NASA Hubble Space Telescope Daily Report #5057
HUBBLE SPACE TELESCOPE DAILY REPORT #5057
PERIOD COVERED: 5am March 19 – 5am March 22, 2010 (DOY 078/09:00z-081/09:00z)
OBSERVATIONS SCHEDULED
COS/NUV/FUV 12096
COS FUV Detector Lifetime Adjustment and Sensitivity Test
This program will test the COS FUV Detector sensitivity at several ‘lifetime adjustment’ (cross-dispersion) positions. By collecting identical spectra at different positions on the detector, including some relatively pristine regions, it will be possible to determine if the time dependent-sensitivity changes seen since SM4 are due to illumination, and thus limited to the areas that have collected the most counts.
In addition, the gain and flat field properties of the detector at the additional lifetime positions will be measured, so that if a permanent lifetime adjustment is found to be necessary, the best location can be identified.
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.
WFC3/IR/S/C 11929
IR Dark Current Monitor
Analyses of ground test data showed that dark current signals are more reliably removed from science data using darks taken with the same exposure sequences as the science data, than with a single dark current image scaled by desired exposure time. Therefore, dark current images must be collected using all sample sequences that will be used in science observations. These observations will be used to monitor changes in the dark current of the WFC3-IR channel on a day-to-day basis, and to build calibration dark current ramps for each of the sample sequences to be used by Gos in Cycle 17. For each sample sequence/array size combination, a median ramp will be created and delivered to the calibration database system (CDBS).
WFC3/IR 11928
WFC3/IR Low-Frequency Flat and Geometric Distortion
Multiple observations of globular cluster Omega Cen at multiple infrared wavelengths of IR detector will be used to derive filter dependency of low-frequency sensitivity (L_flat fields) across of IR detector and its time variation. Additionally, the same data will be also used to derive filter-dependant geometric distortion of the detector and its time-dependency.
WFC3/UVIS 11912
UVIS Internal Flats
This proposal will be used to assess the stability of the flat field structure for the UVIS detector throughout the 15 months of Cycle 17. The data will be used to generate on-orbit updates for the delta-flat field reference files used in the WFC3 calibration pipeline, if significant changes in the flat structure are seen.
WFC3/UVIS 11908
Cycle 17: UVIS Bowtie Monitor
Ground testing revealed an intermittent hysteresis type effect in the UVIS detector (both CCDs) at the level of ~1%, lasting hours to days. Initially found via an unexpected bowtie-shaped feature in flatfield ratios, subsequent lab tests on similar e2v devices have since shown that it is also present as simply an overall offset across the entire CCD, i.e., a QE offset without any discernable pattern. These lab tests have further revealed that overexposing the detector to count levels several times full well fills the traps and effectively neutralizes the bowtie. Each visit in this proposal acquires a set of three 3×3 binned internal flatfields: the first unsaturated image will be used to detect any bowtie, the second, highly exposed image will neutralize the bowtie if it is present, and the final image will allow for verification that the bowtie is gone.
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).
COS/FUV 11895
FUV Detector Dark Monitor
The purpose of this proposal is to monitor the FUV detector dark rate by taking long science exposures without illuminating the detector. The detector dark rate and spatial distribution of counts will be compared to pre-launch and SMOV data in order to verify the nominal operation of the detector. Variations of count rate as a function of orbital position will be analyzed to find dependence of dark rate on proximity to the SAA. Dependence of dark rate as function of time will also be tracked.
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/CC 11845
CCD Dark Monitor Part 2
Monitor the darks for the STIS CCD.
COS/NUV/FUV 11741
Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey for O VI, Ne VIII, Mg X, and Si XII Absorption Systems
Currently we can only account for half of the baryons (or less) expected to be found in the nearby universe based on D/H and CMB observations. This “missing baryons problem” is one of the highest-priority challenges in observational extragalatic astronomy. Cosmological simulations suggest that the baryons are hidden in low-density, shock-heated intergalactic gas in the log T = 5 – 7 range, but intensive UV and X-ray surveys using O VI, O VII, and O VIII absorption lines have not yet confirmed this prediction. We propose to use COS to carry out a sensitive survey for Ne VIII and Mg X absorption in the spectra of nine QSOs at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also search for Si XII. This survey will provide more robust constraints on the quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3, and the data will provide rich constraints on the metal enrichment, physical conditions, and nature of a wide variety of QSO absorbers in addition to the warm-hot systems. By comparing the results to other surveys at lower redshifts (with STIS, FUSE, and from the COS GTO programs), the project will also enable the first study of how these absorbers evolve with redshift at z < 1. By combining the program with follow-up galaxy redshift surveys, we will also push the study of galaxy-absorber relationships to higher redshifts, with an emphasis on the distribution of the WHIM with respect to the large-scale matter distribution of the universe.
WFC3/IR 11738
SPIDERWEBS AND FLIES: OBSERVING MASSIVE GALAXY FORMATION IN ACTION
Distant luminous radio galaxies are among the brightest known galaxies in the early Universe, pinpoint likely progenitors of dominant cluster galaxies and are unique laboratories for studying massive galaxy formation. Spectacular images with the ACS and NICMOS of one such object, the “Spiderweb Galaxy” at z = 2.2, show in exquisite detail, hierarchical merging occurring 11 Gyr ago. By imaging 3 additional Spiderweb-like galaxies we wish to study this potentially crucial phase of massive galaxy evolution, when hierarchical merging, galaxy downsizing and AGN feedback are all likely to be occurring. Properties of the complete sample of Spiderweb galaxies will be used to (i) constrain models for the formation and evolution of the most massive galaxies that dominate rich clusters and (ii) investigate the nature of chain and tadpole galaxies, a fundamental but poorly understood constituent of the early Universe.
We shall image rest-frame UV and optical continuum emission from 3 radio galaxies with 2.4 < z < 3.8 that appear clumpy and large in shallow WFPC/PC observations. The new observations will typically reach ~2 magnitudes fainter over 20-40 times larger area than previously. Photometric and morphological parameters will be measured for satellite galaxies ("flies") in the clumpy massive hosts and for galaxies in ~ 1.5 Mpc x 1.5 Mpc regions of surrounding protoclusters. Locations, sizes, elongations, clumpiness, masses, and star formation rates of the merging satellite and protocluster galaxies will be compared with new state of the art simulations. Combination of ACS and WFC3 images will help disentangle the properties of the young and old populations.
Specific goals include: (i) investigating star formation histories of the satellite galaxies and the extended emission, (ii) studying “downsizing” and merging scenarios and (iii) measuring the statistics of linear galaxies and relating them to models for the formation of massive galaxies and to the properties of the important but enigmatic class of chain/tadpole galaxies in the HUDF.
FGS 11704
The Ages of Globular Clusters and the Population II Distance Scale
Globular clusters are the oldest objects in the universe whose age can be accurately determined. The dominant error in globular cluster age determinations is the uncertain Population II distance scale. We propose to use FGS 1R to obtain parallaxes with an accuracy of 0.2 milliarcsecond for 9 main sequence stars with [Fe/H] < -1.5. This will determine the absolute magnitude of these stars with accuracies of 0.04 to 0.06mag. This data will be used to determine the distance to 24 metal-poor globular clusters using main sequence fitting. These distances (with errors of 0.05 mag) will be used to determine the ages of globular clusters using the luminosity of the subgiant branch as an age indicator. This will yield absolute ages with an accuracy of 5%, about a factor of two improvement over current estimates. Coupled with existing parallaxes for more metal-rich stars, we will be able to accurately determine the age for globular clusters over a wide range of metallicities in order to study the early formation history of the Milky Way and provide an independent estimate of the age of the universe.
The Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an absolute magnitude error less than 0.18 mag which is suitable for use in main sequence fitting. Previous attempts at main sequence fitting to metal-poor globular clusters have had to rely on theoretical calibrations of the color of the main sequence. Our HST parallax program will remove this source of possible systematic error and yield distances to metal-poor globular clusters which are significantly more accurate than possible with the current parallax data. The HST parallax data will have errors which are 10 times smaller than the current parallax data. Using the HST parallaxes, we will obtain main sequence fitting distances to 11 globular clusters which contain over 500 RR Lyrae stars. This will allow us to calibrate the absolute magnitude of RR Lyrae stars, a commonly used Population II distance indicator.
WFC3/UVIS/IR 11702
Search for Very High-z Galaxies with WFC3 Pure Parallel
WFC3 will provide an unprecedented probe to the early universe beyond the current redshift frontier. Here we propose a pure parallel program using this new instrument to search for Lyman-break galaxies at 6.5
(1) We will use both the UVIS and the IR channels, and do not need to seek optical data from elsewhere.
(2) Our program will likely triple the size of the probable candidate samples at z~7 and z~8, and will complement other targeted programs aiming at the similar redshift range.
(3) Being a pure parallel program, our survey will only make very limited demand on the scarce HST resources. More importantly, as the pure parallel pointings will be at random sight-lines, our program will be least affected by the bias due to the large scale structure (“cosmic variance”).
(4) We aim at the most luminous LBG population, and will address the bright-end of the luminosity function at z~8 and z~7. We will constrain the value of L* in particular, which is critical for understanding the star formation process and the stellar mass assembly history in the first few hundred million years of the universe.
(5) The candidates from our survey, most of which will be the brightest ones that any surveys would be able to find, will have the best chance to be spectroscopically confirmed at the current 8–10m telescopes.
(6) We will also find a large number of extremely red, old galaxies at intermediate redshifts, and the fine spatial resolution offered by the WFC3 will enable us constrain their formation history based on the study of their morphology, and hence shed light on their connection to the very early galaxies in the universe.
SC 11701
SM4 Realtime (AT/FT) and Simulation Data Receipt
THIS IS NOT AN EXECUTABLE PROGRAM. It exists ONLY to handle the receipt and processing of science data commanded in realtime during the servicing mission (e.g. Functional Test). During Servicing Missions new instruments are given aliveness and functional tests (AT/FT) while still in the shuttle bay. The FT usually consists of a small sampling of exposures commanded in realtime. Since the exposures are not SMS based the ground system has no knowledge of them and they cannot be received and processed by OPUS. This “dummy” proposal is used to make the ground system aware of the non-SMS based exposures hence allowing receipt and processing.
WFC3/UVIS/IR 11700
Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey
The epoch of reionization represents a special moment in the history of the Universe as it is during this era that the first galaxies and star clusters are formed. Reionization also profoundly affects the environment where subsequent generations of galaxies evolve. Our overarching goal is to test the hypothesis that galaxies are responsible for reionizing neutral hydrogen. To do so we propose to carry out a pure parallel WFC3 survey to constrain the bright end of the redshift z>7.5 galaxy luminosity function on a total area of 176 arcmin^2 of sky. Extrapolating the evolution of the luminosity function from z~6, we expect to detect about 20 Lyman Break Galaxies brighter than M_* at z~8 significantly improving the current sample of only a few galaxies known at these redshifts. Finding significantly fewer objects than predicted on the basis of extrapolation from z=6 would set strong limits to the brightness of M_*, highlighting a fast evolution of the luminosity function with the possible implication that galaxies alone cannot reionize the Universe. Our observations will find the best candidates for spectroscopic confirmation, that is bright z>7.5 objects, which would be missed by small area deeper surveys. The random pointing nature of the program is ideal to beat cosmic variance, especially severe for luminous massive galaxies, which are strongly clustered. In fact our survey geometry of 38 independent fields will constrain the luminosity function like a contiguous single field survey with two times more area at the same depth. Lyman Break Galaxies at z>7.5 down to m_AB=26.85 (5 sigma) in F125W will be selected as F098M dropouts, using three to five orbits visits that include a total of four filters (F606W, F098M, F125W, F160W) optimized to remove low-redshift interlopers and cool stars. Our data will be highly complementary to a deep field search for high- z galaxies aimed at probing the faint end of the luminosity function, allowing us to disentangle the degeneracy between faint end slope and M_* in a Schechter function fit of the luminosity function. We waive proprietary rights for the data. In addition, we commit to release the coordinates and properties of our z>7.5 candidates within one month from the acquisition of each field.
WFC3/IR 11696
Infrared Survey of Star Formation Across Cosmic Time
We propose to use the unique power of WFC3 slitless spectroscopy to measure the evolution of cosmic star formation from the end of the reionization epoch at z>6 to the close of the galaxy- building era at z~0.3.Pure parallel observations with the grisms have proven to be efficient for identifying line emission from galaxies across a broad range of redshifts. The G102 grism on WFC3 was designed to extend this capability to search for Ly-alpha emission from the first galaxies. Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will observe about 40 deep (4-5 orbit) fields with the combination of G102 and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.
Our primary science goals at the highest redshifts are: (1) Detect Lya in ~100 galaxies with z>5.6 and measure the evolution of the Lya luminosity function, independent of of cosmic variance; 2) Determine the connection between emission line selected and continuum-break selected galaxies at these high redshifts, and 3) Search for the proposed signature of neutral hydrogen absorption at re-ionization. At intermediate redshifts we will (4) Detect more than 1000 galaxies in Halpha at 0.5
We propose to directly image the star-forming regions of z>2 damped Lya systems (DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope. In contrast to all previous attempts to detect the galaxies giving rise to high redshift DLAs, we will use a novel technique that completely removes the glare of the background quasar. Specifically, we will target quasar sightlines with multiple DLAs and use the higher redshift DLA as a “blocking filter” (via Lyman limit absorption) to eliminate all FUV emission from the quasar. This will allow us to carry out a deep search for FUV emission from the lower redshift DLA, shortward of the Lyman limit of the higher redshift absorber. The unique filter set and high spatial resolution afforded by WFC3/UVIS will then enable us to directly image the lower redshift DLA and thus estimate its size, star- formation rate and impact parameter from the QSO sightline. We propose to observe a sample of 20 sightlines, selected primarily from the SDSS database, requiring a total of 40 HST orbits. The observations will allow us to determine the first FUV luminosity function of high redshift DLA galaxies and to correlate the DLA galaxy properties with the ISM characteristics inferred from standard absorption-line analysis to significantly improve our understanding of the general DLA population.
WFC3/UVIS 11594
A WFC3 Grism Survey for Lyman Limit Absorption at z=2
We propose to conduct a spectroscopic survey of Lyman limit absorbers at redshifts 1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal intends to complete an approved Cycle 15 SNAP program (10878), which was cut short due to the ACS failure. We have selected 64 quasars at 2.3 < z < 2.6 from the Sloan Digital Sky Survey Spectroscopic Quasar Sample, for which no BAL signature is found at the QSO redshift and no strong metal absorption lines are present at z > 2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency dn/dz of the LLS over the column density range 16.0 < log(NHI) < 20.3 cm^-2. Second, we will measure the column density frequency distribution f(N) for the partial Lyman limit systems (PLLS) over the column density range 16.0 < log(NHI) < 17.5 cm^-2. Third, we will identify those sightlines which could provide a measurement of the primordial D/H ratio. By carrying out this survey, we can also help place meaningful constraints on two key quantities of cosmological relevance. First, we will estimate the amount of metals in the LLS using the f(N), and ground based observations of metal line transitions. Second, by determining f(N) of the PLLS, we can constrain the amplitude of the ionizing UV background at z~2 to a greater precision. This survey is ideal for a snapshot observing program, because the on-object integration times are all well below 30 minutes, and follow-up observations from the ground require minimal telescope time due to the QSO sample being bright. COS/FUV/STIS/CCD/MA1 11592 Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A Survey of Galactic Halo Stars at z>3 kpc
Cosmological simulation predicts that highly ionized gas plays an important role in the formation and evolution of galaxies and their interplay with the intergalactic medium. The NASA HST and FUSE missions have revealed high-velocity CIV and OVI absorption along extragalactic sightlines through the Galactic halo. These highly ionized high-velocity clouds (HVCs) could cover 85% of the sky and have a detection rate higher than the HI HVCs. Two competing, equally exciting, theories may explain the origin of these highly ionized HVCs: 1) the “Galactic” theory, where the HVCs are the result of feedback processes and trace the disk-halo mass exchange, perhaps including the accretion of matter condensing from an extended corona; 2) the “Local Group” theory, where they are part of the local warm-hot intergalactic medium, representing some of the missing baryonic matter of the Universe. Only direct distance determinations can discriminate between these models. Our group has found that some of these highly ionized HVCs have a Galactic origin, based on STIS observations of one star at z<5.3 kpc. We propose an HST FUV spectral survey to search for and characterize the high velocity NV, CIV, and SiIV interstellar absorption toward 24 stars at much larger distances than any previous searches (4
WFC3/IR 11202
The Structure of Early-type Galaxies: 0.1-100 Effective Radii
The structure, formation and evolution of early-type galaxies is still largely an open problem in cosmology: how does the Universe evolve from large linear scales dominated by dark matter to the highly non-linear scales of galaxies, where baryons and dark matter both play important, interacting, roles? To understand the complex physical processes involved in their formation scenario, and why they have the tight scaling relations that we observe today (e.g. the Fundamental Plane), it is critically important not only to understand their stellar structure, but also their dark-matter distribution from the smallest to the largest scales. Over the last three years the SLACS collaboration has developed a toolbox to tackle these issues in a unique and encompassing way by combining new non-parametric strong lensing techniques, stellar dynamics, and most recently weak gravitational lensing, with high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic data of early-type lens systems. This allows us to break degeneracies that are inherent to each of these techniques separately and probe the mass structure of early-type galaxies from 0.1 to 100 effective radii. The large dynamic range to which lensing is sensitive allows us both to probe the clumpy substructure of these galaxies, as well as their low-density outer haloes. These methods have convincingly been demonstrated, by our team, using smaller pilot-samples of SLACS lens systems with HST data. In this proposal, we request observing time with WFC3 and NICMOS to observe 53 strong lens systems from SLACS, to obtain complete multi-color imaging for each system. This would bring the total number of SLACS lens systems to 87 with completed HST imaging and effectively doubles the known number of galaxy-scale strong lenses. The deep HST images enable us to fully exploit our new techniques, beat down low-number statistics, and probe the structure and evolution of early- type galaxies, not only with a uniform data-set an order of magnitude larger than what is available now, but also with a fully-coherent and self-consistent methodological approach!
NIC2 11166
The Mass-dependent Evolution of the Black Hole-Bulge Relations
In the local universe, the masses of giant black holes are correlated with the luminosities, masses and velocity dispersions of their host galaxy bulges. This indicates a surprisingly close connection between the evolution of galactic nuclei (on parsec scales) and of stars on kpc scales. A key observational test of proposed explanations for these correlations is to measure how they have evolved over cosmic time. Our ACS imaging of 20 Seyfert 1 galaxies at z=0.37 showed them to have smaller bulges (by a factor of 3) for a given central black hole mass than is found in galaxies in the present-day universe. However, since all our sample galaxies had black hole masses in the range 10^8.0–8.5 Msun, we could only measure the OFFSET in black hole mass to bulge luminosity ratios from the present epoch. By extending this study to black hole masses another factor of 10 lower, we propose to determine the full CORRELATION of black hole mass with host galaxy properties at a lookback time of 4 Gyrs and to test mass-dependency of the evolution. We have selected 14 Seyfert galaxies from SDSS DR5 whose narrow Hbeta emission lines (and estimated nuclear luminosities) imply that they have black hole masses around 10^7 Msuns. We will soon complete our Keck spectroscopic measures of their bulge velocity dispersions. We need a 1-orbit NICMOS image of each galaxy to separate its nonstellar luminosity from its bulge and disk. This will allow us to make the first determination of the full black hole/bulge relations at z=0.37 (e.g. M-L and M-sigma), as well as a test of whether active galaxies obey the Fundamental Plane relation at that epoch.
NIC3/WFC3/IR 11149
Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman Break Galaxies at 5.7
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
12226 – COS 630(DCE_DIAG_CRP_SHUTDOWN) at 080/03:25:11. Diagnostic error 0x22 reported by the DCE and relayed to the ground via the CS resulting in FUV shutdown.
Observations affected: COS FUV ID#74-89 & 92-98 Proposal ID#12096 and COS FUV #2-6 Proposal #11895
12227 – COS 1035 (TA_GLOBAL_THRESHOLD_NOT_EXCEEDED) @ 080/05:47z While preparing to calculate a flux-weighted centroid to determine the location of a target(after a sky scan), a target acquisition macro determined that there are not enough total counts to compute a meaningful flux-weighted centroid. Observation used NUV detector.
Observations possibly affected: COS NUV ID#90-91 Proposal ID#12096
COMPLETED OPS REQUEST:
18835-1 – Dump COS DCE and ExecRam after COS 630 STB @ 080/0735z
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 26 26
FGS REAcq 21 21
OBAD with Maneuver 19 19
SIGNIFICANT EVENTS:
On Sunday morning 12:25 am (DOY 080, 3:25:11 UT), COS Error Message COS 630 – DCE DIAG CRP SHUTDOWN, indicated that the Detector Control Electronics had reset and is now in BOOT Mode.
