Search Publications
The Angular Correlations of Galaxies in the COSMOS Field
Finoguenov, A.; Aussel, H.; Sanders, D. B. +21 more
We present measurements of the two-point galaxy angular correlation function w(θ) in the COSMOS field. Independent determinations of w(θ) as a function of magnitude limit are presented for both the Hubble Space Telescope (HST) ACS catalog and also the ground-based data from Subaru and the Canada-France-Hawaii Telescope. Despite having significantl…
The Abundances of Light Neutron-Capture Elements in Planetary Nebulae. I. Photoionization Modeling and Ionization Corrections
Kallman, T. R.; Dinerstein, Harriet L.; Sterling, N. C.
We have conducted a large-scale survey of 120 planetary nebulae (PNe) to search for the near-infrared emission lines [Kr III] 2.199 µm and [Se IV] 2.287 µm. The neutron (n)-capture elements Se and Kr may be enriched in a PN if its progenitor star experienced s-process nucleosynthesis and third dredge-up. In order to determine Se and Kr…
A narrow-band search for Lyα emitting galaxies at z = 8.8
Lidman, C.; Moorwood, A.; van der Werf, P. +4 more
Aims:The first star forming galaxies in the early universe should be copious Lyα emitters and may play a significant role in ionizing the intergalactic medium (IGM). It has been proposed that the luminosity function of Lyα emitting galaxies beyond z ~ 6 may be used to constrain the neutral fraction of the IGM during this epoch. In this work we rep…
The Chandra view of galaxy mergers
Ponman, Trevor J.; Brassington, Nicola J.; Read, Andrew M.
From a Chandra survey of nine interacting galaxy systems the evolution of X-ray emission during the merger process has been investigated. It is found that the X-ray luminosity peaks ~300Myr before nuclear coalescence, and then dips, even though we know that rapid and increasing activity is still taking place at this time. It is likely that this dr…
On the Variation of the Peak Asymmetry of Low-l Solar p Modes
Howe, R.; Jiménez-Reyes, S. J.; García, R. A. +4 more
The resonant peaks of solar p modes show small amounts of asymmetry in frequency. Here, we use five independent sets of contemporaneous data, collected over a ~=8 yr period, to investigate whether peak asymmetry in low angular degree p modes changes over the solar activity cycle. Three of the data sets are from instruments on board the ESA/NASA SO…
Satellite observations of separator-line geometry of three-dimensional magnetic reconnection
Escoubet, C. P.; Dandouras, I.; Glassmeier, K. -H. +14 more
Detection of a separator line that connects magnetic nulls and the determination of the dynamics and plasma environment of such a structure can improve our understanding of the three-dimensional (3D) magnetic reconnection process. However, this type of field and particle configuration has not been directly observed in space plasmas. Here we report…
The mass-energy budget of the ionised outflow in NGC 7469
Kaastra, J. S.; Kriss, G. A.; Behar, E. +6 more
Although AGN feedback through ionised winds is of great importance in models of AGN/galaxy coevolution, the mass and energy output via these winds, even in the nearby universe, is poorly understood. The issue is complicated by the wide range of ionisation in the winds, which means that multiwavelength observational campaigns are required to obtain…
Suzaku Observation of the Metallicity Distribution in the Intracluster Medium of the Fornax Cluster
Fukazawa, Yasushi; Makishima, Kazuo; Nakazawa, Kazuhiro +10 more
The metallicity distribution in the Fornax cluster was studied with the XIS instrument on board the Suzaku satellite. The K-shell lines of O and Mg were resolved clearly, and the abundances of O, Mg, Si, S, and Fe were measured with great accuracy. The region within a 4' radius of NGC 1399 shows approximately solar abundances of Fe, Si, and S, whi…
Searching for Earth Analogs Around the Nearest Stars: The Disk Age-Metallicity Relation and the Age Distribution in the Solar Neighborhood
Valenti, Jeff A.; Reid, I. Neill; Turnbull, Margaret C. +2 more
The chemical composition of Earth's atmosphere has undergone substantial evolution over the course of its history. It is possible, even likely, that terrestrial planets in other planetary systems have undergone similar changes; consequently, the age distribution of nearby stars is an important consideration in designing surveys for Earth analogs. …
The Aptly Named Phoenix Dwarf Galaxy
Dolphin, Andrew E.; Skillman, Evan D.; Weisz, Daniel R. +1 more
The Local Group galaxy Phoenix has the properties of a dwarf spheroidal galaxy, but an adjacent H I cloud has been recently found to be at the same radial velocity as the stars. The proximity suggests that this cloud is associated with the most recent (<=100 Myr) star formation in Phoenix. We have obtained relatively high sensitivity and high r…