HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #5148



PERIOD COVERED: 5am July 28 - 5am July 29, 2010 (DOY 209/09:00z-210/09:00z)



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 8 8

OBAD with Maneuver 3 3



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.



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 .



COS/NUV/FUV 12086



Generation of 1-D Fixed Pattern Templates



Tests have shown that application of a 1-D fixed pattern template to a

COS spectrum can reduce the fixed pattern noise in G130M or G160M

spectra to an equivalent S/N of about 30/1. For this to be occur, the

template must be derived from data for the same grating and nearly the

same central wavelength as the observation. This is because each grating

has a different cross dispersion profile, and different central

wavelengths fall at different cross dispersion detector locations. As a

result, spectra obtained at each grating and central wavelength setting

are derived from different regions of the detectors -- each with their

own, unique detector features and grid wire shadows.



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/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/IR 11915



IR Internal Flat Fields



This program is the same as 11433 (SMOV) and depends on the completion

of the IR initial alignment (Program 11425). This version contains three

instances of 37 internal orbits: to be scheduled early, middle, and near

the end of Cycle 17, in order to use the entire 110-orbit allocation.



In this test, we will study the stability and structure of the IR

channel flat field images through all filter elements in the WFC3-IR

channel. Flats will be monitored, i.e. to capture any temporal trends in

the flat fields and delta flats produced. High signal observations will

provide a map of the pixel-to-pixel flat field structure, as well as

identify the positions of any dust particles.



WFC3/UV/ACS/WFC/IR 12055



A Panchromatic Hubble Andromeda Treasury - I



We propose to image the north east quadrant of M31 to deep limits in the

UV, optical, and near-IR. HST imaging should resolve the galaxy into

more than 100 million stars, all with common distances and foreground

extinctions. UV through NIR stellar photometry (F275W, F336W with

WFC3/UVIS, F475W and F814W with ACS/WFC, and F110W and F160W with

WFC3/NIR) will provide effective temperatures for a wide range of

spectral types, while simultaneously mapping M31's extinction. Our

central science drivers are to: understand high-mass variations in the

stellar IMF as a function of SFR intensity and metallicity; capture the

spatially-resolved star formation history of M31; study a vast sample of

stellar clusters with a range of ages and metallicities. These are

central to understanding stellar evolution and clustered star formation;

constraining ISM energetics; and understanding the counterparts and

environments of transient objects (novae, SNe, variable stars, x-ray

sources, etc.). As its legacy, this survey adds M31 to the Milky Way and

Magellanic Clouds as a fundamental calibrator of stellar evolution and

star-formation processes for understanding the stellar populations of

distant galaxies. Effective exposure times are 977s in F275W, 1368s in

F336W, 4040s in F475W, 4042s in F814W, 699s in F110W, and 1796s in

F160W, including short exposures to avoid saturation of bright sources.

These depths will produce photon-limited images in the UV. Images will

be crowding-limited in the optical and NIR, but will reach below the red

clump at all radii. The images will reach the Nyquist sampling limit in

F160W, F475W, and F814W.



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/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.
_________________________
David Cottle

UBB Owner & Administrator