We discuss the most recent developments of the spectral analysis package SPEX. We report on the progress made in updating the atomic data that are used in the spectroscopic code. We also present a set of spectral models that are used for the analysis of high-resolution X-ray spectra of photo-ionized plasmas such as occur in active galactic nuclei. These models include absorption line spectroscopy of photoionized layers. The importance and diagnostic power of inner-shell transitions is shown. We illustrate our results with several examples of observed spectra obtained with the XMM-Newton and Chandra grating spectrometers.

The Astrophysical Plasma Emission Code (APEC) collaboration now provides public models for X-ray spectra of collisional equilibrium plasmas. These models facilitate the diagnosis of temperature, density, elemental abundance, charge state, and optical depth. We report benchmarking studies of the APEC models from the Emission Line Project, a project to test these models using high quality stellar coronal spectra. We discuss the implications of the benchmarked atomic data for non-equilibrium collisional models as well. Finally, we discuss the extension of APEC to other applications, such as opacity models for AGN.

The CHIANTI database contains assessed atomic energy levels, wavelengths, radiative transition probabilities and excitation rates necessary to calculate line emissivities and synthetic spectra of a large number of ions of astrophysical interest. CHIANTI also includes a suite of programs to carry out plasma diagnostics. In the present paper we describe the contents of the CHIANTI database, its main applications and its future developments.

Tables of wavelengths, line classifications, and transition probabilities have been critically compiled for ionized spectra of neon (Ne V-VIII), magnesium (Mg V-X), silicon (Si VI-XII), and sulfur (S VIII-XIV) in the 20 Å-170 Å region. The tables provide basic atomic data for about 3300 transitions in support of astronomical studies from the Chandra X-ray Observatory.

An overview of the online atomic database referred to as TIPTOPbase is given, in particular its opacity server (OPserver) and current developments regarding online atomic structure calculations. Efforts to include atomic data for X-ray line modeling and to integrate TIPTOPbase within the International Virtual Observatory Alliance (IVOA) are also mentioned.

The Astrophysical Plasma Emission Database (APED) contains atomic data for the 14 most abundant astrophysical elements, collected from the literature. Although APED was originally designed for use in calculating a collisional-equilibrium X-ray spectrum suitable for analysis of high-resolution data, it is in a general format which can be efficiently used to calculate absorption spectra, photoionization models, and non-equilibrium collisional models. We emphasize original sources; each transition, rate, and energy level in APED contains a bibliographic reference. The APED can be downloaded from http://cxc.harvard.edu/atomdb/, or our website WebGUIDE (http://obsvis.harvard.edu/WebGUIDE/) can be used to search for individual lines or transitions. We are continually working to expand APED (current version 1.3.1) and regularly issue updated collections.

Star cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent star bursts. These newly-formed clusters are built from recycled gas, pre-enriched to various levels within the interacting galaxies. Hence, star clusters of different ages represent a fossil record of the chemical enrichment history of their host galaxy, as well as of the host galaxy’s violent star formation history. We present a new set of evolutionary synthesis models of our GALEV code, specifically developed to include the gaseous emission of presently forming star clusters, and a new tool to analyze multi-color observations with our models. First results for newly-born clusters in the dwarf star-burst galaxy NGC 1569 are presented.

Large amount of new radiative atomic data for I) energy levels, II) oscillator strengths (f), line strengths (S), radiative transition probabilities (A), III) photoioniztion cross sections (σPI) – total and level-specific, and IV) unified total and level-specific electron-ion recombination rate coefficients, αR, including radiative and dielectronic recombination (RR and DR) are reported for various astrophysical applications. Most of the data are with fine structure. These data are not yet available from any databases. Photoionization and recombination data are self-consistent, using the same wave-function for both processes.

We have compiled the atomic and molecular numerical databases which are available through internet. The databases provide basic atomic data, such as collisional ionization and excitation cross sections, which are important for modeling and diagnosing astrophysical plasmas.

The future of Astronomy and Physics programs in the Office of Space Science is presented in the context of the overall NASA Strategic Plan. The highlights of the new road maps for the Origins and Structure and Evolution of the Universe science themes are given. A new initiative, Beyond Einstein, is discussed. New opportunities for technology development, building small missions, and conducting basic research and analysis to support NASA’s strategic goals are outlined. The status of NASA’s archives for data from its astronomy missions is presented.

Discussed here is the issue of discriminating different spectral models for diffuse emission observations with the Chandra ACIS. First background models are considered. Then standard source models such as non-ionization equilibrium and ionization equilibrium models and models with different metal abundances are considered. The datasets used are from Chandra ACIS observations of diffuse emission, in particular of the Cygnus Loop supernova remnant.

Over the last few years the high-quality imaging and spectroscopic data from Chandra and XMM-Newton have added greatly to our knowledge of the physics of radio jets. Supported by optical data, we are now able to understand much about jet energetics. Here I review the current state of knowledge.

The form of the quasar luminosity function and its redshift dependence to z~1 has long been established; powerful evolution is required so that by z=1 there is an increase of order 102 – 103 in the space density of the most luminous sources. However it is more difficult to deduce the form of the LF at high redshifts. In this contribution we discuss how a sample of relatively bright radio sources has been used to determine the high-redshift behavior of the radiodoud quasar luminosity function, and the particular advantages of using a radio-selected sample. Our results illustrate how radio-loud quasar samples can be an efficient probe of the high-redshift. Universe.

The physical and kinematical conditions of the gas surrounding an active galactic nucleus (AGN) offer key diagnostics for understanding the processes occurring in the inner few kpc around the nucleus. Neutral hydrogen can give important insights on these regions. Apart from probing the presence of gas in relatively settled conditions (i.e. circumnuclear disks/tori) it can also trace the presence of extreme outflows. Some examples of these phenomena are briefly presented.

PKS 1257—326 is one of three quasars known to show unusually large and rapid, intra-hour intensity variations, as a result of scintillation in the turbulent Galactic interstellar medium. We have measured time delays in the variability pattern arrival times at the VLA and the ATCA, as well as an annual cycle in the time-scale of variability for this source. Results of the two-station time delay observations are presented here. Implications for the scintillation of this source are discussed in the light of these results, together with results from two years of monitoring with the ATCA.

The discovery of relativistic jets in radio emitting X-ray binaries in our own galaxy has led to the term ‘microquasar’ being coined for these objects. In this paper the properties of microquasars are compared with those of quasars and radio galaxies, with the aim of trying to see how the similarities and differences can inform us about the physical conditions and evolution of jets. GRS1915+105 and SS433 are also discussed in more detail.

Of the 17 poster papers presented at IAU25 Joint Discussion 18, three (1821, 1824,1834) are essentially theoretical, three (1828,1829,1831) deal with polarization, screens and absorbers, one (1818B) considers galaxy formation and evolution, 7 (1817,1820,1826,1830,1835,1836,1837) describe source structure and spectra, and three (1812,1818,1823) deal with Intra-Day Variability (IDV).

The Galileo mission to the Jupiter system afforded the opportunity to make the first ever flyby observations of main belt asteroids. The first encounter, with 951 Gaspra, revealed an irregular, cratered surface that shows evidence of regolith optical space weathering processes. The second encounter, with 243 Ida, resulted in the discovery of the first confirmed satellite of an asteroid, Dactyl. Measurements of Dactyl’s orbit also allowed a useful determination of mass and density for Ida. In addition to these pioneering asteroid observations, Galileo also made observations of Jupiter’s small inner moons and found that they were the major source for material in Jupiter’s tenuous ring system. During it’s final data taking orbit in 2002, Galileo passed within about 250 km of the irregularly shaped satellite Amalthea. Determination of Amalthea’s mass from tracking data yields a bulk density for this small body of less than 1 gm/cc, suggesting a body of relatively high porosity. This is consistent with the growing body of data on small asteroid densities and estimates of their porosity.

At the slowly rotating C-asteroid Mathilde, the Near Earth Asteroid Rendezvous (NEAR) mission imaged only one face of the body but still constrained the density to only 1.3 g/cm3, indicating high porosity. This porosity and the approximate saturation of the surface with giant craters led to suggestions that Mathilde must be a rubble pile. At S-type Eros, NEAR measured elemental abundances and spatially resolved reflectance spectra that appear most consistent with an ordinary chondrite composition, although the Eros composition could not be identified with any known meteorite type. Imaging and altimetry data were interpreted as showing Eros to be a globally consolidated, albeit heavily fractured, collisional shard. A spectacular feature, ponding of regolith on Eros, was discovered. Continuing analyses of NEAR data suggest that Mathilde is not strengthless, and that if it is a rubble pile, large coherent components are present. Both composition and internal structure of Eros pose unresolved issues. Although almost uniform internally, Eros cannot be perfectly so. The density of 2.67 g/cm3 is significantly less than that of ordinary chondrites and suggests significant porosity, but this may not be explained by macroscopic fracturing if these spaces can be filled with particulates.