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NASA Hubble Space Telescope Daily Report #4287

Status Report From: Space Telescope Science Institute
Posted: Monday, January 29, 2007

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HUBBLE SPACE TELESCOPE DAILY REPORT # 4287

- Continuing to collect World Class Science

PERIOD COVERED: UT January 26,27,28, 2007 (DOY 026,027,028)

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.

ACS/HRC 11041

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. For cycle 15 the program will cover 18 months 12.1.06- >05.31.08 and it has been divied into three different proposal each covering six months. The three proposals are 11041-11042-11043.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and highly non-uniform archive, making comprehensive comparative studies among galaxies essentially impossible. We propose to secure HST's lasting impact on the study of nearby galaxies by undertaking a systematic, complete, and carefully crafted imaging survey of ALL galaxies in the Local Universe outside the Local Group. The resulting images will allow unprecedented measurements of: {1} the star formation history {SFH} of a >100 Mpc^3 volume of the Universe with a time resolution of Delta[log{t}]=0.25; {2} correlations between spatially resolved SFHs and environment; {3} the structure and properties of thick disks and stellar halos; and {4} the color distributions, sizes, and specific frequencies of globular and disk clusters as a function of galaxy mass and environment. To reach these goals, we will use a combination of wide-field tiling and pointed deep imaging to obtain uniform data on all 72 galaxies within a volume-limited sample extending to ~3.5 Mpc, with an extension to the M81 group. For each galaxy, the wide-field imaging will cover out to ~1.5 times the optical radius and will reach photometric depths of at least 2 magnitudes below the tip of the red giant branch throughout the limits of the survey volume. One additional deep pointing per galaxy will reach SNR~10 for red clump stars, sufficient to recover the ancient SFH from the color-magnitude diagram. This proposal will produce photometric information for ~100 million stars {comparable to the number in the SDSS survey} and uniform multi- color images of half a square degree of sky. The resulting archive will establish the fundamental optical database for nearby galaxies, in preparation for the shift of high- resolution imaging to the near-infrared.

ACS/WFC 10881

The Ultimate Gravitational Lensing Survey of Cluster Mass and Substructure

We propose a systematic and detailed investigation of the mass, substructure, and thermodynamics of one hundred X-ray luminous galaxy clusters at 0.151} cluster samples. For this ultimate cluster survey, we request ACS SNAPSHOTS through the F606W filter drawn from a target list of 143 clusters.

NIC3 10874

Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses

Deep UDF/NICMOS observations find a significant decrease in the number of galaxy candidates between redshift z=6 and 7, but the sample at z>7 is too small to draw conclusions. From our observations of 15 clusters we have found a number of bright z- dropouts, aided by the lensing amplification. We propose deep NICMOS observations of the best cases of cluster centers where a rare combination of a significant lensing effect and the richness in z-band dropouts in background may dramatically increase the discovery rate. The NICMOS images will reach an unprecedented depth of AB~27.8, or AB~30 in nonlensed intrinsic magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a level that the UDF reaches for z~6 objects. We produce precision mass distribution maps from weak-lensing models, which enable us to derive the candidates' intrinsic magnitudes and their luminosity function. The knowledge of such faint galaxy population at z>7 will facilitate the models of the IGM reionization and future JWST planning.

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}.

NIC3 10861

An ACS Treasury Survey of the Coma cluster of galaxies

We propose to use the unique spatial resolution of HST and ACS to construct a Treasury imaging survey of the core and infall region of the richest local cluster, Coma. We will observe samples of thousands of galaxies down to magnitude B=27.3 with the aim of studying in detail the dwarf galaxy population which, according to hierarchical models of galaxy formation, are the earliest galaxies to form in the universe. Our initial scientific objectives are: 1} A study of the structure of the dwarf galaxies, including scaling laws, nuclear structure and morphology, to compare with hierarchical and evolutionary models of their formation. 2} A study of the stellar populations from colors and color gradients, and how the internal chemical evolution of galaxies is affected by interaction with the cluster gaseous and galaxy environment. 3} To determine the effect of the cluster environment upon morphological features, disks, bulges and bars, by comparing these structure in the Coma sample with field galaxy samples. 4} Identification of dwarf galaxy samples for further study with the new generation of multi-object and integral-field spectrographs on 8-10 metre class telescopes such as Keck, Subaru, Gemini, and GTC. This is the first such survey of a nearby rich cluster. It will provide a key database for studies of galaxy formation and evolution, and a very needed reference for comparison with similar galaxy surveys both in lower density environments in the nearby universe, and in high density environments at high redshifts.

ACS/WFC 10813

MgII Absorption Line Systems: Galaxy Halos or the Metal-Enriched IGM?

MgII QSO absorption lines detected in the spectra of background QSOs were used over a decade ago to infer that all redshift z > 0.2 galaxies have gaseous halos of radius ~ 60 kpc. The actual size of the halo was believed to be proportional to the luminosity of the galaxy. However, these conclusions are now much harder to understand in light of the results from numerical simulations which show how gas evolves in the universe. These models predict that gas and galaxies merely share the same filamentary structures defined by dark matter. If these models are correct, how are MgII systems and galaxies really related? We can better understand the distribution of absorbing gas if we FIRST select galaxies close to QSO sightlines and THEN search for MgII absorption at the redshift of the intervening galaxies. This is the antithesis of the original experiments which sought to find absorbing galaxies based on known MgII systems. The frequency with which we detect MgII lines from randomly selected galaxies should enable us to better understand if absorption arises in the halos of individual galaxies, or if MgII merely arises in the same IGM that galaxies inhabit. We have used ground-based telescopes to indentify twenty z = 0.31-0.55 galaxies within 14-51 kpc of a g < 20 QSO, and to search for MgII absorption at the galaxies' redshifts. Surprisingly, we find that only 50% of our QSOs show MgII absorption. In this proposal, we seek multi-color ACS images of twelve of the fields to i} correlate the incidence of MgII with galaxy morphology; ii} determine if absorption {or lack thereof} is related to galaxy disks or halos; iii} search for signs of galaxy interactions which may explain the large cross-sections of MgII systems; and iv} look for faint interloping galaxies closer to the line of sight than the one we identified. An important component of the program is to observe each field in the SDSS g-, r- and i-bands, to permit an estimate of the photometric redshift of any objects which lie closer to the QSO sightline than the identified galaxy, and which might actually be responsible for the absorption.

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10648 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control) Upon acquisition of signal at 026/12:48:23, the GSAcq(2,3,3)scheduled at 026/12:24:55 - 12:33:00 was observed to have failed to RGA Hold due to stop flag indication on FGS2. Pre-acquisition OBADs (RSS) attitude correction values not available due to LOS. Post-acquisition OBAD/MAP showed 3-axis (RSS) error value of 17.93 arcseconds. Subsequent REacq(2,3,3) at 026/13:56:41 was successful.

10650 - OBAD Failed Identification (ESB 1902) At 026/00:00:00, OBAD1 using trackers FHST-1 and FHST-3 failed. One ESB message 1902 (OBAD Failed Identification) was received. ESB 1805 (T2G_MOVING_TARGET_DETECTED) at 026/16:57:57 also ESB 1806 (T2G_OPEN_LOOP_TIMEOUT) was received at 026/16:58:48. OBAD1 had (RSS) value of 125463.25 arcseconds. OBAD success flag (mnemonic GCHACL09) returned to the "no success" state (a value of 1). Unable to execute OPS REQUEST 17543-2 (OBAD Tables 369 & 370 Dump) prior to next OBAD due to lack of sufficient forward link. Subsequent GSAcq was successful.

10651 - HST entered Inertial Hold Safemode Safetest 'Neon Leakage Test' failed. Acquired 4k data at 027/1308z

10654 - GSACQ(1,2,2) failed to RGA Hold due to SRLEX The GSACQ(1,2,2) failed to RGA Hold at 027/12:25:38 due to a Search Radius Limit Exceeded Error on FGS-1. Analysis of the digitized Sky Survey images does not indicate any obvious problem with the guide stars. The Map immediately following the acquisition reported an ~77 arcsecond error. This acquisition failure does not appear to have anything to do with the subsequent safemode entry at 12:34.

10655 - FHST OBAD (no maneuver) Failed OBAD scheduled at 028/07:36:13 using trackers 1 and 3 failed. During LOS ESB message 1901 " OBAD Too Few Stars" was received.

OBAD scheduled at 028/08:58:03 also failed. ESB message 1901 "OBAD Too Few Stars" as received at 09:00:50.

OBAD scheduled at 028/10:34:00 failed. ESB 1901 was received at 10:36:50.

COMPLETED OPS REQUEST:

  • 17992-0 - Turn NCS CPL Startup Heater
  • 17993-0 - Turn on PCE
  • 17994-0 - Dump Table 320
  • 17996-0 - Power on GEA
  • 17995-0 - Dump HST486 Table (SPA AREA)
  • 17998-1 - Safemode Recovery from Inertial Hold
  • 17999-0 - Safe NICMOS
  • 18000-1 - Uplink N02Z5630C,Set ATP Pointer, & Clear ENGREPs
  • 18001-0 - Open ACS PDU 2 Relay
  • 17997-1 - Re-enable Neon Leakage Test/Power on FHSTs

COMPLETED OPS NOTES:

  • 16624-0 - Reset NCS Min/Max Buffer (Generic)
  • 17543-2 - Dump OBAD tables after failed OBAD (Generic)
  • 17597-7 - FHST Stuck-on-Bottom Macro Execution (Generic)
  • 17659-0 - ESTR Reconditioning (Generic)
  • 17929-0 - Set TMDIAG Slots to Monitor Aero Torques (Generic)
  • 17946-1 - MA/GN Mode Recorder Dump Test (Generic)
  • 17966-0 - Monitor FHST Sanity Check via TMDIAG Slots 0-2 (Generic)

SCHEDULED SUCCESSFUL FGS GSacq 07 05 FGS REacq 09 09 OBAD with Maneuver 34 33

SIGNIFICANT EVENTS:

Flash Report - Inertial Hold DOY 07/027

HST entered Inertial Hold Safemode on 2007/027/12:34:38 GMT (Sat, 01/27/97) following a Total Pressure Sensor (TPS) limit violation. Autonomous safing actions included powering off the FHSTs and the FGS High Voltage and terminating High Gain Antennae (HGA) tracking. Data review following the safemode entry revealed: "Structure Current Safing Test limit was exceeded ~10sec prior to safemode entry, but HST structure current returned within limits before the test could fail." ACS safed due to loss of power "NICMOS Cryo-Cooler safed due to a Total Pressure Sensor (TPS) limit violation. Note: NO Indication of NEON Leak." All other HST science instruments and spacecraft subsystems were functioning nominally. At 10:00 am and 1:00 pm EST in GSFC B3/S107A, Status meetings were held with the Mission Operations Team, Science Institute and HST Project. HST Project gave approval to proceed with HST recovery from Inertial Hold safe mode.

Flash Report:

01/28/07, 9am Inertial Hold Status Mtg At 9:00 am, Sun, 01/28/07. HST Project granted approval to proceed with the following:

1) Re-enable the Neon Leakage Test and power on the FHSTs on 1/28/07

2) Open ACS PDU 2 Relay on 01/28/07

3) Prepare for NCS power on as early as 01/29/07

Flash Report: ACS PDU 2 Relay Open The ACS PDU 2 relay was opened via Ops Request 18001 at 17:26:36 GMT. No anomalous structure current signature was observed when the PDU 2 relay was opened.

Flash Report:

Ops Request 17997-1 for re-enabling the Neon Leak Safing test and powering the FHSTs back on was completed at 2007/028 17:45. The Safing system is now in its nominal configuration, with all Two-Gyro Science mode Safing tests and macros enabled. Fixed-Head Star Tracker performance has been nominal since power-on. Control mode transitions into T2G Rate Damping and Attitude Hold were performed as expected. The FHST Maps at 028/19:15 and 028/20:10 both measured less than 1 degree of RSS attitude error.

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