Search Publications
Chemical Consequences of the C/O Ratio on Hot Jupiters: Examples from WASP-12b, CoRoT-2b, XO-1b, and HD 189733b
Moses, J. I.; Madhusudhan, N.; Visscher, C. +1 more
Motivated by recent spectroscopic evidence for carbon-rich atmospheres on some transiting exoplanets, we investigate the influence of the C/O ratio on the chemistry, composition, and spectra of extrasolar giant planets both from a thermochemical equilibrium perspective and from consideration of disequilibrium processes like photochemistry and tran…
What Determines the Density Structure of Molecular Clouds? A Case Study of Orion B with Herschel
Hill, T.; André, Ph.; Arzoumanian, D. +19 more
A key parameter to the description of all star formation processes is the density structure of the gas. In this Letter, we make use of probability distribution functions (PDFs) of Herschel column density maps of Orion B, Aquila, and Polaris, obtained with the Herschel Gould Belt survey (HGBS). We aim to understand which physical processes influenc…
Joint Analysis of Cluster Observations. II. Chandra/XMM-Newton X-Ray and Weak Lensing Scaling Relations for a Sample of 50 Rich Clusters of Galaxies
Hoekstra, Henk; Babul, Arif; Mahdavi, Andisheh +3 more
We present a study of multiwavelength X-ray and weak lensing scaling relations for a sample of 50 clusters of galaxies. Our analysis combines Chandra and XMM-Newton data using an energy-dependent cross-calibration. After considering a number of scaling relations, we find that gas mass is the most robust estimator of weak lensing mass, yielding 15%…
Generating artificial light curves: revisited and updated
Papadakis, I. E.; Emmanoulopoulos, D.; McHardy, I. M.
The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by sampling irregularities, establishing detection limits for future observatories are just some of the applica…
An Overview of the Dwarf Galaxy Survey
Poglitsch, A.; Sturm, E.; Ciesla, L. +38 more
The Dwarf Galaxy Survey (DGS) program is studying low-metallicity galaxies using 230 hr of far-infrared (FIR) and submillimetre (submm) photometric and spectroscopic observations of the Herschel Space Observatory and draws from this a rich database of a wide range of wavelengths tracing the dust, gas and stars. This sample of 50 galaxies includes …
The ultraluminous state revisited: fractional variability and spectral shape as diagnostics of super-Eddington accretion
Middleton, Matthew J.; Sutton, Andrew D.; Roberts, Timothy P.
Although we are nearing a consensus that most ultraluminous X-ray sources (ULXs) below 1041 erg s-1 represent stellar mass black holes accreting in a super-Eddington `ultraluminous' accretion state, little is yet established of the physics of this extreme accretion mode. Here, we use a combined X-ray spectral and timing analy…
The FMOS-COSMOS Survey of Star-forming Galaxies at z ~ 1.6. I. Hα-based Star Formation Rates and Dust Extinction
Daddi, E.; Rodighiero, G.; Sanders, D. B. +26 more
We present the first results from a near-IR spectroscopic survey of the COSMOS field, using the Fiber Multi-Object Spectrograph on the Subaru telescope, designed to characterize the star-forming galaxy population at 1.4 < z < 1.7. The high-resolution mode is implemented to detect Hα in emission between 1.6-1.8 µm with f Hα &…
The Formation of IRIS Diagnostics. II. The Formation of the Mg II h&k Lines in the Solar Atmosphere
De Pontieu, B.; Leenaarts, J.; Carlsson, M. +2 more
NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h&k lines as well as a slit-jaw imager centered at Mg II k. Understanding the observations requires forward modeling of Mg II h&k line formation from three-…
The Suzaku view of highly ionized outflows in AGN - I. Statistical detection and global absorber properties
Reeves, James N.; Tombesi, Francesco; Miller, Lance +4 more
We present the results of a new spectroscopic study of Fe K-band absorption in active galactic nuclei (AGN). Using data obtained from the Suzaku public archive we have performed a statistically driven blind search for Fe XXV Heα and/or Fe XXVI Lyα absorption lines in a large sample of 51 Type 1.0-1.9 AGN. Through extensive Monte Carlo simulations …
HST/WFC3 Confirmation of the Inside-out Growth of Massive Galaxies at 0 < z < 2 and Identification of Their Star-forming Progenitors at z ~ 3
van Dokkum, Pieter G.; Franx, Marijn; Muzzin, Adam +6 more
We study the structural evolution of massive galaxies by linking progenitors and descendants at a constant cumulative number density of n c = 1.4 × 10-4 Mpc-3 to z ~ 3. Structural parameters were measured by fitting Sérsic profiles to high-resolution CANDELS HST WFC3 J 125 and H 160 imaging in…