Spitzer Observations of High Redshift Radio Galaxies

We present the results of a comprehensive Spitzer survey of 70 radio galaxies across 1<z<5.2. Using IRAC, IRS and MIPS imaging we determine the rest-frame AGN contribution to the stellar emission peak at 1.6um. The stellar luminosities are found to be consistent with that of a giant elliptical with a stellar mass of 10^11-12Msun. The mean stellar mass remains constant at \~10^11.5Msun up to z=3 indicating that the upper end of the mass function is already in place by this redshift. The mid-IR luminosities imply bolometric IR luminosities that would classify all sources as ULIRGs. The mid-IR to radio luminosity generally correlate implying a common origin for these emissions. The ratio is higher than that found for lower redshift, ie z<1, radio galaxies.Comment: 6 pages, 5 figures, to appear in the proceedings of "The Spitzer Science Center 2005 Conference: Infrared Diagnostics of Galaxy Evolution", held in Pasadena, November 200

Consistency between the radio and MIR faint source counts using the radio-MIR correlation

We show from the recent extrapolation of the radio-FIR correlation to the MIR that the 20 cm and 15 um differential source counts are likely to come from the same parent population.Comment: 2 pages, 2 figures, to appear in proceedings of 'Multi-wavelength AGN surveys', Cozumel, 200

A 12 μm ISOCAM survey of the ESO-Sculptor field

We present a detailed reduction of a mid-infrared 12 μm (LW10 filter) ISOCAM open time observation performed on the ESOSculptor Survey field (Arnouts et al. 1997, A&AS, 124, 163). A complete catalogue of 142 sources (120 galaxies and 22 stars), detected with high significance (equivalent to 5σ), is presented above an integrated flux density of 0.24 mJy. Star/galaxy separation is performed by a detailed study of colour-colour diagrams. The catalogue is complete to 1 mJy and, below this flux density, the incompleteness is corrected using two independent methods. The first method uses stars and the second uses optical counterparts of the ISOCAM galaxies; these methods yield consistent results. We also apply an empirical flux density calibration using stars in the field. For each star, the 12 μm flux density is derived by fitting optical colours from a multi-band χ^2 to stellar templates (BaSel-2.0) and using empirical optical-IR colour-colour relations. This article is a companion analysis to our 2007 paper (Rocca-Volmerange et al. 2007, A&A, 475, 801) where the 12 μm faint galaxy counts are presented and analysed per galaxy type with the evolutionary code PÉGASE.3

The 12 μm ISO-ESO-Sculptor and 24 μm Spitzer faint counts reveal a population of ULIRGs as dusty massive ellipticals: Evolution by types and cosmic star formation

Context. Multi-wavelength galaxy number counts provide clues to the nature of galaxy evolution. The interpretation per galaxy type of the mid-IR faint counts obtained with ISO and Spitzer, consistent with the analysis of deep UV-optical-near IR galaxy counts, provide new constraints on the dust and stellar emission. Discovering the nature of new populations, such as high redshift ultra-luminous (≥10^(12) L_⊙) infrared galaxies (ULIRGs), is also crucial for understanding galaxy evolution at high redshifts. Aims. We first present the faint galaxy counts at 12 μm from the catalogue of the ISO-ESO-Sculptor Survey (ISO-ESS) published in a companion article (Seymour et al. 2007a, A&A, 475, 791). They go down to 0.31 mJy after corrections for incompleteness. We verify the consistency with the existing ISO number counts at 15 μm. Then we analyse the 12 μm (ISO-ESS) and the 24 μm (Spitzer) faint counts, to constrain the nature of ULIRGs, the cosmic star formation history and time scales for mass buildup. Methods. We show that the “normal” scenarios in our evolutionary code PÉGASE, which had previously fitted the deep UV-opticalnear IR counts, are unsuccessful at 12 μm and 24 μm. We thus propose a new ULIRG scenario adjusted to the observed cumulative and differential 12 μm and 24 μm counts and based on observed 12 μm and 25 μm IRAS luminosity functions and evolutionary optical/mid-IR colours from PÉGASE. Results. We succeed in simultaneously modelling the typical excess observed at 12 μm, 15 μm (ISO), and 24 μm (Spitzer) in the cumulative and differential counts by only changing 9% of normal galaxies (1/3 of the ellipticals) into ultra-bright dusty galaxies evolving as ellipticals, and interpreted as distant ULIRGs. These objects present similarities with the population of radio-galaxy hosts at high redshift. No number density evolution is included in our models even if minor starbursts due to galaxy interactions remain compatible with our results. Conclusions. Higher spectral and spatial resolution in the mid-IR, together with submillimeter observations using the future Herschel observatory, will be useful to confirm these results

The 12 μm ISO-ESO-Sculptor and 24 μm Spitzer faint counts reveal a population of ULIRGs as dusty massive ellipticals: Evolution by types and cosmic star formation

Context. Multi-wavelength galaxy number counts provide clues to the nature of galaxy evolution. The interpretation per galaxy type of the mid-IR faint counts obtained with ISO and Spitzer, consistent with the analysis of deep UV-optical-near IR galaxy counts, provide new constraints on the dust and stellar emission. Discovering the nature of new populations, such as high redshift ultra-luminous (≥10^(12) L_⊙) infrared galaxies (ULIRGs), is also crucial for understanding galaxy evolution at high redshifts. Aims. We first present the faint galaxy counts at 12 μm from the catalogue of the ISO-ESO-Sculptor Survey (ISO-ESS) published in a companion article (Seymour et al. 2007a, A&A, 475, 791). They go down to 0.31 mJy after corrections for incompleteness. We verify the consistency with the existing ISO number counts at 15 μm. Then we analyse the 12 μm (ISO-ESS) and the 24 μm (Spitzer) faint counts, to constrain the nature of ULIRGs, the cosmic star formation history and time scales for mass buildup. Methods. We show that the “normal” scenarios in our evolutionary code PÉGASE, which had previously fitted the deep UV-opticalnear IR counts, are unsuccessful at 12 μm and 24 μm. We thus propose a new ULIRG scenario adjusted to the observed cumulative and differential 12 μm and 24 μm counts and based on observed 12 μm and 25 μm IRAS luminosity functions and evolutionary optical/mid-IR colours from PÉGASE. Results. We succeed in simultaneously modelling the typical excess observed at 12 μm, 15 μm (ISO), and 24 μm (Spitzer) in the cumulative and differential counts by only changing 9% of normal galaxies (1/3 of the ellipticals) into ultra-bright dusty galaxies evolving as ellipticals, and interpreted as distant ULIRGs. These objects present similarities with the population of radio-galaxy hosts at high redshift. No number density evolution is included in our models even if minor starbursts due to galaxy interactions remain compatible with our results. Conclusions. Higher spectral and spatial resolution in the mid-IR, together with submillimeter observations using the future Herschel observatory, will be useful to confirm these results

Electronic Regulator: Breadboard and Conceptual Space Flight Versions

The Electronic Regulator Project at TRW has constructed a breadboard system demonstrating pressure regulator operation over a wide range of flow conditions. The test hardware is composed of pneumatic-actuated, solenoid-controlled valves and associated tubing, gas volumes and transducers. System control, data recording and data reduction functions are controlled by a 486-class PC running Labview software. This breadboard system has demonstrated that a single system, using several control modes, is versatile enough to be used across the TRW spacecraft product line, from the very low Xenon flows associated with an electric propulsion system, to the high Helium flows required in a constant thrust situation such as in the AXAF spacecraft. A conceptual flight version, composed largely of off-the-shelf parts, has been designed and evaluated relative to requirements of various TRW spacecraft

South Africa’s land reform programme: A case study of the relocation of the Stockenström community to Friemersheim in the Western Cape during the apartheid era

Magister Artium (Development Studies) - MA(DVS)This research places in context a proposed case study of land and property rights of a dispossessed Stockenström (Eastern Cape) community forcibly removed to Friemersheim (Western Cape) during the apartheid era, between 1985 and 1986. This dispossessed community has yet to receive appropriate compensation for that expropriation in the form of restoration of their property rights. This study examines the specifics of the legislative framework, which underpinned the circumstances of their land expropriation, as well as the pattern of land dispossession in South Africa during this era. To this end, it examines the impact of land-related apartheid legislation, which directly and indirectly influenced this community. It focuses on discussions, many of the parliamentary proclamations and statutes such as those passed in 1913, and beyond, which provided the legal context for large-scale land grabs, and contrasts these with the post-1994 land reformation programme. Finally, this research examines the practical implementation of the 1994 land reform programme, especially the component of restitution, with particular reference to the displaced Stockenström community who find themselves facing huge challenges in a democratic South Africa, even after they applied the new rights accorded to them in the land reform programme. It outlines the significance of the new legislative rights conferred on those dispossessed and tracks their land claims successes and failures

The career perceptions of educational psychology students and professionals : a thesis presented in partial fulfilment of the requirements for the degree of Master of Educational Psychology at Massey University, Albany, New Zealand

Contemporary career literature indicates that careers are becoming less traditional. Two new careers concepts are that of the boundaryless and protean career orientations. Career adaptability is also essential for individuals to maintain personal flexibility and the ability to cope. The current study used an online survey to investigate whether or not these new concepts of career applied to educational psychology students and practicing educational psychologists. Quantitative results from the survey indicated that both students and professionals held boundaryless and protean attitudes. Late-career psychologists and psychologists working outside the Ministry of Education held more boundaryless attitudes. A high degree of career adaptability was also found, especially in terms of career agency, and with students reporting higher levels of perceived support than did professionals. Quantitative data from the survey were consistent with these findings. Overall, it appeared that participants combined contemporary career attitudes with aspects of the traditional career. They understood the hierarchical opportunities available to them but also favoured innovative new endeavours