HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT    #5031

 

PERIOD COVERED: 5am February 10 - 5am February 11, 2010 (DOY 041/10:00z-042/10:00z)

 

OBSERVATIONS SCHEDULED

 

ACS/WFC 11995

 

CCD Daily Monitor (Part 2)

 

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 320 orbits (20 weeks) from 1 February 2010 to 20 June

2010.

 

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/MA1/MA2 11616

 

The Disks, Accretion, and Outflows (DAO) of T Tau Stars

 

Classical T Tauri stars undergo magnetospheric accretion, power

outflows, and possess the physical and chemical conditions in their

disks to give rise to planet formation. Existing high resolution FUV

spectra verify that this spectral region offers unique diagnostics of

these processes, which have the potential to significantly advance our

understanding of the interaction of a star and its accretion disk. To

date the limited results are intriguing, with dramatic differences in

kinematic structure in lines ranging from C IV to H2 among the few stars

that have been observed. We propose to use HST/COS to survey the disks,

outflows, and accretion (the DAO) of 26 CTTS and 6 WTTS in the FUV at

high spectral resolution. A survey of this size is essential to

establish how properties of accretion shocks, winds and disk irradiation

depend on disk accretion rate. Specifically, our goals are to (1)

measure the radiation from and understand the physical properties of the

gas very near the accretion shock as a function of accretion rate using

emission line profiles of hot lines (C IV, Si IV, N V, and He II); (2)

measure the opacity, velocity, and temperature at the base of the

outflow to constrain outflow models using wind absorption features; and

(3) characterize the radiation incident on disks and protoplanetary

atmospheres using H2 line and continuum emission and reconstructed

bright Ly-alpha line emission.

 

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/ACS/UVIS 11803

 

Observing Cluster Assembly Around the Massive Cluster RXJ0152-13

 

We request ACS imaging for groups and filaments in the outskirts of two

z=0.8 forming clusters of galaxies. These images will be combined with

an unparalleled dataset of wide-field spectroscopy from Magellan, with

~2200 confirmed members (~3200 by the summer) of the superstructures

surrounding the two clusters. We will estimate merger rates and

determine the morphological composition of the galaxy populations within

the infalling groups and filaments identified in our spectroscopic

dataset. The HST data are critical to understand how the early-type

galaxy fraction remains constant in cluster centers, while clusters

double in mass through the steady accretion of lower mass groups. One

possibility is that the galaxies in the filaments and infalling groups

already have predominantly early-type morphologies, while another is

that galaxies transform during, and possibly even in connection with,

the process of infall. Our unique dataset of spectroscopic membership,

when combined with the exquisite high- resolution imaging of ACS and

WF3, will enable us to witness the accretion of galaxies unto massive

clusters and how this process affects their properties.

 

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 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:

12185 - REAcq(1, 2,1) scheduled at 041/15:20:18 took two attempts to achieve FL.

 

           Observations possibly affected: COS 57 - 58 Proposal ID#11616

 

12186 - GSAcq(2,1,1) scheduled at 041/21:46:43- 21:54:14 resulted to

           fine lock backup (1,0,1) using FGS-1 due to scan step limit exceeded on

           FGS-2.

 

           Observations possibly affected: WFC3 100 - 103 Proposal ID#11548.

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED SUCCESSFUL

FGS GSAcq               08           08

FGS REAcq               07           07

OBAD with Maneuver 04           04

 

SIGNIFICANT EVENTS: (None)