HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5112

PERIOD COVERED: 5am June 7 - 5am June 8, 2010 (DOY 158/09:00z-159/09:00z)

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

12297 - REAcq(1,2,1) at 159/07:28:29z failed, FGS Sequential Attitude update failed at

           159/07:31z. Initial GSACQ(1,2,1) at 159/06:02:27z was successful.

           Observations affected: WFC3 49 - 52, proposal ID#11926.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                     SCHEDULED   SUCCESSFUL

FGS GSAcq             13               13      

FGS REAcq               4                3

OBAD with Maneuver 8                8      

SIGNIFICANT EVENTS: (None)

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 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.

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/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/STIS/CCD/MA1 11592

Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A

Survey of Galactic Halo Stars at z>3 kpc

Cosmological simulation predicts that highly ionized gas plays an

important role in the formation and evolution of galaxies and their

interplay with the intergalactic medium. The NASA HST and FUSE missions

have revealed high-velocity CIV and OVI absorption along extragalactic

sightlines through the Galactic halo. These highly ionized high-velocity

clouds (HVCs) could cover 85% of the sky and have a detection rate

higher than the HI HVCs. Two competing, equally exciting, theories may

explain the origin of these highly ionized HVCs: 1) the "Galactic"

theory, where the HVCs are the result of feedback processes and trace

the disk-halo mass exchange, perhaps including the accretion of matter

condensing from an extended corona; 2) the "Local Group" theory, where

they are part of the local warm-hot intergalactic medium, representing

some of the missing baryonic matter of the Universe. Only direct

distance determinations can discriminate between these models. Our group

has found that some of these highly ionized HVCs have a Galactic origin,

based on STIS observations of one star at z<5.3 kpc. We propose an HST

FUV spectral survey to search for and characterize the high velocity NV,

CIV, and SiIV interstellar absorption toward 24 stars at much larger

distances than any previous searches (4<d<21 kpc, 3<|z|<13 kpc). COS

will provide atomic to highly ionized species (e.g.,OI, CII, CIV, SiIV)

that can be observed at sufficient resolution (R~22, 000) to not only

detect these highly ionized HVCs but also to model their properties and

understand their physics and origins. This survey is only possible

because of the high sensitivity of COS in the FUV spectral range.

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

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.

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.

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/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/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   11926

IR Zero Points

We will measure and monitor the zeropoints through the IR filters using

observations of the white dwarf standard stars, GD153, GD71 and GD191B2B

and the solar analog standard star, P330E. Data will be taken monthly

during Cycle 17. Observations of the star cluster, NGC 104, are made

twice to check color transformations. We expect an accuracy of 2% in the

wide filter zeropoints relative to the HST photometric system, and 5% in

the medium- and narrow-band filters.

WFC3/UV 12119

Rapid Response: Unexpected Jupiter Impact

On 3 June 2010, amateur astronomers A. Wesley and C. Go independently

captured observations of an impact on Jupiter: the bright flash of an

impact itself, not the dark aftermath as seen in 2009. This event was

completely unexpected given the recent impact in 2009, and contradicts

recently revised predictions of jovian impact rates. Three circumstances

make this 2009 event unique: first, the event was captured on video;

second, it was on the jovian day-side and hence fully visible from

Earth; and third, it was at low latitude (i.e., favorably placed on the

planet). These factors will permit a lightcurve to be extracted, which

is critical for determining the energy of the explosion and hence the

size of the impacting body (not available for the 2009 event and

available for only a few 1994 events by Galileo). As of this writing, no

dark impact site has been detected with telescopes of any aperture,

including the Gemini North telescope. Hubble may be the only facility

with high enough spatial resolution to detect the 2010 impact site. If

Hubble images show a site, then the body's trajectory might be

obtainable. If no site is detected, then Hubble will confirm that this

is the first observation of a meteor on another atmosphere-bearing

planet. If an event of this size occurred on Earth, it would be likely

be termed a Type 1 Low-Altitude Airburst, like Tunguska or larger. Thus,

this new event could become the best-observed analogue of a terrestrial

airburst of the size that dominates the impact threat to humans. The

observations we propose should provide independent constraints on

penetration depth and atmospheric effects. This data will strongly

inform our understanding of terrestrial airbursts and allow better

quantification of the associated threat. We request a single orbit to

image the impact latitude on the planet's central meridian. Of critical

importance are Hubble's unique UV sensitivity (critical for assessing

aspects of the 2009 impact, and not obtainable from any ground-based

facility) and Hubble's high spatial resolution (also not obtainable in

the visible form any ground-based telescope).

WFC3/UVIS 11707

Detecting Isolated Black Holes through Astrometric Microlensing

This proposal aims to make the first detection of isolated stellar-mass

black holes (BHs) in the Milky Way, and to determine their masses. Until

now, the only directly measured BH masses have come from radial-velocity

measurements of X-ray binaries. Our proposed method uses the astrometric

shifts that occur when a galactic-bulge microlensing event is caused by

a BH lens. Out of the hundreds of bulge microlensing events found

annually by the OGLE and MOA surveys, a few are found to have very long

durations (>200 days). It is generally believed that the majority of

these long-duration events are caused by lenses that are isolated BHs.

To test this hypothesis, we will carry out high-precision astrometry of

5 long-duration events, using the ACS/HRC camera. The expected

astrometric signal from a BH lens is >1.4 mas, at least 7 times the

demonstrated astrometric precision attainable with the HRC.

This proposal will thus potentially lead to the first unambiguous

detection of isolated stellar-mass BHs, and the first direct mass

measurement for isolated stellar-mass BHs through any technique.

Detection of several BHs will provide information on the frequency of

BHs in the galaxy, with implications for the slope of the IMF at high

masses, the minimum mass of progenitors that produce BHs, and

constraints on theoretical models of BH formation.

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.