HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT      #5019

PERIOD COVERED: 5am January 25 - 5am January 26, 2010 (DOY 025/10:00z-026/10:00z)

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/FUV 11895

FUV Detector Dark Monitor

The purpose of this proposal is to 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/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.

NIC2/WFC3/IR 11548

Infrared Imaging of Protostars in the Orion A Cloud: The Role of

Environment in Star Formation

We propose NICMOS and WFC3/IR observations of a sample of 252 protostars

identified in the Orion A cloud with the Spitzer Space Telescope. These

observations will image the scattered light escaping the protostellar

envelopes, providing information on the shapes of outflow cavities, the

inclinations of the protostars, and the overall morphologies of the

envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron

spectra of 75 of the protostars. Combining these new data with existing

3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured

with the Spitzer Space Telescope, we will determine the physical

properties of the protostars such as envelope density, luminosity,

infall rate, and outflow cavity opening angle. By examining how these

properties vary with stellar density (i.e. clusters vs. groups vs.

isolation) and the properties of the surrounding molecular cloud; we can

directly measure how the surrounding environment influences protostellar

evolution, and consequently, the formation of stars and planetary

systems. Ultimately, this data will guide the development of a theory of

protostellar evolution.

STIS/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

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 11849

STIS CCD Hot Pixel Annealing

This purpose of this activity is to repair radiation induced hot pixel

damage to the STIS CCD by warming the CCD to the ambient instrument

temperature and annealing radiation-damaged pixels.

Radiation damage creates hot pixels in the STIS CCD Detector. Many of

these hot pixels can be repaired by warming the CCD from its normal

operating temperature near -83 deg. C to the ambient instrument

temperature (~ +5 deg. C) for several hours. The number of hot pixels

repaired is a function of annealing temperature. The effectiveness of

the CCD hot pixel annealing process is assessed by measuring the dark

current behavior before and after annealing and by searching for any

window contamination effects.

STIS/CCD/MA2 11568

A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations

of Stars with Archived FUV Observations

We propose to obtain high-resolution STIS E230H SNAP observations of

MgII and FeII interstellar absorption lines toward stars within 100

parsecs that already have moderate or high-resolution far-UV (FUV),

900-1700 A, observations available in the MAST Archive. Fundamental

properties, such as temperature, turbulence, ionization, abundances, and

depletions of gas in the local interstellar medium (LISM) can be

measured by coupling such observations. Due to the wide spectral range

of STIS, observations to study nearby stars also contain important data

about the LISM embedded within their spectra. However, unlocking this

information from the intrinsically broad and often saturated FUV

absorption lines of low-mass ions, (DI, CII, NI, OI), requires first

understanding the kinematic structure of the gas along the line of

sight. This can be achieved with high resolution spectra of high-mass

ions, (FeII, MgII), which have narrow absorption lines, and can resolve

each individual velocity component (interstellar cloud). By obtaining

short (~10 minute) E230H observations of FeII and MgII, for stars that

already have moderate or high- resolution FUV spectra, we can increase

the sample of LISM measurements, and thereby expand our knowledge of the

physical properties of the gas in our galactic neighborhood. STIS is the

only instrument capable of obtaining the required high resolution data

now or in the foreseeable future.

WFC3/ACS/IR 11677

Is 47 Tuc Young? Measuring its White Dwarf Cooling Age and Completing a

Hubble Legacy

With this proposal we will firmly establish the age of 47 Tuc from its

cooling white dwarfs. 47 Tuc is the nearest and least reddened of the

metal-rich disk globular clusters. It is also the template used for

studying the giant branches of nearby resolved galaxies. In addition,

the age sensitive magnitude spread between the main sequence turnoff and

horizontal branch is identical for 47 Tuc, two bulge globular clusters

and the bulge field population. A precise relative age constraint for 47

Tuc, compared to the halo clusters M4 and NGC 6397, both of which we

recently dated via white dwarf cooling, would therefore constrain when

the bulge formed relative to the old halo globular clusters. Of

particular interest is that with the higher quality ACS data on NGC

6397, we are now capable with the technique of white dwarf cooling of

determining ages to an accuracy of +/-0.4 Gyrs at the 95% confidence

level. Ages derived from the cluster turnoff are not currently capable

of reaching this precision. The important role that 47 Tuc plays in

galaxy formation studies, and as the metal-rich template for the

globular clusters, makes the case for a white dwarf cooling age for this

metal-rich cluster compelling.

Several recent analyses have suggested that 47 Tuc is more than 2 Gyrs

younger than the Galactic halo. Others have suggested an age similar to

that of the most metal poor globular clusters. The current situation is

clearly uncertain and obviously a new approach to age dating this

important cluster is required.

With the observations of 47 Tuc, this project will complete a legacy for

HST. It will be the third globular cluster observed for white dwarf

cooling; the three covering almost the full metallicity range of the

cluster system. Unless JWST has its proposed bluer filters (700 and 900

nm) this science will not be possible perhaps for decades until a large

optical telescope is again in space. Ages for globular clusters from the

main sequence turnoff are less precise than those from white dwarf

cooling making the science with the current proposal truly urgent.

WFC3/IR 11189

Probing the Early Universe with GRBs

Cosmology is beginning to constrain the nature of the earliest stars and

galaxies to form in the Universe, but direct observation of galaxies at

z>6 remains highly challenging due to their scarcity, intrinsically

small size, and high luminosity distance. GRB afterglows, thanks to

their extreme luminosities, offer the possibility of circumventing these

normal constraints by providing redshifts and spectral information which

couldn't be obtained through direct observation of the host galaxies

themselves. In addition, the association of GRBs with massive stars

means that they are an indicator of star formation, and that their hosts

are likely responsible for a large proportion of the ionizing radiation

during that era. Our collaboration is conducting a campaign to rapidly

identify and study candidate very high redshift bursts, bringing to bear

a network of 2, 4 and 8m telescopes with near-IR instrumentation. Swift

has proven capable of detecting faint, distant GRBs, and reporting

accurate positions for many bursts in near real-time. Here we propose to

continue our HST program of targeting GRBs at z~6 and above. HST is

crucial to this endeavor, allowing us (a) to characterize the basic

properties, such as luminosity and color, and in some cases

morphologies, of the hosts, which is essential to understanding these

primordial galaxies and their relationship to other galaxy populations;

and (b) to monitor the late time afterglows and hence compare them to

lower-z bursts and test the use of GRBs as standard candles.

WFC3/UVIS 11583

The Star Formation Rate In Nearby Elliptical Galaxies

Small amounts of star formation in normal elliptical galaxies are

suggested by several results: some surprisingly young ages from optical

line-index dating; cooling X-ray gas; and mid-IR dust emission.

Previously, it was difficult to detect low levels of star formation, but

UV imaging with WFPC3 will permit us to conclusively identify individual

O/B stars in nearby normal ellipticals by their UV colors and

magnitudes. This technique is orders of magnitude more sensitive than

previous methods, allowing detections of star formation to levels of

1E-4 Msolar/yr. Proof of concept is provided by a very long UV ACS

observation of M87 that revealed many O/B stars. We propose observations

of four normal ellipticals where recent star formation is likely. This

will yield their star formation rates and the locations of such

activity.

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).

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: (None)

COMPLETED OPS NOTES: (None)

                      SCHEDULED  SUCCESSFUL             

FGS GSAcq               5               5       

FGS REAcq              10             10               

OBAD with Maneuver 5               5       

SIGNIFICANT EVENTS: (None)