Search Publications

Relativistic iron K X-ray reverberation in NGC 4151
DOI: 10.1111/j.1365-2966.2012.20587.x Bibcode: 2012MNRAS.422..129Z

Fabian, A. C.; Reynolds, C. S.; Cackett, E. M. +1 more

Recent X-ray observations have enabled the study of reverberation delays in active galactic nuclei (AGN) for the first time. All the detections so far are in sources with a strong soft excess, and the measured delay is between the hard (1-3 keV) direct continuum and the soft excess (0.5-1 keV), interpreted as the reflection continuum smeared by re…

2012 Monthly Notices of the Royal Astronomical Society
XMM-Newton 157
The surface composition of Iapetus: Mapping results from Cassini VIMS
DOI: 10.1016/j.icarus.2012.01.008 Bibcode: 2012Icar..218..831C

Nicholson, Philip D.; Baines, Kevin H.; Buratti, Bonnie J. +11 more

Cassini VIMS has obtained spatially resolved imaging spectroscopy data on numerous satellites of Saturn. A very close fly-by of Iapetus on September 10, 2007 provided the best data on the spectral signature and spatial extent of dark material on Iapetus. This Cassini Rev 49 Iapetus fly-by provided spatially resolved imaging spectroscopy data of th…

2012 Icarus
Cassini 157
A Redshift Survey of Herschel Far-infrared Selected Starbursts and Implications for Obscured Star Formation
DOI: 10.1088/0004-637X/761/2/140 Bibcode: 2012ApJ...761..140C

Berta, S.; Magnelli, B.; Lutz, D. +30 more

We present Keck spectroscopic observations and redshifts for a sample of 767 Herschel-SPIRE selected galaxies (HSGs) at 250, 350, and 500 µm, taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. The redshift distribution of these SPIRE sources from the Herschel Multitiered Extragal…

2012 The Astrophysical Journal
Herschel 157
Multi-wavelength View of Kiloparsec-scale Clumps in Star-forming Galaxies at z ~ 2
DOI: 10.1088/0004-637X/757/2/120 Bibcode: 2012ApJ...757..120G

Ferguson, Henry C.; Giavalisco, Mauro; Koekemoer, Anton M. +2 more

This paper studies the properties of kiloparsec-scale clumps in star-forming galaxies at z ~ 2 through multi-wavelength broadband photometry. A sample of 40 clumps is identified from Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) z-band images through auto-detection and visual inspection from 10 galaxies with 1.5 < z < 2.5 in…

2012 The Astrophysical Journal
eHST 156
The Deflection of the Two Interacting Coronal Mass Ejections of 2010 May 23-24 as Revealed by Combined in Situ Measurements and Heliospheric Imaging
DOI: 10.1088/0004-637X/759/1/68 Bibcode: 2012ApJ...759...68L

Möstl, C.; Farrugia, C. J.; Temmer, M. +4 more

In 2010 May 23-24, Solar Dynamics Observatory (SDO) observed the launch of two successive coronal mass ejections (CMEs), which were subsequently tracked by the SECCHI suite on board STEREO. Using the COR2 coronagraphs and the heliospheric imagers (HIs), the initial direction of both CMEs is determined to be slightly west of the Sun-Earth line. We …

2012 The Astrophysical Journal
SOHO 156
Optimal estimation retrievals of the atmospheric structure and composition of HD 189733b from secondary eclipse spectroscopy
DOI: 10.1111/j.1365-2966.2011.20013.x Bibcode: 2012MNRAS.420..170L

Fletcher, L. N.; Lee, J. -M.; Irwin, P. G. J.

Recent spectroscopic observations of transiting hot Jupiters have permitted the derivation of the thermal structure and molecular abundances of H2O, CO2, CO and CH4 in these extreme atmospheres. Here, for the first time, we apply the technique of optimal estimation to determine the thermal structure and composition…

2012 Monthly Notices of the Royal Astronomical Society
eHST 156
Bipolar Magnetic Regions on the Sun: Global Analysis of the SOHO/MDI Data Set
DOI: 10.1088/0004-637X/745/2/129 Bibcode: 2012ApJ...745..129S

Kosovichev, A. G.; Stenflo, J. O.

The magnetic flux that is generated by dynamo processes inside the Sun emerges in the form of bipolar magnetic regions. The properties of these directly observable signatures of the dynamo can be extracted from full-disk solar magnetograms. The most homogeneous, high-quality synoptic data set of solar magnetograms has been obtained with the Michel…

2012 The Astrophysical Journal
SOHO 155
First Detection of Water Vapor in a Pre-stellar Core
DOI: 10.1088/2041-8205/759/2/L37 Bibcode: 2012ApJ...759L..37C

Caselli, Paola; Codella, Claudio; Aikawa, Yuri +11 more

Water is a crucial molecule in molecular astrophysics as it controls much of the gas/grain chemistry, including the formation and evolution of more complex organic molecules in ices. Pre-stellar cores provide the original reservoir of material from which future planetary systems are built, but few observational constraints exist on the formation o…

2012 The Astrophysical Journal
Herschel 155
The morphologies of massive galaxies at 1 < z < 3 in the CANDELS-UDS field: compact bulges, and the rise and fall of massive discs
DOI: 10.1111/j.1365-2966.2012.22087.x Bibcode: 2012MNRAS.427.1666B

Ferguson, H. C.; McLure, R. J.; Dunlop, J. S. +16 more

We have used high-resolution, Hubble Space Telescope, near-infrared imaging to conduct a detailed analysis of the morphological properties of the most massive galaxies at high redshift, modelling the WFC3/IR H160-band images of the ≃200 galaxies in the CANDELS-UDS field with photometric redshifts 1 < z < 3, and stellar masses M

2012 Monthly Notices of the Royal Astronomical Society
eHST 155
No Clear Submillimeter Signature of Suppressed Star Formation among X-Ray Luminous Active Galactic Nuclei
DOI: 10.1088/2041-8205/760/1/L15 Bibcode: 2012ApJ...760L..15H

Magnelli, B.; Altieri, B.; Daddi, E. +18 more

Many theoretical models require powerful active galactic nuclei (AGNs) to suppress star formation in distant galaxies and reproduce the observed properties of today's massive galaxies. A recent study based on Herschel-SPIRE submillimeter observations claimed to provide direct support for this picture, reporting a significant decrease in the mean s…

2012 The Astrophysical Journal
Herschel 153