HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4578

 

PERIOD COVERED: UT March 28,29,30, 2008 (DOY 088,089,090)

 

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.

 

NIC 11495

 

The first direct detection of an extrasolar planetary stratosphere?

 

We request NICMOS grism spectroscopy to observe the transit of WASP-3b.

This newly discovered planet is the hottest nearby planet discovered so

far. The atmosphere is predicted to be so hot that TiO and VO remain in

the gas phase, creating a hot, strongly absorbing stratosphere. This

molecular absorption will cause a 6% enhancement in the transit depth at

0.8 microns, compared to that at 1.3 microns. NICMOS/G096 and

NICMOS/G141 observations will therefore provide a straightforward test

of the hot stratosphere hypothesis. The HST observations will provide a

precisely determined radius measurement. This is required to drive

advances in theories of planetary formation, evolution, and atmospheric

physics and chemistry. The atmospheric TiO and VO absorption is

predicted to cause an anomalously high IR brightness temperature for the

planet. We need HST's direct test of the hot stratosphere hypothesis

promptly to enable appropriate cold-Spitzer observations to be planned

and interpreted. Spitzer is likely to exhaust its cryogens before these

observations could be scheduled via the cycle 17 GO process.

 

NIC1/NIC2/NIC3 11330

 

NICMOS Cycle 16 Extended Dark

 

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

 

WFPC2 11326

 

Polarizers Closeout (Internal Observations)

 

Verify stability of polarization calibration.

 

FGS 11300

 

Mass and Radius of a Near-Chandrasekhar-limit magnetic white dwarf

 

REJ0317-853 is a unique object. According to our analyses it is the most

massive white dwarf ever found, with a mass of 1.35 solar masses,

approaching the Chandrasekhar limit. With a period of just 725 seconds

it is the most rapidly rotating isolated white dwarf ever found.

Moreover, RE J0317-853 is the hottest magnetic white dwarf discovered so

far and has a strong magnetic field varying from about 180 to more than

700 MG over the stellar surface. Due to its strong polarization and high

mass it has been used to test gravitational theories predicting

gravitational birefringence. However, the existing mass and radius

determination is indirect and still uncertain and would greatly profit

from a high- precision parallax determination with the HST FGS.

 

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 11210

 

The Architecture of Exoplanetary Systems

 

Are all planetary systems coplanar? Concordance cosmogony makes that

prediction. It is, however, a prediction of extrasolar planetary system

architecture as yet untested by direct observation for main sequence

stars other than the Sun. To provide such a test, we propose to carry

out FGS astrometric studies on four stars hosting seven companions. Our

understanding of the planet formation process will grow as we match not

only system architecture, but formed planet mass and true distance from

the primary with host star characteristics for a wide variety of host

stars and exoplanet masses. We propose that a series of FGS astrometric

observations with demonstrated 1 millisecond of arc per-observation

precision can establish the degree of coplanarity and component true

masses for four extrasolar systems: HD 202206 {brown dwarf+planet}; HD

128311 {planet+planet}, HD 160691 = mu Arae {planet+planet}, and HD

222404AB = gamma Cephei {planet+star}. In each case the companion is

identified as such by assuming that the minimum mass is the actual mass.

For the last target, a known stellar binary system, the companion orbit

is stable only if coplanar with the AB binary orbit.

 

WFPC2 11198

 

Pure Parallel Imaging in the NDWFS Bootes Field

 

The NOAO Deep-Wide Field Survey {NDWFS} Bootes field is the target of

one of the most extensive multiwavelength campaigns in astronomy. In

addition to ground-based optical and near-infrared imaging, deep radio

mapping, and extensive spectroscopy, this entire region has been imaged

by the Chandra, Spitzer {IRAC and MIPS}, and GALEX missions. Robust

photometric redshifts {calibrated using over 20,000 spectroscopic

redshifts} exist for all sources brighter than R=24.5 or than 13 uJy at

4.5 microns. To enhance the value of this data set, we propose pure

parallel observations for all approved Cycle 16 programs in this region

that lack coordinated parallel observations. The primary aim of this

program will be to provide a database useful for the broad range of

science programs underway in this region.

 

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.

 

NIC3 11195

 

Morphologies of the Most Extreme High-Redshift Mid-IR-luminous Galaxies

II: The `Bump' Sources

 

The formative phase of some of the most massive galaxies may be

extremely luminous, characterized by intense star- and AGN-formation.

Till now, few such galaxies have been unambiguously identified at high

redshift, and thus far we have been restricted to studying the

low-redshift ultraluminous infrared galaxies as possible analogs. We

have recently discovered a sample of objects which may indeed represent

this early phase in galaxy formation, and are undertaking an extensive

multiwavelength study of this population. These objects are optically

extremely faint {R>26} but nevertheless bright at mid-infrared

wavelengths {F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with

Spitzer/IRS reveals that they have redshifts z~2, implying luminosities

~1E13 Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping,

categories. Sources with brighter F[24um] exhibit power-law SEDs and SiO

absorption features in their mid-IR spectra characteristic of AGN,

whereas those with fainter F[24um] show a "bump" characteristic of the

redshifted 1.6um peak from a stellar population, and PAH emission

characteristic of starformation. We have begun obtaining HST images of

the brighter sources in Cycle 15 to obtain identifications and determine

kpc-scale morphologies for these galaxies. Here, we aim to target the

second class {the "bump" sources} with the goal of determining if these

constitute morphologically different objects, or simply a "low-AGN"

state of the brighter class. The proposed observations will help us

determine whether these objects are merging systems, massive obscured

starbursts {with obscuration on kpc scales!} or very reddened {locally

obscured} AGN hosted by intrinsically low-luminosity galaxies.

 

WFPC2 11169

 

Collisions in the Kuiper belt

 

For most of the 15 year history of observations of Kuiper belt objects,

it has been speculated that impacts must have played a major role in

shaping the physical and chemical characteristics of these objects, yet

little direct evidence of the effects of such impacts has been seen. The

past 18 months, however, have seen an explosion of major new discoveries

giving some of the first insights into the influence of this critical

process. From a diversity of observations we have been led to the

hypotheses that: {1} satellite-forming impacts must have been common in

the Kuiper belt; {2} such impacts led to significant chemical

modification; and {3} the outcomes of these impacts are sufficiently

predictable that we can now find and study these impact-derived systems

by the chemical and physical attributes of both the satellites and the

primaries. If our picture is correct, we now have in hand for the first

time a set of incredibly powerful tools to study the frequency and

outcome of collisions in the outer solar system. Here we propose three

linked projects that would answer questions critical to the multiple

prongs of our hypothesis. In these projects we will study the chemical

effects of collisions through spectrophotometric observations of

collisionally formed satellites and through the search for additional

satellites around primaries with potential impact signatures, and we

will study the physical effects of impacts through the examination of

tidal evolution in proposed impact systems. The intensive HST program

that we propose here will allow us to fully test our new hypotheses and

will provide the ability to obtain the first extensive insights into

outer solar system impact processes.

 

WFPC2 11161

 

Revealing the Explosion Geometry of Nearby GRB-SNe

 

The connection between gamma-ray bursts and Type Ibc supernovae is

well-established in broad terms. However, our recent identification of

an intermediate class of sub-energetic GRBs, and the overall overlap in

Nickel production between GRB-SNe and ordinary SNe Ibc suggest that the

properties leading to the production of a relativistic engine are yet to

be uncovered. A fundamental difference between the two classes of

explosions may be imprinted in the overall geometry of the explosion.

The relativistic component of GRBs is known to be highly collimated, but

it is unclear if the SN blast is spherical or mildly collimated as well.

Here we propose HST observations of the late (>30 days) decay tails of

two GRB-SNe as an independent measure of the Nickel mass synthesized in

the explosion. A comparison to the Nickel mass inferred from the peak

brightness of the SNe will provide a direct measure of the explosion

asymmetry, since at late time the explosion is essentially spherical.

These observations will form the core of a multi-wavelength (optical,

X-ray, radio) effort to fully characterize all aspects of the

explosions, from the energy and geometry of the relativistic material

(VLA, Chandra) to the early SN evolution (Keck, Magellan). The proposed

observations require two slow-response (>30 days) TOOs, ideally suited

to the 2-gyro operations of HST.

 

NIC3 11153

 

The Physical Nature and Age of Lyman Alpha Galaxies

 

In the simplest scenario, strong Lyman alpha emission from high redshift

galaxies would indicate that stellar populations younger than 10 Myrs

dominate the UV. This does not, however, constrain the stellar

populations older than 100 Myrs, which do not contribute to UV light.

Also, the Lyman alpha line can be boosted if the interstellar medium is

both clumpy and dusty. Different studies with small samples have reached

different conclusions about the presence of dust and old stellar

populations in Lyman alpha emitters. We propose HST- NICMOS and

Spitzer-IRAC photometry of 35 Lyman-alpha galaxies at redshift

4.5<z<6.5, in order to determine their spectral energy distribution

{SED} extending through rest-frame optical. This will allow us to

measure accurately {1} The total stellar mass in these objects,

including old stars which may have formed at redshifts {z > 8} not

easily probed by any other means. {2} The dust extinction in the

rest-frame UV, and therefore a correction to their present

star-formation rates. Taken together, these two quantities will yield

the star-formation histories of Lyman alpha galaxies, which form fully

half of the known galaxies at z=4-6. They will tell us whether these are

young or old galaxies by straddling the 4000A break. Data from NICMOS is

essential for these compact and faint {i=25-26th magnitude AB} high

redshift galaxies, which are too faint for good near-IR photometry from

the ground.

 

WFPC2 11130

 

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge

Paradigm, Part II

 

The recent progress in the study of central black holes in galactic

nuclei has led to a general consensus that supermassive {10^6-10^9 solar

mass} black holes are closely connected with the formation and

evolutionary history of large galaxies, especially their bulge

component. Two outstanding issues, however, remain unresolved. Can

central black holes form in the absence of a bulge? And does the mass

function of central black holes extend below 10^6 solar masses?

Intermediate-mass black holes {<10^6 solar masses}, if they exist, may

offer important clues to the nature of the seeds of supermassive black

holes. Using the SDSS, our group has successfully uncovered a new

population of AGNs with intermediate-mass black holes that reside in

low-luminosity galaxies. However, very little is known about the

detailed morphologies or structural parameters of the host galaxies

themselves, including the crucial question of whether they have bulges

or not. Surprisingly, the majority of the targets of our Cycle 14 pilot

program have structural properties similar to dwarf elliptical galaxies.

The statistics from this initial study, however, are really too sparse

to reach definitive conclusions on this important new class of black

holes. We wish to extend this study to a larger sample, by using the

Snapshot mode to obtain WFPC2 F814W images from a parent sample of 175

AGNs with intermediate- mass black holes selected from our final SDSS

search. We are particularly keen to determine whether the hosts contain

bulges, and if so, how the fundamental plane properties of the host

depend on the mass of their central black holes. We will also

investigate the environment of this unique class of AGNs.

 

WFPC2 11124

 

The Origin of QSO Absorption Lines from QSOs

 

We propose using WFPC2 to image the fields of 10 redshift z ~ 0.7

foreground {FG} QSOs which lie within ~29-151 kpc of the sightlines to

high-z background {BG} QSOs. A surprisingly high fraction of the BG QSO

spectra show strong MgII {2796,2803} absorption lines at precisely the

same redshifts as the FG QSOs. The high resolution capabilities of WFPC2

are needed to understand the origin of these absorption systems, in two

ways. First, we wish to explore the FG QSO environment as close as

possible to the position of the BG QSO, to search for interloping group

or cluster galaxies which might be responsible for the absorption, or

irregularly shaped post-merger debris between the FG and BG QSO which

may indicate the presence of large amount of disrupted gas along a

sightline. Similarly, high resolution images are needed to search for

signs of tidal interactions between any galaxies which might be found

close to the FG QSO. Such features might provide evidence of young

merging events causing the start of QSO duty cycles and producing

outflows from the central AGN. Such winds may be responsible for the

observed absorption lines. Second, we seek to measure the intrinsic

parameters of the FG QSO host galaxy, such as luminosity and morphology,

to correlate with the properties of the MgII absorption lines. We wish

to observe each field through the F814W filter, close to the rest- frame

B-band of the FG QSO. These blue data can reveal enhanced star formation

regions close to the nucleus of the host galaxy, which may be indicative

of galaxy mergers with the FG QSO host. The FG QSO environment offers

quite a different set of phenomena which might be responsible for MgII

absorption, providing an important comparison to studies of MgII

absorption from regular field galaxies.

 

NIC3 11120

 

A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic

Center

 

The Galactic center (GC) is a unique site for a detailed study of a

multitude of complex astrophysical phenomena, which may be common to

nuclear regions of many galaxies. Observable at resolutions

unapproachable in other galaxies, the GC provides an unparalleled

opportunity to improve our understanding of the interrelationships of

massive stars, young stellar clusters, warm and hot ionized gases,

molecular clouds, large scale magnetic fields, and black holes. We

propose the first large-scale hydrogen Paschen alpha line survey of the

GC using NICMOS on the Hubble Space Telescope. This survey will lead to

a high resolution and high sensitivity map of the Paschen alpha line

emission in addition to a map of foreground extinction, made by

comparing Paschen alpha to radio emission. This survey of the inner 75

pc of the Galaxy will provide an unprecedented and complete search for

sites of massive star formation. In particular, we will be able to (1)

uncover the distribution of young massive stars in this region, (2)

locate the surfaces of adjacent molecular clouds, (3) determine

important physical parameters of the ionized gas, (4) identify compact

and ultra-compact HII regions throughout the GC. When combined with

existing Chandra and Spitzer surveys as well as a wealth of other

multi-wavelength observations, the results will allow us to address such

questions as where and how massive stars form, how stellar clusters are

disrupted, how massive stars shape and heat the surrounding medium, and

how various phases of this medium are interspersed.

 

WFPC2 11083

 

The Structure, Formation and Evolution of Galactic Cores and Nuclei

 

A surprising result has emerged from the ACS Virgo Cluster Survey

{ACSVCS}, a program to obtain ACS/WFC gz imaging for a large, unbiased

sample of 100 early-type galaxies in the Virgo Cluster. On subarcsecond

scales {i.e., <0.1"-1"}, the HST brightness profiles vary systematically

from the brightest giants {which have nearly constant surface brightness

cores} to the faintest dwarfs {which have compact stellar nuclei}.

Remarkably, the fraction of galaxy mass contributed by the nuclei in the

faint galaxies is identical to that contributed by supermassive black

holes in the bright galaxies {0.2%}. These findings strongly suggest

that a single mechanism is responsible for both types of Central Massive

Object: most likely internally or externally modulated gas inflows that

feed central black holes or lead to the formation of "nuclear star

clusters". Understanding the history of gas accretion, star formation

and chemical enrichment on subarcsecond scales has thus emerged as the

single most pressing question in the study of nearby galactic nuclei,

either active or quiescent. We propose an ambitious HST program {199

orbits} that constitutes the next, obvious step forward:

high-resolution, ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W}

imaging for the complete ACSVCS sample. By capitalizing on HST's unique

ability to provide high-resolution images with a sharp and stable PSF at

UV and IR wavelengths, we will leverage the existing optical HST data to

obtain the most complete picture currently possible for the history of

star formation and chemical enrichment on these small scales. Equally

important, this program will lead to a significant improvement in the

measured structural parameters and density distributions for the stellar

nuclei and the underlying galaxies, and provide a sensitive measure of

"frosting" by young stars in the galaxy cores. By virtue of its superb

image quality and stable PSF, NICMOS is the sole instrument capable of

the IR observations proposed here. In the case of the WFPC2

observations, high-resolution UV imaging {< 0.1"} is a capability unique

to HST, yet one that could be lost at any time.

 

NIC2 10852

 

Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri

stars

 

The formation of planetary systems is intimately linked to the dust

population in circumstellar disks, thus understanding dust grain

evolution is essential to advancing our understanding of how planets

form. By combining {1} the coronagraphic polarimetry capabilities of

NICMOS, {2} powerful 3-D radiative transfer codes, and {3} observations

of objects known to span the Class II- III stellar evolutionary phases,

we will gain crucial insight into dust grain growth. By observing

objects representative of a known evolutionary sequence of YSOs, we will

be able to investigate how the dust population evolves in size and

distribution during the crucial transition from a star+disk system to a

system containing planetesimals. When combine with our previous study on

dust grain evolution in the Class I-II phase, the proposed study will

help to establish the fundamental time scales for the depletion of

ISM-like grains: the first step in understanding the transformation from

small submicron sized dust grains, to large millimeter sized grains, and

untimely to planetary bodies.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

11236 - GSacq(2,1,2) failed to RGA control.

           GSacq(2,1,2) scheduled at 090/17:10:06 failed to RGA control. The GSacq

           failed due to receiving stop flags QF2STOPF and QSTOP on FGS 2. OBAD1

           showed errors of V1=1299.52, V2=100.45, V3=-60.96 and RSS=1304.82. OBAD2

           showed errors of V1=-8.74, V2=-2.04, V3=-7.01 and RSS=11.38.

 

 

11237 - REacq(2,1,2) failed to RGA control.

           The REacq(2,1,2) scheduled at 090/18:45:33 failed during LOS due to

           receiving stop flags on FGS 1 and FGS 2. OBAD2 had an RSS value of

           5.20a-s.

 

 

COMPLETED OPS REQUEST:

18218-1 - TGS/KFSP Safemode Reconfiguration @088/1000z @ 088/13:43:31z

18054-0 - Preview KF Sun Vector Data via Telemetry Diags (Generic) @ 088/13:47z

 

COMPLETED OPS NOTES: (None)

 

                        SCHEDULED      SUCCESSFUL  

FGS GSacq                26                  25       

FGS REacq                16                  15      

OBAD with Maneuver 84                   84                 

 

SIGNIFICANT EVENTS:

 

FLASH REPORT KFSP SAFEMODE RECONFIGURATION:

Ops Request 18218 was successfully executed at 13:43:31 on day 088

(March 28) to uplink and reconfigure FSW with KFSP as a potential

safemode response. Initial configuration of KFSP parameters were

performed first using IP-151 to set the proper UKF/KFSP control gains

and limits, followed by resetting of UKF database parameters for maximum

error counts for MSS and gyro A using IP-127 and modifying the

co-alignment angular limit to the expected value of 30 degrees per

IP-152. Per IP-153, new SMACs, HMACs, safemode response table and

safemode recovery macro were uplinked to configure for usage of KFSP.

Following the completion of IP-153, the new KFSP Bypass test was

enabled, and Ops Note 1681 was executed to restore the limit for the

test.

 

Telemetry was monitored for 1 orbit following the macro uplink and

everything was nominal.