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NASA Hubble Space Telescope Daily Report #4302

Status Report From: Space Telescope Science Institute
Posted: Tuesday, February 20, 2007

image

HUBBLE SPACE TELESCOPE DAILY REPORT # 4302

- Continuing to collect World Class Science

PERIOD COVERED: UT February 16,17,18,19, 2007 (DOY 047,048,049,050)

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 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 11096

Hubble Heritage imaging of Jupiter during the New Horizons encounter HST Proposal 11096

WFPC2 images of Jupiter in Feb 2007 in support of New Horizons flyby of Jupiter. This Hubble Heritage DD program is working in concert with the existing GO programs by John Clarke {10862} and John Spencer {10871}.

S/C 11094

SBC Filter Wheel Checkout

Following the side 2 electronics failure it is proposed to return to side 1 and operate the SBC. Several tests will be performed before resuming normal operations. The following proposal is one of these and should be held until the return to side 1 is approved. This proposal's purpose is to command the SBC Filter Wheel to each of its positions in both directions of motion and verify {via the mechanism's positional encoding readout} proper execution of the commands.

WFPC2 11093

Hubble Heritage Observations of PNe with WFPC2

This is a proposal for observation of a set of PNe using a common WFPC2 observation sequence.

WFPC2 11089

WFPC2 UV Throughput Check after 27-Jan-2007 Safemode

Check UV throughput of standard star GRW+70D5824 in all four chips following safemode caused by ACS Side 2 failure.

NIC3 11082

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond

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 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are approaching a full census of galaxy populations, our attention needs to turn towards understanding and quantifying the physical mechanisms that trigger and regulate the large-scale star formation rates {SFRs} in galaxies.

NIC3 11064

CYCLE 15 NICMOS SPECTROPHOTOMETRY CALIBRATION PROGRAM

Now that the spectrophotometric capabilities of the NICMOS grism have been established, cycle 15 observations are needed to refine the sensitivity estimates, to check for sensitivity loss with time, to improve the accuracy of the linearity correction, to improve the secondary flux standards by re-observation, and to expand the G206 data set now that the sky subtraction technique has been shown to produce useful fluxes for some of the fainter secondary standards. These faint secondary IR standards will be a significant step towards establishing flux standards for JWST, as well as for SNAP, Spitzer, and SOFIA. 1.Re- observe the 3 primary WDs GD71, G191B2b, & GD153 twice each, once at the beginning and once near the end of the 18 month cycle. To date, we have only 2 observation of each star, while the corresponding STIS data set for these primary standards ranges from 6 to 23 obs. No observations exist for GD71 or GD153 with G206, so that the current G206 sensitivity is defined solely by G191B2B. Purposes: Refine sensitivities, measure sens losses. Orbits: 2 for each of 6 visits = 12 2. Re-observe WD1057 & WD1657 plus another P041C lamp-on visit to improve the scatter in the non-lin measurements per Fig. 8 of NIC ISR 2006-02. The WD stars require 2 orbits each, while the lamp-on test is done in one. The very faintest and most crucial standard WD1657 has 2 good visits already, so to substantially improve the S/N, two visits of two orbits are needed. Include G206 for P041C in the lamp-off baseline part of that orbit. Orbits: WD1057-2, WD1657-4, P041C-1 --> 7 3. Re-observe 9 secondary standards to improve S/N of the faint ones and to include G206 for all 9. BD+17 {3 obs} is not repeated in this cycle. Four are bright enough to do in one orbit: VB8, 2M0036+18, P330E, and P177D. Orbits:2*5+4=14 Grand Total orbits over 18 month cycle 15 is 12+6+14=32 {Roelof will submit the P041C lamp-on visit in a separate program.}

NIC1 11061

NICMOS Imaging of Grism Spectrophotometric Standards

In this program we will take imaging observations with all 3 cameras with a range of filters of a significant number of stars that are part of the spectroscopic standard star project. These stars will form the fainter reference star backbone for programs as JWST, Sophia, and SNAP. With this program we will: 1. Accurately calibrate relative brightness of standard stars, which can be done more accurately with photometry than with spectroscopy. This has been proven to be vary valuable to straighten out the problems in the spectroscopic data reduction and calibrations so far. 2. Increase the number of stars over a large magnitude range to provide a more accurate cross check of our count rate dependent non-linearity correction 3. Include stars with radically different {very red} spectra to investigate whether the filter curves as measured before flight are still valid by comparing the throughput estimates from these stars to those used for the standard calibration. 4. Repeat a few standard star observations from cycle 7 and post-NCS installation SMOV, to increase the accuracy in the change in sensitivity measurement with just a few observations thanks to the long baseline.

ACS/WFC 11052

Internal Flat Fields

The stability of the CCD P-flat fields will be monitored using the calibration lamps and a sub-sample of the filter set. High signal observations will be used to assess the stability of the pixel-to-pixel flat field structure and to monitor the position of the dust motes.

ACS/SBC 11048

SBC MAMA Recovery

Procedure to be used when ACS MAMA anomalously shuts down. Recovery procedure is designed to carefully bring the MAMA back to operating condition while watching for possible problems. The final step is to do a fold analysis which gives detailed information about how well the instrument is performing. Only the first four visits are to be executed. Visits 5 to 7 whih are a repaeat of 1 to 4 are to be kept on hold.

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.

ACS/WFC 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 routine internal monitor for WFPC2, to be run weekly to monitor the health of the cameras. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {both gain 7 and gain 15 -- to test stability of gains and bias levels}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. These also provide raw data for generating annual super-bias reference files for the calibration pipeline.

WFPC2 11023

WFPC2 CYCLE 15 Standard Darks - part 1

This dark calibration program obtains dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels. Over an extended period these data will also provide a monitor of radiation damage to the CCDs.

FGS 10989

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

ACS/WFC 10918

Reducing Systematic Errors on the Hubble Constant: Metallicity Calibration of the Cepheid PL Relation

Reducing the systematic errors on the Hubble constant is still of significance and of immediate importance to modern cosmology. One of the largest remaining uncertainties in the Cepheid-based distance scale {which itself is at the foundation of the HST Key Project determination of H_o} which can now be addressed directly by HST, is the effect of metallicity on the Cepheid Period-Luminosity relation. Three chemically distinct regions in M101 will be used to directly measure and thereby calibrate the change in zero point of the Cepheid PL relation over range of metallicities that run from SMC-like, through Solar, to metallicities as high as the most metal-enriched galaxies in the pure Hubble flow. ACS for the first time offers the opportunity to make a precise calibration of this effect which currently accounts for at least a third of the total systematic uncertainty on Ho. The calibration will be made in the V and I bandpasses so as to be immediately and directly applicable to the entire HST Cepheid-based distance scale sample, and most especially to the highest-metallicity galaxies that were hosts to the Type Ia supernovae, which were then used to extend the the distance scale calibration out to cosmologically significant distances.

WFPC2 10890

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

The formative phase 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, restricting us to the study of 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 bright at mid-IR wavelengths {F[24um]>0.8mJy}, but deep ground based imaging suggests extremely faint {and in some cases extended} optical counterparts {R~24-27}. Deep K-band images show barely resolved galaxies. Mid-infrared spectroscopy with Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS F814W and NIC2 F160W images of these sources and their environs in order to determine kpc-scale morphologies and surface photometry for these galaxies. The proposed observations will help us determine whether these extreme objects are merging systems, massive obscured starbursts {with obscuration on kpc scales!} or very reddened {locally obscured} AGN hosted by intrinsically low-luminosity galaxies.

NIC1 10879

A search for planetary-mass companions to the nearest L dwarfs - completing the survey

We propose to extend the most sensitive survey yet undertaken for very low-mass companions to ultracool dwarfs. We will use NICMOS to complete imaging of an all-sky sample of 87 L dwarfs in 80 systems within 20 parsecs of the Sun. The combination of infrared imaging and proximity allows us to search for companions with mass ratios q>0.25 at separations exceeding ~3 AU, while probing companions with q>0.5 at ~1.5 AU separation. This resolution is crucial, since no ultracool binaries are known in the field with separations exceeding 15 AU. Fifty L dwarfs from the 20-parsec sample have high- resolution imaging, primarily through our Cycle 13 HST proposal which identified six new binaries, including an L/T system. Here, we propose to target the remaining 30 dwarfs

WFPC2 10871

Observations of the Galilean Satellites in Support of the New Horizons Flyby

On February 28 2007 the New Horizons {NH} spacecraft will fly by Jupiter on its way to Pluto, and will conduct an extensive series of observations of the Jupiter system, including the Galilean satellites. We propose HST observations to support and complement the New Horizons observations in four ways: 1} Determine the distribution and variability of Io's plumes in the two weeks before NH closest approach, to look for correlations with Io- derived dust streams that may be detected by New Horizons, to understand the origin of the dust streams; 2} Imaging of SO2 and S2 gas absorption in Io's plumes in Jupiter transit, which cannot be done by NH; 3} Color imaging of Io's surface to determine the effects of the plumes and volcanos seen by New Horizons on the surface- New Horizons cannot image the sunlit surface in color due to saturation; 4} Imaging of far-UV auroral emissions from the atmospheres of Io, Europa, and Ganymede in Jupiter eclipse, near- simultaneously with disk-integrated NH UV spectra, to locate the source of the UV emissions seen by NH and use the response of the satellite atmospheres to the eclipse to constrain production mechanisms.

NIC2, ACS/WFC 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.

ACS/WFC 10798

Dark Halos and Substructure from Arcs & Einstein Rings

The surface brightness distribution of extended gravitationally lensed arcs and Einstein rings contains super-resolved information about the lensed object, and, more excitingly, about the smooth and clumpy mass distribution of the lens galaxies. The source and lens information can non-parametrically be separated, resulting in a direct "gravitational image" of the inner mass-distribution of cosmologically-distant galaxies {Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}. With this goal in mind, we propose deep HST ACS-F555W/F814W and NICMOS-F160W WFC imaging of 20 new gravitational-lens systems with spatially resolved lensed sources, of the 35 new lens systems discovered by the Sloan Lens ACS Survey {Bolton et al. 2005} so far, 15 of which are being imaged in Cycle-14. Each system has been selected from the SDSS and confirmed in two time- efficient HST-ACS snapshot programs {cycle 13&14}. High-fidelity multi-color HST images are required {not delivered by the 420s snapshots} to isolate these lensed images {properly cleaned, dithered and extinction-corrected} from the lens galaxy surface brightness distribution, and apply our "gravitational maging" technique. Our sample of 35 early-type lens galaxies to date is by far the largest, still growing, and most uniformly selected. This minimizes selection biases and small-number statistics, compared to smaller, often serendipitously discovered, samples. Moreover, using the WFC provides information on the field around the lens, higher S/N and a better understood PSF, compared with the HRC, and one retains high spatial resolution through drizzling. The sample of galaxy mass distributions - determined through this method from the arcs and Einstein ring HST images - will be studied to: {i} measure the smooth mass distribution of the lens galaxies {dark and luminous mass are separated using the HST images and the stellar M/L values derived from a joint stellar-dynamical analysis of each system}; {ii} quantify statistically and individually the incidence of mass-substructure {with or without obvious luminous counter- parts such as dwarf galaxies}. Since dark-matter substructure could be more prevalent at higher redshift, both results provide a direct test of this prediction of the CDM hierarchical structure-formation model.

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.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

ACS/WFC 10520

Resolving the Complex Star Formation History of the Leo I Dwarf Spheroidal Galaxy

Determining the star formation histories {SFHs} and chemical evolution of nearby galaxies gives us powerful constrains on the physical processes that regulate galaxy evolution. The SFHs can be measured most accurately by comparing the observed densities of stars in color-magnitude diagrams {CMDs} to predictions from stellar evolutionary models. WFPC2 imaging of the Leo I dSph shows it is unique because its stellar population is relatively young. Approximately 68% of its stars formed between 1 and 7 Gyr ago and only 12% of its stars formed >~ 10 Gyr ago. We propose to vastly improve the derived SFH of Leo I by exploiting ACS/WFC's higher quantum efficiency at bluer wavelengths, higher spatial resolution, and larger field-of-view. The figure of merit for our proposed observations, defined as the age resolution times the number of stars detected, will be a factor of 12 higher than existing WFPC2 observations. To surmount the degeneracy of age and metallicity in the CMD, we have independently measured the metallicity distribution of its stars using spectroscopy. Simultaneously modeling the metallicity distribution and CMD, we will firmly constrain the evolution of the Leo I dSph, a unique example of an isolated dwarf galaxy that has not been influenced by interactions with the Milky Way or M31.

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

HSTARS:

10694 - GSAcq (2,3,3) results in fine lock backup (2,0,2) REAcq (2,3,3) scheduled at 047/10:38:25-10:45:34 resulted in fine lock backup (2,0,2) using FGS 2, due to (QF3STOPF) stop flag indication on secondary FGS 3.

10696 - GSacq(2,1,1) failed to RGA control GSacq(2,1,1) scheduled at 047/14:02:15 failed to RGA control due to receiving stop flag QF2STOPF on FGS 2 at 14:05:41.

10697 - Multiple REacq(1,3,3) failures to RGA control REacq failed at 13:46:57 with a STOP flag for FGS 1. F3SSCEB (F3 Star Select Compensation Error B) flagged out at 13:47:56. REacq scheduled at 15:18:26 also failed with a STOP flag for FGS1. REacq scheduled at 16:55:24 also failed with a STOP flag for FGS1. Monitoring all three failures the following was noted: The failure occurred after fine lock for both FGS's and during the vehicle offset maneuver. The star used for FGS 1 tracks outside the FGS FOV during this maneuver. Upon AOS @ 19:17, the REacq scheduled at 18:30:14 failed with a STOP flag for FGS1. Upon AOS @ 20:29, the REacq scheduled at 20:06:07 failed with a STOP flag for FGS1.

10699 - GSAcq(2,1,2) failed to RGA Hold (Gyro Control) Upon acquisition of signal at 050/11:51:21, the GSAcq(2,1,2) scheduled at 050/11:43:25 - 11:51:30 had failed to RGA Hold due to (QF2STOPF) stop flag indication on FGS2.

10702 - GSAcq (2,1,2) failed due to Search Radius Limit Exceeded on FGS 2 At AOS (051/09:12:16) GSAcq (2,1,2) scheduled 051/08:29:56-08:37:10 had failed due to search radius limit exceeded on FGS 2.

COMPLETED OPS REQUEST:

18018-4 - Configure ACS to Side 1 Safe Mode

18017-0 - SMAC20 Version 'M' Install

18019-4 - Configure ACS for Side 1 Operations

COMPLETED OPS NOTES: (None)

                         SCHEDULED      SUCCESSFUL 
FGS GSacq                 26                  23         
FGS REacq                 29                  24               
OBAD with Maneuver  107                107                 

SIGNIFICANT EVENTS:

Flash Report:

As of 047/16:22:43 ACS is configured to its Safe mode on Side 1, and the on-board SMAC20 has been updated to the new version M to support ACS Side 1 SBC-only operations. Flash Report: As of 048/00:28:33. ACS CS FSW 4.02A has been successfully loaded, validated, and activated in the transition to the Operate state. ACS is configured to intercept the 050 SMS and resume SBC science activities. Flash Report: Results of the ACS SBC Filter Wheel Test ACS completed the SBC filter wheel test. Flash Report: The SI SEs at GSFC have been notified that ACS Flag 2 can be cleared for normal SBC operations.

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