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Daily Report #4650
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT #4650 PERIOD COVERED: 5am July 10 - 5am July 11, 2008 (DOY192/0900z-193/0900z) OBSERVATIONS SCHEDULED ACS/SBC 11151 Evaluating the Role of Photoevaporation of Protoplanetary Disk Dispersal Emission produced by accretion onto the central star leads to photoevaporation, which may play a fundamental role in disk dispersal. Models of disk photoevaporation by the central star are challenged by two potential problems: the emission produced by accretion will be substantially weaker for low-mass stars, and photoevaporation must continue as accretion slows. Existing FUV spectra of CTTSs are biased to solar-mass stars with high accretion rates, and are therefore insufficient to address these problems. We propose use HST/ACS SBC PR130L to obtain FUV spectra of WTTSs and of CTTSs at low masses and mass accretion rates to provide crucial data to evaluate photoevaporation models. We will estimate the FUV and EUV luminosities of low-mass CTTSs with small mass accretion rates, CTTSs with transition disks and slowed accretion, and of magnetically-active WTTSs. FGS 11212 Filling the Period Gap for Massive Binaries The current census of binaries among the massive O-type stars is seriously incomplete for systems in the period range from years to millennia because the radial velocity variations are too small and the angular separations too close for easy detection. Here we propose to discover binaries in this observational gap through a Faint Guidance Sensor SNAP survey of relatively bright targets listed in the Galactic O Star Catalog. Our primary goal is to determine the binary frequency among those in the cluster/association, field, and runaway groups. The results will help us assess the role of binaries in massive star formation and in the processes that lead to the ejection of massive stars from their natal clusters. The program will also lead to the identification of new, close binaries that will be targets of long term spectroscopic and high angular resolution observations to determine their masses and distances. The results will also be important for the interpretation of the spectra of suspected and newly identified binary and multiple systems. FGS 11214 HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic Beta Pic and AU Mic are two nearby Vega-type debris disk stars. Both of these disk systems have been spatially resolved in exquisite detail, predominantly via the ACS coronagraph and WFPC-2 cameras onboard HST. These images exhibit a wealth of morphological features which provide compelling indirect evidence that these systems likely harbor short-period planetary body{ies}. We propose to use the superlative astrometric capabilities of HST/FGS to directly detect these planets, hence provide the first direct planet detection in a Vega-type system whose disk has been imaged at high spatial resolution. NIC1/NIC2/NIC3 11318 NICMOS Cycle 16 Multiaccum Darks The purpose of this proposal is to monitor the dark current, read noise, and shading profile for all three NICMOS detectors throughout the duration of Cycle 16. This proposal is a slightly modified version of proposal 10380 of cycle 13 and 9993 of cycle12 and is the same as Cycle 15. Covers the period from April 08 to November 08 (inclusive) NIC1/NIC2/NIC3 11330 NICMOS Cycle 16 Extended Dark This takes a series of Darks in parallel to other instruments. NIC1/NIC2/NIC3 8795 NICMOS Post-SAA Calibration - CR Persistence Part 6 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 i mages. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors. NIC2 11799 NICMOS Non-linearity Calibration for Faint Objects NICMOS has played a key role in probing the deep near infrared regime for a decade. It has been the only instrument available to observe objects in the near infrared that are not visible from the ground. In particular, it has played a major role in the SN Ia observations at redshifts z1. However, the calibration of NICMOS has turned out to be difficult due to the apparent non-linearity of the detectors. The NICMOS calibration team has described the non-linearity as a power law based on data in the range of ~50-5000 ADU/s. The correction relies on an extrapolation of two orders of magnitude in flux at count rates close to the sky level (0.1 ADU/s) where space observations are particularly prized - and where SN Ia observations are made. Precise measurements of faint objects require us to reduce the uncertainties from this extrapolation. Here we propose to derive the absolute calibration in the sky limited regime and to characterize the non-linearity over the entire dynamic range for the camera/filter combination: NIC2/F110W. WEPC2 11196 An Ultraviolet Survey of Luminous Infrared Galaxies in the Local Universe At luminosities above 10^11.4 L_sun, the space density of far-infrared selected galaxies exceeds that of optically selected galaxies. These Luminous Infrared Galaxies {LIRGs} are primarily interacting or merging disk galaxies undergoing starbursts and creating/fueling central AGN. We propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a sample of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy Sample {RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS imaging observations, to have significant numbers of bright {23 B 21 mag} star clusters in the central 30 arcsec. The HST UV data will be combined with previously obtained HST, Spitzer, and GALEX images to {i} calculate the ages of the clusters as function of merger stage, {ii} measure the amount of UV light in massive star clusters relative to diffuse regions of star formation, {iii} assess the feasibility of using the UV slope to predict the far-IR luminosity {and thus the star formation rate} both among and within IR-luminous galaxies, and {iv} provide a much needed catalog of rest- frame UV morphologies for comparison with rest-frame UV images of high-z LIRGs and Lyman Break Galaxies. These observations will achieve the resolution required to perform both detailed photometry of compact structures and spatial correlations between UV and redder wavelengths for a physical interpretation our IRX-Beta results. The HST UV data, combined with the HST ACS, Spitzer, Chandra, and GALEX observations of this sample, will result in the most comprehensive study of luminous starburst galaxies to date. WFPC2 11167 A Unique High Resolution Window to Two Strongly Lensed Lyman Break Galaxies On rare occasions, the otherwise very faint Lyman Break Galaxies {LBGs} are magnified by gravitational lensing to provide exceptional targets for detailed spectroscopic and imaging studies. We propose HST WFPC2 and NICMOS imaging of two strongly lensed Lyman Break Galaxies {LBGs} that were recently discovered by members of our team. These two LBGs -- the "8 O'Clock Arc" and the "SDSS J1206+5142 Arc" -- are currently the brightest known LBGs, roughly 3 times brighter than the former record-holder, MS1512-cB58 {a.k.a. "cB58"}. The z=2.73 "8 O'Clock Arc" extends ~10 arcsec in length and is magnified by a factor of 12. The z=2.00 "SDSS J1206+5142 Arc" also extends ~10 arcsec in length and is magnified by a factor of 30. Due to their brightness and magnification, these two strongly lensed LBGs offer an unprecedented opportunity for the very detailed investigation of two individual galaxies at high redshift. We are currently pursuing a vigorous ground-based campaign to obtain multi- wavelength {UV, optical, NIR, radio} observations of these two LBGs, but our campaign currently lacks a means of obtaining high-resolution optical/NIR imaging -- a lack that currently only HST can address. Our prime objective for this proposal is to obtain high resolution HST images of these two systems with two-orbit WFPC2 images in the BVI bands and two-orbit NICMOS/NIC2 images in the J and H bands. These data will allow us to construct detailed lensing models, probe the mass and light profiles of the lenses and their environments, and constrain the star formation histories and rest-frame UV/optical spectral energy distributions of the LBGs. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: #11384 REacq(1,2,2) failed to RGA control @ 193/02:33z. REacq(1,2,2) scheduled at 193/02:30:57z failed to RGA control at 02:33:51z. Stop flags QF1STOPF and QSTOP were received for FGS 1. There were no other flags or ESB messages. Observations affected: WFPC 101 -102 Proposal ID#11167, NIC 167 Proposal ID#11330. #11385 GSacq(1,2,1) failed due to search radius limit exceeded @193/06:56z. During LOS, GSacq(1,2,1) scheduled at 193/06:56:46z failed due to search radius limit exceeded on FGS 1. ESB message "a05" (FGS Coarse Tract failed - search Radius Limit exceeded) was received. Observations affected:* WFPC 103-105, Proposal ID #11142. COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) ******************************* SCHEDULED**** SUCCESSFUL FGS GSacq*********************** 5******************* 4 FGS REacq*********************** 7******************* 6 OBAD with Maneuver******** ***** 24***************** 24 SIGNIFICANT EVENTS: (None) |
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