Status Report

NASA Hubble Space Telescope Daily Report # 4380

By SpaceRef Editor
June 12, 2007
Filed under , ,
NASA Hubble Space Telescope Daily Report # 4380

Notice: For the foreseeable future, the daily reports may contain apparent discrepancies between some proposal descriptions and the listed instrument usage. This is due to the conversion of previously approved ACS WFC or HRC observations into WFPC2, or NICMOS observations subsequent to the loss of ACS CCD science capability in late January.


– Continuing to collect World Class Science

PERIOD COVERED: UT June 08,09,10, 2007 (DOY 159,160,161)


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 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 images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.

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 indvidual 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.

NIC1 11057

Cycle 15 NICMOS dark current, shading profile, and read noise monitoring program

The purpose of this proposal is to monitor the dark current, read noise, and shading profile for all three NICMOS detectors throughout the duration of Cycle 15. This proposal is a slightly modified version of proposal 10380 of cycle 13 and 9993 of cycle12 and is the same as Cycle 14. that we cut down some exposure time to make the observation fit within 24 orbits.

FGS 10927

The Weight-Watcher Program for Subdwarfs

We propose to use HST/FGS1r to measure five subdwarf spectroscopic binaries to determine masses for the components. Their metallicities, [Fe/H], range from -0.5 to -2.5, and their projected minimum separations range from 9 to 24 mas. These binaries are resolvable with HST/FGS1r but not any ground-based technique. Currently, there are only two subdwarf systems having any mass measurements. The proposed work will boost the total number of subdwarf systems with masses from two to seven, and allow us to construct the first mass-luminosity relation for low-metallicity stars.

NIC2 10893

Sweeping Away the Dust: Reliable Dark Energy with an Infrared Hubble Diagram

We propose building a high-z Hubble Diagram using type Ia supernovae observed in the infrared rest-frame J-band. The infrared has a number of exceptional properties. The effect of dust extinction is minimal, reducing a major systematic tha may be biasing dark energy measurements. Also, recent work indicates that type Ia supernovae are true standard candles in the infrared meaning that our Hubble diagram will be resistant to possible evolution in the Phillips relation over cosmic time. High signal-to-noise measurements of 9 type Ia events at z~0.4 will be compared with an independent optical Hubble diagram from the ESSENCE project to test for a shift in the derived dark energy equation of state due to a systematic bias. Because of the bright sky background, H-band photometry of z~0.4 supernovae is not feasible from the ground. Only the superb image quality and dark infrared sky seen by HST makes this test possible. This experiment may also lead to a better, more reliable way of mapping the expansion history of the universe with the Joint Dark Energy Mission.

NIC2/WFPC2/NIC1 10887

Stellar Populations in a z=4 Lensed Galaxy with NICMOS

We propose to use NICMOS on HST to undertake deep high-resolution H-band imaging of a z=4 galaxy, lensed by a rich foreground cluster into highly-magnified arcs 3-5arcsec in length. By combining this with existing deep K-band imaging from Keck and high-quality archival WFPC2 and ACS data, we can spatially resolve stellar populations along the arcs. The WFPC2 images clearly reveal several bright knots, which may correspond to sites of active star formation. Indeed, our Keck/LRIS spectra {Bunker, Moustakas & Davis 2000} are consistent with OB-star spectral energy distributions in the rest-ultraviolet. However, there are considerable portions of the arcs which appear redder with no Ly-alpha emission, consistent with being post-starburst regions. The sensitivity and resolution afforded by NIC2 is crucial to study the inter-knot flux in H-band {F160W}, a goal unachievable from the ground. In conjunction with our deep Keck K’ data, NIC2 imaging will straddle the 4000Ang+Balmer break and thus allow us to `age-date’ the stellar populations by the inferred amplitude of the break along the transverse extent of the arcs. We can achieve this in 8 orbits, and address whether this star-forming galaxy at z=4 has had extended formation histories – vital for the interpretation of the Lyman Break Galaxies, and their relation to the evolved Extremely Red Objects.

WFPC2 10870

The Ring Plane Crossings of Uranus in 2007

The rings of Uranus turn edge-on to Earth in May and August 2007. In between, we will have a rare opportunity to see the unlit face of the rings. With the nine optically thick rings essentialy invisible, we will observe features and phenomena that are normally lost in their glare. We will use this opportunity to search thoroughly for the embedded “shepherd” moons long believed to confine the edges of the rings, setting a mass limit roughly 10 times smaller than that of the smallest shepherd currently known, Cordelia. We will measure the vertical thicknesses of the rings and study the faint dust belts only known to exist from a single Voyager image. We will also study the colors of the newly-discovered faint, outer rings; recent evidence suggests that one ring is red and the other blue, implying that each ring is dominated by a different set of physical processes. We will employ near- edge-on photometry from 2006 and 2007 to derive the particle filling factor within the rings, to observe how ring epsilon responds to the “traffic jam” as particles pass through its narrowest point, and to test the latest models for preserving eccentricities and apse alignment within the rings. Moreover, this data set will allow us to continue monitoring the motions of the inner moons, which have been found to show possibly chaotic orbital variations; by nearly doubling the time span of the existing ACS astrometry, the details of the variations will become much clearer.

WFPC2 10869

The upper atmosphere and the escape state of the transiting very-hot-Jupiter HD189733b

The observation of the HD209458b transits in Lyman-alpha revealed that the atmosphere of this planet is escaping. These observations raised the question of the evaporation state of hot-Jupiters. Is the evaporation specific to HD209458b or general to hot-Jupiters? What is the evaporation mechanism, and how does the escape rate depend on the planetary system characteristics? The recent discovery of HD189733b, a planet transiting a bright and nearby K0 star {V=7.7}, offers the unprecedented opportunity to answer these questions. Indeed, among the stars harboring transiting planets, HD189733 presents the largest apparent brightness in Lyman-alpha, providing capabilities to constrain the escape rate to high accuracy. With ACS/PR110L we will observe stellar emission lines to search for atmospheric absorptions during the transits. HD189733b being a very short period planet orbiting a nearby late type star with bright chromospheric emission lines, it is by far the best target to make significant progress in that field.

ACS/SBC 10862

Comprehensive Auroral Imaging of Jupiter and Saturn during the International Heliophysical Year

A comprehensive set of observations of the auroral emissions from Jupiter and Saturn is proposed for the International Heliophysical Year in 2007, a unique period of especially concentrated measurements of space physics phenomena throughout the solar system. We propose to determine the physical relationship of the various auroral processes at Jupiter and Saturn with conditions in the solar wind at each planet. This can be accomplished with campaigns of observations, with a sampling interval not to exceed one day, covering at least one solar rotation. The solar wind plasma density approaching Jupiter will be measured by the New Horizons spacecraft, and a separate campaign near opposition in May 2007 will determine the effect of large-scale variations in the interplanetary magnetic field {IMF} on the Jovian aurora by extrapolation from near-Earth solar wind measurements. A similar Saturn campaign near opposition in Jan. 2007 will combine extrapolated solar wind data with measurements from a wide range of locations within the Saturn magnetosphere by Cassini. In the course of making these observations, it will be possible to fully map the auroral footprints of Io and the other satellites to determine both the local magnetic field geometry and the controlling factors in the electromagnetic interaction of each satellite with the corotating magnetic field and plasma density. Also in the course of making these observations, the auroral emission properties will be compared with the properties of the near-IR ionospheric emissions {from ground-based observations} and non thermal radio emissions, from ground-based observations for Jupiter?s decametric radiation and Cassini plasma wave measurements of the Saturn Kilometric Radiation {SKR}.

WFPC2 10841

A Proper Motion Search for Intermediate Mass Black Holes in Globular Clusters {2nd Epoch Observations}

Establishing the presence or absence of intermediate-mass black holes {IMBH} in globular clusters is crucial for understanding the evolution of dense stellar systems. Observationally, this search has been hampered by the low number of stars with known velocities in the central few arcseconds. This limits our knowledge of the velocity dispersion in the region where the gravitational influence of any IMBH would be felt. In Cycle 13, we successfully obtained ACS/HRC images of the centers of five carefully chosen Galactic globular clusters {GO-10401} for a new proper motion study. Although the science case was approved and the first epoch images obtained, the requested future cycle observations were not granted {due to a general policy decision based on the strong uncertainties at the time concerning the immediate future of HST}. We have now assessed the quality of the first epoch observations. The HRC resolution reveals many isolated stars in to the very center of each cluster that remained blended or unresolved in previous WFPC2 data. Given a two year baseline, we are confident that we can achieve the proper motion precision required to place strict limits on the presence of an IMBH. Therefore, we request the second-epoch, follow-up observations to GO-10401 in order to measure the proper motions of stars in our target clusters. These velocity measurements will allow us to: {i} place constraints on the mass of a central black hole in each cluster; {ii} derive the internal velocity dispersion as a function of cluster radius; {iii} verify or reject previous reports of cluster rotation; and {iv} directly measure velocity anisotropy as a function of radius. If no second epoch data are obtained then the observing time already invested in the first epoch will have been wasted.

NIC2 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at redshifts exceeding 1 are now the leading obstacles to determining the nature of dark energy. We propose a single, integrated set of observations for Cycle 15 that will provide a 40% improvement in constraints on dark energy. This program will observe known Cepheids in six reliable hosts of Type Ia supernovae with NICMOS, reducing the uncertainty in H_0 by a factor of two because of the smaller dispersion along the instability strip, the diminished extinction, and the weaker metallicity dependence in the infrared. In parallel with ACS, at the same time the NICMOS observations are underway, we will discover and follow a sample of Type Ia supernovae at z > 1. Together, these measurements, along with prior constraints from WMAP, will provide a great improvement in HST’s ability to distinguish between a static, cosmological constant and dynamical dark energy. The Hubble Space Telescope is the only instrument in the world that can make these IR measurements of Cepheids beyond the Local Group, and it is the only telescope in the world that can be used to find and follow supernovae at z > 1. Our program exploits both of these unique capabilities of HST to learn more about one of the greatest mysteries in science.

WFPC2 10800

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have relatively fragile test particles which can be used as tracers of the early dynamical evolution of the outer Solar System. We propose to continue a Snapshot program using the ACS/HRC that has a demonstrated discovery potential an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. With this continuation we seek to reach the original goals of this project: to accumulate a sufficiently large sample in each of the distinct populations collected in the Kuiper Belt to be able to measure, with statistical significance, how the fraction of binaries varies as a function of their particular dynamical paths into the Kuiper Belt. Today’s Kuiper Belt bears the imprints of the final stages of giant-planet building and migration; binaries may offer some of the best preserved evidence of that long-ago era.

NIC3 10792

Quasars at Redshift z=6 and Early Star Formation History

We propose to observe four high-redshift quasars {z=6} in the NIR in order to estimate relative Fe/Mg abundances and the central black hole mass. The results of this study will critically constrain models of joint quasar and galaxy formation, early star formation, and the growth of supermassive black holes. Different time scales and yields for alpha-elements {like O or Mg} and for iron result into an iron enrichment delay of ~0.3 to 0.6 Gyr. Hence, despite the well-known complexity of the FeII emission line spectrum, the ratio iron/alpha – element is a potentially useful cosmological clock. The central black hole mass will be estimated based on a recently revised back hole mass – luminosity relationship. The time delay of the iron enrichment and the time required to form a supermassive black hole {logM>8 Msol, tau ~0.5Gyr} as evidenced by quasar activity will be used to date the beginning of the first intense star formation, marking the formation of the first massive galaxies that host luminous quasars, and to constrain the epoch when supermassive black holes start to grow by accretion.

WFPC2 10561

A deep UV imaging survey of the Globular Cluster M 30

We propose to carry out a deep FUV and NUV survey of M30 {NGC 7099} in order to find and study the hot and/or dynamically-formed stellar populations in the globular cluster. In particular, we will {i} search for the UV counterpart to a MSP binary, {ii} find and study the full population of cataclysmic variables in this cluster, {iii} study the UV properties of the cluster’s extensive blue straggler population, {iv} detect the first set of white dwarfs in this cluster. Our survey will be sensitive to variability on time-scales from minutes to weeks, allowing us to search for variable stars in all of the FUV populations.


Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)


10856 – GSAcq (2,0,2) failed due to Search Radius Limit Exceeded on FGS 2 At 2007.160/14:35:16 GSAcq (2,0,2) scheduled at 160/14:31:09-14:36:47 had failed due to Search Radius Limit Exceeded on FGS 2.

OBAD #1 V1 -238.71, V2 4023.22, V3 -1185.43, RSS 4201.01

OBAD #2 V1 -76.88, V2 31.13, V3 -64-97, RSS 105.36

OBAD MAP not available due to ongoing astrometry

OBAD MAP V1 69.99, V2 -35.93, V3 61.70, RSS 99.98 10857 – GSAcq (1,0,1) failed due to Search Radius Limit Exceeded on FGS 1

GSAcq (1,0,1) scheduled from 161/13:12:29-13:18:13 failed due to search radius limit exceeded on FGS 1. Historical extracts showed at 13:16:55 the FGS 1 PMT count reached a high value of 598.00018.

OBAD #1: V1 826.02, V2 3677.62, V3 194.74, RSS 3774.27

OBAD #2: V1 2.77, V2 5.49, V3 4.65, RSS 7.71

OBAD MAP: V1 -15.61, V2 -144.05, V3 -15.07, RSS 145.67 10858 – REAcq (1,2,2) failed to RGA Hold (Gyro Control) REAcq (1,2,2) scheduled from 19:44:23-19:52:00 failed to RGA Hold (Gyro Control) due to QF1STOPF & QSTOP flags on FGS 1.

OBAD #1: V1 -23.85, V2 172.36, V3 -14.01, RSS 174.57

OBAD #2: V1 0.97, V2 -4.67, V3 -7.03, RSS 8.50 At 22:19:39 ReAcq (1,2,2) scheduled from 21:20:19-21:27:56 failed to RGA Hold (Gyro Control) due to QSTOP flag on FGS 1.

OBAD #2 V1 3.04, V2 -7.03, V3 2.12, RSS 7.95 At 22:59:39 REacq(1,2,2) scheduled at 22:56:15 failed to RGA Control due to QSTOP flag on FGS 1. OBAD1 showed errors of V1=-28.18, V2=-616.76, V3=-27.44 and RSS=618.01. OBAD2 showed errors of V1=-0.64, V2=-3.72, V3=-8.15, and RSS = 8.98



                         SCHEDULED      SUCCESSFUL 
FGS GSacq               19                      17 
FGS REacq               21                      18 
OBAD with Maneuver      80                      80 


SpaceRef staff editor.