The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated
by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the highenergy
universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV.
These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3–12 keV with
high spectral resolution of ΔE ≦ 7 eV, enabled by a micro-calorimeter array located in the focal plane of
thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5–80 keV, located in the focal plane of
multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4–12 keV,
with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera
type soft gamma-ray detector, sensitive in the 40–600 keV band. The simultaneous broad bandpass, coupled
with high spectral resolution, will enable the pursuit of a wide variety of important science themes.
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated
by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the
high-energy universe by performing high-resolution, high-throughput spectroscopy with moderate angular
resolution. ASTRO-H covers very wide energy range from 0.3 keV to 600 keV. ASTRO-H allows a combination
of wide band X-ray spectroscopy (5-80 keV) provided by multilayer coating, focusing hard X-ray
mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-12 keV)
provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD
camera as a focal plane detector for a soft X-ray telescope (0.4-12 keV) and a non-focusing soft gamma-ray
detector (40-600 keV) . The micro-calorimeter system is developed by an international collaboration led
by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of
ΔE ~7 eV provided by the micro-calorimeter will enable a wide variety of important science themes to be
The Constellation-X Observatory is currently planned as NASA's next major X-ray observatory to be launched towards
the end of the next decade. The driving science goals for the mission are to: 1) Trace the evolution of Black Holes with
cosmic time and determine their contribution to the energy output of the Universe; 2) Observe matter spiraling into
Black Holes to test the predictions of General Relativity; 3) Use galaxy clusters to trace the locations of Dark Matter and
follow the formation of structure as a function of distance; 4) Search for the missing baryonic matter; 5) Directly observe
the dynamics of Cosmic Feedback to test models for galaxy formation; 6) Observe the creation and dispersion of the
elements in supernovae; and 7) Precisely constrain the equation of state of neutron stars. To achieve these science goals
requires high resolution (R > 1250) X-ray spectroscopy with 100 times the throughput of the Chandra and XMMNewton.
The Constellation-X Observatory will achieve this requirement with a combination of four large X-ray
telescopes on a single satellite operating in the 0.25 to 10 keV range. These telescopes will feed X-ray micro-calorimeter
arrays and grating spectrometers. A hard X-ray telescope system will provide coverage up to at least 40 keV. We
describe the mission science drivers and the mission implementation approach.
Spatially resolved X-ray spectroscopy with high spectral resolution allows the study of astrophysical processes in
extended sources with unprecedented sensitivity. This includes the measurement of abundances, temperatures, densities,
ionisation stages as well as turbulence and velocity structures in these sources. An X-ray calorimeter is planned for the
Russian mission Spektr Röntgen-Gamma (SRG), to be launched in 2011. During the first half year (pointed phase) it will
study the dynamics and composition of of the hot gas in massive clusters of galaxies and in supernova remnants (SNR).
During the survey phase it will produce the first all sky maps of line-rich spectra of the interstellar medium (ISM).
Spectral analysis will be feasible for typically every 5° x 5° region on the sky. Considering the very short time-scale for
the development of this instrument it consists of a combination of well developed systems. For the optics an extra
eROSITA mirror, also part of the Spektr-RG payload, will be used. The detector will be based on spare parts of the
detector flown on Suzaku combined with a rebuild of the electronics and the cooler will be based on the design for the
Japanese mission NeXT. In this paper we will present the science and give an overview of the instrument.
The NeXT (New exploration X-ray Telescope), the new Japanese X-ray Astronomy Satellite following Suzaku,
is an international X-ray mission which is currently planed for launch in 2013. NeXT is a combination of wide
band X-ray spectroscopy (3-80 keV) provided by multi-layer coating, focusing hard X-ray mirrors and hard
X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-10 keV) provided by thin-foil
X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane
detector for a soft X-ray telescope and a non-focusing soft gamma-ray detector. With these instruments, NeXT
covers very wide energy range from 0.3 keV to 600 keV. The micro-calorimeter system will be developed by
international collaboration lead by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with
high spectral resolution of ΔE ~7 eV by the micro-calorimeter will enable a wide variety of important science
themes to be pursued.
How structures of various scales formed and evolved from the early Universe up to present time is a fundamental
question of astrophysics. EDGE will trace the cosmic history of the baryons from the early generations of massive
stars by Gamma-Ray Burst (GRB) explosions, through the period of galaxy cluster formation, down to the very low
redshift Universe, when between a third and one half of the baryons are expected to reside in cosmic filaments undergoing
gravitational collapse by dark matter (the so-called warm hot intragalactic medium). In addition EDGE, with its
unprecedented capabilities, will provide key results in many important fields. These scientific goals are feasible with a
medium class mission using existing technology combined with innovative instrumental and observational capabilities
by: (a) observing with fast reaction Gamma-Ray Bursts with a high spectral resolution (R ~ 500). This enables the study
of their (star-forming) environment and the use of GRBs as back lights of large scale cosmological structures; (b)
observing and surveying extended sources (galaxy clusters, WHIM) with high sensitivity using two wide field of view
X-ray telescopes (one with a high angular resolution and the other with a high spectral resolution). The mission concept
includes four main instruments: a Wide-field Spectrometer with excellent energy resolution (3 eV at 0.6 keV), a Wide-
Field Imager with high angular resolution (HPD 15") constant over the full 1.4 degree field of view, and a Wide Field
Monitor with a FOV of <sup>1</sup>/<sub>4</sub> of the sky, which will trigger the fast repointing to the GRB. Extension of its energy response
up to 1 MeV will be achieved with a GRB detector with no imaging capability. This mission is proposed to ESA as part
of the Cosmic Vision call. We will briefly review the science drivers and describe in more detail the payload of this
The Constellation-X mission will address questions central to the NASA Beyond Einstein Program, using high
throughput X-ray spectroscopy to measure the effects of strong gravity close to the event horizon of black holes, study
the formation and evolution of clusters of galaxies to precisely determine cosmological parameter values, measure the
properties of the Warm-Hot Intergalactic Medium, and determine the equation of state of neutron stars. Achieving these
science goals requires a factor of ~100 increase in sensitivity for high resolution spectroscopy over current X-ray
observatories. This paper briefly describes the Constellation-X mission, summarizes its basic performance parameters
such as effective area and spectral resolution, and gives a general update on the mission. The details of the updated
mission configuration, compatible with a single Atlas-V 551 launch vehicle, are presented.
Suzaku satellite, the Japan-US collaborative mission, was successfully launched on July 10, 2006. It is equipped with 5 soft X-ray telescopes (XRT), one micro-calorimeter (XRS), 4 CCD cameras (XIS), and one hard X-ray detector (HXD). Though XRS is not operational, XIS and HXD provide us with new views of thermal and non-thermal phenomena. Better efficiency and energy resolution of CCD allow us to investigate emission lines from C and O, as well as Fe-K lines. Objectives are planetary nebula, supernova remnants, Galactic center and cluster of galaxies. The status and origin of the plasmas are well examined from the line energies, line ratios, and line broadening. Another area, Suzaku satellite has advantages is broadband spectroscopy with better sensitivity. Targets are X-ray binaries, active galactic nuclei, and cluster of galaxies. Non-thermal components are well determined by the broad band spectra and their variability. Broad iron lines are well confirmed with accurate determination of underlying continuum components. After the performance verification phase with 70 targets, the first term of general observer program (AO-1) has been started from April 1. AO-2 proposals are due December 1, 2006. It is also announce that a Suzaku Symposium will be held on December 4-8, Kyoto, Japan.
The NASA strategic roadmap on the Origin, Evolution, Structure and Destiny of the Universe is one of 13 roadmaps that outline NASA's approach to implement the vision for space exploration. The roadmap outlines a program to address the questions: What powered the Big Bang? What happens close to a Black Hole? What is Dark Energy? How did the infant universe grow into the galaxies, stars and planets, and set the stage for life? The roadmap builds upon the currently operating and successful missions such as HST, Chandra and Spitzer. The program contains two elements, Beyond Einstein and Pathways to Life, performed in three phases (2005-2015, 2015-2025 and >2025) with priorities set by inputs received from reviews undertaken by the National Academy of Sciences and technology readiness. The program includes the following missions: 2005-2015 GLAST, JWST and LISA; 2015-2025 Constellation-X and a series of Einstein Probes; and >2025 a number of ambitious vision missions which will be prioritized by results from the previous two phases.
The Swift Gamma Ray Burst Explorer, chosen in October 1999 as NASA's next MIDEX mission, is now scheduled for launch in October 2004. SWIFT carries three complementary instruments. The Burst Alert Telescope (BAT) identifies gamma-ray bursts (GRBs) and determines their location on the sky to within a few arc-minutes. Rapid slew by the fast-acting SWIFT spacecraft points the two narrow field instruments, an X-ray Telescope (XRT) and an Ultraviolet/Optical Telescope (UVOT), to within the BAT error circle within 70 seconds of a BAT detection. The XRT can determine burst locations to within 5 arc-seconds and measure X-ray spectra and photon flux, whilst the UVOT has a sensitivity down to 24th magnitude and sub arc-second positional accuracy in the optical/uv band. The three instruments combine to make a powerful multi-wavelength observatory with the capability for rapid determination of GRB positions to arc-second accuracy within a minute or so of their discovery, and the ability to measure light-curves and red-shifts of the bursts and after-glows. The paper summarises the mission's readiness for October's launch and operations.
The Constellation X-ray Mission is a high-throughput X-ray facility emphasizing observations at high spectral resolution (R ~ 300-3000) while covering a broad energy band (0.25-60 keV). The mission is intended to achieve a factor of 25-100 increase in sensitivity over current high resolution X-ray spectroscopy missions. Constellation-X is the X-ray astronomy equivalent of the Keck and the VLT, complementing the high spatial resolution capabilities of Changra. Constellation-X achieves its high-throughput and reduces mission risk by dividing the collecting area across four separate spacecraft launched two at a time into an L2 orbit. We describe the overall mission concept and also present a brief overview of alternate concepts which are under consideration. We discuss recent progress on the key technologies, including: lightweight, high-throughput X-ray optics, micro-caloriment spectrometer arrays, low-power and low-weight CCD arrays, lightweight gratings, multilayer coatings to enhance the hard X-ray performance of X-ray optics, and hard X-ray detectors.
Dark Energy dominates the mass-energy content of the universe (about 73%) but we do not understand it. Most of the remainder of the Universe consists of Dark Matter (23%), made of an unknown particle. The problem of the origin of Dark Energy has become the biggest problem in astrophysics and one of the biggest problems in all of science. The major extant X-ray observatories, the Chandra X-ray Observatory and XMM-Newton, do not have the ability to perform large-area surveys of the sky. But Dark Energy is smoothly distributed throughout the universe and the whole universe is needed to study it. There are two basic methods to explore the properties of Dark Energy, viz. geometrical tests (supernovae) and studies of the way in which Dark Energy has influenced the large scale structure of the universe and its evolution. DUO will use the latter method, employing the copious X-ray emission from clusters of galaxies. Clusters of galaxies offer an ideal probe of cosmology because they are the best tracers of Dark Matter and their distribution on very large scales is dominated by the Dark Energy. In order to take the next step in understanding Dark Energy, viz. the measurement of the 'equation of state' parameter 'w', an X-ray telescope following the design of ABRIXAS will be accommodated into a Small Explorer mission in lowearth orbit. The telescope will perform a scan of 6,000 sq. degs. in the area of sky covered by the Sloan Digital Sky Survey (North), together with a deeper, smaller survey in the Southern hemisphere. DUO will detect 10.000 clusters of galaxies, measure the number density of clusters as a function of cosmic time, and the power spectrum of density fluctuations out to a redshift exceeding one. When combined with the spectrum of density fluctuations in the Cosmic Microwave Background from a redshift of 1100, this will provide a powerful lever arm for the crucial measurement of cosmological parameters.
What is the nature of the Dark Energy that is driving the universe apart? Clusters of galaxies offer an ideal probe of cosmology because they are the best tracers of Dark Matter and their distribution on very large scales which is dominated by the Dark Energy. DUO will measure 10.000 clusters of galaxies, the power spectrum of density fluctuations of clusters and their number density as a function of cosmic time. Although designed long before the existence of Dark Energy was claimed, the ABRIXAS type X-ray telescope turns out to be ideally suited for this task: DUO is, in essence, a re-flight of the ABRIXAS X-ray telescope which some modifications of the focal plane instrumentation. First of all, we will use new CCDs which are improved versions of the pn-CCDs successfully flown on XMM-Newton. A modular concept having seven individual cameras in the foci of the seven mirror systems allows us to design the orientation of the seven telescopes with respect to each other matching the scientific needs of the DUO mission. Details of the concept including mechanical, electrical and thermal aspects are given.
The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution spectroscopy. The mission will also perform routine high-resolution X-ray spectroscopy of faint and extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity, and ionization state for a wide range of astrophysical problems. This has enormous potential for the discovery of new unexpected phenomena. The Constellation-X mission is a high priority in the National Academy of Sciences McKee-Taylor Astronomy and Astrophysics Survey of new Astrophysics Facilities for the first decade of the 21st century.
The new frontier in astrophysics is the study of the very first stars, galaxies and black holes in the early Universe. These objects are beyond the grasp of the current generation of X-ray telescopes such as Chandra, and so the Generation-X Vision Mission has been proposed as an X-ray observatory which will be capable of detecting these earliest objects. Xray imaging and spectroscopy of such distant objects will require an X-ray telescope with large collecting area and high angular resolution. The Generation-X concept has 100 m2 collecting area at 1 keV (1000 times larger than Chandra) and 0.1 arcsecond angular resolution (several times better than Chandra and 50 times better than the resolution goal for Constellation-X). The baseline mission involves four 8 m diameter telescopes operating at Sun-Earth L2. Such large telescopes will require either robotic or human-assisted in-flight assembly. To achieve the required effective area with launchable mass, very lightweight grazing incidence X-ray optics must be developed, having an areal density 100 times lower than in Chandra, with perhaps 0.1 mm thick mirrors requiring on-orbit figure control. The suite of available detectors for Generation-X should include a large-area high resolution imager, a cryogenic imaging spectrometer and a grating spectrometer.
The MicroArcsecond Imaging Mission (MAXIM) will resolve the event horizons of black holes with 0.1 microarcsecond imaging in the X-ray bandpass. In the NASA "Beyond Einstein" roadmap, MAXIM takes it place as the "Black hole Imager." In this paper, we will outline the scientific goals for this mission. We will describe the current state of the technology -- including a discussion of several laboratory demonstrations of X-ray interferometry. We will describe some engineering studies we have performed over the past two years.
The MAXIM Pathfinder (MP) mission is under study as a scientific and technical stepping stone for the full MAXIM X-ray interferometry mission. While full MAXIM will resolve the event horizons of black holes with 0.1 microarcsecond imaging, MP will address scientific and technical issues as a 100 microarcsecond imager with some capabilities to resolve microarcsecond structure. We will present the primary science goals of MP. These include resolving stellar coronae, distinguishing between jets and accretion disks in AGN. This paper will also present the baseline design of MP. We will overview the challenging technical requirements and solutions for formation flying, target acquisition, and metrology.
The Constellation-X mission is a large collecting area X-ray facility, emphasizing observations at high spectral resolution (R ~ 300--3000) while covering a broad energy band (0.25-60 keV). By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 25-100 increased sensitivity over current high resolution X-ray spectroscopy missions. Constellation-X is the X-ray astronomy equivalent of large ground-based optical telescopes such as the Keck and the VLT, complementing the high spatial resolution capabilities of Chandra. Key technologies under development for the mission include lightweight high throughput X-ray optics, multilayer coatings to enhance the hard X-ray performance of X-ray optics, micro-calorimeter spectrometer arrays, low power and low weight CCD arrays, lightweight gratings and hard X-ray detectors. Constellation-X will for the first time make high resolution X-ray spectroscopy of faint X-ray source populations a matter of routine. With its increased capabilities, Constellation-X will address many fundamental astrophysics questions such as observing the formation and evolution of clusters of galaxies, constraining the Baryon content of the Universe, observing the effects of strong gravity close to the event horizon of black holes and using these effects to determine the black hole rotation. The Constellation-X mission has received strong endorsements in two recent National Academy of Sciences reports: the Astronomy and Astrophysics Survey and the Committee on the Physics of the Universe.
Building an automated classifier for high-energy sources provides an opportunity to prototype approaches to building the Virtual Observatory with a substantial immediate scientific return. The ClassX collaboration is combining existing data resources with trainable classifiers to build a tool that classifies lists of objects presented to it. In our first year the collaboration has concentrated on developing pipeline software that finds and combines information of interest and in exploring the issues that will be needed for successful classification.
ClassX must deal with many key VO issues: automating access to remote data resources, combining heterogeneous data and dealing with large data volumes. While the VO must attempt to deal with these problems in a generic way, the clear science goals of ClassX allow us to act as a pathfinder exploring particular approaches to addressing these issues.
At the University of Oxford and PowderJect Pharmaceuticals plc, a unique form of needle-free injection technology has been developed. Powdered vaccines and drugs in micro-particle form are accelerated in a high-speed gas flow to sufficient velocity to enter the skin, subsequently achieving a pharmaceutical effect. To optimize the delivery of vaccines and drugs with this method a detailed understanding of the interactive processes that occur between the microparticles and the skin is necessary. Investigations to date of micro-particle delivery into excised human and animal tissue have involved image analyses of histology sections. In the present study, a series of investigations were conducted on excised human and porcine skin using the technique of Multi-Photon fluorescence excitation Microscopy (MPM) to image particles and skin structures post-penetration. Micro-particles of various size and composition were imaged with infrared laser excitation. Three-dimensional images of stratum corneum and epidermal cell deformation due to micro-particle penetration were obtained. Measurements of micro-particle penetration depth taken from z-scan image stacks were used to successfully quantify micro-particle distribution within the skin, without invasively disrupting the skin target. This study has shown that MPM has great potential for the non-invasive imaging of particle skin interactive processes that occur with the transdermal delivery of powdered micro-particle vaccines and drugs.
We describe the design of Lobster-ISS, an X-ray imaging all-sky monitor (ASM) to be flown as an attached payload on the International Space Station. Lobster-ISS is the subject of an ESA Phase-A study which will begin in December 2001. With an instantaneous field of view 162 x 22.5 degrees, Lobster-ISS will map almost the complete sky every 90 minute ISS orbit, generating a confusion-limited catalogue of ~250,000 sources every 2 months. Lobster-ISS will use focusing microchannel plate optics and imaging gas proportional micro-well detectors; work is currently underway to improve the MCP optics and to develop proportional counter windows with enhanced transmission and negligible rates of gas leakage, thus improving instrument throughput and reducing mass. Lobster-ISS provides an order of magnitude improvement in the sensitivity of X-ray ASMs, and will, for the first time, provide continuous monitoring of the sky in the soft X-ray region (0.1-3.5 keV). Lobster-ISS provides long term monitoring of all classes of variable X-ray source, and an essential alert facility, with rapid detection of transient X-ray sources such as Gamma-Ray Burst afterglows being relayed to contemporary pointed X-ray observatories. The mission, with a nominal lifetime of 3 years, is scheduled for launch on the Shuttle c.2009.
Ultra-high resolution imaging in the x-ray has the potential to revolutionize the way astronomers view the heavens. Through the use of interferometry at grazing incidence we can image the x-ray sky at the milli-arcsecond (or better) level. In this paper we describe the baseline design of the Maxim Pathfinder Mission, which will be the first interferometric x-ray observatory whose goal is to image the sky at 100 micro-arcsecond resolution in the 0.5 - 1.5 keV band with about 100 cm<SUP>2</SUP> of collecting area. This resolution is adequate to image the coronae of nearby stars and the accretion disks of quasars.
The Constellation-X mission is a large collecting area x-ray facility, emphasizing observations at high spectral resolution while covering a broad energy band. By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 100 increased sensitivity over current high resolution x-ray spectroscopy missions. The use of focusing optics across the 10-40 keV band will provide a similar factor of 100 increased sensitivity in this band. Key technologies under development for the mission include lightweight high throughput x-ray optics, multilayer coatings to enhance the hard x-ray performance of x-ray optics, micro-calorimeter spectrometer arrays with 2 eV resolution, low power and low weight CCD arrays, lightweight gratings and hard x-ray detectors. When observations commence towards the end of the next decade, Constellation-X will address many pressing questions concerning the extremes of gravity and the evolution of the Universe.
The concept of the lobster eye optics was proposed in the nineteen seventies. It has gained widespread interest in x- ray astronomy for its potential for constructing compact and focusing x-ray all sky monitors with unprecedented sensitivities. The majority of the efforts of developing a practical implementation of this optics has been devoted toward slumping square-pore micro-channel plates. While the advantages of the slumped micro-channel plates are obvious in that they can achieve potentially arc-second angular resolutions, the smoothness requirements for reflecting x- rays are hard to meet by micro-channel plates. It is not clear how the interior of the micro-channel plate pores can be polished to the desired smoothness. In this paper we propose the feasibility of a more straightforward approach of implementing the lobster eye optics with flat glass mirrors assembled in a standard Kirkpatrick-Baez configuration. We demonstrate with both simulations and laboratory test results that this implementation is both practical and meets al the requirements of an x-ray all sky monitor.
Lobster-eye optics have been proposed as an exciting development in the field of x-ray all-sky monitors. However, to date their potential has mainly been analyzed in the context of an all-sky monitor for a small satellite mission. We examine the wide range of parameters available for lobster-eye optics with different configurations. The sensitivity of the various schemes is calculated. We have also examined the current state of the art in actual lobster-eye optics. We present our experimental results and discuss realistic targets for manufacture. The impact of these targets on the calculated sensitivities is also described.
We present a conceptual design for a new x-ray all sky monitor (ASM). Compared with previous ASMs, its salient features are: (1) it has a focusing capability that increases the signal to background ratio by a factor of 3; (2) it has a broad-band width: 200 eV to 15 keV; (3) it has a large x-ray collection area: approximately 10<SUP>2</SUP> cm<SUP>2</SUP>; (4) it has a duty cycle of nearly 100%, and (5) it can measure the position of a new source with an accuracy of a few minutes of arc. These features combined open up an opportunity for discovering new phenomena as well as monitoring existing phenomena with unprecedented coverage and sensitivity.
The x-ray background spectroscopic survey (XBSS) is a SMEX mission proposed to perform a high spectral resolution all-sky survey of diffuse x-ray emission in the 50 - 2000 eV range. This spectral exploration of the x-ray background with high energy resolution will resolve important questions about the role of hot gas in the structure and evolution of the interstellar medium, the Galactic halo, and nearby intergalactic space that cannot be answered in any other way. The temperature distribution, emission measure, ionization distribution, and metallicity of the gases responsible for this emission are unknown. The survey is performed with a 6 by 6 array of cryogenic microcalorimeters that have spectral resolution of approximately 4 eV FWHM. The satellite is spin- stabilized with the spin axis directed toward the sun. The detectors look 90 degrees to the spin axis with a mechanically collimated field of view that is 5 degrees in radius. The instrument scans the entire sky twice in twelve months. During the second survey, deep exposures are performed along selected ecliptic meridians with the span axis fixed for up to 20 days at a time.
The High Throughput X-ray Spectroscopy (HTXS) mission is dedicated to observations at high spectral resolution. The HXTS mission represented a major advanced, providing as much as a factor of 100 increase in sensitivity over currently planned high resolution X-ray spectroscopy missions. This X- ray equivalent of the Keck Telescope will mark the start of a new era when high quality X-ray spectral will be obtained for all classes of X-ray sources, over a wide range of luminosity and distance. With its increased capabilities, HTXS will address many fundamental astrophysics questions such as the origin and distribution of the elements from carbon to zinc, the formation and evolution of clusters of galaxies, the validity of general relativity in the strong gravity limit, the evolution of supermassive black holes in active galactic nuclei, the details of supernova explosions and their aftermath, and the mechanisms involved in the heating of stellar coronae and driving of stellar winds.
W/Si and Co/C multilayers have been deposited on epoxy- replicated Au mirrors from the ASTRO-E telescope project, SPectrum Roentgen Gamma (SRG) flight mirrors, DURAN glass substrates and Si witness wafers. A characterization of the multilayers with both hard x-rays and soft x-rays is presented. The roughness value obtained from the Si wafers and the DURAN glass are in the range 3.0-4.2 angstrom and 4.4-4.6 angstrom, respectively. For the epoxy-replicated Au mirrors roughnesses of 5.0-5.8 angstrom are achieved, while the roughness of the SRG flight mirrors are in the range of 8.5-11.0 angstrom. This clearly indicates the effectiveness of the epoxy-replication process for the production of smooth substrates for multilayer deposition to be used in future x-ray telescopes.
We are studying a Next Generation X-ray Observatory, NGXO, that will provide a high resolution spectral capability with large collecting area, at a relatively low cost. The mission consists of two co-aligned telescope systems that provide coverage from 0.3 - 60 keV. One is optimized to cover the 0.3 - 12 keV band with 2 eV spectral resolution using an array of quantum calorimeters with a peak effective area of 2,000 cm<SUP>2</SUP>. The spectral resolution will be five times better than the calorimeter planned for Astro-E, with more than a ten-fold increase in effective area over previous high resolution x-ray spectroscopy missions. The second telescope will be the first focusing optics to operate in the 10 - 60 keV energy range, and will have arc minute angular resolution with 500 cm<SUP>2</SUP> collecting area at 30 keV. The sensitivities of the two telescopes are matched to make possible many thousands of high quality x-ray spectral observations, from an available population of more than one million galactic and extragalactic x-ray sources. The NGXO mission is capable of addressing new astrophysical problems which include: determining the mass of a black hole, neutron star, or white dwarf in binary systems from x-ray line radial velocity measurements; determining the 0.3 - 60 keV x-ray spectrum from AGN and determining their contribution to the x-ray background in this energy band; measuring Compton reflection spectra from cold material in accretion driven systems; determining the Hubble constant using resonant line absorption of QSO spectra by rich clusters; searching for a hot 10 million degree intergalactic medium; mapping the dynamics of the intracluster medium; mapping the ionization state, abundance and emission from supernova remnants on a 15 arc second angular scale; and measuring mass motion in stellar flares and the dynamics of accretion flows.