NASA Hubble Space Telescope Daily Report #4455
Notice: Due to the conversion of some ACS WFC or HRC observations into WFPC2, or NICMOS observations after the loss of ACS CCD science capability in January, there may be an occasional discrepancy between a proposal’s listed (and correct) instrument usage and the abstract that follows it.
HUBBLE SPACE TELESCOPE DAILY REPORT #4455
– Continuing to collect World Class Science
DAILY REPORT # 4455
PERIOD COVERED: UT September 25, 2007 (DOY 268)
OBSERVATIONS SCHEDULED
NIC1 10889
The Nature of the Halos and Thick Disks of Spiral Galaxies
We propose to resolve the extra-planar stellar populations of the thick disks and halos of seven nearby, massive, edge-on galaxies using ACS, NICMOS, and WFPC2 in parallel. These observations will provide accurate star counts and color-magnitude diagrams 1.5 magnitudes below the tip of the Red Giant Branch sampled along the two principal axes and one intermediate axis of each galaxy. We will measure the metallicity distribution functions and stellar density profiles from star counts down to very low average surface brightnesses, equivalent to ~32 V-mag per square arcsec. These observations will provide the definitive HST study of extra-planar stellar populations of spiral galaxies. Our targets cover a range in galaxy mass, luminosity, and morphology and as function of these galaxy properties we will provide: – The first systematic study of the radial and isophotal shapes of the diffuse stellar halos of spiral galaxies – The most detailed comparative study to date of thick disk morphologies and stellar populations – A comprehensive analysis of halo and thick disk metallicity distributions as a function of galaxy type and position within the galaxy. – A sensitive search for tidal streams – The first opportunity to directly relate globular cluster systems to their field stellar population We will use these fossil records of the galaxy assembly process preserved in the old stellar populations to test halo and thick disk formation models within the hierarchical galaxy formation scheme. We will test LambdaCDM predictions on sub-galactic scales, where it is difficult to test using CMB and galaxy redshift surveys, and where it faces its most serious difficulties.
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=3Ddate/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.
NIC3 11082
NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured Universe
Deep near-infrared imaging provides the only avenue towards understanding a host of astrophysical problems, including: finding galaxies and AGN at z > 7, the evolution of the most massive galaxies, the triggering of star formation in dusty galaxies, and revealing properties of obscured AGN. As such, we propose to observe 60 selected areas of the GOODS North and South fields with NICMOS Camera 3 in the F160W band pointed at known massive M > 10^11 M_0 galaxies at z > 2 discovered through deep Spitzer imaging. The depth we will reach {26.5 AB at 5 sigma} in H_160 allows us to study the internal properties of these galaxies, including their sizes and morphologies, and to understand how scaling relations such as the Kormendy relationship evolved. Although NIC3 is out of focus and undersampled, it is currently our best opportunity to study these galaxies, while also sampling enough area to perform a general NIR survey 1/3 the size of an ACS GOODS field. These data will be a significant resource, invaluable for many other science goals, including discovering high redshift galaxies at z > 7, the evolution of galaxies onto the Hubble sequence, as well as examining obscured AGN and dusty star formation at z > 1.5. The GOODS fields are the natural location for HST to perform a deep NICMOS imaging program, as extensive data from space and ground based observatories such as Chandra, GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are currently available for these regions. Deep high-resolution near-infrared observations are the one missing ingredient to this survey, filling in an important gap to create the deepest, largest, and most uniform data set for studying the faint and distant universe. The importance of these images will increase with time as new facilities come on line, most notably WFC3 and ALMA, and for the planning of future JWST observations.
WFPC2 10900
Optical polarimetry of PSR B0540-69 and its synchrotron nebula.
Polarization measurements of pulsars and of their synchrotron nebulae are uniquely able to provide deep insights into the highly magnetized relativistic environment of young rotating neutron stars. Apart from the radio band, pulsar polarization is best measured in the optical, for the rare cases of detectable optical emission. One of the brightest pulsars together with Crab {PSR B0531+21} and Vela {PSR B0833-45}, for which optical polarization measurements support the newly developed two-pole caustic model {TPC}, is PSR B0540-69 in the Large Magellanic Clouds, often referred as the Crab Twin for their overall similarities in both age and energetics. Together with the Crab, PSR B0540-69 is also the only pulsar embedded in a synchrotron nebula visible at optical wavelengths. We plan to observe PSR B0540-69 and its compact nebula {4 arcsec diameter} with the Advanced Camera for Surveys {ACS} and the Wide Field Channel {WFC} detector using UV and visual polarization filters. Thanks to the superb angular resolution of ACS, these observations will allow us to spectacularly resolve the pulsar from its nebular background, providing the first firm measure of the pulsar polarization which will be crucial to assess, on a broader sample, the validity of the TPC model with respect to other pulsars magnetosphere models. These observations will also provide the first detailed polarization map of the nebula, including the jet and the torus seen in our previous WFPC2 images.
WFPC2 11033
Full Moon Earth Flats Closeout
Flat field exposures will be obtained by observing the moonlit Earth with the broadband WFPC2 filters F606W and F814W, which saturate in the minimum exposure time on the sunlit Earth. These observations will be used to improve the flats currently in the pipeline and are part of the WFPC2 closeout operations. Because CTE effects are large for star flats and small for full field illumination, Earth flats are the superior technique.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
11004 – GSACQ(1,3,3) fine lock backup on FGS 1 GSACQ(1,3,3) at 269/04:44:27 acquired in fine lock backup on FGS 1 only, with QF3STOPF and QSTOP flags set on FGS 3 at 04:50:02. No other flags were seen.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSacq 05 05
FGS REacq 09 09
OBAD with Maneuver 28 28
SIGNIFICANT EVENTS: (None)
