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Now showing items 21-40 of 761

The ages of the disk clusters NGC 188, M67, and NGC 752, using improved opacities and cluster membership data

Guenther, David B.; Dinescu, Dana I.; Demarque, Pierre; Pinsonneault, M. H. (American Astronomical Society, 1995-05)

Theoretical isochrones have been constructed using the OPAL opacities to derive the ages of the open clusters NGC 188, M67, and NGC 752 as well as to estimate the amount of convective overshoot at the convective core edge. ...
Alessi 95 and the short-period Cepheid SU Cassiopeiae

Turner, David Gerald, 1945-; Majaess, Daniel J.; Lane, D. J.; Balam, D. D.; Gieren, W. P.; Storm, J.; Forbes, D. W.; Havlen, R. J.; Alessi, B. (Oxford Academic, 2012-05)

The parameters for the newly discovered open cluster Alessi 95 are established on the basis of available photometric and spectroscopic data, in conjunction with new observations. Colour excesses for spectroscopically ...
Alignments of the dominant galaxies in poor clusters

Fuller, Todd M.; West, Michael J.; Bridges, Terry J. (American Astronomical SocietyIOP Science, 1999-07-01)

We have examined the orientations of brightest cluster galaxies (BCGs) in poor MKW (Morgan, Kayser, and White) and AWM (Albert, White, and Morgan) clusters and find that, like their counterparts in richer Abell clusters, ...
The [alpha/Fe] ratios of very metal-poor stars within the integrated galactic initial mass function theory

Recchi, S.; Calura, F.; Gibson, Brad K.; Kroupa, P. (Oxford University Press, 2014-01)

The aim of this paper is to quantify the amplitude of the predicted plateau in [α/Fe] ratios associated with the most metal-poor stars of a galaxy. We assume that the initial mass function (IMF) in galaxies is steeper ...
[alpha] Centauri AB

Guenther, David B.; Demarque, P. (American Astronomical Society, 2000-03)

Detailed models of [alpha] Centauri A and B based on the Hipparcos, Yale, and Soderhjelm parallaxes are compared. The consequences of the uncertainty in mass, luminosity, surface temperature, and composition on the structure ...
An alternative explanation for the observed variation of solar p-modes with the solar cycle

Lydon, Thomas Joseph; Guenther, David B.; Sofia, S. (American Astronomical SocietyIOP Publishing, 1996-01-10)

By mimicking the effects of a magnetic field on the interior structure of a solar model, observed changes in p-mode frequencies over the course of the solar cycle are explained in terms of a change in the intensity and ...
Analysis of MOST light curves of five young stars in Taurus–Auriga and Lupus 3 star-forming regions

Siwak, Michal; Rucinski, Slavek M.; Matthews, Jaymie M.; Kuschnig, Rainer; Guenther, David B.; Moffat, Anthony F. J.; Sasselov, Dimitar; Weiss, Werner W. (Oxford University Press, 2011-08)

Continuous photometric observations of five young stars obtained by the MOST satellite in 2009 and 2010 in the Taurus and Lupus star formation regions are presented. Using light-curve modelling under the assumption of ...
Analysis of variability of TW Hya as observed by MOST and ASAS in 2009

Siwak, Michal; Rucinski, Slavek M.; Matthews, Jaymie M.; Pojmanski, Grzegorz; Kuschnig, Rainer; Guenther, David B.; Moffat, Anthony F. J.; Sasselov, Dimitar; Weiss, Werner W. (Wiley-Blackwell, 2011-02)

As a continuation of our previous studies in 2007 and 2008, new photometric observations of the T Tauri star TW Hya obtained by the MOST satellite and the All Sky Automated Survey (ASAS) project over 40 d in 2009 with ...
Anchoring the distance scale via X-ray/infrared data for Cepheid clusters: SU Cas

Gallo, Luigi C.; Turner, David Gerald, 1945-; Majaess, Daniel J.; Lane, D. J.; Gieren, W.; Bonatto, C.; Balam, D.; Berdnikov, L. (American Astronomical SocietyIOP Publishing, 2012-07-10)

New X-ray (XMM-Newton) and JHK[subscript s] (Observatoire du Mont-Megantic) observations for members of the star cluster Alessi 95, which Turner et al. discovered hosts the classical Cepheid SU Cas, were used in tandem ...
Angular clustering of z ∼ 2 star-forming and passive galaxies in 2.5 square degrees of deep CFHT imaging

Sato, Taro; Sawicki, Marcin, 1969-; Arcila-Osejo, Liz Maria (Oxford University PressRoyal Astronomical Society, 2014)

We study the angular clustering of z ∼ 2 galaxies using ∼40 000 star-forming (SF) and ∼5000 passively evolving (PE) galaxies selected from ∼2.5 deg[superscript 2] of deep (K[subscript lim] = 23–24 AB) Canada–France–Hawaii ...
Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

Giffin, Nick A.; Makramalla, Miller; Hendsbee, Arthur D.; Robertson, Katherine N.; Sherren, Cody; Pye, Cory C.; Masuda, Jason Douglas, 1977-; Clyburne, Jason A. C. (Royal Society of Chemistry, 2011)

In this paper, we report a novel synthesis of anhydrous 1-hydroxy-2,2,6,6-tetramethyl-piperidine (TEMPO-H). An X-ray crystal structure and full characterization of the compound are included. Compared to hydrated TEMPO-H, ...
Application of DEI and MEI indices to evaluate the effect of fragmentation in oak ‎habitats on species diversity and soil chemical characteristics

Valadi, Gelareh; Eshaghirad, Javad,; Khodakarami, Yahya; Peykani, Mostafa Nemati; Harper, Karen A., 1969- (Urmia University, 2021-12)

In order to introduce and application of DEI (Distance of Edge Influence) and MEI (Magnitude of Edge Influence) indices to determine the distance of edge effect and intensity of the edge effect on herbaceous species and ...
Approaching the precursor nuclei of the third r-process peak with RIBs

Domingo-Pardo, C.; Caballero-Folch, R.; Agramunt, J.; Algora, A.; Arcones, A.; Ameil, F.; Ayyad, Y.; Benlliure, J.; Bowry, M.; Calvino, F.; Estrade, Alfredo (IOP Publishing Limited, 2016)

The rapid neutron nucleosynthesis process involves an enormous amount of very exotic neutron-rich nuclei, which represent a theoretical and experimental challenge. Two of the main decay properties that affect the final ...
Arboreal burials in Nicrophorus spp. (Coleoptera: Silphidae)

Lowe, Amanda J.; Lauff, Randolph F. (Hindawi Publishing Corporation, 2012)

Nicrophorus beetles are well known for interring small vertebrates below ground for the purpose of rearing their young. However, the arboreal use of carrion has not been previously investigated. Nest boxes were suspended ...
Arctic change and coastal communities: overview of the Coastal Zone Canada Conference, Tuktoyaktuk, August 2006

Charles, Anthony Trevor, 1956-; Mathias, Jack; Ayles, Burton; Blakney, Sherrie; Fast, Helen; Irniq, Peter (Arctic Institute of North America, 2008)

This special issue of Arctic represents the output from a conference sponsored by the Coastal Zone Canada Association and organized in large part by Fisheries and Oceans Canada. A number of sponsors (see Acknowledgements) ...
Arcus: exploring the formation and evolution of clusters, galaxies, and stars

Smith, R. K.; Abraham, M.; Allured, R.; Bautz, M.; Bookbinder, J.; Bregman, J.; Brenneman, L.; Brickhouse, N. S.; Burrows, D.; Burwitz, V.; Cheimets, P. N.; Costantini, E.; Dawson, S.; DeRoo, C.; Falcone, A.; Foster, A. R.; Gallo, Luigi C.; Grant, C. E.; Günther, H. M.; Heilmann, R. K; Hertz, E.; Hine, B.; Huenemoerder, D.; Kaastra, J. S.; Kreykenbohm, I.; Madsen, K. K.; McEntaffer, R.; Miller, E.; Miller, J.; Morse, E.; Mushotzky, R.; Nandra, K.; Nowak, M.; Paerels, F.; Petre, R.; Poppenhaeger, K.; Ptak, A.; Reid, P.; Sanders, J.; Schattenburg, M.; Schulz, N.; Smale, A.; Temi, P.; Valencic, L.; Walker, S.; Willingale, R.; Wilms, J.; Wolk, S. J. (Society of Photo-Optical Instrumentation Engineers, 2017-08-29)

Arcus, a Medium Explorer (MIDEX) mission, was selected by NASA for a Phase A study in August 2017. The observatory provides high-resolution soft X-ray spectroscopy in the 12-50Å bandpass with unprecedent-ed sensitivity: ...
Arylation of diethyl alkylmalonates: synthetic route to diethyl alkyl(substituted aryl)malonates with the aid of temporary arene complexation by the cyclopentadienyliron moiety

Piorko, Adam; Abd-El-Aziz, Alaa S.; Lee, Choi Chuck; Sutherland, Ronald G. (Royal Society of Chemistry, 1989)

Nucleophilic substitution of chlorine in the ironcyclopentadienyl hexafluorophosphates of chlorobenzene, isomeric chlorotoluenes and dichlorobenzenes (1 ) with the anions generated from diethyl alkylmalonates (2) and (3) ...
Assessing the probable distribution of the potentially invasive Chinese mystery snail, Cipangopaludina chinensis, in Nova Scotia using a random forest model approach

Kingsbury, Sarah; Fong, Megan; McAlpine, Donald F.; Campbell, Linda (Regional Euro-Asian Biological Invasions Centre (REABIC), 2021)

Non-native species that become invasive threaten natural biodiversity and can lead to socioeconomic impacts. Prediction of invasive species distributions is important to prevent further spread and protect vulnerable ...
Assessment of the extirpated Maritimes walrus using morphological and ancient DNA analysis

McLeod, Brenna A.; Frasier, Timothy, 1976-; Lucas, Zoe (Public Library of Science, 2014-06-12)

Species biogeography is a result of complex events and factors associated with climate change, ecological interactions, anthropogenic impacts, physical geography, and evolution. To understand the contemporary biogeography ...
Assisted Revegetation in a Subarctic Environment: Effects of Fertilization on the Performance of Three Indigenous Plant Species

Deshaies, Alexis; Boudreau, Stéphane; Harper, Karen A., 1969- (Taylor & Francis, 2009-11)

Assisted re-vegetation is particularly difficult in subarctic and arctic ecosystems where the impact of anthropogenic activities can be extensive and natural plant regeneration is slow. The construction of a military base ...