This document introduces the reports by the Commissions and Working Groups of Division IX.

We present initial results from a survey of the Orion A and B molecular clouds made with the InfraRed Array Camera (IRAC) onboard the Spitzer Space Telescope. This survey encompasses a total of 5.6 square degrees with the sensitivity to detect objects below the hydrogen burning limit at an age of 1 Myr. These observations cover a number of known star forming regions, from the massive star forming clusters in the Orion Nebula and NGC 2024, to small groups of low mass stars in the L1641. We combine the IRAC photometry with photometry from the 2MASS point source catalog and use the resulting seven band data to identify stars with infrared excesses due to dusty disks and envelopes. Using the presence of an infrared excess as an indicator of youth, we show the distribution of young stars and protostars in the two molecular clouds. We find that roughly half of the stars are found in dense clusters surrounding the two regions of recent massive star formation in the Orion clouds, NGC 2024 and the Orion Nebula.

We compare [$\alpha$/Fe], metallicity, and age distributions of globular clusters in elliptical, lenticular, and spiral galaxies, which we derive from Lick line index measurements. We find a large number of globular clusters in elliptical galaxies that reach significantly higher [$\alpha$/Fe] values ($>0.5$ dex) than clusters in lenticular and spiral galaxies. Most of these highly $\alpha$-enriched globular clusters are old ($t > 8$ Gyr) and exhibit relatively high metallicities up to solar values. Given the lower [$\alpha$/Fe] ratios of the diffuse stellar population in early-type galaxies, our results suggest that the extremely $\alpha$-enhanced globular clusters are members of the the very first generation of star clusters formed, and that their formation epochs likely predate the formation of the majority of stars in giant early-type galaxies.

We use cosmological sph simulations to investigate the effects of mergers and interactions on the formation of the bulge and disc components of galactic systems. We find that secular evolution during mergers seems to be a key process in the formation of stable disc-bulge systems with observational counterparts and contributes to establish the fundamental relations observed in galaxies. Our findings suggest that the secular evolution phase couples the formation mechanisms of the bulge and disc components. According to our results, depending on the particular stability properties and merger parameters, violents events could drive a morphological loop in which the outcome could be a disc or a spheroid.

The intergalactic medium revealed by the numerous absorption lines seen in quasar spectra (the so-called Ly $\alpha$ forest) is believed to trace the potential wells of the dark matter. This is a unique tool to derive the power-spectrum of the initial fluctuations from high resolution and high S/N ratio spectra. One of the major limitations in these studies is the accuracy to which the quasar continuum is known. To investigate this problem, we have observed at intermediate spectral resolution ten bright and high redshift quasars (2.1 $< z_{em} <$ 4.7) that have also been observed with UVES. We shall compare the continuum determinations for both data sets.

We present X-ray properties of NGC 300 point sources, extracted from 66 ksec of XMM-Newton data taken in 2000 December and 2001 January. A total of 163 sources was detected in the energy range of 0.3–6 keV. We report on the global properties of the sources detected inside the $D_{25}$ optical disk, such as the hardness ratio and X-ray fluxes, and spectral fitting of the brightest sources. We also present some properties of their optical counterparts found in B, V, and R images from the 2.2 m MPG/ESO telescope. Furthermore, we cross-correlate the X-ray sources with SIMBAD, the USNO-A2.0 catalog, and radio catalogues.

We present the main results of our study of photometric solar-analog stars.

Many methods have been proposed for the detection of exoplanets. The minimum detectable planetary size and mass, and the maximum distance from us at which exoplanets are observable, are determined by both technological and environmental constraints. The unique atmospheric conditions found at Dome C offer significant advantages. Using what is now known about the turbulence profile of the atmosphere above Antarctic plateau sites, we explore the potential these sites offer for detecting exoplanets around nearby stars using various methods.

In this paper, we will review recent progress made in the understanding of cosmic silicates and the experimental characterization of relevant analogue materials. We will introduce the main structural properties of silicates. Then we will discuss recent infrared observations with a special emphasis on protoplanetary disks and AGNs. In the experimental section we will describe the optical properties of silicate grains. Here we will concentrate on fundamental optical data and the dependence of the optical behavior on particle shape and temperature.

In recent years there has been rapid progress in the research of Active Galactic Nuclei (AGNs), such as central super-massive black holes (SBH), accretion processes, and their host galaxies. Using data from ROSAT point sources, we found that the soft X-ray spectra of narrow-line Seyfert 1 galaxies (NLS1s) and Blazars become harder during X-ray flux increases, while the spectra of broad-line AGNs (BL AGNs) become softer. From ASCA data, we found that NLS1s and BL AGNs follow the same $\sigma^{2}-M_{MBH}$ relation, where $\sigma^{2}$ is the excess variance in the hard X-ray band. With the accretion efficiency of AGNs, we found that most of the radio-loud quasars possibly possess a Kerr SBH, while the Seyfert 1 galaxies and radio-quiet quasars possess Schwarzschild SBH. We also studied the relation between the central black holes and their host galaxies. It was found that NLS1s appear to have genuinely lower MBH/bulge mass ratios. And the width of the [O III] line is not a good tracer of host velocity dispersion. NLS1s play a special role in our understanding of the evolution of galaxies and their central SBHs.

The X-ray populations of spiral galaxies consist almost entirely of accreting X-ray binaries and supernova remnants. For the most luminous sources, it is possible to use X-ray spectroscopy and variability studies to gain insights into the nature of the sources. However, without unambiguously identified optical counterparts, it is impossible to definitively classify sources as, e.g. high-mass or low-mass X-ray binaries. The nearby interacting galaxy M51 is one of the best-studied galaxies across all wavelengths. At a distance of around 8 Mpc, it is possible to resolve features on scales of a few parsecs both in the X-ray and the optical. Recently, M51 was observed with the Advanced Camera for Surveys on the Hubble Space Telescope as part of a Hubble Legacy program. M51 has also been observed 3 times with the Chandra X-ray observatory. Combining these two datasets, we present initial results on the optical environments of M51 X-ray sources as the first part of a truly multi-wavelength study of X-ray sources in nearby galaxies.

Even a brief glance at astronomical journals indicates the breadth and depth of observational projects making use of photometric and polarimetric techniques. Examples of ongoing photometric and polarimetric research as related by Commission Members follows. I thank the Commission Members, acknowledged below, for their input.

We present results from photometric and spectroscopic survey of giant stars in the Leo I dwarf spheroidal galaxy. We find compelling evidence that this galaxy has been tidally disrupted.

We present a compiled catalogue of effective temperatures, surface gravities iron and magnesium abundances, along with distances, velocity components, and orbital elements for stars in the solar vicinity. Abundances were found from 1412 determinations in 31 publications for 876 dwarfs and subgiants by means of a three-step iteration averaging procedure, with weights assigned to each source of data as well as to each individual determination. The assumed coverage completeness for data sources containing more than 5 stars, as of late 2003, exceeds 90%. For the vast majority of stars in the catalogue, the spatial-velocity components were derived from modern high-precision astrometric observations, and their galactic-orbit elements were computed using a three-component model of the Galaxy, consisting of a disk, a bulge, and a massive extended halo.

The limitation to ground based astronomy is the Earth's atmosphere. The atmosphere above the Antarctic plateau is fundamentally different in many regards compared to the atmosphere at temperate sites. The extreme altitude, cold and low humidity offer a uniquely transparent atmosphere at many wavelengths. Studies at the South Pole have shown additionally that the turbulence properties of the night time polar atmosphere are unlike any mid latitude sites. The lack of high altitude turbulence combined with low wind speeds presents favorable conditions for interferometry. More recent site testing at Dome C has revealed the most superb seeing of any site tested. The unique properties of the polar atmosphere can be exploited for Extra-solar Planet studies with differential astrometry, differential phase and nulling interferometers.

This review discusses near- and mid- infrared observations of Ultracompact (UC) HII regions. The importance of ISO mid-IR fine-structure nebular lines is emphasised, since only a small fraction of UCHII regions are observed directly in the near-IR. The reliability of contemporary atmospheric models for such indirect diagnostics is discussed, whilst a revised spectral type-temperature calibration is presented for Galactic O3 to B3 dwarfs. In particular, fine-structure line derived properties of G29.96–0.02 differ from the direct near-IR spectroscopic result and represents a serious discrepancy which needs to be addressed. Mid-IR MSX and Spitzer imaging permits the identification of those UCHII regions for which far-IR IRAS fluxes are reliable, relevant to the single versus cluster nature of individual sources. High spatial resolution imaging with ground-based 8m telescopes allows more direct tests, as recently applied to G70.29+1.60. Finally, recent Spitzer mid-IR observations of Giant HII regions are briefly discussed.

Comets are among the most primitive bodies of the solar system, and their chemical composition is rich in information on the protosolar nebula and its possible connection with interstellar cloud chemistry. Comets are also a source of light atoms and, possibly, prebiotic organic molecules for the early Earth. We know better and better the abundances of cometary volatiles through spectroscopy, mainly at infrared and radio wavelengths. Another crucial component of cometary matter – organic refractories – is still poorly characterized, however.

We summarize here the $\sim$30 abundances and $\sim$20 upper limits obtained on cometary volatiles and highlight a few species and problems: ethylene glycol, NS, HNC/HCN, $^{14}$N/$^{15}$N, the origin of CN, CS$_{2}$, PAHs, and H$_{2}$O. Comet-to-comet variations and comet internal heliocentric variations can now be studied, and cometary comas can be mapped with a variety of techniques. We list a number of temperature indicators, for they can help understand the relation between IS and cometary matters, which present both a global similarity but also marked differences, such as the high ethylene glycol content of comets.

We conclude by outlining a few key problems to be addressed by future ground-based and space instruments or by cometary sample analysis. For many species, we stress that laboratory data are missing on spectroscopy, photodissociation and collisions with H$_{2}$O.

We discuss the opportunities to use the future ELTs to study in detail the properties and the evolution peculiarities of individual massive stars with a metal content typical of galaxies in the Universe during the first 0.5–1Gyr, corresponding to the earliest known newly formed galaxies at redshifts of $z$ = 6–10. This is possible in principle due to the existence in the local Universe of starbursting galaxies with metallicities of $\sim$1/30 Z$_{\odot}$. The nearest such galaxies are DDO 68 at $\sim$6.5 Mpc with 12+log(O/H) = 7.21 and I Zw 18 at 15 Mpc with 12+log(O/H) = 7.17. For the youngest star clusters (with ages of T $<$ 4–5Myr) in these most metal-poor galaxies, stars with masses up to 40–60 M$_{\odot}$ should be present on both the Main Sequence and the later evolution stages, including the WR stage. They are expected to have apparent magnitudes as bright as $V\,{=}\,21^m$ for DDO 68 and $V\,{=}\,23^m$ for I Zw 18. Good S/N-ratio spectroscopy with telescopes like OWL or JWST, allowing near-milli-arcsecond angular resolution, will provide unique information to check the most up-to-date models of massive star evolution in the very low metallicity regime, and thus, establish a firm basis to model the effects of star formation in ‘primordial’ galaxies, at the epoch of galaxy formation. Such observations will also provide an independent channel to probe the primordial Helium abundance.

In May/June 2005, Chandra observed M81 fifteen times, roughly once every three days, as part of our proposal to explore the days to weeks timescale of variability for extragalactic point sources. Each observation reached a sensitivity of $5\,{\times}\,10^{36}$ erg/s. Because these observations probe the timescale on which X-ray binaries typically evolve, we can now compare extragalactic sources to Galactic X-ray binaries on a more equal level than has been possible in the past. In addition, we can measure and quantify any possible time variability of M81's X-ray luminosity function and investigate alternative methods to characterize a galaxy's dynamic X-ray source population. We present here preliminary results of the observations.

The Spitzer Space Telescope is very efficient at moderate-depth infrared mapping. The Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE) and other projects have now imaged most of the massive star formation regions in the inner Galaxy. In this case, quantity is quality–the large datasets allow statistical and global analysis of star forming regions that was previously difficult. Data such as the GLIMPSE survey is proving useful to study different evolutionary stages of massive star formation, from pre-protostellar clouds through feedback and triggered star formation. We discuss selected team results relevant to each of these stages: mapping infrared dark clouds and the mid-IR extinction law, studies using radiative transfer models of the entire protostellar population of star forming regions such as M16 and M17 (see also Whitney, this conference), feedback and star formation in the G305 and RCW79 giant HII regions, and GLIMPSE's comment on even older objects such as debris disks and PN. Continuing similar analysis will hopefully lead to better understanding of large-scale questions of Galactic star formation such as the total star formation rate and the relationships between star formation and Galactic structure.