HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5113

 

PERIOD COVERED: 5am June 8 - 5am June 9, 2010 (DOY 159/09:00z-160/09:00z)

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

12298 - GSAcq(2,1,1) at 159/19:19:42z resulted in fine lock back-up on FGS1 due to

           scan step limit exceeded on FGS2.

 

           Observations possibly affected: COS 37- 41, Proposal ID#11687.

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                     SCHEDULED   SUCCESSFUL

FGS GSAcq              10              10      

FGS REAcq               6                6      

OBAD with Maneuver 7                7      

 

SIGNIFICANT EVENTS: (None)

 

 

OBSERVATIONS SCHEDULED:

 

ACS/WFC 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.

 

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/WFC/WFC3/IR 11663

 

Formation and Evolution of Massive Galaxies in the Richest Environments

at 1.5 < z < 2.0

 

We propose to image seven 1.5<z<2 clusters and groups from the IRAC

Shallow Cluster Survey with WFC3 and ACS in order to study the formation

and evolution of massive galaxies in the richest environments in the

Universe in this important redshift range. We will measure the evolution

of the sizes and morphologies of massive cluster galaxies, as a function

of redshift, richness, radius and local density. In combination with

allocated Keck spectroscopy, we will directly measure the dry merger

fraction in these clusters, as well as the evolution of Brightest

Cluster Galaxies (BCGs) over this redshift range where clear model

predictions can be confronted. Finally we will measure both the epoch of

formation of the stellar populations and the assembly history of that

stellar mass, the two key parameters in the modern galaxy formation

paradigm.

 

ACS/WFC/WFC3/UVI 11613

 

GHOSTS: Stellar Outskirts of Massive Spiral Galaxies

 

We propose to continue our highly successful GHOSTS HST survey of the

resolved stellar populations of nearby, massive disk galaxies using

SNAPs. These observations provide star counts and color-magnitude

diagrams 2-3 magnitudes below the tip of the Red Giant Branch of the

outer disk and halo of each galaxy. We will measure the metallicity

distribution functions and stellar density profiles from star counts

down to very low average surface brightnesses, equivalent to ~32 V-mag

per square arcsec.

 

This proposal will substantially improve our unique sampling of galaxy

outskirts. Our targets cover a range in galaxy mass, luminosity,

inclination, and morphology. As function of these galaxy properties this

survey provides: - the most extensive, systematic measurement of radial

light profiles and axial ratios of the diffuse stellar halos and outer

disks of spiral galaxies; - a comprehensive analysis of halo metallicity

distributions as function of galaxy type and position within the galaxy;

- an unprecedented study of the stellar metallicity and age distribution

in the outer disk regions where the disk truncations occur; - the first

comparative study of globular clusters and their field stellar

populations.

 

We will use these fossil records of the galaxy assembly process to test

halo formation models within the hierarchical galaxy formation scheme.

 

COS/FUV 11687

 

SNAPing Coronal Iron

 

This is a Snapshot Survey to explore two forbidden lines of highly

ionized iron in late-type coronal sources. Fe XII 1349 (T~ 2 MK) and Fe

XXI 1354 (T~ 10 MK) -- well known to Solar Physics -- have been detected

in about a dozen cool stars, mainly with HST/STIS. The UV coronal

forbidden lines are important because they can be observed with velocity

resolution of better than 15 km/s, whereas even the state-of-the-art

X-ray spectrometers on Chandra can manage only 300 km/s in the kilovolt

band where lines of highly ionized iron more commonly are found. The

kinematic properties of hot coronal plasmas, which are of great interest

to theorists and modelers, thus only are accessible in the UV at

present. The bad news is that the UV coronal forbidden lines are faint,

and were captured only in very deep observations with STIS. The good

news is that 3rd-generation Cosmic Origins Spectrograph, slated for

installation in HST by SM4, in a mere 25 minute exposure with its G130M

mode can duplicate the sensitivity of a landmark 25-orbit STIS E140M

observation of AD Leo, easily the deepest such exposure of a late-type

star so far. Our goal is to build up understanding of the properties of

Fe XII and Fe XXI in additional objects beyond the current limited

sample: how the lineshapes depend on activity, whether large scale

velocity shifts can be detected, and whether the dynamical content of

the lines can be inverted to map the spatial morphology of the stellar

corona (as in "Doppler Imaging''). In other words, we want to bring to

bear in the coronal venue all the powerful tricks of spectroscopic

remote sensing, well in advance of the time that this will be possible

exploiting the corona's native X-ray radiation. The 1290-1430 band

captured by side A of G130M also contains a wide range of key plasma

diagnostics that form at temperatures from below 10, 000 K (neutral

lines of CNO), to above 200, 000 K (semi-permitted O V 1371), including

the important bright multiplets of C II at 1335 and Si IV at 1400;

yielding a diagnostic gold mine for the subcoronal atmosphere. Because

of the broad value of the SNAP spectra, beyond the coronal iron project,

we waive the normal proprietary rights.

 

COS/NUV 11705

 

Physical Properties of Quasar Outflows: From BALs to mini-BALs

 

Accretion disk outflows are important components of quasar environments.

They might play a major role in facilitating accretion, regulating star

formation in the host galaxies and distributing metals to the

surrounding gas. They reveal themselves most conspicuously via broad

absorption lines (BALs), but they appear even more frequently in other

guises such as the weaker and narrower ``mini-BALs.'' How are these

diverse outflow features related? Are mini-BALs really just ``mini''

versions of the BALs, or do they represent a fundamentally different

type of outflow, with different degrees of ionization, column densities,

mass loss rates, physical origins, etc.?

 

We propose HST-COS spectroscopy to make the first quantitative

assessment of the outflow physical conditions across the full range of

weak/narrow mini-BALs to strong/broad BALs. Our strategy is to measure

key diagnostic lines (SVI, OVI, CIII, SIV, PV, etc.) at 930A - 1130A

(rest-frame) in a sample of 7 outflow quasars with known mini-BALs

through weak BALs. We will then 1) combine the COS data with

ground-based spectra of the same quasars to include more lines (CIV,

SiIV) at longer wavelengths, and 2) include in our analysis a nearly

identical UV/optical dataset obtained previously for a sample of quasars

with strong BALs. Our study of this combined dataset will be an

essential next step toward a more global understanding of quasar

outflows.

 

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.

 

WFC3/IR 11666

 

Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the

Prototype Y Dwarf

 

We propose to use HST/NICMOS to image a sample of 27 of the nearest (<

20 pc) and lowest luminosity T-type brown dwarfs in order to identify

and characterize new very low mass binary systems. Only 3 late-type T

dwarf binaries have been found to date, despite that fact that these

systems are critical benchmarks for evolutionary and atmospheric models

at the lowest masses. They are also the most likely systems to harbor Y

dwarf companions, an as yet unpopulated putative class of very cold (T <

600 K) brown dwarfs. Our proposed program will more than double the

number of T5-T9 dwarfs imaged at high resolution, with an anticipated

yield of ~5 new binaries with initial characterization of component

spectral types. We will be able to probe separations sufficient to

identify systems suitable for astrometric orbit and dynamical mass

measurements. We also expect one of our discoveries to contain the first

Y-type brown dwarf. Our proposed program complements and augments

ongoing ground-based adaptive optics surveys and provides pathway

science for JWST.

 

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 possiblity 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 11735

 

The LSD project: dynamics, merging and stellar populations of a sample

of well-studied LBGs at z~3

 

A large observational effort with the ground-based ESO/VLT telescopes

allowed us to obtain deep, spatially-resolved, near-IR spectra of

complete sample of 11 Lyman-Break Galaxies at z~3.1. These observations

were used to obtain, for the first time, the metallicity and the

dynamical properties of a sample of objects that, albeit small, is

representative of the total population of the LBGs. We propose to use

HST to obtain high-resolution optical and near-IR images of this sample

of LBGs in order to study the broad-band morphology and the stellar

light distribution of these galaxies. These images, exploiting the

superior spatial resolution of HST images and the low-background : 1-

will allow a precise measure of the dynamical mass from the velocity

field derived with spectroscopy; 2- will permit a comparison of the

distribution of star formation (from the line emission) with the

underlying stellar population, and, 3- will be used to check if the

complex velocity field and the multiple line-emitting regions detected

in most targets can be ascribed to on-going mergers. This accurate study

will shed light on a number of unsolved problems still affecting the

knowledge of the LBGs.

 

WFC3/IR/WFC3/UVI 11557

 

The Nature of low-ionization BAL QSOs

 

The rare subclass of optically-selected QSOs known as low-ionization

broad absorption line (LoBAL) QSOs show signs of high-velocity gas

outflows and reddened continua indicative of dust obscuration. Recent

studies show that galaxies hosting LoBAL QSOs tend to be ultraluminous

infrared systems that are undergoing mergers, and that have dominant

young (< 100 Myr) stellar populations. Such studies support the idea

that LoBAL QSOs represent a short-lived phase early in the life of QSOs,

when powerful AGN-driven winds are blowing away the dust and gas

surrounding the QSO. If so, understanding LoBALs would be critical in

the study of phenomena regulating black hole and galaxy evolution, such

as AGN feedback and the early stages of nuclear accretion. These

results, however, come from very small samples that may have serious

selection biases. We are therefore taking a more aggressive approach by

conducting a systematic multiwavelength study of a volume limited sample

of LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image

their host galaxies in two bands using WFC3/UVIS and WFC3/IR to study

the morphologies for signs of recent tidal interactions and to map their

interaction and star forming histories. We will thus determine whether

LoBAL QSOs are truly exclusively found in young merging systems that are

likely to be in the early stages of nuclear accretion.

 

WFC3/UVI 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/UVI 11697

 

Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxies

 

Using the superior resolution of HST, we propose to continue our proper

motion survey of Galactic dwarf galaxies. The target galaxies include

one classical dwarf, Leo II, and six that were recently identified in

the Sloan Digital Sky Survey data: Bootes I, Canes Venatici I, Canes

Venatici II, Coma Berenices, Leo IV, and Ursa Major II. We will observe

a total of 16 fields, each centered on a spectroscopically- confirmed

QSO. Using QSOs as standards of rest in measuring absolute proper

motions has proven to be the most accurate and most efficient method.

HST is our only option to quickly determine the space motions of the

SDSS dwarfs because suitable ground-based imaging is only a few years

old and such data need several decades to produce a proper motion. The

two most distant galaxies in our sample will require time baselines of

four years to achieve our goal of a 30-50 km/s uncertainty in the

tangential velocity; given this and the finite lifetime of HST, it is

imperative that first-epoch observations be taken in this cycle. The

SDSS dwarfs have dramatically lower surface brightnesses and

luminosities than the classical dwarfs. Proper motions are crucial for

determining orbits of the galaxies and knowing the orbits will allow us

to test theories for the formation and evolution of these galaxies and,

more generally, for the formation of the Local Group.

 

WFC3/UVI 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<BR>and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals<BR>throughout

the cycle to support subarray science observations. The internals from

this proposal,<BR>along with those from the anneal procedure (11909),

will be used to generate the necessary superbias<BR>and superdark

reference files for the calibration pipeline (CDBS).