HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #5185



PERIOD COVERED: 5am September 20 - 5am September 21, 2010 (DOY 263/09:00z-264/09:00z)



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:



12420 - GSAcq(1,2,1) at 263/23:12:48z and REAcq(1,2,1) scheduled at

264/00:25:23z, at 264/02:01:18z, at 264/03:37:13z, and at 264/05:13:08z all failed

to RGA Hold (gyro control) with Search Radius Limit Exceeded on FGS-1



Observations affected: COS 30-35 Proposal ID#11598; WFC3 18-19 Proposal ID#11905;

STIS 9-10 Proposal ID#11845; WFC3 20-22 & 24-32 Proposal ID#11696; WFC3 23

Proposal ID#11929; STIS 11-13 Proposal ID#11847

.



HSTAR FOR DOY 253-254:

12418 - GSAcq(2,1,1) at 254/05:10:52z required multiple attempts to achieve CT-DV on FGS2

12419 - GSAcq(1,2,1) at 253/19:08:29Z required two attempts to achieve CT-DV on FGS1.





COMPLETED OPS REQUEST:

18568-1 - LBBIAS Updates for Extended Gyro Guiding Intervals

18922-2 - R/T OBAD to Correct Attitude Error

18923-0 - R/T OBAD to Correct Attitude Error Before Next GSacq



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 9 8

FGS REAcq 8 4

OBAD with Maneuver 6 6



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 12166



A Snapshot Survey of The Most Massive Clusters of Galaxies



We propose the continuation of our highly successful HST/ACS SNAPshot

survey of a sample of 123 very X-ray luminous clusters in the redshift

range 0.3-0.7, detected and compiled by the MACS cluster survey. As

demonstrated by dedicated HST observations of the 12 most distant MACS

clusters (GO-09722) as well as by the MACS SNAPshots of an additional 25

obtained with ACS so far in Cycles 14 and 15, these systems frequently

exhibit strong gravitational lensing as well as spectacular examples of

violent galaxy evolution. A large number of additional MACS SNAPs have

since been obtained with WFPC2, leading to the discovery of several more

powerful cluster lenses. The dramatic loss, however, of depth,

field-of-view, and angular resolution compared to ACS led to

significantly reduced scientific returns, underlining the need for ACS

for this project. The proposed observations will provide important

constraints on the cluster mass distributions, on the physical nature of

! galaxy-galaxy and galaxy-gas interactions in cluster cores, and will

yield a set of optically bright, lensed galaxies for further 8-10m

spectroscopy. For those of our targets with existing ACS SNAPshot

images, we propose SNAPshots in the WFC3 F110W and F140W passbands to

obtain colour information that will greatly improve the secure

identification of multiple-image systems and may, in the form of F606W

or F814W dropouts, lead to the lensing-enabled discovery of very distant

galaxies at z>5. Acknowledging the broad community interest in this

sample (16 of the 25 targets of the approved MCT cluster program are

MACS discoveries) we waive our data rights for these observations.



This proposal is an updated and improved version of our successful Cycle

15 proposal of the same title. Alas, SNAP-10875 collected only six

snapshots in the F606W or F814W passbands, due to, first, a clerical

error at STScI which caused the program to be barred from execution for

four months and, ultimately, the failure of ACS. With ACS restored, and

WFC3 providing additional wavelength and redshift leverage, we wish to

resume this previously approved project.



ACS/WFC 12210



SLACS for the Masses: Extending Strong Lensing to Lower Masses and

Smaller Radii



Strong gravitational lensing provides the most accurate possible

measurement of mass in the central regions of early-type galaxies

(ETGs). We propose to continue the highly productive Sloan Lens ACS

(SLACS) Survey for strong gravitational lens galaxies by observing a

substantial fraction of 135 new ETG gravitational-lens candidates with

HST-ACS WFC F814W Snapshot imaging. The proposed target sample has been

selected from the seventh and final data release of the Sloan Digital

Sky Survey, and is designed to complement the distribution of previously

confirmed SLACS lenses in lens-galaxy mass and in the ratio of Einstein

radius to optical half-light radius. The observations we propose will

lead to a combined SLACS sample covering nearly two decades in mass,

with dense mapping of enclosed mass as a function of radius out to the

half-light radius and beyond. With this longer mass baseline, we will

extend our lensing and dynamical analysis of the mass structure and

scaling relations of ETGs to galaxies of significantly lower mass, and

directly test for a transition in structural and dark-matter content

trends at intermediate galaxy mass. The broader mass coverage will also

enable us to make a direct connection to the structure of well-studied

nearby ETGs as deduced from dynamical modeling of their line-of-sight

velocity distribution fields. Finally, the combined sample will allow a

more conclusive test of the current SLACS result that the intrinsic

scatter in ETG mass-density structure is not significantly correlated

with any other galaxy observables. The final SLACS sample at the

conclusion of this program will comprise approximately 130 lenses with

known foreground and background redshifts, and is likely to be the

largest confirmed sample of strong-lens galaxies for many years to come.



ACS/WFC3 11575



The Stellar Origins of Supernovae



Supernovae (SNe) have a profound effect on galaxies, and have been used

recently as precise cosmological probes, resulting in the discovery of

the accelerating Universe. They are clearly very important events

deserving of intense study. Yet, even with nearly 4000 known SNe, we

know relatively little about the stars which give rise to these powerful

explosions. The main limitation has been the lack of spatial resolution

in pre-SN imaging data. However, since 1999 our team has been at the

vanguard of directly identifying SN progenitor stars in HST images. From

this exciting new line of study, the emerging trend from 5 detections

for Type II- Plateau SNe is that their progenitors appear to be

relatively low mass (8 to 20 Msun) red supergiants, although more cases

are needed. Nonetheless, the nature of the progenitors of Type Ib/c SNe,

a subset of which are associated with the amazing gamma-ray bursts,

remains ambiguous. Furthermore, we remain in the continually

embarrassing situation that we still do not yet know which progenitor

systems explode as Type Ia SNe, which are currently being used for

precision cosmology. In Cycle 16 we have triggered on the Type Ic SN

2007gr and Type IIb SN 2008ax so far. We propose to determine the

identities of the progenitors of 4 SNe within 17 Mpc, which we expect to

occur during Cycle 17, through ToO observations using ACS/HRC.



COS/FUV 11895



FUV Detector Dark Monitor



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/FUV 11897



FUV Spectroscopic Sensitivity Monitoring



The purpose of this proposal is to monitor sensitivity in each FUV

grating mode to detect any changes due to contamination or other causes.



COS/FUV 11997



FUV Internal/External Wavelength Scale Monitor



This program monitors the offsets between the wavelength scale set by

the internal wavecal versus that defined by absorption lines in external

targets. This is accomplished by observing two external targets in the

SMC: SK191 with G130M and G160M and Cl* NGC 330 ROB B37 with G140L

(SK191 is too bright to be observed with G140L). The cenwaves observed

in this program are a subset of the ones used during Cycle 17. Observing

all cenwaves would require a considerably larger number of orbits.

Constraints on scheduling of each target are placed so that each target

is observed once every ~2-3 months. Observing the two targets every

month would also require a considerably larger number of orbits.



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 11598



How Galaxies Acquire their Gas: A Map of Multiphase Accretion and

Feedback in Gaseous Galaxy Halos



We propose to address two of the biggest open questions in galaxy

formation - how galaxies acquire their gas and how they return it to the

IGM - with a concentrated COS survey of diffuse multiphase gas in the

halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to

establish a basic set of observational facts about the physical state,

metallicity, and kinematics of halo gas, including the sky covering

fraction of hot and cold material, the metallicity of infall and

outflow, and correlations with galaxy stellar mass, type, and color -

all as a function of impact parameter from 10 - 150 kpc. Theory suggests

that the bimodality of galaxy colors, the shape of the luminosity

function, and the mass-metallicity relation are all influenced at a

fundamental level by accretion and feedback, yet these gas processes are

poorly understood and cannot be predicted robustly from first

principles. We lack even a basic observational assessment of the

multiphase gaseous content of galaxy halos on 100 kpc scales, and we do

not know how these processes vary with galaxy properties. This ignorance

is presently one of the key impediments to understanding galaxy

formation in general. We propose to use the high-resolution gratings

G130M and G160M on the Cosmic Origins Spectrograph to obtain sensitive

column density measurements of a comprehensive suite of multiphase ions

in the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from

the Sloan Digital Sky Survey. In aggregate, these sightlines will

constitute a statistically sound map of the physical state and

metallicity of gaseous halos, and subsets of the data with cuts on

galaxy mass, color, and SFR will seek out predicted variations of gas

properties with galaxy properties. Our interpretation of these data will

be aided by state-of-the-art hydrodynamic simulations of accretion and

feedback, in turn providing information to refine and test such models.

We will also use Keck, MMT, and Magellan (as needed) to obtain optical

spectra of the QSOs to measure cold gas with Mg II, and optical spectra

of the galaxies to measure SFRs and to look for outflows. In addition to

our other science goals, these observations will help place the Milky

Way's population of multiphase, accreting High Velocity Clouds (HVCs)

into a global context by identifying analogous structures around other

galaxies. Our program is designed to make optimal use of the unique

capabilities of COS to address our science goals and also generate a

rich dataset of other absorption-line systems.



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 .



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/CCD 11721



Verifying the Utility of Type Ia Supernovae as Cosmological Probes:

Evolution and Dispersion in the Ultraviolet Spectra



The study of distant type Ia supernova (SNe Ia) offers the most

practical and immediate discriminator between popular models of dark

energy. Yet fundamental questions remain over possible

redshift-dependent trends in their observed and intrinsic properties.

High-quality Keck spectroscopy of a representative sample of 36

intermediate redshift SNe Ia has revealed a surprising, and unexplained,

diversity in their rest-frame UV fluxes. One possible explanation is

hitherto undiscovered variations in the progenitor metallicity.

Unfortunately, this result cannot be compared to local UV data as only

two representative SNe Ia have been studied near maximum light. Taking

advantage of two new `rolling searches' and the restoration of STIS, we

propose a non-disruptive TOO campaign to create an equivalent comparison

local sample. This will allow us to address possible evolution in the

mean UV spectrum and its diversity, an essential precursor to the study

of SNe beyond z~1.



STIS/CCD 11845



CCD Dark Monitor Part 2



Monitor the darks for the STIS CCD.



STIS/CCD 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 11852



STIS CCD Spectroscopic Flats C17



The purpose of this proposal is to obtain pixel-to-pixel lamp flat

fields for the STIS CCD in spectroscopic mode.



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/UV 12215



Searching for the Missing Low-Mass Companions of Massive Stars



Recent results on binary companions of massive O stars appear to

indicate that the distribution of secondary masses is truncated at low

masses. It thus mimics the distribution of companions of G dwarfs and

also the Initial Mass Function (IMF), except that it is shifted upward

by a factor of 20 in mass. These results, if correct, provide a

distribution of mass ratios that hints at a strong constraint on the

star-formation process. However, this intriguing result is derived from

a complex simulation of data which suffer from observational

incompleteness at the low-mass end.



We propose a snapshot survey to test this result in a very direct way.

HST WFC3 images of a sample of the nearest Cepheids (which were formerly

B stars of ~5 Msun) will search for low-mass companions down to M

dwarfs. We will confirm any companions as young stars, and thus true

physical companions, through follow-up Chandra X-ray images. Our survey

will show clearly whether the companion mass distribution is truncated

at low masses, but at a mass much higher than that of the IMF or G

dwarfs.



WFC3/UV/IR 12234



Differentiation in the Kuiper belt: a Search for Silicates on Icy

Bodies.



We currently have a large on-going program (Go Program 11644, 120

orbits) to exploit the superb stability and photometric characteristics

of HST and the broad range in wavelength coverage of the WFC3 to make

broad-band vis/IR spectral observations of a large sample of Kuiper belt

objects. Though the survey is currently only ~50% complete, the quality

and unprecedented signal-to-noise of these observations has revealed the

existence of a previously undiscovered spectral variability not

explainable within our current understanding of these objects.



A possible explanation for this variability is that with this faint set

of Kuiper belt objects, we are beginning to see the difference between

larger differentiated objects and smaller non-differentiated objects.

Its seems that the small and likely undifferentiated objects are

exhibiting silicate features that affect our photometry - features not

exhibited by the icy mantles of larger icy bodies.



We propose a small add-on survey to dramatically increase the scientific

results of our large program. The proposed observations will use the

proven capabilities of WFC3 to make broad and narrow-band photometric

observations to detect spectral features in the 1.0-1.3 micron range of

a small subset of our sources. The 13 targets have been carefully

selected to cover the range of spectral variability detected in our

large program as well as sample the entire dynamical range and physical

sizes of these targets. These observations will allow the identification

of undifferentiated Kuiper belt objects by detection of their silicate

features. As a probe for differentiation, these observations could

constrain the natal locations of different Kuiper belt classes, a

constraint currently unavailable to formation models. This small set of

observations will allow the calibration of the spectral variability seen

in our large program, and drastically enhance the scientific output of

our full Cycle 17 sample.



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/IR 11696



Infrared Survey of Star Formation Across Cosmic Time



We propose to use the unique power of WFC3 slitless spectroscopy to

measure the evolution of cosmic star formation from the end of the

reionization epoch at z>6 to the close of the galaxy-building era at

z~0.3.Pure parallel observations with the grisms have proven to be

efficient for identifying line emission from galaxies across a broad

range of redshifts. The G102 grism on WFC3 was designed to extend this

capability to search for Ly-alpha emission from the first galaxies.

Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will

observe about 40 deep (4-5 orbit) fields with the combination of G102

and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.



Our primary science goals at the highest redshifts are: (1) Detect Lya

in ~100 galaxies with z>5.6 and measure the evolution of the Lya

luminosity function, independent of of cosmic variance; 2) Determine the

connection between emission line selected and continuum-break selected

galaxies at these high redshifts, and 3) Search for the proposed

signature of neutral hydrogen absorption at re-ionization. At

intermediate redshifts we will (4) Detect more than 1000 galaxies in

Halpha at 0.5<z<1.8 to measure the evolution of the extinction-corrected

star formation density across the peak epoch of star formation. This is

over an order-of-magnitude improvement in the current statistics, from

the NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from

0.5<z<2.2; and (6) Estimate the evolution in reddening and metallicty in

star-forming galaxies and measure the evolution of the Seyfert

population. For hundreds of spectra we will be able to measure one or

even two line pair ratios -- in particular, the Balmer decrement and

[OII]/[OIII] are sensitive to gas reddening and metallicity. As a bonus,

the G102 grism offers the possibility of detecting Lya emission at

z=7-8.8.



To identify single-line Lya emitters, we will exploit the wide

0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All

[OII] and [OIII] interlopers detected in G102 will be reliably separated

from true LAEs by the detection of at least one strong line in the G141

spectrum, without the need for any ancillary data. We waive all

proprietary rights to our data and will make high-level data products

available through the ST/ECF.



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.