NASA Hubble Space Telescope Daily Report #4267
HUBBLE SPACE TELESCOPE DAILY REPORT # 4267
– Continuing to collect World Class Science
PERIOD COVERED: UT December 26, 2006 (DOY 360)
OBSERVATIONS SCHEDULED
ACS/WFC 10858
NICMOS Imaging of the z ~ 2 Spitzer Spectroscopic Sample of Ultraluminous Infrared Galaxies
We propose to obtain NICMOS images of the first large sample of high-z ultra-luminous infrared galaxies {ULIRGs} whose redshifts and physical states have been determined with Spitzer mid- IR spectra. The detection of strong silicate absorption and/or PAH emission lines suggest that the these sources are a mixture of highly obscured starbursts, AGNs and composite systems at z=2. Although some of the spectra show PAH emission similar to local starburst ULIRGs, their bolometric luminosities are roughly an order of magnitude higher. One important question is if major mergers, which are the trigger for 95% of local ULIRGs, also drive this enormous energy output observed in our z=2 sample. The NICMOS images will allow us to {1} measure surface brightness profiles of z~2 ULIRGs and establish if major mergers could be common among our luminous sources at these early epochs, {2} determine if starbursts and AGNs classified based on their mid-IR spetra would have different morphological signatures, thus different dynamic state; {3} make comparisons with the similar studies of ULIRGs at z ~ 0 – 1, thus infer any evolutionary connections between high-z ULIRGs and the formation of normal, massive galaxies and quasars observed today.
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 a 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.
ACS/WFC/WFPC2 10584
The link between X-ray source and stellar populations in M81
We propose to perform a deep v~26-27.0 HST-ACS survey of the nearby {3.6 Mpc} spiral galaxy M~81 in order to study the nature of its X-ray source populations detected with Chandra. For the first time in a galaxy other than the Milky-Way or the Magelanic Clouds, we will classify X-ray sources as High-Mass and Low-Mass X-ray binaries {HMXBs, LMXBs} and investigate how these populations depend on their galactic environment. The classification will be performed {a} by finding and classifying unique optical counterparts for the X-ray sources and {b} studying the stellar populations in their vicinity. Both tasks require the <0.1'' resolution of HST-ACS which matches well the positional accuracy of Chandra. Finally we will use these results together with X-ray binary evolution synthesis models in order to constrain X-ray binary {XRB} evolution channels. These data will also be a great resource for studies of the star-formation and star- cluster populations in one of the prototypical spiral galaxies.
NIC1 11063
NICMOS Focus Monitoring
This program is a version of the standard focus sweep used since cycle 7. It has been modified to go deeper and uses more narrow filters for improved focus determination. For Cycle14 a new source has been added in order to accomodate 2-gyro mode: the open cluster NGC1850. The old target, the open cluster NGC3603, will be used whenever available and the new target used to fill the periods when NGC3603 is not visible. Steps: a} Use refined target field positions as determined from cycle 7 calibrations b} Use MULTIACCUM sequences of sufficient dynamic range to account for defocus c} Do a 17-point focus sweep, +/- 8mm about the PAM mechanical zeropoint for each cameras 1 and 2, in 1.0mm steps. d} Use PAM X/Y tilt and OTA offset slew compensations refined from previous focus monitoring/optical alignment activities
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.
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.
NIC3 10894
Probing the Birth of Super Star Clusters with NICMOS
The formation of “super star clusters” represents an extreme mode of star formation in the local universe. Star clusters with radii < 5pc and masses exceeding 10^4 solar masses are now known to be common in starbursts. These clusters are amazingly densely packed with massive stars, and can have a violent impact on their host galaxies and the surrounding IGM. The effects of massive star clusters perhaps were even more important in the earlier universe, when galaxy mergers and starbursts were common, and the formation of massive globular clusters was ubiquitous. However, our knowledge of the formation and early evolution of such massive clusters remains poorly understood, and observations have only begun to probe these stages. The near-IR fluxes and colors of natal clusters change dramatically in their early stages of evolution, providing important diagnostics. We will use NICMOS to explore the early evolution of massive star clusters through observations of a sample of nearby starburst galaxies containing the recently discovered ultra-young massive star clusters. First identified as compact optically- thick free-free radio sources, these natal clusters are still embedded in their birth material and obscured at optical wavelengths. Sensitive, high-resolution observations in the near-IR are critical for investigating the properties of these clusters as they evolve from being completely obscured by their natal clouds to fully emerged and optically visible. NICMOS F160W, F205W, F187N, and F190N {roughly H, K, and Pa-alpha} images will allow us to determine their ages, extinctions, ionizing fluxes, embedded stellar masses, and the morphological relationship between radio, mid-IR, and optically visible clusters. These results will ultimately provide insight into the earliest stages of super star cluster evolution and the properties of massive star formation throughout the universe.
WFPC2 10745
WFPC2 CYCLE 14 INTERNAL MONITOR
This calibration proposal is the Cycle 14 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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
10577 – OBAD Failed OBAD at 22:55:32 failed at 22:58:17 with “OBAD Failed Quaternion”. OBAD errors were reported as “NaN.00”, with RSS sum = 0.00 Guide Star acquisition at 23:01:39 was successful.
COMPLETED OPS REQUEST:
17543-2 – Dump OBAD Tables after failed OBAD
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSacq 10 10
FGS REacq 04 04
OBAD with Maneuver 28 27
SIGNIFICANT EVENTS: (None)
