- Press Release
- Nov 27, 2022
NASA Hubble Space Telescope Daily Report #5000
HUBBLE SPACE TELESCOPE DAILY REPORT #5000**
Continuing to Collect World Class Science
PERIOD COVERED: 5am December 24 – 5am December 28, 2009 (DOY 358/10:00z-362/10:00z)
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).
IR Zero Points
We will measure and monitor the zeropoints through the IR filters using observations of the white dwarf standard stars, GD153, GD71 and GD191B2B and the solar analog standard star, P330E. Data will be taken monthly during Cycle 17. Observations of the star cluster, NGC 104, are made twice to check color transformations. We expect an accuracy of 2% in the wide filter zeropoints relative to the HST photometric system, and 5% in the medium- and narrow-band filters.
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 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).
NUV Internal/External Wavelength Scale Monitor
This program monitors the offsets between the wavelength scale set by the internal wavecal versus that defined by absorption lines in external targets. This is accomplished by observing two external radial velocity standard targets: HD187691 with G225M and G285M and HD6655 with G285M and G230L. The two standard targets have little flux in the wavelength range covered by G185M and so Feige 48 (sdO) is observed with this grating. Both Feige 48 and HD6655 are also observed in SMOV. The cenwaves observed in this program are a subset of the ones used during Cycle 17. Observing all cenwaves would require a considerably larger number of orbits. Constraints on scheduling of each target are placed so that each target is observed once every ~2-3 months. Observing the three targets every month would also require a considerably larger number of orbits.
CCD Daily Monitor (Part 1)
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 352 orbits (22 weeks) from 31 August 2009 to 31 January 2010.
CCD Bias Monitor-Part 1
The purpose of this proposal is to 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.
CCD Dark Monitor Part 1
The purpose of this proposal is to monitor the darks for the STIS CCD.
Observing Cluster Assembly Around the Massive Cluster RXJ0152-13
We request ACS imaging for groups and filaments in the outskirts of two z=0.8 forming clusters of galaxies. These images will be combined with an unparalleled dataset of wide-field spectroscopy from Magellan, with ~2200 confirmed members (~3200 by the summer) of the superstructures surrounding the two clusters. We will estimate merger rates and determine the morphological composition of the galaxy populations within the infalling groups and filaments identified in our spectroscopic dataset. The HST data are critical to understand how the early-type galaxy fraction remains constant in cluster centers, while clusters double in mass through the steady accretion of lower mass groups. One possibility is that the galaxies in the filaments and infalling groups already have predominantly early-type morphologies, while another is that galaxies transform during, and possibly even in connection with, the process of infall. Our unique dataset of spectroscopic membership, when combined with the exquisite high-resolution imaging of ACS and WF3, will enable us to witness the accretion of galaxies unto massive clusters and how this process affects their properties.
The Wavelength Dependence of Accretion Disk Structure
We can now routinely measure the size of quasar accretion disks using gravitational microlensing of lensed quasars. The next step to testing accretion disk models is to measure the size of accretion disks as a function of wavelength, particularly at the UV and X-ray wavelengths that should probe the inner, strong gravity regime. Here we focus on two four-image quasar lenses that already have optical (R band) and X-ray size measurements using microlensing. We will combine the HST observations with ground- based monitoring to measure the disk size as a function of wavelength from the near-IR to the UV. We require HST to measure the image flux ratios in the ultraviolet continuum near the Lyman limit of the quasars. The selected targets have estimated black hole masses that differ by an order of magnitude, and we should find wavelength scalings for the two systems that are very different because the Blue/UV wavelengths should correspond to parts of the disk near the inner edge for the high mass system but not in the low mass system. The results will be modeled using a combination of simple thin disk models and complete relativistic disk models. While requiring only 18 orbits, success for one system requires observations in both Cycles 16 and 17.
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony makes that prediction. It is, however, a prediction of extrasolar planetary system architecture as yet untested by direct observation for main sequence stars other than the Sun. To provide such a test, we propose to carry out FGS astrometric studies on four stars hosting seven companions. Our understanding of the planet formation process will grow as we match not only system architecture, but formed planet mass and true distance from the primary with host star characteristics for a wide variety of host stars and exoplanet masses.
We propose that a series of FGS astrometric observations with demonstrated 1 millisecond of arc per-observation precision can establish the degree of coplanarity and component true masses for four extrasolar systems: HD 202206 (brown dwarf+planet); HD 128311 (planet+planet), HD 160691 = mu Arae (planet+planet), and HD 222404AB = gamma Cephei (planet+star). In each case the companion is identified as such by assuming that the minimum mass is the actual mass. For the last target, a known stellar binary system, the companion orbit is stable only if coplanar with the AB binary orbit.
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/UVIS 11730 Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and In Cycles 11 and 13 we obtained two epochs of ACS/HRC data for fields in the Magellanic Clouds centered on background quasars. We used these data to determine the proper motions of the LMC and SMC to better than 5% and 15% respectively. The results had a number of unexpected implications for the Milky Way-LMC-SMC system and received considerable attention in the literature and in the press. The implied three-dimensional velocities are larger than previously believed and close to the escape velocity in a standard 10^12 solar mass Milky Way dark halo. Our orbit calculations suggest the Clouds may not be bound to the Milky Way or may just be on their first passage, both of which are unexpected in view of traditional interpretations of the Magellanic Stream. Alternatively, the Milky Way dark halo may be a factor two more massive than previously believed, which would be surprising in view of other observational constraints. Also, the relative velocity between the LMC and SMC was larger than expected, leaving open the possibility that the Clouds may not be bound to each other. To further verify and refine our results we requested an additional epoch data in Cycle 16 which is being executed with WFPC2/PC due to the failure of ACS. A detailed analysis of one LMC field shows that the field proper motion using all three epochs of data is consistent within 1-sigma with the two-epoch data, thus verifying that there are no major systematic effects in our previous measurements. The random errors, however, are only smaller by a factor of 1.4 because of the relatively large errors in the WFPC2 data. A prediction for a fourth epoch with measurement errors similar to epochs 1 and 2 shows that the uncertainties will improve by a factor of 3. This will allow us to better address whether the Clouds are indeed bound to each other and to the Milky Way. It will also allow us to constrain the internal motions of various populations within the Clouds, and to determine a distance to the LMC using rotational parallax. Continuation of this highly successful program is therefore likely to provide important additional insights. Execution in SNAPshot mode guarantees maximally efficient use of HST resources. COS/NUV/FUV 11727 UV Spectroscopy of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe Much of our information about galaxy evolution and the interaction between galaxies and the IGM at high-z has been provided by the Lyman Break Galaxies (LBGs). However, it is difficult to investigate these faint and distant objects in detail. To address this, we have used the GALEX All-Sky Imaging Survey and the SDSS to identify for the first time a rare population of low-redshift galaxies with properties remarkably similar to the high-redshift LBGs. These local “Lyman Break Analogs” (LBAs) resemble LBGs in terms of morphology, size, UV luminosity, star formation rate, UV surface brightness, stellar mass, velocity dispersion, metallicity, and dust content. We are assembling a wide range of data on these objects with the goal of using them as local laboratories for better understanding the relevant astrophysical processes in LBGs. These data include HST imaging (95 orbits in Cy15 and 16), Spitzer photometry and spectroscopy, Chandra and XMM X-ray imaging and spectroscopy, and near-IR integral field spectroscopy (VLT, Keck, and Gemini). In this proposal we are requesting the most important missing puzzle piece: far-UV spectra with a signal-to-noise and spectral resolution significantly better than available for typical LBGs. We will use these spectra to study the LBA’s galactic winds, probe the processes that regulate the escape of Ly-a and Lyman continuum radiation, determine chemical abundances for the stars and gas, and constrain the form of the high-end of the Initial Mass Function. Adding these new COS data will give us vital information about these extraordinary sites of star formation in the local universe. In so-doing it will also shed new light on the processes that led to the formation of stars, the building of galaxies, and the enrichment and heating of the IGM in the early universe. COS/NUV/FUV 11726 Mysteries of the North Star: HST/COS Confirmation of Real-Time Evolution and Upper Atmospheric Heating in Polaris The major aims of this proposal are twofold: to confirm and understand the recently observed apparent evolutionary changes of the bright (3.97-day) Cepheid Polaris – and – to further study the recent discovery of hot plasmas (up to 1MK) well above the photospheric temperature of the Cepheid itself. This study will have a major impact on understanding the evolution, structure, heating and dynamics of Cepheid (and related Hybrid Star) atmospheres. In our study – the Secret Lives of Cepheids – Polaris is noteworthy for its well-documented increase in pulsation period (+3.51 sec/year) and decrease in light amplitude over the last 100-150 years, almost ceasing pulsations in the early 1990s. Moreover, our studies of photoelectric photometry and historic visual observations have shown evidence that Polaris may have increased in brightness by almost 0.2-mag over the past century (and possibly by more than 1-mag since Ptolemy). In addition, a study of the IUE database indicates a possible increase in photospheric temperature (which the FUV region is very sensitive to) between 1978/79 and 1991/93, pointing to a change of ~35+/-12 K. More recently, FUSE and Chandra observations of Polaris indicate the presence of C III 977/1176A and O VI 1032/1038A emissions, as well as possible soft X-ray emission, respectively. The source of these hot plasmas could be related to pulsations (shock heating) and/or magnetic activity. To further investigate the evolutionary changes and upper atmospheric emissions of Polaris, we propose for HST/COS medium resolution spectrometry covering the wavelength range ~1150- 2100A. This wavelength range covers both the high energy emission lines (<1600A) along with the rise in continuum of the F-supergiant photosphere (>1600A). HST/COS is the only instrument capable of carrying out the necessary FUV observations to achieve our scientific goals for Polaris – providing a better understanding of the evolution and heating mechanisms of Cepheids.
Detailed Analysis of Carbon Atmosphere White Dwarfs
We propose to obtain UV spectra for the newly discovered white dwarf stars with a carbon-dominated atmosphere. Model calculations show that these stars emit most of their light in the UV part of the electromagnetic spectrum and that an accurate determination of the flux in this region is crucial for an accurate determination of the atmospheric parameters. It will also provide a unique opportunity to test the atomic data and broadening theory in stellar conditions never met before. This will play a primordial role in our path to understand the origin of these objects as well to obtain a better understanding of the evolution of stars in general. The principal objective we hope to achieve with these observations are 1) obtain accurate surface gravity/mass for these stars, 2) constrain/determine the abundance of other elements (O, He, Mg, Ne etc.), especially oxygen, 3) verify the accuracy of the various theoretical atomic data used in the model calculations, 4) understand the origin and evolution of carbon atmosphere white dwarfs, in particular whether progenitor stars as massive as 10.5 solar masses can produce white dwarfs, rather than supernovae. We propose to observe 5 objects chosen carefully to cover the range of observed properties among carbon atmosphere white dwarfs (effective temperature, surface gravity, abundance of hydrogen/helium and magnetic field).
The Stellar Halos of Dwarf Galaxies
The metal-poor stellar halo is the oldest extended structure in the Galaxy. Such halos are thought to form through hierarchical merging, and contain stars pulled from accreted subhalos. The diffuse stellar halo therefore stores information about the prop reties of the accreted galaxies (i.e., their orbits, stellar masses, and metallicities). It is therefore unsurprising that stellar halos have become a popular probe of the early epoch of galaxy formation.
Almost all current work on stellar halos has focused on massive galaxies, however. We propose to extend the work on stellar halos to much lower mass scales, by studying the halos of faint dwarf galaxies. By taking halo studies into the dwarf galaxy regime, we can probe exceptionally small mass scales for the accreted halos. At these mass scales the effects of reionization and supernova feedback have the largest impact on the galaxy population. Stellar halos of dwarf galaxies are therefore a sensitive probe of the key processes needed to resolve the lack of substructure observed at low masses.
We are requesting two far-field ACS pointings for the three closest isolated nearby dwarf irregular galaxies whose inner halos have already been mapped with the ACS Nearby Galaxy Survey Treasury. These outer fields will allow us to trace the halo out to roughly half the virial radius, further than any previous study. We will use the resulting distribution of halo stars (1) to unambiguously measure the structure of the stellar halo, with minimal contamination from the main galaxy; (2) to constrain the flattening of the stellar halo; (3) to measure the metallicity of halo stars as a function of radius; (4) to correlate any changes in halo profile with changes in metallicity. The resulting data will constrain models of halo accretion and the epoch of reionization.
Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters
PLanetary nebulae (PNe) in globular clusters (GCs) raise a number of interesting issues related to stellar and galactic evolution. The number of PNe known in Milky Way GCs, four, is surprisingly low if one assumes that all stars pass through a PN stage. However, it is likely that the remnants of stars now evolving in galactic GCs leave the AGB so slowly that any ejected nebula dissipates long before the star becomes hot enough to ionize it. Thus there should not be ANY PNe in Milky Way GCs–but there are four! It has been suggested that these Pne are the result of mergers of binary stars within GCs, i.e., that they are descendants of blue stragglers. The frequency of occurrence of PNe in external galaxies poses more questions, because it shows a range of almost an order of magnitude.
I propose a SNAPshot survey aimed at discovering PNe in the GC systems of Local Group galaxies outside the Milky Way. These clusters, some of which may be much younger than their counterparts in our galaxy, might contain many more PNe than those of our own galaxy. I will use the standard technique of emission-line and continuum imaging, which easily discloses PNe. This proposal continues a WFPC2 program started in Cycle 16, but with the more powerful WFC3. As a by-product, the survey will also produce color-magnitude diagrams for numerous clusters for the first time, reaching down to the horizontal branch.
Calibration of Surface Brightness Fluctuations for WFC3/IR
We aim to characterize galaxy surface brightness fluctuations (SBF), and calibrate the SBF distance method, in the F110W and F160W filters of the Wide Field Camera 3 IR channel. Because of the very high throughput of F110W and the good match of F160W to the standard H band, we anticipate that both of these filters will be popular choices for galaxy observations with WFC3/IR. The SBF signal is typically an order of magnitude brighter in the near-IR than in the optical, and the characteristics (sensitivity, FOV, cosmetics) of the WFC3/IR channel will be enormously more efficient for SBF measurements than previously available near-IR cameras. As a result, our proposed SBF calibration will allow accurate distance derivation whenever an early-type or bulge- dominated galaxy is observed out to a distance of 150 Mpc or more (i.e., out to the Hubble flow) in the calibrated passbands. For individual galaxy observations, an accurate distance is useful for establishing absolute luminosities, black hole masses, linear sizes, etc. Eventually, once a large number of galaxies have been observed across the sky with WFC3/IR, this SBF calibration will enable accurate mapping of the total mass density distribution in the local universe using the data available in the HST archive. The proposed observations will have additional important scientific value; in particular, we highlight their usefulness for understanding the nature of multimodal globular cluster color distributions in giant elliptical galaxies.
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.
Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
Using the superior resolution of HST, we propose to continue our proper motion survey of Galactic dwarf galaxies. The target galaxies include one classical dwarf, Leo II, and six that were recently identified in the Sloan Digital Sky Survey data: Bootes I, Canes Venatici I, Canes Venatici II, Coma Berenices, Leo IV, and Ursa Major II. We will observe a total of 16 fields, each centered on a spectroscopically-confirmed QSO. Using QSOs as standards of rest in measuring absolute proper motions has proven to be the most accurate and most efficient method. HST is our only option to quickly determine the space motions of the SDSS dwarfs because suitable ground-based imaging is only a few years old and such data need several decades to produce a proper motion. The two most distant galaxies in our sample will require time baselines of four years to achieve our goal of a 30-50 km/s uncertainty in the tangential velocity; given this and the finite lifetime of HST, it is imperative that first-epoch observations be taken in this cycle. The SDSS dwarfs have dramatically lower surface brightnesses and luminosities than the classical dwarfs. Proper motions are crucial for determining orbits of the galaxies and knowing the orbits will allow us to test theories for the formation and evolution of these galaxies and, more generally, for the formation of the Local Group.
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
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. WFC3/UVIS 11588 Galaxy-Scale Strong Lenses from the CFHTLS Survey We aim to investigate the origin and evolution of early-type galaxies using gravitational lensing, modeling the mass profiles of objects over a wide range of redshifts. The low redshift (z = 0.2) sample is already in place following the successful HST SLACS survey; we now propose to build up and analyze a sample of comparable size (~50 systems) at high redshift (0.4 < z < 0.9) using HST WFC3 Snapshot observations of lens systems identified by the SL2S collaboration in the CFHT legacy survey. 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. COS/NUV/FUV 11522 COS-GTO: Star Formation/Lyman-Alpha A sample of 20 star-forming galaxies will be observed with COS G130M. The galaxies were selected from the Kitt Peak International Spectroscopic Survey (KISSR) data release and cover a broad range of luminosity, oxygen abundance, and reddening. The goal of the program is to characterize the Lyman-alpha properties and establish correlations with fundamental galaxy properties. Each galaxy will be observed for one orbit. COS/NUV/FUV/WFC3/UVIS/IR 11520 COS-GTO: QSO Absorbers, Galaxies and Large-Scale Structures in the Local Universe This is a program to probe the large scale structure of baryons in the universe, including addressing questions of baryon fraction, physical conditions and relationships between absorbers and large-scale structures of galaxies. Besides these specific goals, this proposed GTO program also probes a large enough total path length in Ly alpha and OVI to add significantly to what STIS/FUSE has already observed. Several Galactic High Velocity Cloud Complexes also are probed by these sightlines, particularly the M Complex. The total path length of this proposed program for Ly alpha large-scale structure surveys is delta_z~5.5. We have selected a variety of targets to address these questions, under the following subcategories: 1. Target 8 bright BL Lac objects to search for low contrast Ly alpha absorbers from the warm-hot interstellar medium (WHIM). 2. Ly alpha cloud sizes: The targets are a bright AGN pair which yield tangential distance separations of 100–500 kpc at z=0.01–0.05, where galaxy surveys are excellent. This pair has two filaments and two voids in this distance range. 3. Probes of starburst outflows: The targets are bright AGN, <= 100 kpc in projection out of the minor axis of nearby starburst galaxies. 4. A large galaxy’s gaseous halo: Three probes of the kinematics and metallicity of a single L* galaxy halo. These observations includes G130M, G160M exposures at SNR~20 and G285M at 2850A and SNR~10 for MgII. The 2L* galaxy, ESO 157-G049 (cz=1678 km/s), being probed by these sightlines has an available H I 21cm map from ATCA, H alpha imaging from CTIO and long-slit spectra from MSSSO. 5. Dwarf galaxy winds: These targets probe the kinematics and metallicities of outflows from active and inactive (in terms of star formation) dwarfs. WFC3/ACS/UVIS 11360 Star Formation in Nearby Galaxies Star formation is a fundamental astrophysical process; it controls phenomena ranging from the evolution of galaxies and nucleosynthesis to the origins of planetary systems and abodes for life. The WFC3, optimized at both UV and IR wavelengths and equipped with an extensive array of narrow-band filters, brings unique capabilities to this area of study. The WFC3 Scientific Oversight Committee (SOC) proposes an integrated program on star formation in the nearby universe which will fully exploit these new abilities. Our targets range from the well-resolved R136 in 30 Dor in the LMC (the nearest super star cluster) and M82 (the nearest starbursting galaxy) to about half a dozen other nearby galaxies that sample a wide range of star-formation rates and environments. Our program consists of broad band multiwavelength imaging over the entire range from the UV to the near-IR, aimed at studying the ages and metallicities of stellar populations, revealing young stars that are still hidden by dust at optical wavelengths, and showing the integrated properties of star clusters. Narrow-band imaging of the same environments will allow us to measure star-formation rates, gas pressure, chemical abundances, extinction, and shock morphologies. The primary scientific issues to be addressed are: (1) What triggers star formation? (2) How do the properties of star-forming regions vary among different types of galaxies and environments of different gas densities and compositions? (3) How do these different environments affect the history of star formation? (4) Is the stellar initial mass function universal or determined by local conditions? WFC3/ACS/IR 11235 HST NICMOS Survey of the Nuclear Regions 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 enhanced star formation and Active Galactic Nuclei (AGN) activity, possibly triggered as the objects transform into massive S0 and elliptical merger remnants. We propose NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88 L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample (RBGS: i.e., 60 micron flux density > 5.24 Jy). This sample is ideal not only in its completeness and sample size, but also in the proximity and brightness of the galaxies. The superb sensitivity and resolution of NICMOS NIC2 on HST enables a unique opportunity to study the detailed structure of the nuclear regions, where dust obscuration may mask star clusters, AGN, and additional nuclei from optical view, with a resolution significantly higher than possible with Spitzer IRAC. This survey thus provides a crucial component to our study of the dynamics and evolution of IR galaxies presently underway with Wide-Field, HST ACS/WFC3, and Spitzer IRAC observations of these 88 galaxies. Imaging will be done with the F160W filter (H-band) to examine as a function of both luminosity and merger stage: (i) the luminosity and distribution of embedded star clusters, (ii) the presence of optically obscured AGN and nuclei, (iii) the correlation between the distribution of 1.6 micron emission and the mid-IR emission as detected by Spitzer IRAC, (iv) the evidence of bars or bridges that may funnel fuel into the nuclear region, and (v) the ages of star clusters for which photometry is available via ACS/WFC3 observations. The NICMOS data, combined with the HST ACS, Spitzer, and GALEX observations of this sample, will result in the most comprehensive study of merging and interacting galaxies to date.
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!
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
#12141 GSAcq(2,1,1) @361/01:46z failed due to search radius limit exceeded on FGS2.
Observations affected: ACS #72-75 Proposal #11879; WFC3 #189-191 Proposal #11588; WFC3 #192-193 Proposal #11905.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
FGS GSAcq 43 42
FGS REAcq 24 24
OBAD with Maneuver 23 23
SIGNIFICANT EVENTS: (None)
** 5,000th Edition of Daily Report Fun Facts:
1. Over the years, 3 different groups have compiled the DR: 1 group @ STScI and 2 groups @ GSFC.
2. Once upon a time, DRs specified the month and day, but not the year of issuance. Oops!
3. Originally, DR production was an entirely manual process.
4. The tag line “Continuing to Collect World Class Science” first appeared in Daily Report #3533 on Monday January 20th, 2004.
5. WFPC2 is mentioned more times in DRs than any other SI.
6. Excepting the new SIs, the HSP is mentioned in the fewest DRs. (It was removed in December 1993 to make room for COSTAR.)