Brigitte Rocca-Volmerange

STELIB: A library of stellar spectra at R 2000 ?;??

We present STELIB ? , a new spectroscopic stellar library, available at http://webast.ast.obs-mip.fr/stelib. STELIB consists of an homogeneous library of 249 stellar spectra in the visible range (3200 to 9500 A), with an intermediate spectral resolution (<3 A) and sampling (1 A). This library includes stars of various spectral types and luminosity classes, spanning a relatively wide range in metallicity. The spectral resolution, wavelength and spectral type coverage of this library represents a substantial improvement over previous libraries used in population synthesis models. The overall absolute photo- metric uncertainty is 3%.

Gaia Universe model snapshot - A statistical analysis of the expected contents of the Gaia catalogue

Context. This study has been developed in the framework of the computational simulations that are executed for the preparation of the ESA Gaia astrometric mission. Aims. We focus on describing the objects and characteristics that Gaia will potentially observe without taking into consideration instrumental effects (detection efficiency, observing errors). Methods. The theoretical Universe model prepared for the Gaia simulation has been statistically analysed at a given time. Ingredients of the model are described, with the greatest emplasis on the stellar content, the double and multiple stars, and variability. Results. In this simulation the errors have not yet been included. Hence we estimated the number of objects and their theoretical photometric, astrometric and spectroscopic characteristics if they are perfectly detected. We show that Gaia will be able to potentially observe 1.1 billion of stars (single or part of multiple star systems) of which about 2% are variable stars and 3% have one or two exoplanets. At the extragalactic level, observations will be potentially composed of several millions of galaxies, half a million to 1 million quasars and about 50 000 supernovae that will occur during the five years of the mission.

The European Large Area ISO Survey – II. Mid‐infrared extragalactic source counts

We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um&~1mJy at 6.7um. We separate the stellar contribution from the extragalactic using identifications with APM sources made with the likelihood ratio technique. We quantify the completeness&reliability of our source extraction using (a) repeated observations over small areas, (b) cross-IDs with stars of known spectral type, (c) detections of the PSF wings around bright sources, (d) comparison with independent algorithms. Flux calibration at 15um was performed using stellar IDs; the calibration does not agree with the pre-flight estimates, probably due to effects of detector hysteresis and photometric aperture correction. The 6.7um extragalactic counts are broadly reproduced in the Pearson&Rowan-Robinson model, but the Franceschini et al. (1997) model underpredicts the observed source density by ~0.5-1 dex, though the photometry at 6.7um is still preliminary. At 15um the extragalactic counts are in excellent agreement with the predictions of the Pearson&Rowan-Robinson (1996), Franceschini et al. (1994), Guiderdoni et al. (1997) and the evolving models of Xu et al. (1998), over 7 orders of magnitude in 15um flux density. The counts agree with other estimates from the ISOCAM instrument at overlapping flux densities (Elbaz et al. 1999), provided a consistent flux calibration is used. Luminosity evolution at a rate of (1+z)^3, incorporating mid-IR spectral features, provides a better fit to the 15um differential counts than (1+z)^4 density evolution. No-evolution models are excluded, and implying that below around 10mJy at 15um the source counts become dominated by an evolving cosmological population of dust-shrouded starbursts and/or active galaxies.

CO emission and associated H I absorption from a massive gas reservoir surrounding the z = 3 radio galaxy B3 J2330+3927

We present results of a comprehensive multi-frequency study of the radio galaxy B3 J2330+3927. The 1. �� 9 wide

The European Large Area ISO Survey – III. 90-μm extragalactic source counts

We present results and source counts at 90micron extracted from the Preliminary Analysis of the European Large Area ISO Survey (ELAIS). The survey covered about 11.6 square degrees of the sky in four main areas and was carried out with the PHOT instrument onboard the Infrared Space Observatory (ISO). The survey is at least an order of magnitude deeper than the IRAS 100micron survey and is expected to provide constraints on the formation and evolution of galaxies. The majority of the detected sources are associated with galaxies on optical images. In some cases the optical associations are interacting pairs or small groups of galaxies suggesting the sample may include a significant fraction of luminous infrared galaxies. The source counts extracted from a reliable subset of the detected sources are in agreement with strongly evolving models of the starburst galaxy population.

Rapidly growing black holes and host galaxies in the distant Universe from the Herschel Radio Galaxy Evolution Project

We present results from a comprehensive survey of 70 radio galaxies at redshifts 1 10(12) L-circle dot) or hyper-luminous (L-tot(IR) > 10(13) L-circle dot) infrared galaxies. We fit the infrared SEDs with a set of empirical templates which represent dust heated by a variety of starbursts (SB) and by an active galactic nucleus (AGN). We find that the SEDs of radio galaxies require the dust to be heated by both AGN and SB, but the luminosities of these two components are not strongly correlated. Assuming empirical relations and simple physical assumptions, we calculate the star formation rate (SFR), the black hole mass accretion rate ((M) over dot(BH)), and the black hole mass (M-BH) for each radio galaxy. We find that the host galaxies and their black holes are growing extremely rapidly, having SFR approximate to 100-5000 M-circle dot yr(-1) and. (M) over dot(BH) approximate to 1-100 M(circle dot)yr(-1). The mean specific SFRs (sSFR) of radio galaxies at z > 2 : 5 are higher than the sSFR of typical star forming galaxies over the same redshift range, but are similar or perhaps lower than the galaxy population for radio galaxies at z < 2.5. By comparing the sSFR and the specific. (M) over dot(BH) (s(M) over dot(BH)), we conclude that black holes in radio loud AGN are already, or soon will be, overly massive compared to their host galaxies in terms of expectations from the local M-BH-M-Gal relation. In order to catch up with the black hole, the galaxies require about an order of magnitude more time to grow in mass at the observed SFRs compared to the time the black hole is actively accreting. However, during the current cycle of activity, we argue that this catching up is likely to be difficult because of the short gas depletion times. Finally, we speculate on how the host galaxies might grow sufficiently in stellar mass to ultimately fall onto the local MBH-MGal relation.

Merging History Trees of Dark Matter Haloes: a Tool for Exploring Galaxy Formation Models

A method of deriving and using merging history trees of dark matter galaxy haloes directly from pure gravity N-body simulations is presented. This combines the full nonlinearity of N-body simulations with the flexibility of the semi-analytical approach. Merging history trees derived from power-law initial perturbation spectrum simulations (for indices n = 2 and n = 0) by Warren et al. (1992) are shown. As an example of a galaxy formation model, these are combined with evolutionary stellar population synthesis, via simple scaling laws for star formation rates, showing that if most star formation occurs during merger-induced bursts, then a nearly flat faint-end slope of the galaxy luminosity function may be obtained in certain cases. Interesting properties of hierarchical halo formation are noted: (1) In a given model, merger rates may vary widely between individual haloes, and typically 20%�30% of a halo’s mass may be due to infall of uncollapsed material. (2) Small mass haloes continue to form at recent times: as expected, the existence of young, low redshift, low metallicity galaxies (e.g., Izotov et al. 1997) is consistent with hierarchical galaxy formation models. (3) For n = 2, the halo spatial correlation function can have a very high initial bias due to the high power on large scales.

RAPID COEVAL BLACK HOLE AND HOST GALAXY GROWTH IN MRC 1138-262: THE HUNGRY SPIDER

We present a detailed study of the infrared spectral energy distribution of the high-redshift radio galaxy MRC1138-26 at z = 2.156, also known as the Spiderweb Galaxy. By combining photometry from Spitzer, Herschel and LABOCA we fit the rest-frame 5 300µm emission using a two component, starburst and active galactic nucleus (AGN), model. The total infrared (8 1000µm) luminosity of this galaxy is (1.97±0.28)×10 13 L⊙ with (1.17±0.27) and (0.79±0.09)×10 13 L⊙ due to the AGN and starburst components respectively. The high derived AGN accretion rate of � 20% Eddington, and the measured star formation rate (SFR) of 1390±150M⊙yr −1 , suggest that this massive system is in a special phase of rapid central black hole and host galaxy growth, likely caused by a gas rich merger in a dense environment. The accretion rate is sufficient to power both the jets and the previously observed large outflow. The high SFR and strong outflow suggest this galaxy could potentially exhaust its fuel for stellar growth in a few tens of Myr, although the likely merger of the radio galaxy with nearby satellites suggest bursts of star formation may recur again on time scales of several hundreds of Myr. The age of the radio lobes implies the jet started after the current burst of star formation, and therefore we are possibly witnessing the transition from a merger-induced starburst phase to a radio-loud AGN phase. We also note tentative evidence for [CII]158µm emission. This paper marks the first results from the Herschel Galaxy Evolution Project (Project HeRG ´ E), a systematic study of the evolutionary state of 71 high redshift, 1 < z < 5.2, radio galaxies. Subject headings: galaxies: active, formation, high redshift, individual (MRC 1138-262)

A search for distant radio galaxies from SUMSS and NVSS — I. Sample definition, radio and K-band imaging

We present the first results from a pilot study to search for distant radio galaxies in the southern hemisphere (δ 15 mJy. We observed 71 sources without bright optical or near-infrared counterparts at 1.385 GHz with the ATCA, providing ∼5 arcsec resolution images and subarcsec positional accuracy. To identify their host galaxies, we obtained near-infrared K-band images with IRIS2 at the AAT and Soft at the NTT. We identify 92 per cent of the USS sources down to K ∼ 20.5. The SUMSS-NVSS USS sources have a surface density more than 4 times higher than USS sources selected at lower frequencies. This is due to the higher effective selection frequency, and the well-matched resolutions of both surveys constructed using the same source fitting algorithm. The scattering of α > -1.3 sources into the USS sample due to spectral index uncertainties can account for only 35 per cent of the observed USS sources. Because our sample appears to contain a similar fraction of very distant (z > 3) galaxies, selecting USS sources from SUMSS-NVSS should allow us to identify large numbers of massive galaxies at high redshift.

Jet and torus orientations in high redshift radio galaxies

We examine the relative orientation of radio jets and dusty t ori surrounding the AGN in powerful radio galaxies at z > 1. The radio core dominance R = P 20 GHz core /P 500 MHz extended serves as an orientation indicator, measuring the ratio bet ween the anisotropic Doppler-beamed core emission and the isotropic lobe emission. Assuming a fix ed cylindrical geometry for the hot, dusty torus, we derive i ts inclination i by fitting optically-thick radiative transfer models to spe ctral energy distributions obtained with the Spitzer Space Telescope. We find a highly significant anti-correlation ( p 1.3.