Notice: Due to the conversion of some ACS WFC or HRC observations into

WFPC2, or NICMOS observations after the loss of ACS CCD science

capability in January, there may be an occasional discrepancy between a

proposal's listed (and correct) instrument usage and the abstract that

follows it.

 

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       # 4456

 

PERIOD COVERED: UT September 26, 2007 (DOY 269)

 

OBSERVATIONS SCHEDULED

 

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.

 

NIC3 11082

 

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive

Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured

Universe

 

(uses ACS/SBC and WFPC2)

 

Deep near-infrared imaging provides the only avenue towards

understanding a host of astrophysical problems, including: finding

galaxies and AGN at z > 7, the evolution of the most massive galaxies,

the triggering of star formation in dusty galaxies, and revealing

properties of obscured AGN. As such, we propose to observe 60 selected

areas of the GOODS North and South fields with NICMOS Camera 3 in the

F160W band pointed at known massive M > 10^11 M_0 galaxies at z > 2

discovered through deep Spitzer imaging. The depth we will reach {26.5

AB at 5 sigma} in H_160 allows us to study the internal properties of

these galaxies, including their sizes and morphologies, and to

understand how scaling relations such as the Kormendy relationship

evolved. Although NIC3 is out of focus and undersampled, it is currently

our best opportunity to study these galaxies, while also sampling enough

area to perform a general NIR survey 1/3 the size of an ACS GOODS field.

These data will be a significant resource, invaluable for many other

science goals, including discovering high redshift galaxies at z > 7,

the evolution of galaxies onto the Hubble sequence, as well as examining

obscured AGN and dusty star formation at z > 1.5. The GOODS fields are

the natural location for HST to perform a deep NICMOS imaging program,

as extensive data from space and ground based observatories such as

Chandra, GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are

currently available for these regions. Deep high-resolution

near-infrared observations are the one missing ingredient to this

survey, filling in an important gap to create the deepest, largest, and

most uniform data set for studying the faint and distant universe. The

importance of these images will increase with time as new facilities

come on line, most notably WFC3 and ALMA, and for the planning of future

JWST observations.

 

NIC3 11107

 

Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy

Formation in the Early Universe

 

We have used the ultraviolet all-sky imaging survey currently being

conducted by the Galaxy Evolution Explorer {GALEX} to identify for the

first time a rare population of low- redshift starbursts with properties

remarkably similar to high-redshift Lyman Break Galaxies {LBGs}. These

"compact UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,

SFR, surface brightness, mass, metallicity, kinematics, dust, and color.

The UVLG sample offers the unique opportunity of investigating some very

important properties of LBGs that have remained virtually inaccessible

at high redshift: their morphology and the mechanism that drives their

star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS

in order to 1} characterize their morphology and look for signs of

interactions and mergers, and 2} probe their star formation histories

over a variety of timescales. The images show a striking trend of

small-scale mergers turning large amounts of gas into vigorous

starbursts {a process referred to as dissipational or "wet" merging}.

Here, we propose to complete our sample of 31 LBG analogs using the

ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a

statistical sample to study the mechanism that triggers star formation

in UVLGs and its implications for the nature of LBGs. Specifically, we

will 1} study the trend between galaxy merging and SFR in UVLGs, 2}

artificially redshift the FUV images to z=1-4 and compare morphologies

with those in similarly sized samples of LBGs at the same rest-frame

wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence

and morphology of significant stellar mass in "pre-burst" stars, and 4}

study their immediate environment. Together with our Spitzer

{IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form

a unique union of data that may for the first time shed light on how the

earliest major episodes of star formation in high redshift galaxies came

about. This proposal was adapted from an ACS HRC+WFC proposal to meet

the new Cycle 16 observing constraints, and can be carried out using the

ACS/SBC and WFPC2 without compromising our original science goals.

 

WEPC2 11196

 

An Ultraviolet Survey 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 starbursts and creating/fueling central AGN. We

propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a

sample of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy

Sample {RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS

imaging observations, to have significant numbers of bright {23 < B < 21

mag} star clusters in the central 30 arcsec. The HST UV data will be

combined with previously obtained HST, Spitzer, and GALEX images to {i}

calculate the ages of the clusters as function of merger stage, {ii}

measure the amount of UV light in massive star clusters relative to

diffuse regions of star formation, {iii} assess the feasibility of using

the UV slope to predict the far- IR luminosity {and thus the star

formation rate} both among and within IR-luminous galaxies, and {iv}

provide a much needed catalog of rest-frame UV morphologies for

comparison with rest-frame UV images of high-z LIRGs and Lyman Break

Galaxies. These observations will achieve the resolution required to

perform both detailed photometry of compact structures and spatial

correlations between UV and redder wavelengths for a physical

interpretation our IRX-Beta results. The HST UV data, combined with the

HST ACS, Spitzer, Chandra, and GALEX observations of this sample, will

result in the most comprehensive study of luminous starburst galaxies to

date.

 

WFPC2 11105

 

The LBV progenitor of SN 2005gl - a new key to massive star evolution

puzzles

 

The currently accepted theory regarding the last stages of massive star

evolution maintains that the evolution of the envelope is coupled to

that of the stellar core. For this reason, very massive stars are

expected to shed their outer hydrogen envelopes before they develop

large iron cores, and ultimately, explode as core-collapse supernovae

{SNe}. It is therefore a strict prediction of current models that

massive stars {certainly those above ~40 solar mass} will explode as

hydrogen-poor SNe, i.e., of Types Ib and Ic. In particular, the class of

luminous blue variables {LBVs} such as eta-Carina, which are known to be

very massive {up to 100 solar masses and above} are expected to lose

their entire hydrogen envelopes prior to their ultimate explosions as

SNe. However, using pre-explosion HST/WFPC2 imaging of the location of

the recent hydrogen-rich type IIn SN 2005gl, we have identified {Gal-Yam

et al. 2007} its putative progenitor as a very luminous point source

{with absolute V magnitude of -10.2}. If this is a single star, it must

be an LBV from luminosity considerations {no other stars are as

luminous}. If our progenitor identification is correct, at least in some

cases, massive stars explode before losing most of their hydrogen

envelope, indicating the core and envelope are decoupled, and requiring

revision of stellar evolution theory. Here, we propose a single-orbit

HST observation of the location of SN 2005gl designed to test whether

the point source we identified as its LBV progenitor has indeed

disappeared {as expected from a single star} or remained unchanged {as

expected, e.g., if it is a compact star cluster}. These data are the

last observational ingredient required to firmly establish {or refute}

the explosion of an LBV as a type IIn SN, with fundamental implications

for the theory of massive star evolution. Since the new data will be

compared to pre-explosion WFPC2 images, this program is perfectly suited

to be carried out with the WFPC2 camera.

 

WFPC2/NIC2 11193

 

A comprehensive study of the low-mass stellar population in the Galactic

starburst region NGC 3603

 

NGC 3603, located in the Carina spiral arm, is one of the most luminous

giant HII regions in the Milky Way, and as such it is often referred to

as a prime template for extragalactic starbursts. While previous studies

were focusing on the high and intermediate mass stellar content of the

central starburst cluster, which powers the HII region, the effects of

the starburst environment with its large number of ionizing O stars on

the emerging low- mass population are unknown. As the most nearby, most

easily accessible starburst, NGC 3603 provides the best testbed to study

the long-lived, low-mass stars originating from a starburst environment.

Taking advantage of the large field of view and high sensitivity of

WFPC2, we want to survey the stellar population in an area of 10pc x

10pc {6' x 6'} down to a mass limit of 0.2 to 0.5 Mo. This will enable

us to derive the total cluster mass, look for spatial variations in the

initial mass function, determine the age of the dispersed low-mass

population in the HII region and search for evidence of sequential star

formation. Ultimately, we aim at reconstructing the low-mass stellar

initial mass function of the starburst epoch in NGC 3603, which in turn

will advance our understanding of extragalactic starburst phenomena and

the emerging low-mass stars as observed in ancient populations. The

observations of NGC 3603 are part of our larger effort to study intense

star-forming regions in the Milky Way, LMC and SMC.

 

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               06                 06                

FGS REacq               08                 08                  

OBAD with Maneuver 28                 28              

 

SIGNIFICANT EVENTS: (None)

 

 

-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager

CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)

NASA GSFC PH#: 301-286-2876

"The Hubble Space Telescope is the astronomical observatory and key to unlocking the most cosmic mysteries of the past, present and future."    - 7/26/6