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       #4482

 

PERIOD COVERED: UT November 2,3,4, 2007 (DOY 306,307,308)

 

OBSERVATIONS SCHEDULED

 

NIC1/NIC2/NIC3 8794

 

NICMOS Post-SAA calibration - CR Persistence Part 5

 

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 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.

 

WFPC2 11418

 

Investigating the Spectacular Outburst of Comet 17P/Holmes

 

Comet 17P/Holmes is currently undergoing a spectacular eruption in

activity, with its brightness increasing by ~14 mag over a 24 hour

period. The comet is shedding huge amounts of dust, presumably

associated with a major splitting event at the nucleus. The high spatial

resolution and high sensitivity of Hubble has proven to be invaluable

during previous observations of several fragmenting comets, and the 2007

apparition of 17P/Holmes represents another excellent opportunity to

investigate this important cometary phenomenon. We request 3 orbits of

WFPC2 observations to measure the size and V-R color of the principal

nucleus, perform a deep search for large fragments released during the

outburst, monitor the temporal development of the event, and search for

a satellite whose collision with the principal nucleus may have

triggered the current outburst, as was suggested for the similar

outburst observed in 1892.

 

NIC1/NIC2/NIC3 11330

 

NICMOS Cycle 16 Extended Dark

 

This takes a series of Darks in parallel to other instruments.

 

WFPC2 11307

 

Completing the ACS Nearby Galaxy Survey with WFPC2

 

We are requesting 25 orbits of Director's Discretionary Time to complete

the primary science goals of our highly-ranked ACS Nearby Galaxy Survey

Treasury program {ANGST}. Our program lost ~2/3 of its orbits due to the

ACS failure. Roughly half of these were restored as a result of an

appeal to the Telescope Time Review Board which re-scoped the program.

The Board's response to our appeal was explicit in terms of which

targets were to be observed and how. We were directed to request

Director's discretionary time for the components of the appeal which

were not granted by the Review Board, but which were vital to the

success of the program. The observing strategy for ANGST is two-fold: to

obtain one deep field per galaxy which enables derivation of an accurate

ancient star formation history, and to obtain radial tilings sufficient

for recovering the full star formation history. The Review Board granted

WFPC2 observations for deep fields in 7 galaxies, but no time for radial

tilings. However, recovering the full star formation history of a galaxy

is not possible without additional radial coverage. We have searched the

archives for observations which may be used in place of the tilings

{conceding some of the Treasury goals, but providing significant

constraints on the full star formation history}, and have identified

suitable observations for all but two of the galaxies. Here we request

DD time for radial tilings for those last two galaxies.

 

WFPC2 11229

 

SEEDS: The Search for Evolution of Emission from Dust in Supernovae with

HST and

 

The role that massive stars play in the dust content of the Universe is

extremely uncertain. It has long been hypothesized that dust can

condense within the ejecta of supernovae {SNe}, however there is a

frustrating discrepancy between the amounts of dust found in the early

Universe, or predicted by nucleation theory, and inferred from SN

observations. Our SEEDS collaboration has been carefully revisiting the

observational case for dust formation by core-collapse SNe, in order to

quantify their role as dust contributors in the early Universe. As dust

condenses in expanding SN ejecta, it will increase in optical depth,

producing three simultaneously observable phenomena: {1} increasing

optical extinction; {2} infrared {IR} excesses; and {3} asymmetric

blue-shifted emission lines. Our SEEDS collaboration recently reported

all three phenomena occurring in SN2003gd, demonstrating the success of

our observing strategy, and permitting us to derive a dust mass of up to

0.02 solar masses created in the SN. To advance our understanding of the

origin and evolution of the interstellar dust in galaxies, we propose to

use HST's WFPC2 and NICMOS instruments plus Spitzer's photometric

instruments to monitor ten recent core- collapse SNe for dust formation

and, as a bonus, detect light echoes that can affect the dust mass

estimates. These space-borne observations will be supplemented by

ground- based spectroscopic monitoring of their optical emission line

profiles. These observations would continue our 2-year HST and Spitzer

monitoring of this phenomena in order to address two key questions: Do

all SNe produce dust? and How much dust do they produce? As all the SN

are within 15 Mpc, each SN stands an excellent chance of detection with

HST and Spitzer and of resolving potential light echoes.

 

FGS 11228

 

Extrasolar Planet XO-2b

 

We propose observations of the newly discovered extrasolar planet XO-2b

and its twin star XO-2. When combined with the transit light curve, the

FGS-derived parallax will constrain the stellar mass of the host star

XO-2. From the high signal-to-noise near-IR time series resulting from

NICMOS grism spectroscopy, we will refine the system parameters, in

particular radii of the star and planet. From the same data, we will

search for evidence of water vapor in the atmosphere via transmission

spectroscopy. Differential observations with NICMOS in the spectroscopic

mode will be used to search for the small spectral changes that occur

during planetary transits resulting from absorption of stellar light as

it passes through the planetary atmosphere. Water is an important

constituent, the detection of which would provide information on Oxygen,

and it has a convenient strong band well- positioned for NICMOS.

 

NIC2 11219

 

Active Galactic Nuclei in nearby galaxies: a new view of the origin of

the radio-loud radio- quiet dichotomy?

 

Using archival HST and Chandra observations of 34 nearby early-type

galaxies {drawn from a complete radio selected sample} we have found

evidence that the radio-loud/radio-quiet dichotomy is directly connected

to the structure of the inner regions of their host galaxies in the

following sense: [1] Radio-loud AGN are associated with galaxies with

shallow cores in their light profiles [2] Radio-quiet AGN are only

hosted by galaxies with steep cusps. Since the brightness profile is

determined by the galaxy's evolution, through its merger history, our

results suggest that the same process sets the AGN flavour. This

provides us with a novel tool to explore the co-evolution of galaxies

and supermassive black holes, and it opens a new path to understand the

origin of the radio-loud/radio-quiet AGN dichotomy. Currently our

analysis is statistically incomplete as the brightness profile is not

available for 82 of the 116 targets. Most galaxies were not observed

with HST, while in some cases the study is obstructed by the presence of

dust features. We here propose to perform an infrared NICMOS snapshot

survey of these 82 galaxies. This will enable us to i} test the reality

of the dichotomic behaviour in a substantially larger sample; ii} extend

the comparison between radio-loud and radio-quiet AGN to a larger range

of luminosities.

 

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.

 

FGS 11211

 

An Astrometric Calibration of Population II Distance Indicators

 

In 2002 HST produced a highly precise parallax for RR Lyrae. That

measurement resulted in an absolute magnitude, M{V}= 0.61+/-0.11, a

useful result, judged by the over ten refereed citations each year

since. It is, however, unsatisfactory to have the direct,

parallax-based, distance scale of Population II variables based on a

single star. We propose, therefore, to obtain the parallaxes of four

additional RR Lyrae stars and two Population II Cepheids, or W Vir

stars. The Population II Cepheids lie with the RR Lyrae stars on a

common K-band Period-Luminosity relation. Using these parallaxes to

inform that relationship, we anticipate a zero-point error of 0.04

magnitude. This result should greatly strengthen confidence in the

Population II distance scale and increase our understanding of RR Lyrae

star and Pop II Cepheid astrophysics.

 

WFPC2 11167

 

A Unique High Resolution Window to Two Strongly Lensed Lyman Break

Galaxies

 

On rare occasions, the otherwise very faint Lyman Break Galaxies {LBGs}

are magnified by gravitational lensing to provide exceptional targets

for detailed spectroscopic and imaging studies. We propose HST WFPC2 and

NICMOS imaging of two strongly lensed Lyman Break Galaxies {LBGs} that

were recently discovered by members of our team. These two LBGs -- the

"8 O'Clock Arc" and the "SDSS J1206+5142 Arc" -- are currently the

brightest known LBGs, roughly 3 times brighter than the former

record-holder, MS1512-cB58 {a.k.a. "cB58"}. The z=2.73 "8 O'Clock Arc"

extends ~10 arcsec in length and is magnified by a factor of 12. The

z=2.00 "SDSS J1206+5142 Arc" also extends ~10 arcsec in length and is

magnified by a factor of 30. Due to their brightness and magnification,

these two strongly lensed LBGs offer an unprecedented opportunity for

the very detailed investigation of two individual galaxies at high

redshift. We are currently pursuing a vigorous ground-based campaign to

obtain multi-wavelength {UV, optical, NIR, radio} observations of these

two LBGs, but our campaign currently lacks a means of obtaining

high-resolution optical/NIR imaging -- a lack that currently only HST

can address. Our prime objective for this proposal is to obtain high

resolution HST images of these two systems with two-orbit WFPC2 images

in the BVI bands and two-orbit NICMOS/NIC2 images in the J and H bands.

These data will allow us to construct detailed lensing models, probe the

mass and light profiles of the lenses and their environments, and

constrain the star formation histories and rest-frame UV/optical

spectral energy distributions of the LBGs.

 

WFPC2 11079

 

Treasury Imaging of Star Forming Regions in the Local Group:

Complementing the GALEX and NOAO Surveys

 

We propose to use WFPC2 to image the most interesting star-forming

regions in the Local Group galaxies, to resolve their young stellar

populations. We will use a set of filters including F170W, which is

critical to detect and characterize the most massive stars, to whose hot

temperatures colors at longer wavelengths are not sensitive. WFPC2's

field of view ideally matches the typical size of the star-forming

regions, and its spatial resolution allows us to measure individual

stars, given the proximity of these galaxies. The resulting H-R diagrams

will enable studies of star-formation properties in these regions, which

cover largely differing metallicities {a factor of 17, compared to the

factor of 4 explored so far} and characteristics. The results will

further our understanding of the star-formation process, of the

interplay between massive stars and environment, the properties of dust,

and will provide the key to interpret integrated measurements of

star-formation indicators {UV, IR, Halpha} available for several

hundreds more distant galaxies. Our recent deep surveys of these

galaxies with GALEX {FUV, NUV} and ground-based imaging {UBVRI, Halpha,

[OIII] and [SII]} provided the identification of the most relevant SF

sites. In addition to our scientific analysis, we will provide catalogs

of HST photometry in 6 bands, matched corollary ground-based data, and

UV, Halpha and IR integrated measurements of the associations, for

comparison of integrated star-formation indices to the resolved

populations. We envisage an EPO component.

 

WFPC2 11038

 

Narrow Band and Ramp Filter Closeout

 

These observations are to improve calibration of narrow band and ramp

filters. We also test for changes in the filter properties during

WFPC2's 14 years on-board HST.

 

WFPC2 11035

 

Photometric Zero Points Closeout

 

Updated zero points will be obtained by observing NGC 2419 for which

extensive BVRI ground based observations exist, and the field in 47 Tuc

used for frequent monitoring of ACS. For NGC 2419 emphasis is given to

repeating observations obtained in earlier epochs, and to covering

filters near standard BVRI. For 47 Tuc emphasis is given to covering a

large set of broadband filters from F300W through F850LP to maximise

transformation capabilities between filters of WFPC2 and ACS.

 

WFPC2 11029

 

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly

Monitor

 

Intflat observations will be taken to provide a linearity check: the

linearity test consists of a series of intflats in F555W, in each gain

and each shutter. A combination of intflats, visflats, and earthflats

will be used to check the repeatability of filter wheel motions.

{Intflat sequences tied to decons, visits 1-18 in prop 10363, have been

moved to the cycle 15 decon proposal xxxx for easier scheduling.} Note:

long-exposure WFPC2 intflats must be scheduled during ACS anneals to

prevent stray light from the WFPC2 lamps from contaminating long ACS

external exposures.

 

NIC1 10889

 

The Nature of the Halos and Thick Disks of Spiral Galaxies

 

We propose to resolve the extra-planar stellar populations of the thick

disks and halos of seven nearby, massive, edge-on galaxies using ACS,

NICMOS, and WFPC2 in parallel. These observations will provide accurate

star counts and color-magnitude diagrams 1.5 magnitudes below the tip of

the Red Giant Branch sampled along the two principal axes and one

intermediate axis of each galaxy. We will measure the metallicity

distribution functions and stellar density profiles from star counts

down to very low average surface brightnesses, equivalent to ~32 V-mag

per square arcsec. These observations will provide the definitive HST

study of extra-planar stellar populations of spiral galaxies. Our

targets cover a range in galaxy mass, luminosity, and morphology and as

function of these galaxy properties we will provide: - The first

systematic study of the radial and isophotal shapes of the diffuse

stellar halos of spiral galaxies - The most detailed comparative study

to date of thick disk morphologies and stellar populations - A

comprehensive analysis of halo and thick disk metallicity distributions

as a function of galaxy type and position within the galaxy. - A

sensitive search for tidal streams - The first opportunity to directly

relate globular cluster systems to their field stellar population We

will use these fossil records of the galaxy assembly process preserved

in the old stellar populations to test halo and thick disk formation

models within the hierarchical galaxy formation scheme. We will test

LambdaCDM predictions on sub-galactic scales, where it is difficult to

test using CMB and galaxy redshift surveys, and where it faces its most

serious difficulties.

 

ACS/SBC 10864

 

Mapping the Gaseous Content of Protoplanetary and Young Planetary

Systems with ACS

 

One of the key problems in planetary system formation is understanding

how rapidly, and over what time interval Jovian planets can form. Dust

in the protoplanetary disk is critical in planetesimal formation, but it

is the gas which produces giant planets, and which is essential for

their migration. However, compared to data on the circumstellar dust,

information on the gas component is sparse, especially in the

planet-formation zone. This severely limits our ability to put

observational constraints on giant planet formation, except to note that

the process must be largely complete by 12 Myr, given the paucity of

Herbig Ae or classical T Tauri stars older than 10-12 Myr. In the FUV,

photo-excited molecular hydrogen transitions have the requisite contrast

to the stellar photosphere, accretion shock, and reflection nebulosity,

and can be traced 50-100 AU from the exciting stars in both envelopes

and outflow cavities and protoplanetary disks. Central disk cavities, an

expected consequence of planet formation, larger than 0.1" are directly

detectable in HST FUV spectra, while smaller cavities may be detected by

comparison with protoplanetary disks which are still accreting onto

their stars. We propose augmenting existing HST coronagraphic imagery of

6 Herbig Fe and T Tauri disks with ACS Solar-Blind Channel Lyman alpha

imagery and slitless spectroscopy simultaneously sampling the disk in

molecular hydrogen and small-grain reflection nebulosity. These data

will be used to quantify the amount of vertical stratification in these

disks, to map the mass-loss geometry from the star, and to determine

whether removal of molecular material precedes, lags, or is contemporary

with clearing of the dust.

 

ACS/WFC 10812

 

Space Motions for the Draco and Sextans Dwarf Spheroidal Galaxies

 

We will use the powerful astrometric capabilities of HST to measure

proper motions for the Draco and Sextans dwarf spheroidal galaxies that

will yield tangential velocities accurate to about 30 km/s. These two

galaxies are the last inside a galactocentric radius of 200~kpc without

measured proper motions. Knowing their orbits is critical for our

understanding of the low-luminosity satellites of the Milky Way. In

particular they are critical for understanding why Ursa Minor has

survived tidal disruption on its plunging orbit and how Carina formed a

large intermediate-age stellar population despite its small mass.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

11044 - GSACQ(2,1,1) fails to acquire fine lock while LOS

           Upon acquisition of signal at 12:53:01, one 486 ESB message "A0A" (FGS

           Fine Lock failed-Timed out waiting for fine lock) was observed.

           GSACQ(2,1,1) at 11:52:45 appears to not have acquired fine lock, #44

           commands did not update from previous values seen at LOS 11:07:30. All

           acquisition events occurred while vehicle was LOS. OBAD map at 12:29:12

           had RSS error of 1877.48 arcseconds, indicating that vehicle had drifted

           far off target.

 

           REACQ(2,1,1) at 13:28:01 was successful.

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED      SUCCESSFUL  

FGS GSacq               24                 23             

FGS REacq               18                 18               

OBAD with Maneuver 84                 84        

 

SIGNIFICANT EVENTS: (None)