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Daily 3821
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3821 PERIOD COVERED: DOY 80 OBSERVATIONS SCHEDULED ACS/HRC 10377 ACS Earth Flats High signal sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently used by the pipeline and will provide a comparison with flats derived via other techniques: L- flats from stellar observations, sky flats from stacked GO observations, and internal flats using the calibration lamps. Weekly coronagraphic monitoring is required to assess the changing position of the spots. ACS/HRC/WFC 10367 ACS CCDs daily monitor- cycle 13 - part 1 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. ACS/HRC/WFC 10399 Accurate and Robust Calibration of the Extragalactic Distance Scale with the Maser Galaxy NGC4258 II The extragalactic distance scale {EDS} is defined by a comparison of Cepheid Period- Luminosity {PL} relations for nearby galaxies and the LMC, whose uncertain distance is thereby the SOLE anchor. Studies of masers orbiting the central black hole in NGC4258 have provided the most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new radio data and analysis techniques will reduce the uncertainty to 3.5% {0.07 mag} by 2005. Since this distance is well determined and based on geometric arguments, NGC4258 can provide a much needed new anchor for the EDS. Ultimately, the combination of an independent measurement of H0 and measurements of CMB fluctuations {e.g., WMAP} can be used to directly constrain cosmological parameters including the equation of state of dark energy. In our Cycle 12 proposal, we defined a program spanning two cycles. The Cycle 12 portion was accepted. We have acquired WFC images and are constructing well sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13 observations is to address systematic sources of error and is crucial for the success of the entire program. To disentangle the effects of reddening and metallicity, and to characterize the effects of blending, we require 50 orbits to obtain H-band photometry {NICMOS/NIC2} and high resolution images {ACS/HRC}. ACS/WFC 10235 Dark vs. luminous matter in the CenA/M83 galaxy complex The distribution of dark vs. luminous matter on scales of 0.1-1.0 Mpc remains poorly understood. For a nearby group, the total mass can be determined from the radius of "the zero-velocity surface", which separates the group from the general Hubble flow. This new method requires the measurement of accurate distances and radial velocities of galaxies around the group, but gives total mass estimates independent of assumptions about the state of relaxation or orbital characteristics. The mass pertains to the group at the full scale to which it is bound. Upon application in several nearest groups, the method yields mass estimates in agreement with the sum of the virial masses of subcomponents. However, the typical total M/L ratio for the nearby groups of ~30 Mo/Lo implies a local mean density of matter which is only 1/7 the canonical global density . The nearby complex of galaxies around Cen A and M83 resembles our Local Group by the dumb-bell concentration of objects around a pair of dominant galaxies. Accurate distances have been acquired recently for ~20 group members by the TRGB method using HST. We will measure TRGB distances to the 17 remaining galaxies in the region. These observations will constrain the dynamical state of the halo surrounding the nearest giant E-galaxy Cen A, providing a comparison with the halos of the nearest spirals. ACS/WFC 10378 ACS Polarimetry Calibration Observations are made of the Boomerang Nebula {highly polarized reflection nebula} to calibrate the ACS polarizers. ACS/WFC/NIC2/WFPC2 10413 Resolving the Red Giant Population in Early Type Galaxies This project addresses the fundamental issue of the age and abundance of the stellar populations in early type galaxies. We propose deep imaging observations with ACS/WFC in F606W, F814W, and NICMOS/NIC2 in F110W, F160W to create optical/IR color-magnitude diagrams of the upper red giant branch in the nearest example of a bona fide elliptical galaxy, NGC3379, and simultaneously in the disk and halo of its companion, the S0 galaxy NGC3384. These observations will build upon the results from our NICMOS study of NGC3379, which produced the first deep IR color-magnitude data for a normal, luminous elliptical galaxy. This is the most direct way to establish the metallicity, metallicity spread, and presence of intermediate age populations in these representative Hubble types, exploring their star formation histories and evolution. The data will enable comparison with M32, the M31 halo, NGC5128, and other nearby galaxies similarly observed with HST. ACS/WFC/WFPC2 10424 The White Dwarf Cooling Age and Dynamical History of the Metal-Poor Globular Cluster NGC 6397 We propose to determine the white dwarf cooling age in the nearest metal-poor {[Fe/H]=- 2} globular cluster, NGC 6397. This globular cluster provides the best opportunity to test the white dwarf cooling age in such a metal-poor system and at the same time provide a comparison with the more metal-rich cluster {M4} which we recently successfully observed with HST. Any {or even no} age difference between these clusters will be important in understanding the age-metallicity relation for these systems which reflects the star formation history in the early Galaxy. The absolute age is an important cosmological constraint. We expect to be able to detect age DIFFERENCES between these clusters at the 0.5 Gyr level and absolute ages should be accurate to 1.0 Gyr. In addition, and in contrast with M4, NGC 6397 is highly dynamically evolved, has a collapsed core, and the distribution of its white dwarfs throughout the cluster have almost certainly been modified by dynamical processes. We are using N-body simulations specifically developed for this cluster to understand these modifications and to include their effects in our measurement of the white dwarf luminosity function and cooling age. Among the dynamical questions we expect to answer with this proposal a 1} what was the primordial binary frequency in NGC 6397? 2} can we explain the high central concentration with a population of massive white dwarfs and/or neutron stars? 3} do we see sufficient central binaries to reverse the core collapse of the cluster? NIC1/NIC2/NIC3 8792 NICMOS Post-SAA calibration - CR Persistence Part 3 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 10169 Star Formation in Luminous Infrared Galaxies: giant HII Regions and Super Star Clusters Luminous Infrared Galaxies {LIRGs, LIR = 10^11-10^12Lsol} and Ultraluminous Infrared Galaxies {LIR10^12Lsol} account for approximately 75% of all the galaxies detected in the mid-infrared in the redshift range z=0-1.5. In the local universe it is found that LIRGs are predominantly powered by intense star formation {SF}. However, the physical conditions and processes governing such dramatic activity over scales of tens to a few hundred parsecs are poorly known. In the last decade HST has been playing a significant role, mainly with the discovery of super star clusters {SSCs}, and more recently, giant HII regions. Based on observations of a few LIRGs, we found that these giant HII regions and associated SSCs appear to be more common in LIRGs than in normal galaxies, and may dominate the star formation activity in LIRGs. A larger sample is required to address fundamental questions. We propose an HST/NICMOS targeted campaign of a volume limited sample {v5200km/s} of 24 LIRGs. This proposal will probe the role of giant HII regions in the overall energetics of the current star formation, their relation to SSCs, and the dependence of star formation properties on other parameters of LIRGs. Such detailed knowledge of the SF properties of LIRGs in the local universe is essential for understanding galaxies at high redshift. NIC3 10150 NICMOS observations of A1689 The potential of galaxy clusters as ``cosmic telescopes'' has been known for a long time, but practical results in the pre-ACS era have been scarce due to two main problems: the uncertainty in determining the magnification distribution of the cluster {the ``optics'' of the instrument} and the presence of numerous bright cluster galaxies which cover the field of view and hinder the detection of background galaxies. We have developed techniques to solve these two problems working with our ACS observations of A1689, the most powerful lens in the sky, and for the first time we have been able to determine the "specifications" of a cosmic telescope with a useful level of precision, thanks to the detection and identification of more than 100 multiple images with reliable redshift information. We propose to observe the high magnification region in the A1689 field in the F110W band with a 3x3 mosaic of NIC3 pointings; the resulting image will reach a lens-corrected limiting magnitudes of 29.5 for point sources, surpassing in depth the UDF NICMOS observations and providing an unique dataset with multiple scientific returns. WFPC2 10359 WFPC2 CYCLE 13 Standard Darks 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. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: None OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 8 8 FGS Reacq 7 7 FHST Update 11 11 LOSS of LOCK SIGNIFICANT EVENTS: None |
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