HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5126

 

PERIOD COVERED: 5am June 25 - 5am June 28, 2010 (DOY 176/09:00z-179/09:00z)

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

12311 - REAcq(2,3,3) scheduled at 177/14:42:15z initially failed FL walk

           down with scan step limit exceeded on FGS3. The second attempt was

           successful.

 

           Observations possibly affected ACS 62, 61, Proposal ID#11591

 

 

12312 - GSAcq1,2,1 scheduled at 178/01:38:48z resulted in Fine Lock

           Back-up on FGS1.

 

           Observations possibly affected: WFC3 1-3, Proposal ID#11662

 

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED SUCCESSFUL

FGS GSAcq               20            20

FGS REAcq               25            25       

OBAD with Maneuver 11            11       

 

SIGNIFICANT EVENTS: (None)

 

 

 

OBSERVATIONS SCHEDULED:

 

WFC3/UV 12118

 

PTF10fqs: A Luminous Red Nova in the Spiral Messier 99

 

The Palomar Transient Factory (PTF) has discovered a rare type of

transient in the luminosity "gap'' between novae and supernovae. Located

in a spiral arm of Messier 99, PTF10fqs is very red (effective

temperature 3500 K) and slowly evolving. The spectrum is dominated by

intermediate-width H-alpha (680 km/s) and calcium lines. The explosion

signature is similar to M85 OT2006-1, SN 2008S and NGC 300-OT2008. The

origin of these events is shrouded in mystery and controversy (and in

some cases, in dust). Here, we propose a single-orbit observation to

derive a precise astrometric position of this transient while it is

still bright. This would allow us to firmly tie this HST observation

with future searches of any remnant and serve as legacy observation for

this rare and interesting source.

 

ACS/WFC 12016

 

The Stars and Edge-on Disks of PDS 144: An Intermediate-Mass Analog of

Wide T Tauri Multiple Stars

 

High-Inclination PMS stars are optimally oriented to measure disk size,

height, to detect jets, and to directly probe disk composition. Placing

these data into evolutionary context requires dates for the systems and

measurements of L bol, and extinction. For such stars, X-ray data

provide L x, but also N(H) and the total extinction. FUV data measures L

UV, and constrains the shape of the extinction curve. Recent studies

have suggested that the frequency of Jovian-mass planets is higher for

systems with intermediate-mass stars, due to disk mass or composition.

While suitable low mass YSOs are well-represented in the Chandra and HST

archives, similar data are lacking for higher mass systems. We propose

joint Chandra and HST imaging of PDS 144 to fill this gap.

 

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.

 

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/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/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 11907

 

UVIS Cycle 17 Contamination Monitor

 

The UV throughput of WFC3 during Cycle 17 is monitored via weekly

standard star observations in a subset of key filters covering 200-600nm

and F606W, F814W as controls on the red end. The data will provide a

measure of throughput levels as a function of time and wavelength,

allowing for detection of the presence of possible contaminants.

 

STIS/MA1 11861

 

MAMA FUV Flats

 

This program will obtain FUV-MAMA observations of the STIS internal

Krypton lamp to construct an FUV flat applicable to all FUV modes.

 

STIS/MA1/MA2 11857

 

STIS Cycle 17 MAMA Dark Monitor

 

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

 

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

 

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or

five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.

This will give more information on the brightness of the FUV MAMA dark

current as a function of the amount of time that the HV has been on, and

for the NUV MAMA will give a better measure of the short term

temperature dependence.

 

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.

 

STIS/CC 11845

 

CCD Dark Monitor Part 2

 

Monitor the darks for the STIS CCD.

 

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.

 

COS/NUV 11667

 

Detailed Probing of a 3000 km/s Ly-alpha + Metal Line Absorption Complex

Near Two Galaxies at z=0.67

 

At intermediate redshifts, Ly-alpha absorbers cluster around rich

metal-line systems [those with numerous low and high ionization species

(Bahcall et al.)], and at z=3, higher ionization clouds reside at the

velocity extremes of clustered Ly-alpha lines, a signature of the

physics of collapse and layered gas structures (Songaila & Cowie). These

extraordinary HI environments provide unique astrophysical laboratories

for probing relatively high overdensity IGM structures and for placing

powerful constraints on our understanding of the intergalactic medium

and extended galaxy halos in the context of structure evolution,

galactic stellar feedback chemical enrichment to large galactocentric

distances, and the cosmic baryon budget.

 

We have undertaken a comprehensive study of the remarkable 1400 km/s

velocity width, optically thin Ly-alpha only complex (five components)

at z=0.67 within 1600 km/s of the Lyman limit z=0.66 metal-line system

toward TON 153 (Churchill et al.). We have collected FOS, STIS, and

HIRES quasar spectra covering the Lyman series, OVI, CIV, and MgII

absorption, an F702W/WFPC-2 image, and set of ground based narrow-band

SDSS filter images of the quasar field. Two galaxies aligned in velocity

with the z=0.67 Ly-alpha complex and z=0.66 metal-line system lie within

100 kpc of the quasar sightline; the absorption is not consistent with

our standard model of extended "halo" gas for either galaxy, which

suggests that a large scale structure (i.e., filament) may extend

between these galaxies.

 

We propose to obtain G160M/1600 and G185M/1921+1941 (S/N>10) COS spectra

of the z=1.01 quasar TON 153 to obtain detailed kinematic, chemical, and

ionization conditions of this extraordinary absorber/galaxy system

(total velocity spread 3000 km/s). The propose observations will provide

an unprecedented first high resolution examination of the full Lyman

series and MgII, CIV, and OVI metal lines arising in galaxy halos or a

possible large scale structure (i.e., filament) associated with

thoroughly studied galaxies. We aim to discern if the HI extends between

the galaxies and test for multiphase absorption signatures suggestive of

a galactic feedback or large scale collapsing structure.

 

WFC3/UV/IR 11664

 

The WFC3 Galactic Bulge Treasury Program: Populations, Formation

History, and Planets

 

Exploiting the full power of the Wide Field Camera 3 (WFC3), we propose

deep panchromatic imaging of four fields in the Galactic bulge. These

data will enable a sensitive dissection of its stellar populations,

using a new set of reddening-free photometric indices we have

constructed from broad-band filters across UV, optical, and near-IR

wavelengths. These indices will provide accurate temperatures and

metallicities for hundreds of thousands of individual bulge stars.

Proper motions of these stars derived from multi-epoch observations will

allow separation of pure bulge samples from foreground disk

contamination. Our catalogs of proper motions and panchromatic

photometry will support a wide range of bulge studies.

 

Using these photometric and astrometric tools, we will reconstruct the

detailed star-formation history as a function of position within the

bulge, and thus differentiate between rapid- and extended-formation

scenarios. We will also measure the dependence of the stellar mass

function on metallicity, revealing how the characteristic mass of star

formation varies with chemistry. Our sample of bulge stars with accurate

metallicities will include 12 candidate hosts of extrasolar planets.

Planet frequency is correlated with metallicity in the solar

neighborhood; our measurements will extend this knowledge to a remote

environment with a very distinct chemistry.

 

Our proposal also includes observations of six well-studied globular and

open star clusters; these observations will serve to calibrate our

photometric indices, provide empirical population templates, and

transform the theoretical isochrone libraries into the WFC3 filter

system. Besides enabling our own program, these products will provide

powerful new tools for a host of other stellar-population investigations

with HST/WFC3. We will deliver all of the products from this Treasury

Program to the community in a timely fashion.

 

 

WFC3/UVIS/IR 11662

 

Improving the Radius-Luminosity Relationship for Broad-Lined AGNs with a

New Reverberation Sample

 

The radius-luminosity (R-L) relationship is currently the fundamental

basis for all techniques used to estimate black hole masses in AGNs, in

both the nearby and distant universe. However, the current R-L

relationship is based on 34 objects that cover a limited range in black

hole mass and luminosity. To improve our understanding of black hole

growth and evolution, the R-L relationship must be extended to cover a

broader range of black hole masses using the technique known as

reverberation mapping. To this end, we have been awarded an

unprecedented 64 nights on the Lick Observatory 3-m telescope between

March 24 and May 31, 2008, to spectroscopically monitor 12 AGNs in order

to measure their black hole masses. To properly determine the

luminosities of these 12 AGNs, we must correct them for their

host-galaxy starlight contributions using high-resolution images.

Previous work by Bentz et al. (2006) has shown that the starlight

correction to AGN luminosity measurements is an essential component to

interpreting the R-L relationship. The correction will be substantial

for each of the 12 sources we will monitor, as the AGNs are relatively

faint and embedded in nearby, bright galaxies. Starlight corrections are

not possible with ground-based images, as the PSF and bulge

contributions become indistinguishable under typical seeing conditions,

and adaptive optics are not yet operational in the spectral range where

the corrections are needed. In addition, spectral decompositions are

very model-dependent and are limited by the degree of accuracy to which

we understand emission processes and stellar populations in galaxies.

Without correcting for starlight, we will be unable to apply the results

of our Spring 2008 campaign to the body of knowledge from previous

reverberation mapping work. Therefore, we propose to obtain high

resolution, high dynamic range images of the host galaxies of the 12

AGNs in our ground-based monitoring sample, as well as one white dwarf

which will be used as a PSF model.

 

 

ACS/WFC 11655

 

Dynamics of the Galactic Bulge/bar

 

We request second-epoch ACS observations of four star fields in the

Galactic bar. These will allow us to measure proper motions for tens of

thousands of stars well below the turnoff, to construct a dynamical

model for the bulge/bar (in combination with data already in hand from

other HST fields, and from VLT spectroscopy), and hence to take a unique

look at the internal dynamical structure of the central regions of our

Galaxy. By relating the kinematics with stellar population we can

elucidate the formation history of the bulge and bar, and their relation

to the surrounding Galactic disk. This is a resubmission of an approved

Cycle 15 proposal that was hit by the ACS malfunction.

 

WFC3/IR 11648

 

WFC3 Spectroscopy of an X-ray Luminous Galaxy Cluster at z>2

 

We propose to obtain deep WFC3+G141 grism observations to

spectroscopically confirm a remarkable z>2 cluster of galaxy candidate.

Over a 1000 arcmin^2 field imaged with Spitzer's IRAC we have discovered

a compact (<30ÕÕ diameter) concentration of extremely red galaxies with

a factor of >40 overdensity over the adjacent field. Among these

galaxies for which we can derive meaningful photometric redshifts, 17

are consistent with zphot=2-2.5, making it very likely that the

concentration is a real cluster at such high redshift. This is further

supported by a 3.5 sigma detection of extended X-Ray emission on

XMM-Newton data, by a likely color magnitude sequence of red galaxies,

and by the presence of a giant galaxy consistent with a BCG at the

cluster redshift. The general faintness of the red galaxies in all

optical bands and their high redshifts prevent confirmation of this

cluster with ordinary optical spectroscopy. The WFC3 camera with G141

grism provides the only way to confirm this record high-z cluster and

measure its redshift from spectral breaks typical of old stellar

populations. Our deep integrations will reveal redshifts for at least 19

ultra-red galaxies in the area and of a similar number of bluer galaxies

at the cluster redshift. Knowledge of the cluster redshift based on the

HST spectra will allow us to reach important scientific aims: find the

most distant Xray emitting evolved galaxy cluster, determine membership

of the other galaxies from photometric SED analysis, study their stellar

population properties, characterize the color-magnitude relation with

constraints on the formation redshift. The proposed observations will

establish a first z>2 benchmark for cluster field comparisons of galaxy

formation at this highest redshift and will firmly establish the

progenitors of local rich Abell clusters.

 

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.

 

WFC3/ACS/IR 11597

 

Spectroscopy of IR-Selected Galaxy Clusters at 1 < z < 1.5

 

We propose to obtain WFC3 G141 and G102 slitless spectroscopy of galaxy

clusters at 1 < z < 1.5 that were selected from the IRAC survey of the

Bootes NDWFS field. Our IRAC survey contains the largest sample of

spectroscopically confirmed clusters at z > 1. The WFC3 grism data will

measure H-alpha to determine SFR, and fit models to the low resolution

continua to determine stellar population histories for the brighter

cluster members, and redshifts for the red galaxies too faint for

ground-based optical spectroscopy.

 

WFC3/IR 11591

 

Are Low-Luminosity Galaxies Responsible for Cosmic Reionization?

 

Our group has demonstrated that massive clusters, acting as powerful

cosmic lenses, can constrain the abundance and properties of

low-luminosity star-forming sources beyond z~6; such sources are thought

to be responsible for ending cosmic reionization. The large

magnification possible in the critical regions of well-constrained

clusters brings sources into view that lie at or beyond the limits of

conventional exposures such as the UDF. We have shown that the

combination of HST and Spitzer is particularly effective in delivering

the physical properties of these distant sources, constraining their

mass, age and past star formation history. Indirectly, we therefore gain

a valuable glimpse to yet earlier epochs. Recognizing the result (and

limitations) of blank field surveys, we propose a systematic search

through 10 lensing clusters with ACS/F814W and WFC3/[F110W+F160W] (in

conjunction with existing deep IRAC data). Our goal is to measure with

great accuracy the luminosity function at z~7 over a range of at least 3

magnitude, based on the identification of about 50 lensed galaxies at

6.5<z<8. Our survey will mitigate cosmic variance and extend the search

both to lower luminosities and, by virtue of the WFC3/IRAC combination,

to higher redshift. Thanks to the lensing amplification spectroscopic

follow-up will be possible and make our findings the most robust prior

to the era of JWST and the ELTs.

 

ACS/SBC/COS/NUV/FUV 11579

 

The Difference Between Neutral- and Ionized-Gas Metal Abundances in

Local Star-Forming Galaxies with COS

 

The metallicity of galaxies and its evolution with redshift is of

paramount importance for understanding galaxy formation. Abundances in

the interstellar medium (ISM) are typically determined using

emission-line spectroscopy of HII regions. However, since HII regions

are associated with recent SF they may not have abundances typical for

the galaxy as a whole. This is true in particular for star-forming

galaxies (SFGs), in which the bulk of the metals may be contained in the

neutral gas. It is therefore important to directly probe the metal

abundances in the neutral gas. This can be done using absorption lines

in the Far UV. We have developed techniques to do this in SFGs, where

the absorption is measured for sightlines toward bright SF regions

within the galaxy itself. We have successfully applied this technique to

a sample of galaxies observed with FUSE. The results have been very

promising, suggesting in I Zw 18 that abundances in the neutral gas may

be up to 0.5 dex lower than in the ionized gas. However, the

interpretation of the FUSE data is complicated by the very large FUSE

aperture (30 arcsec), the modest S/N, and the limited selection of

species available in the FUSE bandpass. The advent of COS on HST now

allows a significant advance in all of these areas. We will therefore

obtain absorption line spectroscopy with G130M in the same sample for

which we already have crude constraints from FUSE. We will obtain

ACS/SBC images to select the few optimal sightlines to target in each

galaxy. The results will be interpreted through line-profile fitting to

determine the metal abundances constrained by the available lines. The

results will provide important new insights into the metallicities of

galaxies, and into outstanding problems at high redshift such as the

observed offset between the metallicities of Lyman Break Galaxies and

Damped Lyman Alpha systems.

 

WFC3/UVIS 11565

 

A Search for Astrometric Companions to Very Low-Mass, Population II

Stars

 

We propose to carry out a Snapshot search for astrometric companions in

a subsample of very low-mass, halo subdwarfs identified within 120

parsecs of the Sun. These ultra-cool M subdwarfs are local

representatives of the lowest-mass H burning objects from the Galactic

Population II. The expected 3-4 astrometric doubles that will be

discovered will be invaluable in that they will be the first systems

from which gravitational masses of metal-poor stars at the bottom of the

main sequence can be directly measured.

 

WFC3/UV 11556

 

Investigations of the Pluto System

 

We propose a set of high SNR observations of the Pluto system that will

provide improved lightcurves, orbits, and photometric properties of Nix

and Hydra. The key photometric result for Nix and Hydra will be a vastly

improved lightcurve shape and rotation period to test if the objects are

in synchronous rotation or not. A second goal of this program will be to

retrieve a new epoch of albedo map for the surface of Pluto. These

observations will also improve masses and in some case densities for the

bodies in the Pluto system.