Search Publications
On the physical structure of IRC +10216. Ground-based and Herschel observations of CO and C2H
Waters, L. B. F. M.; Barlow, M. J.; de Koter, A. +17 more
Context. The carbon-rich asymptotic giant branch star IRC +10 216 undergoes strong mass loss, and quasi-periodic enhancements of the density of the circumstellar matter have previously been reported. The star's circumstellar environment is a well-studied and complex astrochemical laboratory, in which many molecular species have been proved to be p…
Interstellar matter and star formation in W5-E. A Herschel view
Abergel, A.; Roussel, H.; André, Ph. +7 more
Aims: We identify the young stellar objects (YSOs) present in the vicinity of the W5-E H ii region, and study the influence of this H ii region on the star formation process in its surrounding molecular material.
Methods: W5-E has been observed with the Herschel-PACS and -SPIRE photometers, as part of the HOBYS key program; maps have bee…
"TNOs are Cool": A survey of the trans-Neptunian region. VI. Herschel/PACS observations and thermal modeling of 19 classical Kuiper belt objects
Fornasier, S.; Hartogh, P.; Lellouch, E. +20 more
Context. Trans-Neptunian objects (TNO) represent the leftovers of the formation of the solar system. Their physical properties provide constraints to the models of formation and evolution of the various dynamical classes of objects in the outer solar system.
Aims: Based on a sample of 19 classical TNOs we determine radiometric sizes, geometri…
Physical conditions in the gas phases of the giant H II region LMC-N 11 unveiled by Herschel . I. Diffuse [C II] and [O III] emission in LMC-N 11B
Poglitsch, A.; Sturm, E.; Lebouteiller, V. +10 more
Context. The Magellanic Clouds provide a nearby laboratory for metal-poor dwarf galaxies. The low dust abundance enhances the penetration of UV photons into the interstellar medium (ISM), resulting in a relatively larger filling factor of the ionized gas. Furthermore, there is very likely a molecular gas reservoir probed by the [C ii] 157 µm…
Secondary Magnetic Islands Generated by the Kelvin-Helmholtz Instability in a Reconnecting Current Sheet
Drake, J. F.; Swisdak, M.; Fermo, R. L.
Magnetic islands or flux ropes produced by magnetic reconnection have been observed on the magnetopause, in the magnetotail, and in coronal current sheets. Particle-in-cell simulations of magnetic reconnection with a guide field produce elongated electron current layers that spontaneously produce secondary islands. Here, we explore the seed mechan…
Revision of Solar Spicule Classification
Liu, Y.; Su, J. T.; Wang, J. X. +4 more
Solar spicules are the fundamental magnetic structures in the chromosphere and may play a key role in channeling the chromosphere and corona. Recently, it was suggested by De Pontieu et al. that there were two types of spicules with very different dynamic properties, which were detected by the space-time plot technique in the Ca II H line (3968 Å)…
Clustering Properties of BzK-selected Galaxies in GOODS-N: Environmental Quenching and Triggering of Star Formation at z ~ 2
Dickinson, Mark; Grogin, Norman A.; Yan, Chi-Hung +19 more
Using a sample of BzK-selected galaxies at z ~ 2 identified from the CFHT/WIRCAM near-infrared survey of GOODS-North, we discuss the relation between star formation rate (SFR), specific star formation rate (SSFR), and stellar mass (M *), and the clustering of galaxies as a function of these parameters. For star-forming galaxies (sBzKs),…
Automatically Detecting and Tracking Coronal Mass Ejections. I. Separation of Dynamic and Quiescent Components in Coronagraph Images
Morgan, Huw; Habbal, Shadia Rifai; Byrne, Jason P.
Automated techniques for detecting and tracking coronal mass ejections (CMEs) in coronagraph data are of ever increasing importance for space weather monitoring and forecasting. They serve to remove the biases and tedium of human interpretation, and provide the robust analysis necessary for statistical studies across large numbers of observations.…
Broad-line Region Physical Conditions in Extreme Population A Quasars: A Method to Estimate Central Black Hole Mass at High Redshift
Sulentic, Jack W.; Marziani, Paola; Negrete, C. Alenka +1 more
We describe a method for estimating physical conditions in the broad-line region (BLR) for a significant subsample of Seyfert 1 nuclei and quasars. Several diagnostic ratios based on intermediate (Al III λ1860, Si III] λ1892) and high (C IV λ1549, Si IV λ1397) ionization lines in the UV spectra of quasars are used to constrain density, ionization,…
Unmasking the Supernova Impostors
Kochanek, C. S.; Stanek, K. Z.; Szczygieł, D. M.
The canonical picture of a supernova impostor is a short (~months) -11 <~ MV <~ -14 optical transient from a massive (M * >~ 40 M ⊙) star during which the star ejects a dense shell of material. Dust formed in the ejecta then obscures the star. In this picture, the geometric expansion of the shell leads to …