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Daily Report #4523
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 4523 PERIOD COVERED: UT January 009, 2008 (DOY 009) OBSERVATIONS SCHEDULED 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 DARKs. 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 11219 Active Galactic Nuclei in nearby galaxies: a new view of the origin of the radio-loud radio-quiet dichotomy? Using archival HST and Chandra observations of 34 nearby early-type galaxies {drawn from a complete radio selected sample} we have found evidence that the radio-loud/radio-quiet dichotomy is directly connected to the structure of the inner regions of their host galaxies in the following sense: [1] Radio-loud AGN are associated with galaxies with shallow cores in their light profiles [2] Radio-quiet AGN are only hosted by galaxies with steep cusps. Since the brightness profile is determined by the galaxy's evolution, through its merger history, our results suggest that the same process sets the AGN flavour. This provides us with a novel tool to explore the co-evolution of galaxies and supermassive black holes, and it opens a new path to understand the origin of the radio-loud/radio-quiet AGN dichotomy. Currently our analysis is statistically incomplete as the brightness profile is not available for 82 of the 116 targets. Most galaxies were not observed with HST, while in some cases the study is obstructed by the presence of dust features. We here propose to perform an infrared NICMOS snapshot survey of these 82 galaxies. This will enable us to i} test the reality of the dichotomic behaviour in a substantially larger sample; ii} extend the comparison between radio-loud and radio-quiet AGN to a larger range of luminosities. NIC3 10874 Search for Extremely Faint z7 Galaxy Population with Cosmic Lenses Deep UDF/NICMOS observations find a significant decrease in the number of galaxy candidates between redshift z=6 and 7, but the sample at z7 is too small to draw conclusions. From our observations of 15 clusters we have found a number of bright z-dropouts, aided by the lensing amplification. We propose deep NICMOS observations of the best cases of cluster centers where a rare combination of a significant lensing effect and the richness in z-band dropouts in background may dramatically increase the discovery rate. The NICMOS images will reach an unprecedented depth of AB~27.8, or AB~30 in nonlensed intrinsic magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a level that the UDF reaches for z~6 objects. We produce precision mass distribution maps from weak-lensing models, which enable us to derive the candidates' intrinsic magnitudes and their luminosity function. The knowledge of such faint galaxy population at z7 will facilitate the models of the IGM reionization and future JWST planning. WFPC2 11104 The nature of radio transients We have conducted the first ever blind, wide-field survey for radio transients (Levinson et al. 2002; Gal-Yam et al. 2006). We have discovered four radio transients and explored their nature using radio and optical follow-up observations. One is a known pulsar, one is a z~0.1 AGN, and one is most probably an optically obscured radio supernova (SN) in the nearby galaxy NGC 4216 (the first such event to be discovered by a wide field radio survey). The last source appears not to be associated with a bright host galaxy (to a limit of R 24.5 mag). We request 4 orbits of WFPC2 F606W imaging to check whether we can establish an association between this radio transient and any of three nearby faint resolved galaxies we have detected from the ground. If the source is associated with any of these galaxies it would represent a new type of extra-galactic radio bursts, more luminous than, e.g., radio afterglows of gamma-ray bursts. Alternatively, ruling out an association with these galaxies would disfavor an extra-galactic nature of this object, and suggest instead that this is a radio outburst of a faint Galactic compact object, probably a new type of radio-flaring neutron star. If this is the case, the high luminosity (9 mJy) and relatively high galactic latitude (33 degrees) of this source may indicate it is relatively nearby. This single source represents a large population (comparable in sky density to AGN, pulsars, and radio SNe) and thus merits intensive study. A modest investment of HST time, leveraged by massive ground-based radio and optical efforts, will allow us to identify a new class of radio sources, and complete a census of the variable radio sky down to ~6 mJy, leaving no unidentified objects. This result can be directly scaled to predict the number and type of transient sources expected to be detected by future surveys with the next generation radio arrays, such as ATA and SKA. Since our science critically requires HST's spatial resolution (rather than sensitivity) it is perfectly suited to be carried out with WFPC2. WFPC2 11217 The Light Echoes around V838 Monocerotis V838 Monocerotis, which burst upon the astronomical scene in early 2002, is a completely unanticipated new object. It underwent a large-amplitude and very luminous outburst, during which its spectrum remained that of an extremely cool supergiant. A rapidly evolving set of light echoes around V838 Mon was discovered soon after the outburst, and quickly became the most spectacular display of the phenomenon ever seen. These light echoes provide the means to accomplish three unique types of measurements based on continued HST imaging during the event: {1} Study effects of MHD turbulence at high resolution and in 3 dimensions; {2} Construct the first unambiguous and fully 3-D map of a circumstellar dust envelope in the Milky Way; {3} Study dust physics in a unique setting where the spectrum and light curve of the illumination, and the scattering angle, are unambiguously known. We have also used our HST data to determine the distance to V838 Mon through direct geometric techniques. Because of the extreme rarity of light echoes, this is almost certainly the only opportunity to achieve such results during the lifetime of HST. We propose two visits during Cycle 16, in order to continue the mapping of the circumstellar dust and to accomplish the other goals listed above. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: (None) COMPLETED OPS REQUEST: 18169-0 Add G1 UKF Input Configuration COMPLETED OPS NOTES: (None) SCHEDULED SUCCESSFUL FGS GSacq 05 05 FGS REacq 08 08 OBAD with Maneuver 26 26 SIGNIFICANT EVENTS: Ops Request 18169-0 execution succeeded at 2008/009 14:11:43. The Kalman filter was disabled, gyro 1 input was enabled, and the UKF was re-initialized. UKF performance was nominal following re-initialization; peak attitude estimate errors of about 3 degrees RSS occurred after initialization and steady-state performance exhibited less than 1 degree error. This UKF re-configuration establishes the OGS OOT input configuration for pre-test performance monitoring. |
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