Hubble Space Telescope Near-infrared Snapshot Survey of 3CR Radio Source Counterparts. II. An Atlas and Inventory of the Host Galaxies, Mergers, and Companions

We present the second part of an H-band (1.6 μm) “atlas” of z \u3c 0.3 3CR radio galaxies, using the Hubble Space Telescope Near Infrared Camera and Multi- Object Spectrometer (HST NICMOS2). We present new imaging for 21 recently acquired sources, and host galaxy modeling for the full sample of 101 (including 11 archival) – an 87% completion rate. Two different modeling techniques are applied, following those adopted by the galaxy morphology and the quasar host galaxy communities. Results are compared, and found to be in excellent agreement, although the former breaks down in the case of strongly nucleated sources

An Optical-Infrared Jet in 3C 133

We report the discovery of a new optical-IR synchrotron jet in the radio galaxy 3C 133 from our HST/NICMOS snapshot survey. The jet and eastern hotspot are well resolved, and visible at both optical and IR wavelengths. The IR jet follows the morphology of the inner part of the radio jet, with three distinct knots identified with features in the radio. The radio-IR SED’s of the knots are examined, along with those of two more distant hotspots at the eastern extreme of the radio feature. The detected emission appears to be synchrotron, with peaks in the NIR for all except one case, which exhibits a power-law spectrum throughout

Tackling transition:the value of peer mentoring

This paper is aimed at those interested in the promotion of student retention in higher education; particularly those with an interest in peer mentoring as a means of student support. It critically discusses the results of an exploratory study analysing the perceptions of peer mentors and mentees within five universities in the United Kingdom. The aim of the study was to analyse how student peer mentoring can aid transition into university by focusing specifically on how senior students can support their junior counterparts in their first year at university. The paper discusses the results of a survey which was completed by 329 student peer mentors and mentees. Focusing on the benefits and outcomes of participation in Mentoring Programmes, the survey was distinctive in that it asked mentors and mentees similar questions. From a theoretical perspective, the paper contributes to debates about peer support in higher education showing that participation in such programmes can have positive outcomes from both social and pedagogic perspectives. Practically speaking, the results have important implications for Higher Education Institutions as the research highlights the importance of putting into place formally structured Peer Mentoring Programmes which facilitate student support at a time when new students are most at risk of ‘dropping out’

Spectropolarimetric evidence for a kicked supermassive black hole in the quasar E1821+643

Original article can be found at: http://iopscience.iop.org/2041-8205 Copyright American Astronomical Society [Full text of this article is not available in the UHRA]We report spectropolarimetric observations of the quasar E1821+643 (z = 0.297), which suggest that it may be an example of gravitational recoil due to anisotropic emission of gravitational waves following the merger of a supermassive black hole (SMBH) binary. In total flux, the broad Balmer lines are redshifted by approximate to 1000 km s(-1) relative to the narrow lines and have highly red asymmetric profiles, whereas in polarized flux the broad Ha line exhibits a blueshift of similar magnitude and a strong blue asymmetry. We show that these observations are consistent with a scattering model in which the broad-line region has two components, moving with different bulk velocities away from the observer and toward a scattering region at rest in the host galaxy. If the high-velocity system is identified as gas bound to the SMBH, this implies that the SMBH is itself moving with a velocity similar to 2100 km s(-1) relative to the host galaxy. We discuss some implications of the recoil hypothesis and also briefly consider whether our observations can be explained in terms of scattering of broad-line emission originating from the active component of an SMBH binary, or from an outflowing wind.Peer reviewe

NICMOS Polarimetry of ''Polar-scattered'' Seyfert 1 Galaxies

The nuclei of Seyfert 1 galaxies exhibit a range of optical polarization characteristics that can be understood in terms of two scattering regions producing orthogonal polarizations: an extended polar scattering region (PSR) and a compact equatorial scattering region (ESR), located within the circum-nuclear torus. Here we present NICMOS 2.0 μm imaging polarimetry of six "polar-scattered" Seyfert 1 (S1) galaxies, in which the PSR dominates the optical polarization. The unresolved nucleus (<0farcs58) is significantly polarized in only three objects, but five of the six exhibit polarization in a 0farcs58-1farcs5 circum-nuclear annulus. In Fairall 51 and ESO 323-G077, the polarization position angle at 2 μm (θ2 μm) is consistent with the average for the optical spectrum(θ v ), implying that the nuclear polarization is dominated by polar scattering at both wavelengths. The same is probably true for NGC 3227. In both NGC 4593 and Mrk 766, there is a large difference between θ2 μm and θ v off-nucleus, where polar scattering is expected to dominate. This may be due to contamination by interstellar polarization in NGC 4593, but there is no clear explanation in the case of the strongly polarized Mrk 766. Lastly, in Mrk 1239, a large change (≈60°) in θ2 μm between the nucleus and the annulus indicates that the unresolved nucleus and its immediate surroundings have different polarization states at 2 μm, which we attribute to the ESR and PSR, respectively. A further implication is that the source of the scattered 2 μm emission in the unresolved nucleus is the accretion disk, rather than torus hot dust emission. Based on observations made with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 10160