TY  - JOUR
A1  - Arridge, Christopher S.
A1  - Achilleos, N.
A1  - Agarwal, Jessica
A1  - Agnor, C. B.
A1  - Ambrosi, R.
A1  - Andre, N.
A1  - Badman, S. V.
A1  - Baines, K.
A1  - Banfield, D.
A1  - Barthelemy, M.
A1  - Bisi, M. M.
A1  - Blum, J.
A1  - Bocanegra-Bahamon, T.
A1  - Bonfond, B.
A1  - Bracken, C.
A1  - Brandt, P.
A1  - Briand, C.
A1  - Briois, C.
A1  - Brooks, S.
A1  - Castillo-Rogez, J.
A1  - Cavalie, T.
A1  - Christophe, B.
A1  - Coates, Andrew J.
A1  - Collinson, G.
A1  - Cooper, J. F.
A1  - Costa-Sitja, M.
A1  - Courtin, R.
A1  - Daglis, I. A.
A1  - De Pater, Imke
A1  - Desai, M.
A1  - Dirkx, D.
A1  - Dougherty, M. K.
A1  - Ebert, R. W.
A1  - Filacchione, Gianrico
A1  - Fletcher, Leigh N.
A1  - Fortney, J.
A1  - Gerth, I.
A1  - Grassi, D.
A1  - Grodent, D.
A1  - Grün, Eberhard
A1  - Gustin, J.
A1  - Hedman, M.
A1  - Helled, R.
A1  - Henri, P.
A1  - Hess, Sebastien
A1  - Hillier, J. K.
A1  - Hofstadter, M. H.
A1  - Holme, R.
A1  - Horanyi, M.
A1  - Hospodarsky, George B.
A1  - Hsu, S.
A1  - Irwin, P.
A1  - Jackman, C. M.
A1  - Karatekin, O.
A1  - Kempf, Sascha
A1  - Khalisi, E.
A1  - Konstantinidis, K.
A1  - Kruger, H.
A1  - Kurth, William S.
A1  - Labrianidis, C.
A1  - Lainey, V.
A1  - Lamy, L. L.
A1  - Laneuville, Matthieu
A1  - Lucchesi, D.
A1  - Luntzer, A.
A1  - MacArthur, J.
A1  - Maier, A.
A1  - Masters, A.
A1  - McKenna-Lawlor, S.
A1  - Melin, H.
A1  - Milillo, A.
A1  - Moragas-Klostermeyer, Georg
A1  - Morschhauser, Achim
A1  - Moses, J. I.
A1  - Mousis, O.
A1  - Nettelmann, N.
A1  - Neubauer, F. M.
A1  - Nordheim, T.
A1  - Noyelles, B.
A1  - Orton, G. S.
A1  - Owens, Mathew
A1  - Peron, R.
A1  - Plainaki, C.
A1  - Postberg, F.
A1  - Rambaux, N.
A1  - Retherford, K.
A1  - Reynaud, Serge
A1  - Roussos, E.
A1  - Russell, C. T.
A1  - Rymer, Am.
A1  - Sallantin, R.
A1  - Sanchez-Lavega, A.
A1  - Santolik, O.
A1  - Saur, J.
A1  - Sayanagi, Km.
A1  - Schenk, P.
A1  - Schubert, J.
A1  - Sergis, N.
A1  - Sittler, E. C.
A1  - Smith, A.
A1  - Spahn, Frank
A1  - Srama, Ralf
A1  - Stallard, T.
A1  - Sterken, V.
A1  - Sternovsky, Zoltan
A1  - Tiscareno, M.
A1  - Tobie, G.
A1  - Tosi, F.
A1  - Trieloff, M.
A1  - Turrini, D.
A1  - Turtle, E. P.
A1  - Vinatier, S.
A1  - Wilson, R.
A1  - Zarkat, P.
T1  - The science case for an orbital mission to Uranus: Exploring the origins and evolution of ice giant planets
JF  - Planetary and space science
N2  - Giant planets helped to shape the conditions we see in the Solar System today and they account for more than 99% of the mass of the Sun's planetary system. They can be subdivided into the Ice Giants (Uranus and Neptune) and the Gas Giants (Jupiter and Saturn), which differ from each other in a number of fundamental ways. Uranus, in particular is the most challenging to our understanding of planetary formation and evolution, with its large obliquity, low self-luminosity, highly asymmetrical internal field, and puzzling internal structure. Uranus also has a rich planetary system consisting of a system of inner natural satellites and complex ring system, five major natural icy satellites, a system of irregular moons with varied dynamical histories, and a highly asymmetrical magnetosphere. Voyager 2 is the only spacecraft to have explored Uranus, with a flyby in 1986, and no mission is currently planned to this enigmatic system. However, a mission to the uranian system would open a new window on the origin and evolution of the Solar System and would provide crucial information on a wide variety of physicochemical processes in our Solar System. These have clear implications for understanding exoplanetary systems. In this paper we describe the science case for an orbital mission to Uranus with an atmospheric entry probe to sample the composition and atmospheric physics in Uranus' atmosphere. The characteristics of such an orbiter and a strawman scientific payload are described and we discuss the technical challenges for such a mission. This paper is based on a white paper submitted to the European Space Agency's call for science themes for its large-class mission programme in 2013.
KW  - Uranus
KW  - Magnetosphere
KW  - Atmosphere
KW  - Natural satellites
KW  - Rings
KW  - Planetary interior
Y1  - 2014
U6  - https://doi.org/10.1016/j.pss.2014.08.009
SN  - 0032-0633
VL  - 104
SP  - 122
EP  - 140
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - GEN
A1  - Cohen, Abby
A1  - Campisano, Christopher
A1  - Arrowsmith, J. Ramon
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, Richard Bernhart
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, F.
A1  - Tiercelin, J.-J.
A1  - Trauth, Martin  H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - O’Grady, R.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, Joellen
A1  - Foerster, Verena
A1  - Dommain, René
A1  - Rucina, J. S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, Annett
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, Tannis
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, Timothy
A1  - Sier, Mark Jan
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, Chad
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project
BT  - inferring the environmental context of human evolution from eastern African rift lake deposits
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 611 
KW  - Turkana-Basin
KW  - Adar formation
KW  - climate-change
KW  - olorgesailie formation
KW  - Southern Ethiopia
KW  - global climate
KW  - Kenya Rift
KW  - Pleistocene
KW  - variability
KW  - patterns
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412498
IS  - 611
ER  - 
TY  - JOUR
A1  - Corcoran, Michael F.
A1  - Nichols, Joy S.
A1  - Pablo, Herbert
A1  - Shenar, Tomer
A1  - Pollock, Andy M. T.
A1  - Waldron, Wayne L.
A1  - Moffat, Anthony F. J.
A1  - Richardson, Noel D.
A1  - Russell, Christopher M. P.
A1  - Hamaguchi, Kenji
A1  - Huenemoerder, David P.
A1  - Oskinova, Lida
A1  - Hamann, Wolf-Rainer
A1  - Naze, Yael
A1  - Ignace, Richard
A1  - Evans, Nancy Remage
A1  - Lomax, Jamie R.
A1  - Hoffman, Jennifer L.
A1  - Gayley, Kenneth
A1  - Owocki, Stanley P.
A1  - Leutenegger, Maurice
A1  - Gull, Theodore R.
A1  - Hole, Karen Tabetha
A1  - Lauer, Jennifer
A1  - Iping, Rosina C.
T1  - A coordinated X-Ray and optical campaign of the nearest massive eclipsing binary, delta ORIONIS Aa. I. Overview of thr X-Ray spectrum
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of delta Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, delta Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, delta Ori Aa2, has a much lower X-ray luminosity than the brighter primary (delta Ori Aa1), delta Ori Aa provides a unique system with which to test the spatial distribution of the X-ray emitting gas around delta Ori Aa1 via occultation by the photosphere of, and wind cavity around, the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ks and covering nearly the entire binary orbit. The companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities obtained simultaneously with the X-ray data to better constrain the system parameters, and model the effects of X-rays on the optical and UV spectra. We find that the X-ray emission is dominated by embedded wind shock emission from star Aa1, with little contribution from the tertiary star Ab or the shocked gas produced by the collision of the wind of Aa1 against the surface of Aa2. We find a similar temperature distribution to previous X-ray spectrum analyses. We also show that the line half-widths are about 0.3-0.5 times the terminal velocity of the wind of star Aa1. We find a strong anti-correlation between line widths and the line excitation energy, which suggests that longer-wavelength, lower-temperature lines form farther out in the wind. Our analysis also indicates that the ratio of the intensities of the strong and weak lines of Fe XVII and Ne X are inconsistent with model predictions, which may be an effect of resonance scattering.
KW  - binaries: close
KW  - binaries: eclipsing
KW  - stars: early-type
KW  - stars: individual (Delta Ori)
KW  - stars: mass-loss
KW  - X-rays: stars
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/809/2/132
SN  - 0004-637X
SN  - 1538-4357
VL  - 809
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Nichols, Joy
A1  - Huenemoerder, David P.
A1  - Corcoran, Michael F.
A1  - Waldron, Wayne
A1  - Naze, Yael
A1  - Pollock, Andy M. T.
A1  - Moffat, Anthony F. J.
A1  - Lauer, Jennifer
A1  - Shenar, Tomer
A1  - Russell, Christopher M. P.
A1  - Richardson, Noel D.
A1  - Pablo, Herbert
A1  - Evans, Nancy Remage
A1  - Hamaguchi, Kenji
A1  - Gull, Theodore
A1  - Hamann, Wolf-Rainer
A1  - Oskinova, Lida
A1  - Ignace, Rosina
A1  - Hoffman, Jennifer L.
A1  - Hole, Karen Tabetha
A1  - Lomax, Jamie R.
T1  - A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, delta ORIONIS Aa. II. X-RAY VARIABILITY
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral data set of the delta Ori Aa binary system. The four observations, obtained with Chandra ACIS HETGS, have a total exposure time of approximate to 479 ks and provide nearly complete binary phase coverage. Variability of the total X-ray flux in the range of 5-25 is is confirmed, with a maximum amplitude of about +/- 15% within a single approximate to 125 ks observation. Periods of 4.76 and 2.04 days are found in the total X-ray flux, as well as an apparent overall increase in the flux level throughout the nine-day observational campaign. Using 40 ks contiguous spectra derived from the original observations, we investigate the variability of emission line parameters and ratios. Several emission lines are shown to be variable, including S XV, Si XIII, and Ne IX. For the first time, variations of the X-ray emission line widths as a function of the binary phase are found in a binary system, with the smallest widths at phi = 0.0 when the secondary delta Ori Aa2 is at the inferior conjunction. Using 3D hydrodynamic modeling of the interacting winds, we relate the emission line width variability to the presence of a wind cavity created by a wind-wind collision, which is effectively void of embedded wind shocks and is carved out of the X-ray-producing primary wind, thus producing phase-locked X-ray variability.
KW  - binaries: close
KW  - binaries: eclipsing
KW  - stars: individual ([HD 36486]delta Ori A)
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/809/2/133
SN  - 0004-637X
SN  - 1538-4357
VL  - 809
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Richardson, Noel D.
A1  - Russell, Christopher M. P.
A1  - St-Jean, Lucas
A1  - Moffat, Anthony F. J.
A1  - St-Louis, Nicole
A1  - Shenar, Tomer
A1  - Pablo, Herbert
A1  - Hill, Grant M.
A1  - Ramiaramanantsoa, Tahina
A1  - Corcoran, Michael
A1  - Hamuguchi, Kenji
A1  - Eversberg, Thomas
A1  - Miszalski, Brent
A1  - Chene, Andre-Nicolas
A1  - Waldron, Wayne
A1  - Kotze, Enrico J.
A1  - Kotze, Marissa M.
A1  - Luckas, Paul
A1  - Cacella, Paulo
A1  - Heathcote, Bernard
A1  - Powles, Jonathan
A1  - Bohlsen, Terry
A1  - Locke, Malcolm
A1  - Handler, Gerald
A1  - Kuschnig, Rainer
A1  - Pigulski, Andrzej
A1  - Popowicz, Adam
A1  - Wade, Gregg A.
A1  - Weiss, Werner W.
T1  - The variability of the BRITE-est Wolf-Rayet binary, gamma(2) Velorum-I. Photometric and spectroscopic evidence for colliding winds
JF  - Monthly notices of the Royal Astronomical Society
N2  - We report on the first multi-colour precision light curve of the bright Wolf-Rayet binary gamma(2) Velorum, obtained over six months with the nanosatellites in the BRITE-Constellation fleet. In parallel, we obtained 488 high-resolution optical spectra of the system. In this first report on the data sets, we revise the spectroscopic orbit and report on the bulk properties of the colliding winds. We find a dependence of both the light curve and excess emission properties that scales with the inverse of the binary separation. When analysing the spectroscopic properties in combination with the photometry, we find that the phase dependence is caused only by excess emission in the lines, and not from a changing continuum. We also detect a narrow, high-velocity absorption component from the He perpendicular to lambda 5876 transition, which appears twice in the orbit. We calculate smoothed-particle hydrodynamical simulations of the colliding winds and can accurately associate the absorption from He perpendicular to to the leading and trailing arms of the wind shock cone passing tangentially through our line of sight. The simulations also explain the general strength and kinematics of the emission excess observed in wind lines such as C III lambda 5696 of the system. These results represent the first in a series of investigations into the winds and properties of gamma(2) Velorum through multi-technique and multi-wavelength observational campaigns.
KW  - stars: early type
KW  - stars: individual: gamma(2) Vel
KW  - stars: mass loss
KW  - stars: winds
KW  - outflows
KW  - stars: Wolf-Rayet
Y1  - 2017
U6  - https://doi.org/10.1093/mnras/stx1731
SN  - 0035-8711
SN  - 1365-2966
VL  - 471
SP  - 2715
EP  - 2729
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Pablo, Herbert
A1  - Richardson, Noel D.
A1  - Moffat, Anthony F. J.
A1  - Corcoran, Michael
A1  - Shenar, Tomer
A1  - Benvenuto, Omar
A1  - Fuller, Jim
A1  - Naze, Yael
A1  - Hoffman, Jennifer L.
A1  - Miroshnichenko, Anatoly
A1  - Apellaniz, Jesus Maiz
A1  - Evans, Nancy
A1  - Eversberg, Thomas
A1  - Gayley, Ken
A1  - Gull, Ted
A1  - Hamaguchi, Kenji
A1  - Hamann, Wolf-Rainer
A1  - Henrichs, Huib
A1  - Hole, Tabetha
A1  - Ignace, Richard
A1  - Iping, Rosina
A1  - Lauer, Jennifer
A1  - Leutenegger, Maurice
A1  - Lomax, Jamie
A1  - Nichols, Joy
A1  - Oskinova, Lida
A1  - Owocki, Stan
A1  - Pollock, Andy
A1  - Russell, Christopher M. P.
A1  - Waldron, Wayne
A1  - Buil, Christian
A1  - Garrel, Thierry
A1  - Graham, Keith
A1  - Heathcote, Bernard
A1  - Lemoult, Thierry
A1  - Li, Dong
A1  - Mauclaire, Benjamin
A1  - Potter, Mike
A1  - Ribeiro, Jose
A1  - Matthews, Jaymie
A1  - Cameron, Chris
A1  - Guenther, David
A1  - Kuschnig, Rainer
A1  - Rowe, Jason
A1  - Rucinski, Slavek
A1  - Sasselov, Dimitar
A1  - Weiss, Werner
T1  - A coordinated X-Ray and optical campaign of the nearest massive eclipsing binary, delta ORIONIS Aa. III. Analysis of optical photometric (most) and spectroscopic (ground based) variations
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system delta Ori A, consisting of a binary O9.5II+early-B (Aa1 and Aa2) with P = 5.7 days, and a more distant tertiary (O9 IV P > 400 years). This data was collected in concert with X-ray spectroscopy from the Chandra X-ray Observatory. Thanks to continuous coverage for three weeks, the MOST light curve reveals clear eclipses between Aa1 and Aa2 for the first time in non-phased data. From the spectroscopy, we have a well-constrained radial velocity (RV) curve of Aa1. While we are unable to recover RV variations of the secondary star, we are able to constrain several fundamental parameters of this system and determine an approximate mass of the primary using apsidal motion. We also detected second order modulations at 12 separate frequencies with spacings indicative of tidally influenced oscillations. These spacings have never been seen in a massive binary, making this system one of only a handful of such binaries that show evidence for tidally induced pulsations.
KW  - binaries: close
KW  - binaries: eclipsing
KW  - stars: early-type
KW  - stars: individual (delta Ori A)
KW  - stars: mass-loss
KW  - stars: variables: general
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/809/2/134
SN  - 0004-637X
SN  - 1538-4357
VL  - 809
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -