HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      #4910

PERIOD COVERED: 5am August 14 - 5am August 17, 2009 (DOY 226/09:00z-229/09:00z)

OBSERVATIONS SCHEDULED

WFC3/UV 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/UV 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.

WFC3/UV 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 (11909), will be

used to generate the necessary superbias and superdark reference files

for the calibration pipeline (CDBS).

COS/NUV 11896

NUV Spectroscopic Sensitivity Monitoring

Purpose is to monitor sensitivity of each NUV grating mode to detect any

change due to contamination or other causes.

STIS/CCD 11846

CCD Bias Monitor-Part 1

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 11844

CCD Dark Monitor Part 1

Monitor the darks for the STIS CCD.

FGS 11789

An Astrometric Calibration of Population II Distance Indicators

In 2002 HST produced a highly precise parallax for RR Lyrae. That

measurement resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a

useful result, judged by the over ten refereed citations each year

since. It is, however, unsatisfactory to have the direct,

parallax-based, distance scale of Population II variables based on a

single star. We propose, therefore, to obtain the parallaxes of four

additional RR Lyrae stars and two Population II Cepheids, or W Vir

stars. The Population II Cepheids lie with the RR Lyrae stars on a

common K-band Period-Luminosity relation. Using these parallaxes to

inform that relationship, we anticipate a zero-point error of 0.04

magnitude. This result should greatly strengthen confidence in the

Population II distance scale and increase our understanding of RR Lyrae

star and Pop II Cepheid astrophysics.

FGS 11788

The Architecture of Exoplanetary Systems

Are all planetary systems coplanar? Concordance cosmogony makes that

prediction. It is, however, a prediction of extrasolar planetary system

architecture as yet untested by direct observation for main sequence

stars other than the Sun. To provide such a test, we propose to carry

out FGS astrometric studies on four stars hosting seven companions. Our

understanding of the planet formation process will grow as we match not

only system architecture, but formed planet mass and true distance from

the primary with host star characteristics for a wide variety of host

stars and exoplanet masses.

We propose that a series of FGS astrometric observations with

demonstrated 1 millisecond of arc per-observation precision can

establish the degree of coplanarity and component true masses for four

extrasolar systems: HD 202206 (brown dwarf+planet); HD 128311

(planet+planet), HD 160691 = mu Arae (planet+planet), and HD 222404AB =

gamma Cephei (planet+star). In each case the companion is identified as

such by assuming that the minimum mass is the actual mass. For the last

target, a known stellar binary system, the companion orbit is stable

only if coplanar with the AB binary orbit.

ACS/WFC3 11695

Searching for the Bottom of the Initial Mass Function

The measurement of the minimum mass of the IMF would provide a

fundamental test of theories of star and planet formation. In a Cycle 13

program, we used ACS and ground-based near-IR imaging and spectroscopy

to measure the IMF down to a completeness limit of 10 M_Jup (i~24) in a

800"x1000" area in the southern subcluster of the Chamaeleon I

star-forming region (2 Myr, 160 pc). There is no sign of a low-mass

cutoff in this IMF measurement. To provide a better constraint on the

minimum mass of the IMF, we propose to obtain ACS images of this field

again and use the two ACS epochs to identify substellar cluster members

down to the detection limit of the data (i~27) via their proper motions.

In this way, we will improve the completeness limit of our IMF

measurement to 3 M_Jup. In addition, to improve the number statistics of

our measurement of the substellar IMF in Chamaeleon I, we propose to

double the number of objects in the IMF sample by performing ACS imaging

of a second field toward the northern subcluster.

STIS/CCD/MA 11690

EG And: Providing the Missing Link Required for Modelling Red Giant

Mass-loss

For the majority of red giant stars the basic mass-loss processes at

work are unknown. Indeed, for stars of spectral types between K0 III and

M5-M6 III, much remains unknown about the regions above the visible

photosphere and the transportation of the processed material outwards to

the ISM. Eclipsing symbiotic binary systems, consisting of an evolved

giant in orbit with a white dwarf, provide an opportunity to take

advantage of the finite size of the hot component to probe different

levels of the chromosphere and wind acceleration region in absorption.

This provides spatially resolved thermal, ionisation and dynamic

information on the wind which can then be compared against predictions

of hydrodynamical stellar atmosphere codes. The symbiotic binary EG And

can be considered as a rosetta stone for understanding the winds of

these objects. The system is ideal on a number of counts for utilising

the ultraviolet eclipse of the white dwarf (WD) component to probe,

layer-by-layer, the thermal and dynamic conditions at the very base of

the wind and chromosphere of the RG. This information is vital for

constraining, testing and calibrating the new generation of cool giant

wind+chromosphere models and is not possible to obtain for isolated RGs.

This team has studied the UV eclipses of this system in depth and

detail, however in order to definitively constrain the wind acceleration

profile and identify the location of the temperature rise just above the

photosphere we require 4 STIS E140M observations of EG And at specific

orbital phases. We are also requesting a E230M observation of an

isolated spectral standard, corresponding to the RG in the binary, which

will help place the EG And results into the context of the general RG

population from analysis of the MgII wind diagnostic lines.

ACS/WFC3 11669

The Origins of Short Gamma-Ray Bursts

During the past decade extraordinary progress has been made in

determining the origin of long- duration gamma-ray bursts. It has been

conclusively shown that these objects derive from the deaths of massive

stars. Nonetheless, the origin of their observational cousins,

short-duration gamma-ray bursts (SGRBs) remains a mystery. While SGRBs

are widely thought to result from the inspiral of compact binaries, this

is a conjecture. SGRBs have been found in elliptical galaxies, Abell

Clusters, star-forming dwarfs and even an edge-on spiral. Whether they

primarily result from an old population, a young population, or rapid

evolution of binaries in globular clusters remains open.

Here we propose to employ two related sets of observations which may

dramatically advance our understanding of short bursts. The first is a

variant of a technique that we pioneered and used to great effect in

elucidating the origins of long-duration bursts. We will examine a

statistical sample of hosts and measure the degree to which SGRB

locations trace the red or blue light of their hosts, and thus old or

young stellar populations. This will allow us to study the demographics

of the SGRB population in a manner largely free of the distance

dependent selection effects which have so far bedeviled this field. In

the second line of attack we will use two targets of opportunity to

obtain extremely precise positions of up to two nearby bursts -- one on

a star-forming galaxy and the other on a elliptical. Observation of the

star-formation galaxy could link at least some bursts directly to a

young population; however, a discovery in later images of a globular

cluster at the site of the explosion in an elliptical would provide

revolutionary evidence that SGRBs are formed from compact binaries.

WFC3/IR/ACS 11647

A Deep Exploration of Classes of Long Period Variable Stars in M31

We propose a thrifty but information-packed investigation with WFC3/IR

F160W and F110W providing crucial information about Long Period

Variables in M31, at a level of detail that has recently allowed the

discovery of new variable star classes in the Magellanic Clouds, a very

different stellar population. These observations are buttressed by an

extensive map of the same fields with ACS and WFPC2 exposures in F555W

and F814W, and a massive ground-based imaging patrol producing

well-sampled light curves for more than 400, 000 variable stars. Our

primary goal is to collect sufficient NIR data in order to analyze and

classify the huge number of long-period variables in our catalog (see

below) through Period-Luminosity (P/L) diagrams. We will produce

accurate P/L diagrams for both the bulge and a progression of locations

throughout the disk of M31. These diagrams will be similar in quality to

those currently in the Magellanic Clouds, with their lower metallicity,

radically different star formation history, and larger spread in

distance to the variables. M31 offers an excellent chance to study more

typical disk populations, in a manner which might be extended to more

distant galaxies where such variables are still visible, probing a much

more evenly spread progenitor age distribution than cepheids (and

perhaps useful as a distance scale alternative or cross-check). Our data

will also provide a massive and unique color-magnitude dataset; we

expect that this study will produce several important results, among

them a better understanding of P/L and P/L-color relations for pulsating

variables which are essential to the extragalactic distance ladder. We

will view these variables at a common distance over a range of

metallicities (eliminating the distance-error vs. metallicity ambiguity

between the LMC and SMC), allow further insight into possible

faint-variable mass-loss for higher metallicities, and in general

produce a sample more typical of giant disk galaxies predominant in many

studies.

ACS 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.

STIS/CCD 11567

Boron Abundances in Rapidly Rotating Early-B Stars

Models of rotation in early-B stars predict that rotationally driven

mixing should deplete surface boron abundances during the main-sequence

lifetime of many stars. However, recent work has shown that many boron

depleted stars are intrinsically slow rotators for which models predict

no depletion should have occurred, while observations of nitrogen in

some more rapidly rotating stars show less mixing than the models

predict. Boron can provide unique information on the earliest stages of

mixing in B stars, but previous surveys have been biased towards

narrow-lined stars because of the difficulty in measuring boron

abundances in rapidly rotating stars. The two targets observed as part

of our Cycle 13 SNAP program 10175, just before STIS failed, demonstrate

that it is possible to make useful boron abundance measurements for

early-B stars with Vsin(i) above 100 km/s. We propose to extend that

survey to a large enough sample of stars to allow statistically

significant tests of models of rotational mixing in early-B stars.

WFC3/UVI 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.

COS/FUV 11492

FUV Sensitivity

This activity confirms COS sensitivity versus wavelength over the entire

observable spectrum for all FUV gratings and central wavelength

settings. Obtain quick look sensitivity visit early in SMOV. Later,

after wavelength calibration is verified, perform a precise-centering

acquisition and observe an appropriate HST flux standard star (chosen

from the HST prime standard and FASTEX lists) with the PSA. (A limited

BOA characterization is obtained in Visit 13 using primary standard

GD153.) No off aperture- center observations are performed in this

activity (see COS32, program 11490, for off- center characterizations).

Spectra will be obtained to meet a Poisson S/N criterion of ~30 per

sensitivity extraction bin or higher; substantially higher S/N

characterization will be utilized in routine Cycle 17 calibration.

COS 11486

COS FUV Target Acquisition Algorithm Verification

Verify the ability of the COS FSW to place an isolated point source at

the center of the aperture, both for the BOA and PSA, using dispersed

light from the object using the FUV gratings. The various options for

target centering should be exercised and shown to work properly. This

test is for acquisitions in dispersed-light mode only. This program is

modeled from SMOV activity summary COS28.

This program should be executed two or more weeks after visit 12 of

11469, and after the SIAF update, so that we have confirmed that NUV

imaging acquisitions work properly with the BOA.

COS 11476

COS NUV External Spectroscopic Performance - Part 1

The goal of this project is to measure the spectral resolution of

absorption lines for each of the four COS NUV gratings. We will acquire

science data at the central wavelength of each grating through both PSA

and BOA apertures. We will also evaluate the effect of small pointing

errors on the spectral resolution by acquiring additional spectra at

spatially offset positions. The targets chosen for these observations

have sharp absorption lines and will be either unresolved or marginally

resolved at the COS resolution.

Our observations with the PSA will target the subdwarf B star Feige 48

(PG 1144+651). These observations will implement the following

procedure: First, a target acquisition is performed to place the target

at the center of the aperture. For each NUV grating we obtain moderately

high S/N (~ 40 per resel counting statistics) observations at one

central wavelength setting with the PSA. Next we repeat the sequence of

observations at each of four additional positions, offset 0.25

arcseconds from the aperture center to form a diamond pattern. All of

these observations will be performed in TIME-TAG mode with FLASH=YES,

but with two differences: First, the summed exposure time for all four

offset positions is equal to the exposure time of the central position.

Second, the central position utilizes a four-position FP-split pattern

(FP-POS=AUTO) while the offset positions are each split into two

sub-exposures, one with FP-POS=3 and one with FP-POS=1. For one grating

(G185M) and central wavelength (1850 A) we obtain a TIME-TAG exposure

with FLASH=NO to verify the auto-wavecal capability of the NUV channel.

The observations with the BOA will be performed on the bright O subdwarf

BD+75D325, a bright (M_V = 9.6) HST calibration standard. Here we obtain

a single TIME-TAG exposure for each of the four NUV gratings with the

object centered in the BOA to evaluate the spectral resolution in this

mode. We aim for S/N = 20 in these observations.

The number of exposures in this program is somewhat larger than the

number described in the Activity Summary, but is necessary to perform

the intended
 11476( 16) - 20-Mar-2009 11:53:32 - [ 2]

tests of the COS spectral resolution.

This activity is SMOV program COS 16.

IMPLEMENTATION METHOD: Stored Commanding

DATA REQUIREMENTS: Approximately 420 MB

DEPENDENCIES: Execute after verification based upon results of activity

COS 15 (Internal NUV Wavelength Calibration)

APPLICABLE SMOV REQUIREMENTS: L.10.4.2.3.7.2; L.10.4.2.3.13;

L.10.4.2.1.8

COS 11472

COS NUV Dispersed-light Acquisition Algorithm Verification

Verify the ability of the COS FSW to place an isolated point source at

the center of the aperture, both for the BOA and PSA, using dispersed

light from the object using an NUV grating. The various options for

target centering should be exercised and shown to work properly.

COS 11471

COS NUV Imaging Acquisition Algorithm Verification

Verify the ability of the COS FSW to place an isolated point source at

the center of the aperture, both for the BOA and PSA, and for MIRRORA

and MIRRORB. The various options for target centering should be

exercised and shown to work properly. This test is for acquisitions in

imaging mode only. Acquisitions using dispersed light are tested in

separate SMOV activities.

ACS 11465

ACS CCD Monitoring and Calibration for WFC3

This program is a smaller version of our routine CCD monitoring program,

designed to run throughout SMOV, after which our regular Cycle 17 CAL

proposal will begin. This program obtains the bias and dark frames

needed to generate reference files for calibrating science data, and

allows us to monitor detector noise and the growth of hot pixels.

WFC3 11447

WFC3 IR Dark Current, Readnoise, and Background

This proposal obtains full-frame, four-amp readout images.

Un-illuminated internals are taken at regularly spaced intervals

throughout SMOV in order to assess and monitor readnoise and dark

current (of both light-sensitive pixels and reference pixels), and bad

(warm, hot, dead, variable) pixels. In addition, externals aimed at

fields with sparse stellar density are taken to measure diffuse

background light.

This program corresponds to WFC3-34.

WFC3 11446

WFC3 UVIS Dark Current, Readnoise, and CTE

This proposal obtains full-frame, four-amp readout bias and dark frames

at regularly-spaced intervals throughout SMOV in order to assess and

monitor dark current, bad (warm, hot, dead) pixels, and readnoise. In

addition, a set of internals using the WFC3 calsystem are taken to

provide a baseline CTE measurement. WFC3-33

STIS20 11402

STIS-20 NUV MAMA Dark Monitor

The STIS NUV-MAMA dark current is dominated by a phosphorescent glow

from the detector window. Meta-stable states in this window are

populated by cosmic ray impacts, which, days later, can be thermally

excited to an unstable state from which they decay, emitting a UV

photon. The equilibrium population of these meta-stable states is larger

at lower temperatures; so warming up the detector from its cold safing

will lead to a large, but temporary, increase in the dark current.

To monitor the decay of this glow, and to determine the equilibrium dark

current for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be

taken each week during the SMOV period. Once the observed dark current

has reached an approximate equilibrium with the mean detector

temperature, the frequency of this monitor can be reduced to one pair of

darks per week.

NIC2 11208

The Co-evolution of Spheroids and Black Holes in the Last Six Billion

Years

The masses of giant black holes are correlated with the luminosities,

masses, and velocity dispersions of the bulges of their host galaxies.

This empirical correlation of phenomena on widely different scales {from

pcs to kpcs} suggests that the formation and evolution of galaxies and

central black holes are closely linked. In Cycle 13, we have started a

campaign to map directly the co-evolution of spheroids and black-holes

by measuring in observationally favorable redshift windows the empirical

correlations connecting their properties. By focusing on Seyfert 1s,

where the nucleus and the stars contribute comparable fractions of total

light, black hole mass and bulge dispersion are obtained from Keck

spectroscopy. HST is required for accurate measurement of the non

stellar AGN continuum, the morphology of the galaxy, and the structural

parameters of the bulge. The results at z=0.36 indicate a surprisingly

fast evolution of bulges in the past 4 Gyrs {significant at the 95%CL},

in the sense that bulges were significantly smaller for a given black

hole mass. Also, the large fraction of mergers and disturbed galaxies

{4+2 out of 20} identifies gas-rich mergers as the mechanisms

responsible for bulge-growth. Going to higher redshift -- where

evolutionary trends should be stronger -- is needed to confirm these

tantalizing results. We propose therefore to push our investigation to

the next suitable redshift window z=0.57 {lookback-time 6 Gyrs}. Fifteen

objects are the minimum number required to map the evolution of the

empirical correlations between bulge properties and black-hole mass, and

to achieve a conclusive detection of evolution {>99%CL}.

NIC2/WFPC2 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7

Using HST and Spitzer

We aim to determine physical properties of IR luminous galaxies at

0.3<z<2.7 by requesting coordinated HST/NIC2 and MIPS 70um observations

of a unique, 24um flux-limited sample with complete Spitzer mid-IR

spectroscopy. The 150 sources investigated in this program have S{24um}

> 0.8mJy and their mid-IR spectra have already provided the majority

targets with spectroscopic redshifts {0.3<z<2.7}. The proposed

150~orbits of NIC2 and 66~hours of MIPS 70um will provide the physical

measurements of the light distribution at the rest-frame ~8000A and

better estimates of the bolometric luminosity. Combining these

parameters together with the rich suite of spectral diagnostics from the

mid-IR spectra, we will {1} measure how common mergers are among LIRGs

and ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers

of z>1 ULIRGs, as in the local Universe. {2} study the co-evolution of

star formation and blackhole accretion by investigating the relations

between the fraction of starburst/AGN measured from mid-IR spectra vs.

HST morphologies, L{bol} and z. {3} obtain the current best estimates of

the far-IR emission, thus L{bol} for this sample, and establish if the

relative contribution of mid-to-far IR dust emission is correlated with

morphology {resolved vs. unresolved}.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

11979 - Loss of lock on FGS 1 occurred at 18:07:39 with recovery at

           226/18:08:49. FGS 2 lost lock at 226/18:07:48 and recovered

           at 226/18:08:15.

          Observations affected: COS 57 - 61, Proposal ID# 11472.

11982 - GSAcq(2,3,3)at 228/14:20:10 failed due to search radius limit

           exceeded(SRLEX) on FGS 2 and FGS 3.

           Observations affected: ACS 59 - 62 Proposal ID# 11647,

                                          WFC3 109 Proposal ID# 11647.

11984 - GSAcq(2,1,1) scheduled at 229/05:23:31 - 05:31:02 failed to RGA

           Hold (gyro control) due to search radius limit exceeded on FGS-2.

           Observations affected: WFC3 5,6 Proposal ID# 11905,  

                                           STIS 1 Proposal ID# 11567.

COMPLETED OPS REQUEST:

18685-0 - Null genslews for proposal 11492 - slots 1 and 2 @ 226/16:30z

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL      FAILURE TIMES

FGS GSAcq              21                  19     

FGS REAcq               21                  21               

OBAD with Maneuver 23                  23                

LOSS of LOCK                                                  226/18:07:39z

SIGNIFICANT EVENTS: (None)