HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT      #4923

PERIOD COVERED: 5am September 2 - 5am September 3, 2009 (DOY 245/09:00z-246/09:00z)

OBSERVATIONS SCHEDULED

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.

COS/NUV 11480

COS NUV Structural and Thermal Stability

The goal of this program is to measure OTA-COS pointing jitter or

drifts, over timescales of seconds to hours. In particular, our

priorities are to test the level of OSM1 drift, thermal day-night

transitions, and orbital 'breathing'. Pointing-related thermal offsets

with their related drifts during thermal settling will be overlaid upon

the signatures of the other components of positional change. Three

different instrumental configurations/transitions will be tested: NUV

and FUV spectroscopy, and NUV imaging using Mirror A, all with the PSA.

No FP-POS motions, nor grating changes, will be made during the

spectroscopy in order to limit the variables contributing to any changes

in position of the spectra.

ID: COS 20 (11480) & COS 35 (11493) This is the NUV portion of this

experiment. It was initially estimated to be a 6-orbit program, but has

been expanded to 10 orbits in order to improve the statistical sample of

the day-night/breathing transitions.

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.

STIS/CCD 11843

STIS CCD Performance Monitor

This activity measures the baseline performance and commandability of

the CCD subsystem. Only primary amplifier D is used. Bias and Flatfield

exposures are taken in order to measure bias level, read noise, CTE, and

gain. Numerous bias frames are taken to permit construction of

"superbias" frames in which the effects of read noise have been rendered

negligible. Full frame and binned observations are made, with binning

factors of 2 x 1, 1 x 2, 2 x 2. Bias frames are taken in subarray

readouts to check the bias level for ACQ and ACQ/PEAK observations. All

exposures are internals.

STIS/CCD 11844

CCD Dark Monitor Part 1

Monitor the darks for the STIS CCD.

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 11850

CCD Sparse Field CTE Internal

CTE measurements are made using the "internal sparse field test", along

the parallel axis. The "Pos=" optional parameter, introduced during

Cycle 11, is used to provide off- center MSM positionings of some slits.

All exposures are internals.

STIS/CCD/MA1/MA2 11690

EG And: Providing the Missing Link Required for Modeling 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 utilizing

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.

STIS/CCD/MA2 11860

MAMA Spectroscopic Sensitivity and Focus Monitor

Monitor sensitivity of each MAMA grating mode to detect any change due

to contamination or other causes. Also monitor the STIS focus in a

spectroscopic and an imaging mode.

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.

WFC3/ACS/IR 11235

HST NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies

in the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared

selected galaxies exceeds that of optically selected galaxies. These

`luminous infrared galaxies' (LIRGs) are primarily interacting or

merging disk galaxies undergoing enhanced star formation and Active

Galactic Nuclei (AGN) activity, possibly triggered as the objects

transform into massive S0 and elliptical merger remnants. We propose

NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88

L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised

Bright Galaxy Sample (RBGS: i.e., 60 micron flux density > 5.24 Jy).

This sample is ideal not only in its completeness and sample size, but

also in the proximity and brightness of the galaxies. The superb

sensitivity and resolution of NICMOS NIC2 on HST enables a unique

opportunity to study the detailed structure of the nuclear regions,

where dust obscuration may mask star clusters, AGN, and additional

nuclei from optical view, with a resolution significantly higher than

possible with Spitzer IRAC. This survey thus provides a crucial

component to our study of the dynamics and evolution of IR galaxies

presently underway with Wide-Field, HST ACS/WFC3, and Spitzer IRAC

observations of these 88 galaxies. Imaging will be done with the F160W

filter (H-band) to examine as a function of both luminosity and merger

stage: (i) the luminosity and distribution of embedded star clusters,

(ii) the presence of optically obscured AGN and nuclei, (iii) the

correlation between the distribution of 1.6 micron emission and the

mid-IR emission as detected by Spitzer IRAC, (iv) the evidence of bars

or bridges that may funnel fuel into the nuclear region, and (v) the

ages of star clusters for which photometry is available via ACS/WFC3

observations. The NICMOS data, combined with the HST ACS, Spitzer, and

GALEX observations of this sample, will result in the most comprehensive

study of merging and interacting galaxies to date.

WFC3/ACS/IR 11563

Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to

<0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields

The first generations of galaxies were assembled around redshifts

z~7-10+, just 500-800 Myr after recombination, in the heart of the

reionization of the universe. We know very little about galaxies in this

period. Despite great effort with HST and other telescopes, less than

~15 galaxies have been reliably detected so far at z>7, contrasting with

the ~1000 galaxies detected to date at z~6, just 200-400 Myr later, near

the end of the reionization epoch. WFC3 IR can dramatically change this

situation, enabling derivation of the galaxy luminosity function and its

shape at z~7-8 to well below L*, measurement of the UV luminosity

density at z~7-8 and z~8-9, and estimates of the contribution of

galaxies to reionization at these epochs, as well as characterization of

their properties (sizes, structure, colors). A quantitative leap in our

understanding of early galaxies, and the timescales of their buildup,

requires a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can

achieve this with 192 WFC3 IR orbits on three disjoint fields

(minimizing cosmic variance): the HUDF and the two nearby deep fields of

the HUDF05. Our program uses three WFC3 IR filters, and leverages over

600 orbits of existing ACS data, to identify, with low contamination, a

large sample of over 100 objects at z~7-8, a very useful sample of ~23

at z~8-9, and limits at z~10. By careful placement of the WFC3 IR and

parallel ACS pointings, we also enhance the optical ACS imaging on the

HUDF and a HUDF05 field. We stress (1) the need to go deep, which is

paramount to define L*, the shape, and the slope alpha of the luminosity

function (LF) at these high redshifts; and (2) the far superior

performance of our strategy, compared with the use of strong lensing

clusters, in detecting significant samples of faint z~7-8 galaxies to

derive their luminosity function and UV ionizing flux. Our recent z~7.4

NICMOS results show that wide-area IR surveys, even of GOODS-like depth,

simply do not reach faint enough at z~7-9 to meet the LF and UV flux

objectives. In the spirit of the HDF and the HUDF, we will waive any

proprietary period, and will also deliver the reduced data to STScI. The

proposed data will provide a Legacy resource of great value for a wide

range of archival science investigations of galaxies at redshifts z~2-9.

The data are likely to remain the deepest IR/optical images until JWST

is launched, and will provide sources for spectroscopic followup by

JWST, ALMA and EVLA.

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 11432

UVIS Internal Flats

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

structure for the UVIS detector. Flat fields will be obtained for all

filters using the internal D2 and tungsten lamps.

This proposal corresponds to Activity Description ID WF19. It should

execute only after the following proposals have executed: WF08 - 11421

WF09 - 11422 WF11 - 11424 WF15 - 11428

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 (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.

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.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS: (None)

COMPLETED OPS REQUEST:

18695-0 - Adjust NCS PID Control Setpoints @ 245/150021z

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL 

FGS GSAcq               8                    8             

FGS REAcq               8                    8               

OBAD with Maneuver 6                    6               

SIGNIFICANT EVENTS:

NCS PID Control Setpoint Adjustment

OR 18695-0 to adjust the NCS PID control setpoint temperature was

successfully completed at 145/15:00:21 UTC.