HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT    #4643

PERIOD COVERED: 5am June 30 - 5am July 1, 2008 (DOY 182/0900z-183/0900z)

OBSERVATIONS SCHEDULED

ACS/SBC 11158

HST Imaging of UV Emission in Quiescent Early-type Galaxies

We have constructed a sample of early type galaxies at z~0.1 that have

blue UV-optical colors, yet also show no signs of optical emission, or

extended blue light. We have cross-correlated the SDSS catalog and the

Galaxy Evolution Explorer Medium Imaging Survey to select a sample of

galaxies where this UV emission is strongest. The origin of the UV

rising flux in these galaxies continues to be debated, and the

possibility that some fraction of these galaxies may be experiencing low

levels of star formation cannot be excluded. There is also a possibility

that low level AGN activity {as evidenced by a point source} is

responsible We propose to image the UV emission using the HST/SBC and to

explore the morphology of the UV emission relative to the optical light.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA Calibration - CR Persistence Part 6

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 USEAFTER 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 DARKSs. 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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

NIC2 11168

The IMF in the Hidden Galactic Starburst W49A

W49A is one of the most luminous and prolific massive star formation

regions in the disk of our Milky Way. Given the presence of several very

massive OB clusters as well as an unusually high concentration of many

young ultra-compact HII regions (UCHIIR) -- all embedded in about 1

million solar masses of molecular gas -- it is arguably the best

Galactic template for a luminous starburst region. We propose to obtain

NICMOS imaging of the central part of W49A, covering a strip from the

central, massive OB cluster to the ring of UCHIIRs. Our goals are to

resolve and characterize the central star cluster and determine its IMF

down to about 1 solar mass. We want to characterize the distribution of

intermediate-mass YSOs, and identify the NIR counterparts to the

UCHIIRs. The combination of the proposed HST/NICMOS data with our

recently obtained Spitzer observations would allow a great step forward

in the understanding of massive star and cluster formation.

NIC3 11545

A NICMOS Survey of Newly-Discovered Young Massive Clusters

We are on the cusp of a revolution in massive star research triggered by

2MASS and Spitzer/GLIMPSE, and now is the ideal time to capitalize on

these projects by performing the first survey of massive stars in young

stellar clusters throughout the Galactic plane. A search of the 2MASS

and GLIMPSE surveys has produced over 450 newly-identified massive

stellar cluster candidates in the Galactic plane which are hidden from

our view at optical wavelengths due to extinction. Here we propose a

program of 29 orbits to image the most promising candidate clusters in

broad and narrow band filters using HST/NICMOS. We will be complementing

these observations with approved Spitzer and Chandra programmes,

numerous approved and planned ground-based spectroscopic observations,

and state-of-the-art modelling. We expect to substantially increase the

numbers of massive stars known in the Galaxy, including main sequence OB

stars and post-main sequence stars in the Red Supergiant, Luminous Blue

Variable and Wolf-Rayet stages. Ultimately, this programme will address

many of the fundamental topics in astrophysics: the slope to the initial

mass function (IMF), an upper-limit to the masses of stars, the

formation and evolution of the most massive stars, gamma-ray burst (GRB)

progenitors, the chemical enrichment of the interstellar medium, and

nature of the first stars in the Universe.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

#11367  NICMOS Suspended @ 182/0938z

with a status buffer message NICMOS 632, P=201, T=22310, indicating

MECH_2_MAX_RETRIES_EXCEEDED. The number of positioning error

retries attempted during a Filter Wheel 2 movement exceeded the

maximum limit. Per CTMline report the move was to the F110W

filter position. Observations affected: NICMOS #38-73 (Proposals

#11168, #08795 & #11545).

COMPLETED OPS REQUEST:

18242-1  NICMOS memory dump after suspend @ 182/1311z

18243-0  NICMOS Suspend Recovery @ 182/1820z

COMPLETED OPS NOTES: (NONE) 

                                SCHEDULED      SUCCESSFUL   

FGS GSacq                       07                    07                 

FGS REacq                       07                    07                  

OBAD with Maneuver         28                    28                   

SIGNIFICANT EVENTS:

A NICMOS suspend event occured at 182/0938z (30 June/5:38am), see

HSTAR #11367 write-up above. NICMOS was recovered and positioned for

science operations at 182/1818z (30 June/2:18pm). This put NICMOS back

on the science timeline for observation #74 in Proposal #11545 at

182/1836z (30 June/2:36pm).