NASA Hubble Space Telescope Daily Report #5075
HUBBLE SPACE TELESCOPE DAILY REPORT #5075
Continuing to Collect World Class Science
PERIOD COVERED: 5am April 14 – 5am April 15, 2010 (DOY 104/09:00z-105/09:00z)
OBSERVATIONS SCHEDULED
ACS/WFC 11995
CCD Daily Monitor (Part 2)
This program comprises basic tests for measuring the read noise and dark current of the ACS WFC and for tracking the growth of hot pixels. The recorded frames are used to create bias and dark reference images for science data reduction and calibration. This program will be executed four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To facilitate scheduling, this program is split into three proposals. This proposal covers 320 orbits (20 weeks) from 1 February 2010 to 20 June 2010.
ACS/WFC/WFC3/IR 11802
WFC3/IR Observations of Strongly Lensing Clusters
We propose WFC3/IR observations of the massive lensing clusters Abell 1689 and Abell 1703 to constrain the properties of both cluster and background field galaxies. The dataset will also help constrain the photometric redshift of A1689-zD1, the bright galaxy candidate at z~7.6.
NIC2/WFC3/IR 11548
Infrared Imaging of Protostars in the Orion A Cloud: The Role of Environment in Star Formation
We propose NICMOS and WFC3/IR observations of a sample of 252 protostars identified in the Orion A cloud with the Spitzer Space Telescope. These observations will image the scattered light escaping the protostellar envelopes, providing information on the shapes of outflow cavities, the inclinations of the protostars, and the overall morphologies of the envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron spectra of 75 of the protostars. Combining these new data with existing 3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured with the Spitzer Space Telescope, we will determine the physical properties of the protostars such as envelope density, luminosity, infall rate, and outflow cavity opening angle. By examining how these properties vary with stellar density (i.e. clusters vs. groups vs. isolation) and the properties of the surrounding molecular cloud; we can directly measure how the surrounding environment influences protostellar evolution, and consequently, the formation of stars and planetary systems. Ultimately, this data will guide the development of a theory of protostellar evolution.
STIS/CC 11845
CCD Dark Monitor Part 2
Monitor the darks for the STIS CCD.
STIS/CC 11847
CCD Bias Monitor-Part 2
Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns.
STIS/CCD/MA2 11568
A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations of Stars with Archived FUV Observations
We propose to obtain high-resolution STIS E230H SNAP observations of MgII and FeII interstellar absorption lines toward stars within 100 parsecs that already have moderate or high-resolution far-UV (FUV), 900-1700 A, observations available in the MAST Archive. Fundamental properties, such as temperature, turbulence, ionization, abundances, and depletions of gas in the local interstellar medium (LISM) can be measured by coupling such observations. Due to the wide spectral range of STIS, observations to study nearby stars also contain important data about the LISM embedded within their spectra. However, unlocking this information from the intrinsically broad and often saturated FUV absorption lines of low-mass ions, (DI, CII, NI, OI), requires first understanding the kinematic structure of the gas along the line of sight. This can be achieved with high resolution spectra of high-mass ions, (FeII, MgII), which have narrow absorption lines, and can resolve each individual velocity component (interstellar cloud). By obtaining short (~10 minute) E230H observations of FeII and MgII, for stars that already have moderate or high- resolution FUV spectra, we can increase the sample of LISM measurements, and thereby expand our knowledge of the physical properties of the gas in our galactic neighborhood. STIS is the only instrument capable of obtaining the required high resolution data now or in the foreseeable future.
WFC3/ACS/IR 11584
Resolving the Smallest Galaxies with ACS
An order of magnitude more dwarf galaxies are expected to inhabit the Local Group, based on currently accepted galaxy formation models, than have been observed. This discrepancy has been noted in environments ranging from the field to rich clusters, with evidence emerging that lower density regions contain fewer dwarfs per giant than higher density regions, in further contrast to model predictions. However, there is no complete census of the faintest dwarf galaxies in any environment. The discovery of the smallest and faintest dwarfs is hampered by the limitations in detecting such compact or low surface brightness galaxies, and this is compounded by the great difficulty in determining accurate distances to, or ascertaining group membership for, such faint objects. The M81 group provides a powerful means for establishing membership for faint galaxies in a low density region. With a distance modulus of 27.8, the tip of the red giant branch (TRGB) appears at I ~ 24, just within the reach of ground based surveys. We have completed a 65 square degree survey in the region around M81 with the CFHT/MegaCam. Half of our survey was completed before Cycle 16 and we were awarded time with WFPC2 to observe 15 new candidate dwarf galaxy group members in F606W and F814W bands in order to construct color-magnitude diagrams from which to measure accurate TRGB distances and determine star formation and metallicity histories. The data obtained show that 8 – 9 of these objects are galaxies at the same distance as M81. In completing our survey, we have discovered an additional 8 candidate galaxies we propose to image with ACS in order to measure TRGB distances and establish membership. We also wish to re-observe our smallest candidate group member and a tidal dwarf candidate with deeper observations made possible with ACS. Once membership has been established for this second set of candidates, we will have a complete census of the dwarf galaxy population in the M8 group to M_r ~ -10, allowing us to obtain a firm measurement of the luminosity function faint-end slope, and, combined with previous HST data, to provide a complete inventory of the age and abundance properties for the collapsed core of the M81 group.
WFC3/UVIS 11905
WFC3 UVIS CCD Daily Monitor
The behavior of the WFC3 UVIS CCD will be monitored daily with a set of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K subarray biases are acquired at less frequent intervals throughout the cycle to support subarray science observations. The internals from this proposal, along with those from the anneal procedure (Proposal 11909), will be used to generate the necessary superbias and superdark reference files for the calibration pipeline (CDBS).
WFC3/UVIS/IR 11662
Improving the Radius-Luminosity Relationship for Broad-Lined AGNs with a New Reverberation Sample
The radius-luminosity (R-L) relationship is currently the fundamental basis for all techniques used to estimate black hole masses in AGNs, in both the nearby and distant universe. However, the current R-L relationship is based on 34 objects that cover a limited range in black hole mass and luminosity. To improve our understanding of black hole growth and evolution, the R-L relationship must be extended to cover a broader range of black hole masses using the technique known as reverberation mapping. To this end, we have been awarded an unprecedented 64 nights on the Lick Observatory 3-m telescope between March 24 and May 31, 2008, to spectroscopically monitor 12 AGNs in order to measure their black hole masses. To properly determine the luminosities of these 12 AGNs, we must correct them for their host-galaxy starlight contributions using high-resolution images. Previous work by Bentz et al. (2006) has shown that the starlight correction to AGN luminosity measurements is an essential component to interpreting the R-L relationship. The correction will be substantial for each of the 12 sources we will monitor, as the AGNs are relatively faint and embedded in nearby, bright galaxies. Starlight corrections are not possible with ground-based images, as the PSF and bulge contributions become indistinguishable under typical seeing conditions, and adaptive optics are not yet operational in the spectral range where the corrections are needed. In addition, spectral decompositions are very model-dependent and are limited by the degree of accuracy to which we understand emission processes and stellar populations in galaxies. Without correcting for starlight, we will be unable to apply the results of our Spring 2008 campaign to the body of knowledge from previous reverberation mapping work. Therefore, we propose to obtain high resolution, high dynamic range images of the host galaxies of the 12 AGNs in our ground-based monitoring sample, as well as one white dwarf which will be used as a PSF model.
STIS/CCD 11849
STIS CCD Hot Pixel Annealing
This purpose of this activity is to repair radiation induced hot pixel damage to the STIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation damaged pixels. Radiation damage creates hot pixels in the STIS CCD Detector. Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near -83 C to the ambient instrument temperature (~ +5 C) for several hours. The number of hot pixels repaired is a function of annealing temperature. The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
12247 – STIS CCD Dark Image Shifted One Column to the Left
The STIS Science Team has reported the one dark science image taken on 2010/003/13:37:00.000 for Proposal 11849 – STIS CCD Hot Pixel Annealing.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 12 12
FGS REAcq 8 8
OBAD with Maneuver 6 6
SIGNIFICANT EVENTS: (None)
