HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT       #4947

 

PERIOD COVERED: 5am October 7 - 5am October 8, 2009 (DOY 280/09:00z-281/09:00z)

 

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/FUV/ACS/WFC/WFC3/UV/ 11632 NUV The Gaseous Corona of M31

 

We propose to obtain ultraviolet spectroscopy of the halo of M31, to

probe for a hot corona on scales of 30-40 pc from the galaxy. We seek to

obtain absorption line spectra of O I, Mg II, Si II, C IV, and Si IV

toward bright QSOs located behind the galaxy. One of the sightlines

falls on the projection of Ibata's giant stream. All background sources

have been vetted with GALEX photometry and are therefore bright enough

for observation. If hot gas is detected with this initial study, we will

endeavor to use a grid of background sources to map the structure and

kinematics of this gas in detail. M31 is the nearest major spiral galaxy

for which such a study can be undertaken, other than our own Milky Way.

Recent studies find a substantial population of HI high velocity clouds

at distances form M31 of up to 50 kpc, and there is well documented

evidence of disrupted satellites and tidal streams. These observations

will shed light on the hot gaseous halo of M31, but also will help in

interpreting QSO sightlines at high redshift.

 

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.

 

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.

 

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.

 

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.

 

WFC3/IR 11618

 

WFC3 Observations of VeLLOs and the Youngest Star Forming Environments

 

The Cores-to-Disks Spitzer Legacy team has discovered a number of

extremely low luminosity sources embedded deep within nearby (< 300 pc)

cores previously thought to be starless. With substellar masses, these

low luminosity sources represent either the youngest low-mass protostars

yet detected or the first embedded brown dwarfs. In either case, they

represent a new observed class of sources referred to as VeLLOs (Very

Low Luminosity Objects). We propose WFC3 F160W observations of a small

sample of these sources, to be combined with deep ground-based

observations at Ks, to address a broad set of issues concerning VeLLOs

and the environments within which they are forming. First, the

morphology of their outflow cavities will be traced, yielding estimates

of the inclinations and opening angles of the cavities and the

evolutionary stages of the VeLLOs. Second, our observations will reveal

background stars seen through the densest regions of cores harboring

these VeLLOs. The color-excesses of the background stars will yield the

highest angular resolution extinction maps necessary to directly probe

the inner density structure of these cores, found very soon after the

onset of collapse, which would constrain the initial conditions of

collapse within these isolated environments. In addition, we will

construct similar maps of the dense pre-protostellar core L694-2 and the

protostellar core B335. These maps will provide a snapshot of the

evolution of the inner density structure of a core prior to low-mass

star formation and soon thereafter, for comparison with the inner

density structure of cores that have formed VeLLOs. Finally, these

extinction maps will enable us to determine the core "centers", or

positions of peak column densities. Comparison of these centers with the

positions of the VeLLOs may yield insight regarding potential

differences between the formation of low-mass stars and brown dwarfs.

 

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/UV/IR 11664

 

The WFC3 Galactic Bulge Treasury Program: Populations, Formation

History, and Planets

 

Exploiting the full power of the Wide Field Camera 3 (WFC3), we propose

deep panchromatic imaging of four fields in the Galactic bulge. These

data will enable a sensitive dissection of its stellar populations,

using a new set of reddening-free photometric indices we have

constructed from broad-band filters across UV, optical, and near-IR

wavelengths. These indices will provide accurate temperatures and

metallicities for hundreds of thousands of individual bulge stars.

Proper motions of these stars derived from multi-epoch observations will

allow separation of pure bulge samples from foreground disk

contamination. Our catalogs of proper motions and panchromatic

photometry will support a wide range of bulge studies.

 

Using these photometric and astrometric tools, we will reconstruct the

detailed star-formation history as a function of position within the

bulge, and thus differentiate between rapid- and extended-formation

scenarios. We will also measure the dependence of the stellar mass

function on metallicity, revealing how the characteristic mass of star

formation varies with chemistry. Our sample of bulge stars with accurate

metallicities will include 12 candidate hosts of extrasolar planets.

Planet frequency is correlated with metallicity in the solar

neighborhood; our measurements will extend this knowledge to a remote

environment with a very distinct chemistry.

 

Our proposal also includes observations of six well-studied globular and

open star clusters; these observations will serve to calibrate our

photometric indices, provide empirical population templates, and

transform the theoretical isochrone libraries into the WFC3 filter

system. Besides enabling our own program, these products will provide

powerful new tools for a host of other stellar-population investigations

with HST/WFC3. We will deliver all of the products from this Treasury

Program to the community in a timely fashion.

 

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:

12038 - GSAcq(2,1,1) scheduled at 280/21:48:22 - 21:56:12 and

           REAcq(2,1,1) scheduled at 280/23:25:27, at 281/01:01:57, at 281/02:37:08

           and at 281/04:12:59 all resulted in fine lock backup (2,0,2) using FGS-2

           due to Scan Step Limit Exceeded on FGS-1.

 

           Observations possibly affected: WFC3 87-100 Proposal ID# 11664.

           STIS 23 Proposal ID# 11844.

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                       SCHEDULED      SUCCESSFUL

FGS GSAcq               06                  06                    

FGS REAcq               10                  10                 

OBAD with Maneuver 05                  05                

 

SIGNIFICANT EVENTS: (None)