HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT      #4934

 

PERIOD COVERED: 5am September 18 - 5am September 21, 2009 (DOY 261/09:00z-264/09:00z)

 

OBSERVATIONS SCHEDULED

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA Calibration - CR Persistence Part 6

 

This is a new procedure proposed to alleviate the CR-persistence problem

of NICMOS. Dark frames will be obtained immediately upon exiting the SAA

contour 23, and every time a NICMOS exposure is scheduled within 50

minutes of coming out of the SAA. The darks will be obtained in parallel

in all three NICMOS cameras. The post-SAA darks will be non-standard

reference files available to users with a 'Use After' date/time mark.

The keyword 'UseAfter=date/time' will also be added to the header of

each post-SAA dark frame. The keyword must be populated with the time,

in addition to the date, because HST crosses the SAA ~8 times per day,

so each post-SAA dark will need to have the appropriate time specified,

for users to identify the ones they need. Both the raw and processed

images will be archived as post-SAA darks. Generally we expect that all

NICMOS science/calibration observations started within 50 minutes of

leaving an SAA will need such MAPs to remove the CR persistence from the

science images. Each observation will need its own CRMAP, as different

SAA passages leave different imprints on the NICMOS detectors.

 

NIC1/NIC2/NIC3 11947

 

Extended Dark Monitoring

 

This program takes a series of darks to obtain darks (including

amplifier glow, dark current, and shading profiles) for all three

cameras in the read-out sequences used in Cycle 17. A set of 12 orbits

will be observed every two months for a total of 72 orbits for a 12

month Cycle 17. This is a continuation of Cycle 16 program 11330 scaled

down by ~80%.

 

The first orbit (Visit A0) should be scheduled in the NICMOS SMOV after

the DC Transfer Test (11406) and at least 36h before the Filter Wheel

Test (11407). Data download using fast track.

 

The following 28 orbits (visit A1-N2) should be scheduled AFTER the SMOV

Proposal 11407 (Filter Wheel Test). This is done in order to monitor the

dark current following an adjustment of the NCS set-point. These visits

should be executed until the final temperature is reached during SMOV.

 

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/UVIS 11925

 

UVIS Detector Linearity

 

This proposal will measure the in-orbit linear response of the UVIS

detectors by sampling over the response curve through saturation. This

program uses exposures of a standard star field (NGC 1850) to measure

the absolute values, and exposures of a tungsten lamp to measure

positional variations in response, following a similar procedure as the

ground tests.

 

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 11912

 

UVIS Internal Flats

 

This proposal will be used to assess the stability of the flat field

structure for the UVIS detector throughout the 15 months of Cycle 17.

The data will be used to generate on- orbit updates for the delta-flat

field reference files used in the WFC3 calibration pipeline, if

significant changes in the flat structure are seen.

 

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 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).

 

ACS/WFC3 11879

 

CCD Daily Monitor (Part 1)

 

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 352 orbits (22 weeks) from 31 August 2009 to 31 January

2010.

 

STIS/CCD 11846

 

CCD Bias Monitor-Part 1

 

The purpose of this proposal is to 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

 

The purpose of this proposal is to 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.

 

FGS 11704

 

The Ages of Globular Clusters and the Population II Distance Scale

 

Globular clusters are the oldest objects in the universe whose age can

be accurately determined. The dominant error in globular cluster age

determinations is the uncertain Population II distance scale. We propose

to use FGS 1R to obtain parallaxes with an accuracy of 0.2

milliarcsecond for 9 main sequence stars with [Fe/H] < -1.5. This will

determine the absolute magnitude of these stars with accuracies of 0.04

to 0.06mag. This data will be used to determine the distance to 24

metal-poor globular clusters using main sequence fitting. These

distances (with errors of 0.05 mag) will be used to determine the ages

of globular clusters using the luminosity of the subgiant branch as an

age indicator. This will yield absolute ages with an accuracy of 5%,

about a factor of two improvement over current estimates. Coupled with

existing parallaxes for more metal-rich stars, we will be able to

accurately determine the age for globular clusters over a wide range of

metallicities in order to study the early formation history of the Milky

Way and provide an independent estimate of the age of the universe.

 

The Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an

absolute magnitude error less than 0.18 mag which is suitable for use in

main sequence fitting. Previous attempts at main sequence fitting to

metal-poor globular clusters have had to rely on theoretical

calibrations of the color of the main sequence. Our HST parallax program

will remove this source of possible systematic error and yield distances

to metal- poor globular clusters which are significantly more accurate

than possible with the current parallax data. The HST parallax data will

have errors which are 10 times smaller than the current parallax data.

Using the HST parallaxes, we will obtain main sequence fitting distances

to 11 globular clusters which contain over 500 RR Lyrae stars. This will

allow us to calibrate the absolute magnitude of RR Lyrae stars, a

commonly used Population II distance indicator.

 

ACS/WFC3 11670

 

The Host Environments of Type Ia Supernovae in the SDSS Survey

 

The Sloan Digital Sky Survey Supernova Survey has discovered nearly 500

type Ia supernovae and created a large, unique, and uniform sample of

these cosmological tools. As part of a comprehensive study of the

supernova hosts, we propose to obtain Hubble ACS images of a large

fraction of these galaxies. Integrated colors and spectra will be

measured from the ground, but we require high-resolution HST imaging to

provide accurate morphologies and color information at the site of the

explosion. This information is essential in determining the systematic

effects of population age on type Ia supernova luminosities and

improving their reliability in measuring dark energy. Recent studies

suggest two populations of type Ia supernovae: a class that explodes

promptly after star-formation and one that is delayed by billions of

years. Measuring the star-formation rate at the site of the supernova

from colors in the HST images may be the best way to differentiate

between these classes.

 

WFC3/UVIS 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/UVIS 11559

 

Jovian Upheaval and Its Impact on Vortices

 

We propose observations of Jupiter with global coverage at high

resolution to quantify changes in its atmosphere during and following

the global upheaval. Only HST has the capability to obtain images with

enough spatial resolution and contrast to extract velocity fields (we

will use our newly developed technique to accomplish this), and with

WFC3 we can image Jupiter in its entirety in a single exposure. We are

in particular interested in the Red Oval BA: Will the Oval be long

lived, remain red, or turn white again, disappear? Both the merger of

its precursors, and change in color has never before been witnessed. The

Great Red Spot: This storm system appears to decrease in size and has

become rounder, both as derived from its associated cloud deck, but also

from its potential vorticity, a more dynamically-relevant quantity. How

will the GRS evolve? Will it swallow the new vortices detected in

amateur images at this same latitude band? How will this effect the

potential vorticity? In addition, we hope to understand disturbances and

stagnation points, both of which were detected during the present global

upheaval: are these cyclonic regions, can they spawn anticyclones (as

suggested by amateur images)?

 

COS/NUV/FUV/WFC3/UVIS/IR 11534

 

COS-GTO: Atmosphere of a Transiting Planet

 

COS observations of a transiting planet at different orbital locations

will be useful in identifying the chemical content, size, temperature,

and flows in the atmosphere of a transiting planet.

 

COS/NUV/FUV 11487

 

COS FUV Internal/External Wavelength Scales

 

Observe external radial velocity standard targets in Time-Tag

(Flash=Yes) mode with all grating and central wavelength combinations.

The purpose is to obtain zero point offsets for the wavelength scale

(internal wavecal lamp scale to external standard wavelength scale) and

PSA dispersion relations for all central wavelengths.

 

Following this determination, adjustments of the nominal science target

spectral range for each grating and central wavelength combination will

be made via SMS-patchable constant for nominal OSM1 positions

corresponding to each central wavelength. Subsequent to this

modification of the wavelength scale (and its verification via analysis

of COS30 - Program 11488), FUV science-related operations and

wavelength- dependent EROs can commence.

 

COS/NUV 11471

 

COS NUV Imaging Acquisition Algorithm Verification

 

The purpose of this proposal is to 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 Mirror A and Mirror B. 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.

 

NIC1/NIC2/NIC3/S/C 11407

 

NICMOS Filter Wheel Test

 

This is an engineering test (described in SMOV4 Activity Description

NICMOS-04) to verify the aliveness, functionality, operability, and

electro-mechanical calibration of the NICMOS filter wheel motors and

assembly after NCS restart in SMOV4. This test has been designed to

obviate concerns over possible deformation or breakage of the filter

wheel "soda-straw" shafts due to excess rotational drag torque and/or

bending moments which may be imparted due to changes in the dewar

metrology from warm-up/cool- down. This test should be executed after

the NCS (and filter wheel housing) has reached and approximately

equilibrated to its nominal operating temperature.

 

WFC3/ACS/IR 11359

 

Panchromatic WFC3 Survey of Galaxies at Intermediate z: Early Release

Science Program for Wide Field Camera 3.

 

The unique panchromatic capabilities of WFC3 will be used to survey the

structure and evolution of galaxies at the peak of the galaxy assembly

epoch. Deep ultraviolet and near-IR imaging and slitless spectroscopy of

existing deep multi-color ACS fields will be used to gauge

star-formation and the growth of stellar mass as a function of

morphology, structure and surrounding density in the critical epoch 1 <

z < 4. Images in the F225W, F275W, and F336W filters will identify

galaxies at z < 1.5 from their UV continuum breaks, and provide

star-formation indicators tied directly to both local and z > 3

populations. Deep near-IR (F125W and F160W) images will probe the

stellar mass function well below 10^9 Msun for mass-complete samples.

Lastly, the WFC3 slitless UV and near-IR grisms will be used to measure

redshifts and star-formation rates from H- alpha and rest-frame UV

continuum slope. This WFC3 ERS program will survey one 4 x 2 mosaic for

a total area of 50 square arcminutes to 5-sigma depths of m_AB = 27 in

most filters from the mid-UV through the near-IR.

 

This multicolor high spatial resolution data set will allow the user to

gauge the growth of galaxies through star-formation and merging. High

precision photometric and low- resolution spectroscopic redshifts will

allow accurate determinations of the faint-end of the luminosity and

mass functions, and will shed light on merging and tidal disruption of

stellar and gaseous disks. The WFC3 images will also allow detailed

studies of the internal structure of galaxies, and the distribution of

young and old stellar populations. This program will demonstrate the

unique power of WFC3 by applying its many diverse modes and full

panchromatic capability to a forefront problem in astrophysics.

 

FGS 11213

 

Distances to Eclipsing M Dwarf Binaries

 

We propose HST FGS observations to measure accurate distances of 5

nearby M dwarf eclipsing binary systems, from which model-independent

luminosities can be calculated. These objects have either poor or no

existing parallax measurements. FGS parallax determinations for these

systems, with their existing dynamic masses determined to better than

0.5%, would serve as model-independent anchor points for the low-mass

end of the mass-luminosity diagram.

 

WFC3/ACS/IR 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, and (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:

12014 - GSAcq(2,1,1) scheduled at 261/16:17:51z failed to RGA Hold (gyro

           control) with Search Radius Limit Exceeded on FGS-2 at 261/16:23:06z.

 

           Observations affected: WFC3 111 - 114, Proposal ID# 11559

 

 

12015 - GSAcq (1,2,1) scheduled from 263/04:26:41z - 04:33:41z resulted in

           Fine Lock Back-up (2,0,2) at 263/04:31:43z using FGS 2

 

           Observations possibly affected: WFC3 165 - 166, Proposal ID# 11594.

 

 

COMPLETED OPS REQUEST:

18706-0 - Set up Tasking orders for NICMOS FW test @ 261/1551z

18707-0 - Configure Tasking Orders after FW test EDD dumps completed @ 261/2312z

18708-1 - Enable NICMOS Filter Wheel flag to continue test @ 262/1742z

 

 

COMPLETED OPS NOTES: (None)

 

                        SCHEDULED      SUCCESSFUL

FGS GSAcq               24                  23    

FGS REAcq               17                  17                

OBAD with Maneuver 25                  25                      

 

SIGNIFICANT EVENTS: (None)