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Daily 3739
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3739 PERIOD COVERED: DOY 322 OBSERVATIONS SCHEDULED ACS/HRC 9792 Uncovering the CV population in M15: a deep, time-resolved, far-UV survey of the cluster core We propose to carry out a deep, far-ultraviolet {FUV}, time-resolved for faint cataclysmic variables {CVs} and other dynamically-formed objects in the globular cluster {GC} M15. We will use the ACS/SBC to carry out 6 epochs of FUV imaging of this cluster in a single filter, and will use two additional visits to obtain images in other FUV and NUV filters. Since crowding is not a problem in the FUV, this will yield time-resolved FUV photometry of all blue objects in the cluster core. Our CV census will be both deep enough to be essentially complete and ``broad'' enough to involve all of the following CV characteristics: {1} UV brightness; {2} blue FUV spectral shape; {3} strong CIV and HeII emission; {4} short time-scale {$sim$ minutes} variability {flickering, WD spin}; {6} intermediate time-scale {$sim$ hours} variability {orbital variations}; {7} long time-scale {$sim$ weeks} variability {dwarf nova eruptions}. We will thus find the CV population in M15, if it exists. In addition, our survey will detect numerous blue stragglers and hot white dwarfs, as well as any other blue objects near the core. Finally, our photometry will yield high-quality FUV light curves of the two low-mass x-ray binaries in M15. 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/WFPC2 10384 Focus Monitor The focus of HST is measured from WFPC2/PC and ACS/HRC images of stars. Multiple exposures are taken in parallel over an orbit to determine the influence of breathing on the derived mean focus. Observations are taken of clusters with suitable orientations to ensure stars appear in all fields. ACS/WFC 10334 i-Band Dropouts around High-z Radio Quasars We will carry out deep F606W/F814W or F775W/F850LP imaging of three high-redshift radio quasars to search for an excess of dropouts. Also see program 9291 and 9777. ACS/WFC 9788 A Narrow-band Snapshot Survey of Nearby Galaxies We propose to use ACS/WFC to conduct the first comprehensive HST narrow-band {H- alpha + [N II]} imaging survey of the central regions of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will cover, at high angular resolution extending over a large field, an unprecedented number of galaxies representing many different environments. It will have important applications for many astrophysical problems of current interest, and it will be an invaluable addition to the HST legacy. The observations will be conducted in snapshot mode, drawing targets from a complete sample of 145 galaxies selected from the Palomar spectroscopic survey of nearby galaxies. Our group will use the data for two primary applications. First, we will search for nuclear emission-line disks suitable for future kinematic measurements with STIS, in order to better constrain the recently discovered relations between black hole mass and bulge properties. Preliminary imaging of the type proposed here must be done, sooner or later, if we are to make progress in this exciting new field. Second, we will investigate a number of issues related to extragalactic star formation. Specifically, we will systematically characterize the properties of H II regions and super star clusters on all galactic scales, from circumnuclear regions to the large-scale disk. ACS/WFC/NIC2 10189 PANS-Probing Acceleration Now with Supernovae Type Ia supernovae {SNe Ia} provide the most direct evidence for an accelerating Universe, a result widely attributed to dark energy. Using HST in Cycle 11 we extended the Hubble diagram with 6 of the 7 highest-redshift SNe Ia known, all at z1.25, providing conclusive evidence of an earlier epoch of cosmic deceleration. The full sample of 16 new SNe Ia match the cosmic concordance model and are inconsistent with a simple model of evolution or dust as alternatives to dark energy. Understanding dark energy may be the biggest current challenge to cosmology and particle physics. To understand the nature of dark energy, we seek to measure its two most fundamental properties: its evolution {i.e., dw/dz}, and its recent equation of state {i.e., w{z=0}}. SNe Ia at z1, beyond the reach of the ground but squarely within the reach of HST with ACS, are crucial to break the degeneracy in the measurements of these two basic aspects of dark energy. The SNe Ia we have discovered and measured with HST in Cycle 11, now double the precision of our knowledge of both properties. Here we propose to quadruple the sample of SNe Ia at z1 in the next two cycles, complementing on-going surveys from the ground at z1, and again doubling the precision of dark energy constraints. Should the current best fit model prove to be the correct one, the precision expected from the current proposal will suffice to rule out a cosmological constant at the 99% confidence level. Whatever the result, these objects will provide the basis with which to extend our empirical knowledge of this newly discovered and dominant component of the Universe, and will remain one of the most significant legacies of HST. In addition, our survey and follow-up data will greatly enhance the value of the archival data within the target Treasury fields for galaxy studies. ACS/WFC/WFPC2 10138 Searching for the Bottom of the Initial Mass Function The minimum mass of the Initial Mass Function {IMF} should be a direct reflection of the physical processes that dominate in the formation of stars and brown dwarfs. To date, the IMF has been measured down to 10 M_Jup in a few young clusters; there is no sign of a low-mass cutoff in the data for these clusters. We propose to obtain deep images in the SDSS i and z filters {i=26, z=25} with the ACS/WFC on HST for a 800"x1000" field in the Chamaeleon I star-forming region {2 Myr, 160 pc}. By combining these HST data {0.8, 0.9 um} with comparably deep broad-band photometry from ground-based telescopes {1.2, 1.6, 2.2 um} and SIRTF {3.6, 4.5, 5.8, 8.0 um}, we will measure the mass function of brown dwarfs down to the mass of Jupiter and thus determine the lowest mass at which objects can form in isolation in a typical star forming cluster. FGS 10106 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. When these parallaxes {with 1-sigma precisions of 10% or better} are added to our recent HST FGS parallax determination of delta Cep {Benedict et al 2002}, we anticipate determining the Period-Luminosity relation zero point with a 0.03 mag precision. In addition to permitting the test of assumptions that enter into other Cepheid distance determination techniques, this calibration will reintroduce Galactic Cepheids as a fundamental step in the extragalactic distance scale ladder. A Period-Luminosity relation derived from solar metallicity Cepheids can be applied directly to extragalactic solar metallicity Cepheids, removing the need to bridge with the Large Magellanic Cloud and its associated metallicity complications. FGS 10432 Precise Distances to Nearby Planetary Nebulae We propose to carry out astrometry with the FGS to obtain accurate and precise distances to four nearby planetary nebulae. In 1992, Cahn et al. noted that ``The distances to Galactic planetary nebulae remain a serious, if not THE most serious, problem in the field, despite decades of study.'' Twelve years later, the same statement still applies. Because the distances to planetary nebulae are so uncertain, our understanding of their masses, luminosities, scale height, birth rate, and evolutionary state is severely limited. To help remedy this problem, HST astrometry can guarantee parallaxes with half the error of any other available approach. These data, when combined with parallax measurements from the USNO, will improve distance measurements by more than a factor of two, producing more accurate distances with uncertainties that are of the order of ~6%. Lastly, most planetary nebula distance scales in the literature are statistical. They require several anchor points of known distance in order to calibrate their zero point. Our program will provide "gold standard" anchor points by the end of 2006, a decade before any anticipated results from future space astrometry missions. NIC1 10208 NICMOS Differential Imaging Search for Planetary Mass Companions to Nearby Young Brown Dwarfs We propose to use the differential spectral imaging capability of HST/NICMOS {NIC1} to search for planetary mass companions. We target the twelve most nearby {within 30 pc}, isolated {no known close companion}, and young { 1Gyr} brown dwarfs. All of them have spectral type L and show signs of Lithium absorption, which clearly proves their substellar nature and youth. Planetary mass companions with masses down to 6 Jupiter masses, and at separations larger than 3 A.U. are bright enough for a direct detection with HST/NICMOS using the spectral differential imaging technique in two narrow-band filters placed on and off molecular bands. The proposed project has the potential to lead to the first direct detection of a planetary mass object in orbit around a nearby brown dwarf. 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. NIC1/Spacecraft 10382 NICMOS Focus Stability The purpose of this activity is to determine the best focus. This program will execute in one month intervals starting about 1 month after the last execution of proposal 9994 {the previous focus monitoring program}. The program starts with a focus sweep using only the NIC1 camera {visit 11}. The following observation is with the NIC2 camera {visit 12} after about 45 days. This pattern is repeated throughout the period except for Feb 15 where also the NIC3 camera is used. In total this will result in 9 orbits. Notice that VISIT #1 #2 refers to visits for #1 sequential visit number for a given camera #2 camera in question visit 32 is therefore the third visit for camera 2. NIC3 9824 NIC3 SNAPs of nearby galaxies imaged in the mid-UV: the remarkable cool stellar population in late-type galaxies. We propose a NIC3 H-band {F160W} SNAPshot survey of 48 nearby mid- to late-type galaxies covering all inclinations. In Cycle 9 and 10, we imaged ~100 galaxies in the mid- UV {F300W/F255W} and I-band {F814W} with WFPC2, and obtained UBVR CCD surface photometry from the ground. Early-mid-type galaxies show the usual small radial color- gradients, where disks become somewhat bluer at larger radii. But, remarkably, the majority of {lower luminosity, smaller and rounder} late-type galaxies shows the opposite trend and becomes redder outwards in all filters. While young UV/blue-bright stellar populations dominate their inner morphology, most late-type galaxies must have a significant halo or thick disk of older stars. Combining our proposed NIC3 H-band with existing WFPC2 images will span the wavelength range 0.29-1.6 micron at resolutions of 0.04-0.16" {FWHM}. This Panchromatic Nearby Galaxy Atlas will be applicable to a wide range of problems, and will be made public immediately. Our NIC3/F160W science goals are to: {1} Establish the nature of the old outer stellar population. All target galaxies have z0.005, allowing us to resolve any luminous, cool supergiant population. NIC3 is essential to make a pixel-to-pixel color-magnitude study of the nature, distribution and uniformity of the outer stellar populations, which will constrain dwarf galaxy formation theories. {2} Determine galaxy structure at 5-20 pc resolution, tracing the old stellar population and mass distribution compared to the star-forming regions seen in the mid- UV. A range of inclinations is needed to distinguish between old thick disks or halos in late-type galaxies. {3} Make a multi-wavelength pixel-to-pixel decomposition to help delineate the effects of dust, age, and metallicity. Since we must cover a range of inclinations, NIC3 H-band is essential to map the effects from dust, and see how these may affect the studies of {1} and {2}. S/C 10440 2-Gyro T2G On-Orbit Test: FHST Activities This proposal contains the FHST activities that will be scheduled during the on-orbit test. Activities include FHST shutter opens and closes, FHST Availability on and off, On- Board Attitude Determination {OBAD or OAD} without the following attitude correction. All these visits will be scheduled as parallels on top of the pointed visits in proposal 10439. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: 17308-1 Off-line the +DD, +C, and +B Post TGS Test @ 322/1729z 17315-1 V2 FGS Attitude Error Threshold Change @ 322/2303z OPS NOTES EXECUTED: 1289-0 HST486 Full RAM Memory Dump @ 323/0100z SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 08 08 FGS Reacq 06 06 FHST Update 18 18 LOSS of LOCK SIGNIFICANT EVENTS: Successfully off-lined +DD (Battery 1, 4-string SPA), +C (Battery 2, 4-string SPA), and +B (Battery 4, 4-string SPA) @ 322/17:29Z (OR 17308-1 with attached IP-073 script). For the first orbit following the reconfiguration, TRSWCC reached Trickle Charge in 45 minutes and 42 minutes for the second orbit. Successfully changed the V2 FGS 44 command attitude error threshold from 0.5 to 0.3 arcsec @ 322/23:03Z (OR 17315). The first GS acquisition following the change occurred @ 322/23:50Z. There was no real-time telemetry during the acquisition, but telemetry returned @ 323/00:10Z revealed the acquisition was nominal. |
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