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Daily 3806
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3806 PERIOD COVERED: DOY 59 OBSERVATIONS SCHEDULED ACS/HRC 10255 A Never Before Explored Phase Space: Resolving Close White Dwarf / Red Dwarf Binaries We propose an ACS Snapshot imaging survey to resolve a well-defined sample of highly probable white dwarf plus red dwarf close binaries. These candidates were selected from a search for white dwarfs with infrared excess from the 2MASS database. They represent unresolved systems {separations less than approximately 2" in the 2MASS images} and are distributed over the whole sky. Our HST+ACS observations will be sensitive to a separation range {1-20 AU} never before probed by any means. The proposed study will be the first empirical test of binary star parameters in the post-AGB phase, and cannot be accomplished from the ground. By resolving as few as 20 of our ~100 targets with HST, we will be able to characterize the distribution of orbital semi- major axes and secondary star masses. ACS/HRC 10375 Stability of the ACS CCD: Flat fielding, Photometry, Geometry This program will verify that the low frequency flat fielding, the photometry, and the geometric distortion are stable in time and across the field of view of the CCD detectors. A moderately crowded stellar field, located ~6' West of the center of the cluster 47 Tuc, is observed every three months with the WFC and HRC using the full suite of broad and narrow band filters. The same field has been observed during SMOV to derive low frequency corrections to the ground flats and to create a master catalogue of positions and magnitudes from dithered observations of the cluster. In Cycles 11-12, this field was observed again using single pointings at various roll angles. The positions and magnitudes of objects are used to monitor local and large scale variations in the plate scale and the sensitivity of the detectors. The Cycle 13 program will continue to monitor these effects and will derive an independent measure of the detector CTE. 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 10401 A Proper Motion Search for Intermediate Mass Black Holes in Globular Clusters Establishing the presence or absence of intermediate-mass black holes {IMBH} in globular clusters is crucial for understanding the evolution of dense stellar systems. We propose a systematic search for IMBHs by conducting an imaging/proper motion study of the centers of five of the closest, most centrally concentrated Galactic globular clusters. ACS/HRC observations allow for accurate proper motion measurements for stars all the way into the center of each cluster. Our approach consists of exploiting the blue/near-ultraviolet wavelength range in each of cycles 13 and 14, in order to dim both the bright red giants and the background of faint red stars, hence alleviating the crowding problems experienced by previous studies. Both filter and target selection are critical for the success of this project, and no previous HST program has an appropriate combination to allow proper motion measurements for most stars into the very centers of crowded clusters. The velocity measurements will allow us to: {i} place constraints on the mass of a central black hole in each cluster {detailed calculations show that the proposed observations are sufficient to detect any central black hole with a mass as low as 3000 solar masses at the greater than 3 sigma level}; {ii} derive the internal velocity dispersion as a function of cluster radius; {iii} verify or reject previous reports of cluster rotation; and {iv} directly measure any velocity anisotropy as a function of radius. 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/WFC 10217 The ACS Fornax Cluster Survey The two rich clusters nearest to the Milky Way, and the only large collections of early- type galaxies within ~ 25 Mpc, are the Virgo and Fornax Clusters. We propose to exploit the exceptional imaging capabilities of the ACS/WFC to carry out the most comprehensive imaging survey to date of early-type galaxies in Fornax: the ACS Fornax Cluster Survey. Deep ACS/WFC images -- in the F475W {g'} and F850LP {z'} bands -- will be acquired for 44 E, S0, dE, dE, N and dS0 cluster members. In Cycle 11, we initiated a similar program targeting early-type galaxies in the Virgo Cluster {the ACS Virgo Cluster Survey; GO-9401}. Our proposed survey of Fornax would yield an extraordinary dataset which would complement that already in hand for Virgo, and allow a definitive study of the role played by environment in the structure, formation and evolution of early-type galaxies and their globular cluster systems, nuclei, stellar populations, dust content, nuclear morphologies and merger histories. It would also be a community resource for years to come and, together with the ACS Virgo Cluster Survey, constitute one of the lasting legacies of HST. ACS/WFC 10374 ACS photometric Stability This program consists of three parts. In the first part we will observe a subset of the ACS white dwarfs with HRC and ACS to verify repeatability to ~0.2%, because the filter shifts are based on photometric differences between stars of ~1%. These observations are also required to establish relative magnitudes of the primary WD standards at the 0.1% level. Targets should be GD153 and G191B2B, which seems to have the largest V mag error of ~0.008 mag. One orbit on the most important filters, including the grism and the prisms, should be expended with each camera for both stars for a total of 4 orbits. In the second part will observe with HRC and WFC a solar analog star, P330E, to estimate any shifts in the short and the long wavelength cutoffs of selected filters. Complete filter bandpasses can be derived directly from the ratio of grism observations with and without the filter in place. The grism is on filter wheel 1, while four filters of interest F330W, F344N, F660N, and F814W are on wheel 2. Each grism observation requires 3 settings: filter alone, filter+grism, and grism alone. In the third part we obtain high S/N photometric and spectroscopic observations of three red stars, VB-8 {M7}, 2M0038+18 {L3.5} and 2M0559-14 {T5} with HRC and WFC to verify the photometry at the new standard position and to obtain accurate calibration {1% or better} of the grism spectra. 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. NIC3 10385 Spectrophotometry of Solar Analog Stars and Nicmos Grism Calibration NICMOS IR Standards {4 orbits} In cycle 12, 24 orbits were used to measure the NICMOS grism mode sensitivities and to establish a set of IR flux standards with a goal of 1% accuracy. However, the G096 setting shows up to 5% peak-to-peak range among the sensitivities derived from the three primary WD standards, as shown in Figure 1 {for the Phase 1 proposal}. The possible causes of this large scatter include changes in the flat field, a systematic change of sensitivity with time, and a fundamental limitation of the repeatability for stars at the WD flux levels. The same residuals for STIS in the 0.8- 1.0 micron overlap range are 1%, so that the problem is not with the fluxes for the three primary standard stars. Either there is a systematic trend in the Nicmos grism data that can be removed with more monitoring; or alternatively, repeating the cycle 12 observations should reduce the error in the mean sensitivity by sqrt{2}, if the deviations among the stars are random instrumental fluctuations. The NICMOS cycle 13 calibration program includes 2 orbits to repeat the observations of the bright standard BD+17d4708, which has a very high S/N, so that any change in its response should reflect an instrumental sensitivity difference between cycle 12 and 13. The four Nicmos orbits in this program include one each for GD71 and GD153 in G096 and G141, while two orbits are required for the repeat of G191B2B, where the G206 mode is also included. NIC3/WFPC2 10403 Ultraviolet Imaging of the UDF The Hubble Deep Field North has uninterrupted observations at wavelengths from Far- UV through NICMOS H-band, but the UDF goes no bluer than B-band. We propose to complete the UDF coverage with deep ultraviolet imaging of the Ultra-Deep Field {UDF} with the ACS-SBC in the Far-UV {1500 Angstrom} and WFPC2 in the Near-UV {F300W}. We will reach point source limits of ABmag=28.5, a factor of ten fainter than the GALEX ultradeep surveys. Our dataset will add to the value of the UDF legacy, and requires the unique capabilities of HST. In the spirit of the UDF, we submit this proposal in the Treasury category. We request a modest allocation of observing time for a Treasury program: 62 orbits. We will provide science quality images and photometric catalogs to enable a range of research topics by the community. The science goals of the team are to investigate the episode of strong star formation activity in galaxies out to z=1, through the rest-frame FUV luminosity function and the internal color structure of galaxies. Far-UV number counts suggest that moderate redshift {z~0.5} starbursts are undergoing a single, rapid burst of star-formation. We will investigate this result by measuring the faint-end slope, alpha, of the luminosity function. We will measure the star formation properties of moderate redshift starburst galaxies and compare their morphologies in the UV, optical, and near-IR. This catalog of starbursts will also be important to the astronomical community in correlating unobscured star-formation with the sources detected in the Spitzer Space Telescope legacy observations of the field. With the high spatial resolution data, will set strict limits on the flux escaping in intermediate redshift {1z2} galaxies at wavelengths below the rest-frame Lyman limit, and thus infer the contribution of star forming galaxies at z~5 to the metagalactic ionizing radiation. 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. WFPC2 10363 WFPC2 CYCLE 13 Intflat and Visflat Sweeps and Filter Rotation Anomaly Monitor Using intflat observations, this WFPC2 proposal is designed to monitor the pixel-to-pixel flatfield response and provide a linearity check. The intflat sequences, to be done once during the year, are similar to those from the Cycle 12 program 10075. The images will provide a backup database in the event of complete failure of the visflat lamp as well as allow monitoring of the gain ratios. The sweep is a complete set of internal flats, cycling through both shutter blades and both gains. The linearity test consists of a series of intflats in F555W, in each gain and each shutter. As in Cycle 12, we plan to continue to take extra visflat, intflat, and earthflat exposures to test the repeatability of filter wheel motions. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9727: U2,3RD Roll Delay Update Failed on FHST 2 @59/12:18z - FHST Roll Delay Update U2,3RD scheduled at 059/12:17:18 failed with error box results indicating "2 failed" for mnemonics QEBSTFG0, QEBSTFG1, QEBSTFG2. 486 status buffer message 901 was received at 12:18:13. Under investigation. COMPLETED OPS REQs: None OPS NOTES EXECUTED: 1308-0 Adjust Recharge Ratio Limits for HIGHSUN/ORBIT Time @060/0001z (Closed) SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 10 10 FGS Reacq 05 05 FHST Update 13 12 59/1218z (HSTAR 9727) LOSS of LOCK SIGNIFICANT EVENTS: None |
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