Search Publications
On why the iron K-shell absorption in AGN is not a signature of the local warm/hot intergalactic medium
Done, Chris; Terashima, Yuichi; Hayashida, Kiyoshi +5 more
We present a comparison between the 2001 XMM-Newton and 2005 Suzaku observations of the quasar, PG1211+143, at z = 0.0809. Variability is observed in the 7 keV iron K-shell absorption line (at 7.6 keV in the quasar frame), which is significantly weaker in 2005 than during the 2001 XMM-Newton observation. From a recombination time-scale of <4 yr…
The formation and assembly of a typical star-forming galaxy at redshift z~3
Richard, Johan; Stark, Daniel P.; Ellis, Richard S. +3 more
Recent studies of galaxies ~2-3Gyr after the Big Bang have revealed large, rotating disks, similar to those of galaxies today. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation indicates that gas accretion is likely to be the dominant mode by which galaxies grow, because major mergers of galaxies wo…
Hubble Space Telescope STIS Optical Transit Transmission Spectra of the Hot Jupiter HD 209458b
Sing, David K.; Lecavelier des Etangs, A.; Vidal-Madjar, A. +2 more
We present the transmission spectra of the hot Jupiter HD 209458b taken with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Our analysis combines data at two resolutions and applies a complete pixel-by-pixel limb-darkening correction to fully reveal the spectral line shapes of atmospheric absorption features. Terrestri…
The nature of UCDs: Internal dynamics from an expanded sample and homogeneous database
Ferrarese, L.; Infante, L.; Rejkuba, M. +9 more
Context: The internal dynamics of ultra-compact dwarf galaxies (UCDs) has attracted increasing attention, with most of the UCDs studied to date located in the Virgo cluster.
Aims: Our aim is to perform a comprehensive census of the internal dynamics of UCDs in the Fornax cluster, and to shed light on the nature of the interface between star cl…
High-Cadence Observations of a Global Coronal Wave by STEREO EUVI
Veronig, Astrid M.; Temmer, Manuela; Vršnak, Bojan
We report a large-scale coronal wave (so-called EIT wave) observed with high cadence by EUVI on board STEREO in association with the GOES B9.5 flare and double CME event on 2007 May 19. The EUVI instruments provide us with the unprecedented opportunity to study the dynamics of flare/CME associated coronal waves. The coronal wave under study reveal…
Proper Motions of the Large Magellanic Cloud and Small Magellanic Cloud: Re-Analysis of Hubble Space Telescope Data
Piatek, Slawomir; Pryor, Carlton; Olszewski, Edward W.
Kallivayalil et al. have used the Hubble Space Telescope to measure proper motions of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) using images in 21 and five fields, respectively, all centered on known quasi-stellar objects (QSOs). These results are more precise than previous measurements, but have surprising and important ph…
Titan’s Rotation Reveals an Internal Ocean and Changing Zonal Winds
Iess, Luciano; Stiles, Bryan W.; Kirk, Randolph L. +6 more
Cassini radar observations of Saturn’s moon Titan over several years show that its rotational period is changing and is different from its orbital period. The present-day rotation period difference from synchronous spin leads to a shift of ~0.36° per year in apparent longitude and is consistent with seasonal exchange of angular momentum between th…
North polar region of Mars: Advances in stratigraphy, structure, and erosional modification
Herkenhoff, Kenneth E.; Tanaka, Kenneth L.; Skinner, James A. +5 more
We have remapped the geology of the north polar plateau on Mars, Planum Boreum, and the surrounding plains of Vastitas Borealis using altimetry and image data along with thematic maps resulting from observations made by the Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter spacecraft. New and revised geographic and …
Magnetic support of the optical emission line filaments in NGC 1275
Fabian, A. C.; Gallagher, J. S., III; Conselice, C. J. +4 more
The giant elliptical galaxy NGC 1275, at the centre of the Perseus cluster, is surrounded by a well-known giant nebulosity of emission-line filaments, which are plausibly in excess of 108years old. The filaments are dragged out from the centre of the galaxy by radio-emitting `bubbles' rising buoyantly in the hot intracluster gas, before…
A New Method to Separate Star-forming from AGN Galaxies at Intermediate Redshift: The Submillijansky Radio Population in the VLA-COSMOS Survey
Bondi, M.; Aussel, H.; Sanders, D. B. +21 more
We explore the properties of the submillijansky radio population at 20 cm by applying a newly developed optical color-based method to separate star-forming (SF) from active galactic nucleus (AGN) galaxies at intermediate redshifts (zlesssim 1.3). Although optical rest-frame colors are used, our separation method is shown to be efficient and not bi…