HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       #4690

 

PERIOD COVERED: 5am September 5 - 5am September 8, 2008 (DOY 249/0900z-252/0900z)

 

OBSERVATIONS SCHEDULED

 

NIC2 11826

 

NICMOS Pre-/post-SM4 Photometry Test

 

This proposal contains the necessary exposures to re-calibrate NICMOS.

We will observe all filters that are not part of the standard monitoring

program with a standard 4-point (NIC1 & NIC2) and 7-point (NIC3) dither

pattern.

 

NIC1/NIC2/NIC3 11820

 

NICMOS Post-SAA Calibration - CR Persistence Part 7

 

Internals for CR persistence

 

NIC2 11548

 

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

Environment in Star Formation

 

We propose NICMOS 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.

 

WFPC2 11500

 

ERO: WFPC2 Image of Eta Car

 

This is a WFPC2 program to be executed before SM4 but used in

coordination with EROs. It will be among the last images to be taken

with WFPC2.

 

FGS 11298

 

Calibrating Cosmological Chronometers: White Dwarf Masses

 

We propose to use HST/FGS1R to determine White Dwarf {WD} masses. The

unmatched resolving power of HST/FGS1R will be utilized to follow up

four selected WD binary pairs. This high precision obtained with

HST/FGS1R simply cannot be equaled by any ground based technique. This

proposed effort complements that done by CoI Nelan in which a sample of

WDs is being observed with HST/FGS1R. This proposal will dramatically

increase the number of WDs for which dynamical mass measurements are

possible, enabling a better calibration of the WD mass-radius relation,

cooling curves, initial to final mass relations, and ultimately giving

important clues to the star formation history of our Galaxy and the age

of its disk as well as in other galaxies. {This project is part of

Subasavage's PhD thesis work at Georgia State University.}

 

WFPC2 11235

 

HST NICMOS Survey of the Nuclear Regions 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 enhanced star formation and Active

Galactic Nuclei {AGN} activity, possibly triggered as the objects

transform into massive S0 and elliptical merger remnants. We propose

NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88

L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised

Bright Galaxy Sample {RBGS: i.e., 60 micron flux density > 5.24 Jy}.

This sample is ideal not only in its completeness and sample size, but

also in the proximity and brightness of the galaxies. The superb

sensitivity and resolution of NICMOS NIC2 on HST enables a unique

opportunity to study the detailed structure of the nuclear regions,

where dust obscuration may mask star clusters, AGN and additional nuclei

from optical view, with a resolution significantly higher than possible

with Spitzer IRAC. This survey thus provides a crucial component to our

study of the dynamics and evolution of IR galaxies presently underway

with Wide-Field, HST ACS/WFC and Spitzer IRAC observations of these 88

galaxies. Imaging will be done with the F160W filter {H-band} to examine

as a function of both luminosity and merger stage {i} the luminosity and

distribution of embedded star clusters, {ii} the presence of optically

obscured AGN and nuclei, {iii} the correlation between the distribution

of 1.6 micron emission and the mid-IR emission as detected by Spitzer

IRAC, {iv} the evidence of bars or bridges that may funnel fuel into the

nuclear region, and {v} the ages of star clusters for which photometry

is available via ACS/WFC observations. The NICMOS data, combined with

the HST ACS, Spitzer, and GALEX observations of this sample, will result

in the most comprehensive study of merging and interacting galaxies to

date.

 

FGS 11212

 

Filling the Period Gap for Massive Binaries

 

The current census of binaries among the massive O-type stars is

seriously incomplete for systems in the period range from years to

millennia because the radial velocity variations are too small and the

angular separations too close for easy detection. Here we propose to

discover binaries in this observational gap through a Faint Guidance

Sensor SNAP survey of relatively bright targets listed in the Galactic O

Star Catalog. Our primary goal is to determine the binary frequency

among those in the cluster/association, field, and runaway groups. The

results will help us assess the role of binaries in massive star

formation and in the processes that lead to the ejection of massive

stars from their natal clusters. The program will also lead to the

identification of new, close binaries that will be targets of long term

spectroscopic and high angular resolution observations to determine

their masses and distances. The results will also be important for the

interpretation of the spectra of suspected and newly identified binary

and multiple systems.

 

NIC1 11205

 

The Effects of Multiplicity on the Evolution of Young Stellar Objects: A

NICMOS Imaging Study

 

We propose to use NICMOS to investigate the multiplicity of young

stellar objects (YSOs) in the Orion B molecular cloud. Previous

observations with the Spitzer Space Telescope have revealed a remarkable

star forming filament near the NGC 2068 reflection nebula. The

population of YSOs associated with the filament exhibit a surprisingly

wide range of circumstellar evolutionary states, from deeply embedded

protostars to T Tauri accretion disks. Many of the circumstellar disks

themselves show evidence for significant dust evolution, including grain

growth and settling and cleared inner holes, apparently in spite of the

very young age of these stars. We will estimate the binary fraction of a

representative sample of objects in these various stages of evolution in

order to test whether companions may play a significant role in that

evolution.

 

WFPC2 11203

 

A Search for Circumstellar Disks and Planetary-Mass Companions around

Brown Dwarfs in Taurus

 

During a 1-orbit program in Cycle 14, we used WFPC2 to obtain the first

direct image of a circumstellar disk around a brown dwarf. These data

have provided fundamental new constraints on the formation process of

brown dwarfs and the properties of their disks. To search for additional

direct detections of disks around brown dwarfs and to search for

planetary-mass companions to these objects, we propose a WFPC2 survey of

32 brown dwarfs in the Taurus star-forming region.

 

WFPC2 11178

 

Probing Solar System History with Orbits, Masses, and Colors of

Transneptunian Binaries

 

The recent discovery of numerous transneptunian binaries {TNBs} opens a

window into dynamical conditions in the protoplanetary disk where they

formed as well as the history of subsequent events which sculpted the

outer Solar System and emplaced them onto their present day heliocentric

orbits. To date, at least 47 TNBs have been discovered, but only about a

dozen have had their mutual orbits and separate colors determined,

frustrating their use to investigate numerous important scientific

questions. The current shortage of data especially cripples scientific

investigations requiring statistical comparisons among the ensemble

characteristics. We propose to obtain sufficient astrometry and

photometry of 23 TNBs to compute their mutual orbits and system masses

and to determine separate primary and secondary colors, roughly tripling

the sample for which this information is known, as well as extending it

to include systems of two near-equal size bodies. To make the most

efficient possible use of HST, we will use a Monte Carlo technique to

optimally schedule our observations.

 

WFPC2 11156

 

Monitoring Active Atmospheres on Uranus and Neptune

 

We propose Snapshot observations of Uranus and Neptune to monitor

changes in their atmospheres on time scales of weeks and months. Uranus

equinox is only months away, in December 2007. Hubble Space Telescope

observations during the past several years {Hammel et al. 2005, Icarus

175, 284 and references therein} have revealed strongly wavelength-

dependent latitudinal structure, the presence of numerous

visible-wavelength cloud features in the northern hemisphere, at least

one very long-lived discrete cloud in the southern hemisphere, and in

2006 the first dark spot ever seen on Uranus. Long-term ground-based

observations {Lockwood and Jerzekiewicz, 2006, Icarus 180, 442; Hammel

and Lockwood 2007, Icarus 186, 291} reveal seasonal brightness changes

whose origins are not well understood. Recent near- IR images of Neptune

obtained using adaptive optics on the Keck Telescope, together with HST

observations {Sromovsky et al. 2003, Icarus 163, 256 and references

therein} which include previous Snapshot programs {GO 8634, 10170,

10534} show a general increase in activity at south temperate latitudes

until 2004, when Neptune returned to a rather Voyager-like appearance.

Further Snapshot observations of these two dynamic planets will

elucidate the nature of long-term changes in their zonal atmospheric

bands and clarify the processes of formation, evolution, and dissipation

of discrete albedo features.

 

NIC2 11135

 

Extreme Makeovers: Tracing the Transformation of Massive Galaxies at

z~2.5

 

To obtain a full spectroscopic census of the universe at z~2.5 we have

conducted a near-infrared spectroscopic survey for K-selected galaxies.

We found that, in contrast to the local universe, massive high-redshift

galaxies span a wide range of properties, varying from (dusty) star

burst to "red and dead" galaxies. This may imply that massive galaxies

transform from star-forming to quiescent galaxies in the targeted

redshift range. To understand whether the 9 quiescent galaxies in our

sample are the progenitors of local elliptical, we are observing them in

the current cycle with NIC2. For cycle 16 we propose to complete our

sample of massive z~2.5 galaxies and image the remaining 10 galaxies,

which all have emission lines. Based on emission-line diagnostics, 6 of

these galaxies are identified as star-forming objects and 4 harbor an

active galactic nucleus. The goals are to 1) determine whether star

formation in massive z~2.5 galaxies takes place in disks or is triggered

by merger activity, 2) derive the contribution of AGNs to the rest-frame

optical emission, and 3) test whether the morphologies are consistent

with the idea that the star-forming galaxies, AGNs, and quiescent

galaxies represent subsequent phases of an evolutionary sequence. The

combination of both programs will provide the first morphological study

of a spectroscopically confirmed massive galaxy sample at z~2.5.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

11473 - GSAcq(1,2,1) not attempted

           The GSacq(1,2,1) scheduled at 251/00:16:15 was not attempted.

 

           Observations affected: NIC Proposal 175 and 176

 

11475 - REAcq(1,2,1) not attempted

           REacq(1,2,1) scheduled at 251/01:53:31 was not attempted.

 

           Observations affected: NIC Proposal 177, 178 and 179

 

 

11476 - REAcq(1,2,1) fails while LOS

           REACQ(1,2,1) at 13:51:48 appears to have failed but

           engineering recorder data is needed for determination of actual events.

           TERM EXP command was at 14:47:16 (before AOS time), therefore vehicle

           was not expected to be in fine lock at AOS. 

 

           Further information and data extracts after engineering recorder dump

           currently scheduled for day 251/22:41.

 

           Observations affected: WFPC 46, proposal 11178.

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                       SCHEDULED      SUCCESSFUL 

FGS GSacq               26                  25                               

FGS REacq               14                  12   

OBAD with Maneuver 80                  78     

 

SIGNIFICANT EVENTS: (None)