NASA Hubble Space Telescope Daily Report #5092
HUBBLE SPACE TELESCOPE DAILY REPORT #5092
PERIOD COVERED: 5am May 7 – 5am May 10, 2010 (DOY 127/09:00z-130/09:00z)
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
12270 – REAcq(1,2,1) at 129/19:25:47z took 3 attempts to succeed. the first two attempts resulted in scan step limit exceeded on FGS1. Previous GSAcq(1,2,1) at 129/17:58:12z was successful on the first attempt.
12271 – GSAcq(2,0,2) at 130/06:34:11z failed to RGA control due to scan step limit exceeded on FGS 2.
Observations affected: Astrometry proposal ID#11704.
COMPLETED OPS REQUEST:
18855-0 – Null Genslew for proposal 12077 – slot 1 @ 127/1911z
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 28 27
FGS REAcq 18 18
OBAD with Maneuver 18 18
SIGNIFICANT EVENTS: (None)
OBSERVATIONS SCHEDULED
WFC3/IR/S/C 12089
Persistence – Part 2
The IR detectors on WFC3, like other IR detectors, trap charge when exposed to sources near or above the full well of the detector diodes. This charge leaks out, producing detectable afterglow images for periods which can last for several hours, depending on the amount of over exposure. These visits, which consist of tungsten lamp exposures of varying durations followed by darks, are intended to provide a better calibration of persistence over the full area of the IR detector of WFC3.
WFC3/UV 12077
Monitoring the Aftermath of an Asteroid Impact Event
Our Director’s Discretionary program (GO-12053) to image the newly discovered object P/2010 A2 executed successfully on 2010 Jan 25 and 29 with spectacular results. Hubble has apparently borne witness to the first detection of a collision in the asteroid belt. Hubble imaging with the WFC3 has revealed an object unlike anything ever seen before and with details impossible to detect with any other facility. We request 6 more orbits of Hubble time (1 orbit every 20 days over the next few months, until the object enters Hubble’s solar exclusion zone in late-June 2010) to monitor the evolution of this remarkable object and further clarify the nature of this event. These observations may usher in a new era of searching for and characterizing collisional events within the asteroid belt.
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 11926
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.
WFC3/UVIS 11924
WFC3/UVIS External and Internal CTE Monitor
CCD detector Charge Transfer Inefficiency (CTI)-induced losses in photometry and astrometry will be measured using observations of the rich open cluster NGC6791 and with the EPER (Extended Pixel Edge Response) method using tungsten lamp flat field exposures. Although we do not expect to see CTE effects at the outset of Cycle 17, this CTE monitoring program is the first of a multi-cycle program to monitor and establish CTE-induced losses with time. We expect to measure CTE effects with a precision comparable to the ACS measurements.
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).
STIS/MA1 11861
MAMA FUV Flats
This program will obtain FUV-MAMA observations of the STIS internal Krypton lamp to construct an FUV flat applicable to all FUV modes.
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.
WFC3/IR 11838
Completing a Flux-limited Survey for X-ray Emission from Radio Jets
We will measure the changing flow speeds, magnetic fields, and energy fluxes in well-resolved quasar jets found in our short-exposure Chandra survey by combining new, deep Chandra data with radio and optical imaging. We will image each jet with sufficient sensitivity to estimate beaming factors and magnetic fields in several distinct regions, and so map the variations in these parameters down the jets. HST observations will help diagnose the role of synchrotron emission in the overall SED, and may reveal condensations on scales less than 0.1 arcsec.
FGS 11789
An Astrometric Calibration of Population II Distance Indicators
In 2002, HST produced a highly precise parallax for RR Lyrae. That measurement resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a useful result, judged by the over ten refereed citations each year since. It is, however, unsatisfactory to have the direct, parallax-based, distance scale of Population II variables based on a single star. We propose, therefore, to obtain the parallaxes of four additional RR Lyrae stars and two Population II Cepheids, or W Vir stars. The Population II Cepheids lie with the RR Lyrae stars on a common K-band Period-Luminosity relation. Using these parallaxes to inform that relationship, we anticipate a zero point error of 0.04 magnitude. This result should greatly strengthen confidence in the Population II distance scale and increase our understanding of RR Lyrae star and Pop. II Cepheid astrophysics.
WFC3/UV/ACS/WFC 11739
Multiple Stellar Generations in the Unique Globular Clusters NGC 6388 and NGC 6441
Over the last few years HST observations have resulted in one of the most exciting and unexpected developments in stellar population studies: the discovery of multiple generations of stars in several globular clusters. The finding of multiple main sequences in the massive clusters NGC 2808 and Omega Centauri, and multiple subgiant branches in NGC 1851, M54, and NGC 6388 has challenged the long-held paradigm that globular clusters are simple stellar populations. Even more surprising, given the spectroscopic and photometric constraints, the only viable explanation for the main sequence splitting appears to be Helium enrichment, up to an astonishingly high Y=0.4. The conditions under which certain globulars experience the formation of multiple stellar generations remain mysterious, and even more so the helium-enrichment phenomenon. Such an enrichment has important implications for chemical-enrichment, star-formation, and stellar-evolution scenarios, in star clusters and likely elsewhere. To properly constrain the multiple main sequence phenomenon, it is important to determine its extent among GCs: is it limited to Omega Cen and NGC2808, or is it more common? We propose deep WFC3 optical/IR imaging of NGC 6388 and 6441, the two globular clusters that are most likely to host multiple, helium-enriched populations. Our simulations of WFC3 performance suggest that we will be able to detect even the main sequence splittings caused by small He differences (Delta Y <0.03). WFC3/IR 11719 A Calibration Database for Stellar Models of Asymptotic Giant Branch Stars Studies of galaxy formation and evolution rely increasingly on the interpretation and modeling of near-infrared observations. At these wavelengths, the brightest stars are intermediate mass asymptotic giant branch (AGB) stars. These stars can contribute nearly 50% of the integrated luminosity at near infrared and even optical wavelengths, particularly for the younger stellar populations characteristic of high-redshift galaxies (z>1). AGB stars are also significant sources of dust and heavy elements. Accurate modeling of AGB stars is therefore of the utmost importance.
The primary limitation facing current models is the lack of useful calibration data. Current models are tuned to match the properties of the AGB population in the Magellanic Clouds, and thus have only been calibrated in a very narrow range of sub-solar metallicities. Preliminary observations already suggest that the models are overestimating AGB lifetimes by factors of 2-3 at lower metallicities. At higher (solar) metallicities, there are no appropriate observations for calibrating the models.
We propose a WFC3/IR SNAP survey of nearby galaxies to create a large database of AGB populations spanning the full range of metallicities and star formation histories. Because of their intrinsically red colors and dusty circumstellar envelopes, tracking the numbers and bolometric fluxes of AGB stars requires the NIR observations we propose here. The resulting observations of nearby galaxies with deep ACS imaging offer the opportunity to obtain large (100-1000’s) complete samples of AGB stars at a single distance, in systems with well-constrained star formation histories and metallicities.
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. COS/NUV/FUV 11698 The Structure and Dynamics of Virgo’s Multi-Phase Intracluster Medium The dynamical flows of the intracluster medium (ICM) are largely unknown. We propose to map the spatial and kinematic distribution of the warm ICM of the nearby Virgo cluster using the Cosmic Origins Spectrograph. 15 sightlines at a range of impact parameters within the virial radius of the cluster (0.2 – 1.7 Mpc) will be probed for Lyman-alpha absorption and the data compared to blind HI, dust and x-ray surveys to create a multi-phase map of the cluster’s ICM. Absorption line sightlines are commonly 40-100 kpc from a galaxy, allowing the flow of baryons between galaxies and the ICM to be assessed. The velocity distribution of the absorbers will be directly compared to simulations and used to constrain the turbulent motions of the ICM. This proposal will result in the first map of a cluster’s warm ICM and provide important tests for our theoretical understanding of cluster formation and the treatment of gas cooling in cosmological simulations. ACS/WFC3 11669 The Origins of Short Gamma-Ray Bursts During the past decade extraordinary progress has been made in determining the origin of long- duration gamma-ray bursts. It has been conclusively shown that these objects derive from the deaths of massive stars. Nonetheless, the origin of their observational cousins, short-duration gamma-ray bursts (SGRBs) remains a mystery. While SGRBs are widely thought to result from the inspiral of compact binaries, this is a conjecture. SGRBs have been found in elliptical galaxies, Abell Clusters, star-forming dwarfs and even an edge-on spiral. Whether they primarily result from an old population, a young population, or rapid evolution of binaries in globular clusters remains open. Here we propose to employ two related sets of observations which may dramatically advance our understanding of short bursts. The first is a variant of a technique that we pioneered and used to great effect in elucidating the origins of long-duration bursts. We will examine a statistical sample of hosts and measure the degree to which SGRB locations trace the red or blue light of their hosts, and thus old or young stellar populations. This will allow us to study the demographics of the SGRB population in a manner largely free of the distance dependent selection effects which have so far bedeviled this field. In the second line of attack we will use two targets of opportunity to obtain extremely precise positions of up to two nearby bursts — one on a star-forming galaxy and the other on a elliptical. Observation of the star-formation galaxy could link at least some bursts directly to a young population; however, a discovery in later images of a globular cluster at the site of the explosion in an elliptical would provide revolutionary evidence that SGRBs are formed from compact binaries. WFC3/UVIS/IR 11644 A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into the Formation of the Outer Solar System The eight planets overwhelmingly dominate the solar system by mass, but their small numbers, coupled with their stochastic pasts, make it impossible to construct a unique formation history from the dynamical or compositional characteristics of them alone. In contrast, the huge numbers of small bodies scattered throughout and even beyond the planets, while insignificant by mass, provide an almost unlimited number of probes of the statistical conditions, history, and interactions in the solar system. To date, attempts to understand the formation and evolution of the Kuiper Belt have largely been dynamical simulations where a hypothesized starting condition is evolved under the gravitational influence of the early giant planets and an attempt is made to reproduce the current observed populations. With little compositional information known for the real Kuiper Belt, the test particles in the simulation are free to have any formation location and history as long as they end at the correct point. Allowing compositional information to guide and constrain the formation, thermal, and collisional histories of these objects would add an entire new dimension to our understanding of the evolution of the outer solar system. While ground based compositional studies have hit their flux limits already with only a few objects sampled, we propose to exploit the new capabilities of WFC3 to perform the first ever large-scale dynamical-compositional study of Kuiper Belt Objects (KBOs) and their progeny to study the chemical, dynamical, and collisional history of the region of the giant planets. The sensitivity of the WFC3 observations will allow us to go up to two magnitudes deeper than our ground based studies, allowing us the capability of optimally selecting a target list for a large survey rather than simply taking the few objects that can be measured, as we have had to do to date. We have carefully constructed a sample of 120 objects which provides both overall breadth, for a general understanding of these objects, plus a large enough number of objects in the individual dynamical subclass to allow detailed comparison between and within these groups. These objects will likely define the core Kuiper Belt compositional sample for years to come. While we have many specific results anticipated to come from this survey, as with any project where the field is rich, our current knowledge level is low, and a new instrument suddenly appears which can exploit vastly larger segments of the population, the potential for discovery — both anticipated and not — is extraordinary. WFC3/UV/ACS/WFC 11636 First Resolved Imaging of Escaping Lyman Continuum The emission from star-forming galaxies appears to be responsible for reionization of the universe at z > 6. However, the models that attempt to describe the detailed impact of high-redshift galaxies on the surrounding inter-galactic medium (IGM) are strongly dependent upon several uncertain parameters. Perhaps the most uncertain is the fraction of HI-ionizing photons produced by young stars that escape into the IGM. Most attempts to measure this “escape fraction” have produced null results. Recently, a small subset of z~3 Lyman Break Galaxies (LBGs) has been found exhibiting large escape fractions. It remains unclear however, what differentiates them from other LBGs. Several models attempt to explain how such a large fraction of ionizing continuum can escape through the HI and dust in the ISM (eg. “chimneys” created by SNe winds, globular cluster formation, etc.), each producing unique signatures which can be observed with resolved imaging of the escaping Lyman continuum. To date, there are only six LBGs with individual detections of escaping Lyman continuum at any redshift. We propose a single deep, high resolution WFC3/UVIS image of the ionizing continuum (F336W) and the rest-frame UV/optical (F606W/F814W/F160W) of five of these six LBGs with large escape fractions. These LBGs have a high surface density and large escape fractions, and lie at the optimal redshift for Lyman continuum imaging with UVIS filters, making our sample especially suitable for follow-up. With these data we will discern the mechanisms responsible for producing large escape fractions, and therefore gain insight into the process of reionization.
STIS/CCD 11634
Probing the Collimation of Pristine Post-AGB Jets with STIS
The shaping of planetary and protoplanetary nebulae (PNe and PPNe) is probably the most exciting yet least understood problem in the late evolution of ~1-8 solar mass stars. An increasing number of astronomers believe that fast jet-like winds ejected in the PPN phase are responsible for carving out the diverse shapes in the dense envelopes of the Asymptotic Giant Branch (AGB) stars. To date, the properties of these post-AGB jets have not been characterized and, indeed, their launching/collimation mechanism is still subject to controversial debate. This is due to the lack of the direct observations probing the spatio-kinematic structure of post-AGB winds in the stellar vicinity (~10e16cm), which is only possible with HST+STIS.
Recently, STIS observations have allowed us for the first time the DIRECT study of the structure and kinematics of the elusive post-AGB winds in one PPN, He3-1475 (Sanchez Contreras & Sahai 2001). Those winds have been discovered through H-alpha blue-shifted absorption features in the inner 0.3″-0.7″ of the nebula. These STIS observations have revealed an ultra-fast collimated outflow relatively unaffected by the interaction with the AGB wind that is totally hidden in ground-based spectroscopic observations and HST images. The discovery of the pristine ultra-fast (~2300km/s) jet in He3-1475 is the first observational confirmation of the presence of collimated outflows as close as ~10e16cm from the central star. Most importantly, the spatio-kinematic structure of the ultra-fast jet clearly rules out hydrodynamical collimation alone and favors magnetic wind collimation. Therefore, STIS observations provide a unique method of probing the structure, kinematics, and collimation mechanism of the elusive post-AGB winds. We now propose similar observations for a sample of bipolar PPNe with ongoing post-AGB ejections in order to investigate the frequency of jets like those in He3-1475 in other PPNe and elucidate their nature and collimation mechanism. The observational characterization of these winds is indispensable for understanding this violent and important phase of post-AGB evolution.
WFC3/IR 11631
Binary Brown Dwarfs and the L/T Transition
Brown dwarfs traverse spectral types M, L and T as their atmospheric structure evolves and they cool into oblivion. This SNAPSHOT program will obtain WFC3-IR images of 45 nearby late-L and early-T dwarfs to investigate the nature of the L/T transition. Recent analyses have suggested that a substantial proportion of late-L and early-T dwarfs are binaries, comprised of an L dwarf primary and T dwarf secondary. WFC3-IR observations will let us quantify this suggestion by expanding coverage to a much larger sample, and permitting comparison of the L/T binary fraction against ‘normal’ ultracool dwarfs. Only eight L/T binaries are currently known, including several that are poorly resolved: we anticipate at least doubling the number of resolved systems. The photometric characteristics of additional resolved systems will be crucial to constraining theoretical models of these late-type ultracool dwarfs. Finally, our data will also be eminently suited to searching for extremely low luminosity companions, potentially even reaching the Y dwarf regime.
WFC3/UVIS 11628
Globular Cluster Candidates for Hosting a Central Black Hole
We are continuing our study of the dynamical properties of globular clusters and we propose to obtain surface brightness profiles for high concentration clusters. Our results to date show that the distribution of central surface brightness slopes do not conform to standard models. This has important implications for how they form and evolve, and suggest the possible presence of central intermediate-mass black holes. From our previous archival proposals (AR-9542 and AR- 10315), we find that many high concentration globular clusters do not have flat cores or steep central cusps, instead they show weak cusps. Numerical simulations suggest that clusters with weak cusps may harbor intermediate-mass black holes and we have one confirmation of this connection with omega Centauri. This cluster shows a shallow cusp in its surface brightness profile, while kinematical measurements suggest the presence of a black hole in its center. Our goal is to extend these studies to a sample containing 85% of the Galactic globular clusters with concentrations higher than 1.7 and look for objects departing from isothermal behavior. The ACS globular cluster survey (GO-10775) provides enough objects to have an excellent coverage of a wide range of galactic clusters, but it contains only a couple of the ones with high concentration. The proposed sample consists of clusters whose light profile can only be adequately measured from space-based imaging. This would take us close to completeness for the high concentration cases and therefore provide a more complete list of candidates for containing a central black hole. The dataset will also be combined with our existing kinematic measurements and enhanced with future kinematic studies to perform detailed dynamical modeling.
ACS/WFC/WFC3/IR 11624
Black Hole Superkicks: Lmaging the Site of a Gravitational Wave Recoil Event
Recent numerical relativity simulations of coalescing, binary supermassive black holes (SMBHs) predict kick velocities as large as several thousand km/s due to anisotropic emission of gravitational waves. We have recently discovered the best candidate to date for such a recoiling SMBH, the quasar SDSS0927+2943. It shows an exceptional optical emission-line spectrum with two sets of emission lines; one set of very narrow emission lines, and a second set of broad Balmer and broad high-ionization forbidden lines which are blueshifted by 2650 km/s relative to the narrow emission lines. This is the predicted spectroscopic signature of a SMBH recoiling from the core of its host galaxy, carrying with it the broad-line gas while leaving behind the bulk of the narrow-line gas. We apply for HST imaging in two filters for two orbits each in order to confirm the recoil model by detecting the host galaxy of the SMBH and measuring the angular offset of the recoiling SMBH from the host galaxy core; and determining, if possible, the morphology of the host galaxy in order to constrain its merger history. Confirmation of the SMBH ejection model for SDSSJ0927+2943 with HST will show decisively that kicks large enough to remove SMBHs completely from their host galaxies do occur, a result that would have profound implications for models of SMBH evolution and galaxy assembly and for numerical relativity.
WFC3/UV 11602
High-resolution imaging of three new UV-bright lensed arcs
We have identified and spectroscopically confirmed three new strongly lensed, UV-bright star-forming galaxies at z ~ 2 that are similar to the well-studied gravitationally lensed Lyman Break Galaxy (LBG) MS1512-cB58, and are of comparable brightness to the ”8 O’Clock Arc” (Allam et al. 2007) and ”Clone” systems (Lin et al. 2008). The 8 O’Clock Arc and Clone have already been awarded 20 orbits for deep WFPC2 and NICMOS imaging in five bands (HST cycle 16, Program 11167, PI: Allam). Adding these three recently discovered objects thus completes a unique set of the brightest known strongly lensed galaxies at z ~ 2, with magnitudes of r~20-21, and they provide a new window into the detailed study of the properties of high redshift galaxies. We propose 21 orbits for deep WFC3 imaging in five bands (F475W, F606W, F814W, F110W, and F160W) in order to construct detailed lensing models, to probe the mass and light profiles of the lensing galaxies and their environments, and to constrain the spectral energy distributions, star formation histories, and morphologies of the lensed galaxies.
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.
