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Ausgangspunkt für Forschungen zum römischen Imperialismus und zu den dadurch ausgelösten Reaktionen der unterworfenen Gesellschaften bilden oftmals historisch belegte Episoden. Doch die tiefgreifenden soziopolitischen Veränderungen der jeweiligen Gebiete sind nicht nur mit den schriftlichen überlieferten Ereignissen in Zusammenhang zu sehen, sondern sollten auch im Rahmen von längerfristigen Transformationsprozessen untersucht werden. Der römische «Impact» begann somit nicht erst mit der Eroberung eines bestimmten Gebiets, sondern setzte womöglich bereits Jahrzehnte zuvor ein und rief zudem ein breites Spektrum an Reaktionen verschiedener lokaler Gruppierungen hervor. Um diese asychronen und multidimensionalen Abläufe zu verstehen, wird im Rahmen dieses Vortrags einerseits ein neues theoretisches Konzept vorgestellt und andererseits das methodische Vorgehen, wie die Folgen des römischen Imperialismus untersucht werden können, anhand von Fallbeispielen präsentiert. Aus theoretischer Sicht wird mit den aus der Soziologie entlehnten Konzepten «Macht» und «Herrschaft» gearbeitet. «Macht» wird hier als die ständig wachsende und stetige Rekonfiguration des politischen Einflusses auf die lokalen Gesellschaften und zwischen ihnen verstanden; «Herrschaft» ist dann die institutionalisierte und stabilisierte Verwaltung Roms über eine oder mehrere dieser politischen Einheiten. Methodologisch arbeitet das Projekt mit einer Datenbank von ausgewählten Siedlungskammern, die ihrerseits aus einzelnen Siedlungen bestehen. Diese wird aus der Literatur und bereits vorhandenen Datenbanken gespeist. Ziel des Projekts ist es, zu analysieren, wann, wie und warum der römische Einfluss die Siedlungslandschaften der vor- und pararömischen Gesellschaften des römischen Westens zwischen 200 v. und 200 n. Chr. verändert hat. Weitere Untersuchungen betreffen die Fragestellung, ob eine zugrundeliegende Strategie seitens Roms in den transformierten Siedlungsmustern erkannt werden kann. Der Vortrag gibt einen Einblick in die laufenden Arbeiten sowie in die Herausforderungen eines Projektes, das mit grösseren und heterogenen Datenmengen arbeitet.

© 2017. The American Astronomical Society. All rights reserved. We present the first discoveries from a survey of z ≳ 6 quasars using imaging data from the DECam Legacy Survey (DECaLS) in the optical, the UKIRT Deep Infrared Sky Survey (UKIDSS) and a preliminary version of the UKIRT Hemisphere Survey (UHS) in the near-IR, and ALLWISE in the mid-IR. DECaLS will image 9000 deg2of sky down to zAB∼ 23.0, and UKIDSS and UHS will map the northern sky at 0 < decl. < +607deg;, reaching JVEGA∼ 19.6 (5-σ). The combination of these data sets allows us to discover quasars at redshift z ≳ 7 and to conduct a complete census of the faint quasar population at z ≳ 6. In this paper, we report on the selection method of our search, and on the initial discoveries of two new, faint z ≳ 6 quasars and one new z = 6.63 quasar in our pilot spectroscopic observations. The two new z ∼ 6 quasars are at z = 6.07 and z = 6.17 with absolute magnitudes at rest-frame wavelength 1450 Å being M1450= -25.83 and M1450= -25.76, respectively. These discoveries suggest that we can find quasars close to or fainter than the break magnitude of the Quasar Luminosity Function (QLF) at z ≳ 6. The new z = 6.63 quasar has an absolute magnitude of M1450= -25.95. This demonstrates the potential of using the combined DECaLS and UKIDSS/UHS data sets to find z ≳ 7 quasars. Extrapolating from previous QLF measurements, we predict that these combined data sets will yield ∼200 z ∼ 6 quasars to zAB< 21.5, ∼1000 z ∼ 6 quasars to zAB< 23, and ∼30 quasars at z > 6.5 to JVEGA< 19.5.

We present the first discoveries from a survey of $z\gtrsim6$ quasars using imaging data from the DECam Legacy Survey (DECaLS) in the optical, the UKIRT Deep Infrared Sky Survey (UKIDSS) and a preliminary version of the UKIRT Hemisphere Survey (UHS) in the near-IR, and ALLWISE in the mid-IR. DECaLS will image 9000 deg$^2$ of sky down to $z_{\rm AB}\sim23.0$, and UKIDSS and UHS, which will map the northern sky at $06.5$ to $J_{\rm VEGA}, 8 pages, 5 figures, accepted for publication in The Astrophysical Journal

Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (AGN). Population studies of large samples likewise have been very productive for our understanding of AGN. These two themes are coming together in the idea of systematic variability studies of large samples - with SDSS, PanSTARRS, and soon, LSST. I summarise what we have learned about the optical and UV variability of AGN, and what it tells us about accretion discs and the BLR. The most exciting recent results have focused on rare large-scale outbursts and collapses - Tidal Disruption Events, changing-look AGN, and large amplitude microlensing. All of these promise to give us new insight into AGN physics., Comment: Review paper in "Astronomical Surveys and Big Data", ASP Conference series, Vol 505, eds A.M.Mickaelian, A.Lawrence, T.Y.Magakian. Proceedings of Symposium held in Byurakan, Armenia, Oct 2015. 10 pages, 2 figures

This book on astronomical measurement takes a fresh approach to teaching the subject. After discussing some general principles, it follows the chain of measurement through atmosphere, imaging, detection, spectroscopy, timing, and hypothesis testing. The various wavelength regimes are covered in each section, emphasising what is the same, and what is different. The author concentrates on the physics of detection and the principles of measurement, aiming to make this logically coherent. The book is based on a short self contained lecture course for advanced undergraduate students developed and taught by the author over several years.

The advent of sensitive sub-mm array cameras now allows a proper census of dust-enshrouded massive star-formation in very distant galaxies, previously hidden activity to which even the faintest optical images are insensitive. We present the deepest sub-mm survey of the sky to date, taken with the SCUBA camera on the James Clerk Maxwell Telescope and centred on the Hubble Deep Field. The high source density found in this image implies that the survey is confusion-limited below a flux density of 2 mJy. However, within the central 80 arcsec radius independent analyses yield 5 reproducible sources with S(850um) > 2 mJy which simulations indicate can be ascribed to individual galaxies. We give positions and flux densities for these, and furthermore show using multi-frequency photometric data that the brightest sources in our map lie at redshifts z~3. These results lead to integral source counts which are completely inconsistent with a no-evolution model, and imply that massive star-formation activity continues at redshifts > 2. The combined brightness of the 5 most secure sources in our map is sufficient to account for 30 - 50% of the previously unresolved sub-mm background, and we estimate statistically that the entire background is resolved at about the 0.3 mJy level. Finally we discuss possible optical identifications and redshift estimates for the brightest sources. One source appears to be associated with an extreme starburst galaxy at z~1, whilst the remaining four appear to lie in the redshift range 2 < z < 4. This implies a star-formation density over this redshift range that is at least five times higher than that inferred from the ultraviolet output of HDF galaxies., 19 pages, 6 figures (to appear as a Nature Article)

The advent of sensitive sub-mm array cameras now allows a proper census of dust-enshrouded massive star-formation in very distant galaxies, previously hidden activity to which even the deepest optical images are insensitive. We present the deepest sub-mm survey, taken with the SCUBA camera on the James Clerk Maxwell Telescope (JCMT) and centred on the Hubble Deep Field (HDF). The high source density on this image implies that the survey is confusion-limited below a flux density of 2 mJy. However within the central 80 arcsec radius independent analyses yield 5 reproducible sources with S(850um) > 2 mJy which simulations indicate can be ascribed to individual galaxies. These data lead to integral source counts which are completely inconsistent with a no evolution model, whilst the combined brightness of the 5 most secure sources in our map is sufficient to account for 30-50% of the previously unresolved sub-mm background, and statistically the entire background is resolved at about the 0.3 mJy level. Four of the five brightest sources appear to be associated with galaxies which lie in the redshift range 2 < z < 4. With the caveat that this is a small sample of sources detected in a small survey area, these submm data imply a star-formation density over this redshift range that is at least five times higher than that inferred from the rest-frame ultraviolet output of HDF galaxies., to appear in the proceedings of `The Birth of Galaxies', Xth Rencontres de Blois, 4 pages, 1 postscript figure, uses blois.sty (included)