/NICMOS (72 orbits) and Spitzer/IRAC (102 hours) imaging of

spectroscopically confirmed, bright (z<26 mag (AB)) Ly-alpha emitters

(LAEs) and Lyman-break galaxies (LBGs) at 5.7<z<7 selected from the

Subaru Deep Field. Spectroscopic redshifts remove one critical free

parameter from SED modeling while bright source magnitudes ensure

high-quality photometric data. By making accurate determinations of

stellar masses, ages, and star-formation histories, we will specifically

address the following major questions: (1) Do LAEs and LBGs represent

physically different galaxy populations at z>6 as suggested recently?

(2) Is Ly-alpha emission systematically suppressed at z>6 with respect

to continuum emission? (i.e., are we reaching the epoch of incomplete

reionization?), and (3) Do we see any sign of abnormally young stellar

population in any of the z>6 galaxies?



S/C 11639



Catching Accreting WDs Moving into Their Instability Strip(s)



Our past HST studies of the temperatures of 9 accreting, pulsating white

dwarfs in cataclysmic variables show that 3 are in the normal

instability strip for single white dwarfs, but the other 6 are much

hotter (15, 000-16, 500K). This dual strip has been proposed to be due

to mass differences in the white dwarfs related to evolutionary history

and driven by the ionization of different elements in their respective

driving regions. In 2007, GW Lib (the brightest and best studied of the

6 hot accreting pulsators) and V455 And (the brightest and best studied

of the 3 cool accreting pulsators) underwent rare large amplitude dwarf

nova outbursts (known to heat the white dwarf) and their pulsations

disappeared. We propose COS observations to: a) take advantage of the

unprecedented opportunity to view the change in pulsation modes due to

cooling of the white dwarf envelope and b) determine the masses of the

white dwarfs to test the dual strip theory. In addition, a nova that had

its outburst 22 yrs ago has begun non-radial pulsations as it returns to

quiescence. We will use COS to determine its temperature in relation to

the instability strip for the pulsating white dwarfs in dwarf novae.



S/C 12046



COS FUV DCE Memory Dump



Whenever the FUV detector high voltage is on, count rate and current

draw information is collected, monitored, and saved to DCE memory. Every

10 msec the detector samples the currents from the HV power supplies

(HVIA, HVIB) and the AUX power supply (AUXI). The last 1000 samples are

saved in memory, along with a histogram of the number of occurrences of

each current value.



In the case of a HV transient (known as a "crackle" on FUSE), where one

of these currents exceeds a preset threshold for a persistence time, the

HV will shut down, and the DCE memory will be dumped and examined as

part of the recovery procedure. However, if the current exceeds the

threshold for less than the persistence time (a "mini-crackle" in FUSE

parlance), there is no way to know without dumping DCE memory. By

dumping and examining the histograms regularly, we will be able to

monitor any changes in the rate of "mini-crackles" and thus learn

something about the state of the detector.



STIS/CC 11845



CCD Dark Monitor Part 2



Monitor the darks for the STIS CCD.



WFC3/ACS/UVIS 11603



A Comprehensive Study of Dust Formation in Type II Supernovae with HST,

Spitzer, and Gemini



The recent discovery of three extremely bright Type II SNe, (2007it,

2007oc, 2007od) gives us a unique opportunity to combine observations

with HST, Spitzer, and Gemini to study the little understood dust

formation process in Type II Sne. Priority 1 Spitzer Cycle 5 and band 1

Gemini 2008A time has already been approved for this project. Since

late-time Type II Sne are faint and tend to be in crowded fields, we

need the high sensitivity and high spatial resolution of ACS and

NICMOS/NIC2 for these observations. This project is motivated by the

recent detection of large amounts of dust in high redshift galaxies. The

dust in these high-z galaxies must come from young, massive stars so

Type II Sne could be potential sources. The mechanism and the efficiency

of dust condensation in Type II SN ejecta are not well understood,

largely due to the lack of observational data. We plan to produce a

unique dataset, combining spectroscopy and imaging in the visible, near-

and mid-IR covering the key phase, 400-700 days after maximum when dust

is known to form in the SN ejecta. Therefore, we are proposing for

coordinated HST/NOAO observations (HST ACS, NICMOS/NIC2 & Gemini/GMOS

and TReCS) which will be combined with our Spitzer Cycle 5 data to study

these new bright Sne. The results of this program will place strong

constraints on the formation of dust seen in young high redshift (z>5)

galaxies.



WFC3/ACS/UVIS/COS/NUV/STIS 11878 /CCD HST Post-SM4 and Cycle 17 Focal

Plane Calibration



This proposal will determine and monitor the SI positions and

orientations in V2, V3 space. Accuracy goals are < 50 mas for position

and between 0.04 and 0.01 degrees for angle (depending on SI). An

astrometric open cluster (M35) is observed using guidestars with

positions determined to ~ 20 mas. One or more astrometric targets are

placed in the available SIs' major channels and POS TARGs can be used if

necessary to step the target(s) over a significant fraction of the

detector. This proposal will serve to update the SI positions and angles

in the SIAF operational database.



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 11657



The Population of Compact Planetary Nebulae in the Galactic Disk



We propose to secure narrow- and broad-band images of compact planetary

nebulae (PNe) in the Galactic Disk to study the missing link of the

early phases of post-AGB evolution. Ejected AGB envelopes become PNe

when the gas is ionized. PNe expand, and, when large enough, can be

studied in detail from the ground. In the interim, only the HST

capabilities can resolve their size, morphology, and central stars. Our

proposed observations will be the basis for a systematic study of the

onset of morphology. Dust properties of the proposed targets will be

available through approved Spitzer/IRS spectra, and so will the

abundances of the alpha- elements. We will be able thus to explore the

interconnection of morphology, dust grains, stellar evolution, and

populations. The target selection is suitable to explore the nebular and

stellar properties across the galactic disk, and to set constraints on

the galactic evolutionary models through the analysis of metallicity and

population gradients.



WFC3/UVIS 11732



The Temperature Profiles of Quasar Accretion Disks



We can now routinely measure the size of quasar accretion disks using

gravitational microlensing of lensed quasars. At optical wavelengths we

observe a size and scaling with black hole mass roughly consistent with

thin disk theory but the sizes are larger than expected from the

observed optical fluxes. One solution would be to use a flatter

temperature profile, which we can study by measuring the wavelength

dependence of the disk size over the largest possible wavelength

baseline. Thus, to understand the size discrepancy and to probe closer

to the inner edge of the disk we need to extend our measurements to UV

wavelengths, and this can only be done with HST. For example, in the UV

we should see significant changes in the optical/UV size ratio with

black hole mass. We propose monitoring 5 lenses spanning a broad range

of black hole masses with well-sampled ground based light curves,

optical disk size measurements and known GALEX UV fluxes during Cycles

17 and 18 to expand from our current sample of two lenses. We would

obtain 5 observations of each target in each Cycle, similar to our

successful strategy for the first two targets.



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 11908



Cycle 17: UVIS Bowtie Monitor



Ground testing revealed an intermittent hysteresis type effect in the

UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.

Initially found via an unexpected bowtie-shaped feature in flatfield

ratios, subsequent lab tests on similar e2v devices have since shown

that it is also present as simply an overall offset across the entire

CCD, i.e., a QE offset without any discernable pattern. These lab tests

have further revealed that overexposing the detector to count levels

several times full well fills the traps and effectively neutralizes the

bowtie. Each visit in this proposal acquires a set of three 3x3 binned

internal flatfields: the first unsaturated image will be used to detect

any bowtie, the second, highly exposed image will neutralize the bowtie

if it is present, and the final image will allow for verification that

the bowtie is gone.



WFC3/UVIS 11912



UVIS Internal Flats



This proposal will be used to assess the stability of the flat field

structure for the UVIS detector throughout the 15 months of Cycle 17.

The data will be used to generate on-orbit updates for the delta-flat

field reference files used in the WFC3 calibration pipeline, if

significant changes in the flat structure are seen.



WFC3/UVIS/IR 11700



Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey



The epoch of reionization represents a special moment in the history of

the Universe as it is during this era that the first galaxies and star

clusters are formed. Reionization also profoundly affects the

environment where subsequent generations of galaxies evolve. Our

overarching goal is to test the hypothesis that galaxies are responsible

for reionizing neutral hydrogen. To do so we propose to carry out a pure

parallel WFC3 survey to constrain the bright end of the redshift z>7.5

galaxy luminosity function on a total area of 176 arcmin^2 of sky.

Extrapolating the evolution of the luminosity function from z~6, we

expect to detect about 20 Lyman Break Galaxies brighter than M_* at z~8

significantly improving the current sample of only a few galaxies known

at these redshifts. Finding significantly fewer objects than predicted

on the basis of extrapolation from z=6 would set strong limits to the

brightness of M_*, highlighting a fast evolution of the luminosity

function with the possible implication that galaxies alone cannot

reionize the Universe. Our observations will find the best candidates

for spectroscopic confirmation, that is bright z>7.5 objects, which

would be missed by small area deeper surveys. The random pointing nature

of the program is ideal to beat cosmic variance, especially severe for

luminous massive galaxies, which are strongly clustered. In fact our

survey geometry of 38 independent fields will constrain the luminosity

function like a contiguous single field survey with two times more area

at the same depth. Lyman Break Galaxies at z>7.5 down to m_AB=26.85 (5

sigma) in F125W will be selected as F098M dropouts, using three to five

orbits visits that include a total of four filters (F606W, F098M, F125W,

F160W) optimized to remove low-redshift interlopers and cool stars. Our

data will be highly complementary to a deep field search for high- z

galaxies aimed at probing the faint end of the luminosity function,

allowing us to disentangle the degeneracy between faint end slope and

M_* in a Schechter function fit of the luminosity function. We waive

proprietary rights for the data. In addition, we commit to release the

coordinates and properties of our z>7.5 candidates within one month from

the acquisition of each field.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

12220 - REAcq(1,2,1) scheduled at 074/11:34:25z was observed to have

made multiple attempts to achieve Coarse Track Data Valid.



COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 7 7

FGS REAcq 7 7

OBAD with Maneuver 7 7



SIGNIFICANT EVENTS: (None)