Search Publications
DUst around NEarby Stars. The survey observational results
Heras, A. M.; Fridlund, M.; Olofsson, G. +47 more
Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system counterparts are the asteroid and Edgeworth-Kuiper belts.
Aims: The DUNES survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way t…
Explaining the [C II]157.7 µm Deficit in Luminous Infrared Galaxies—First Results from a Herschel/PACS Study of the GOALS Sample
Sturm, E.; Veilleux, S.; Sanders, D. B. +26 more
We present the first results of a survey of the [C II]157.7 µm emission line in 241 luminous infrared galaxies (LIRGs) comprising the Great Observatories All-sky LIRG Survey (GOALS) sample, obtained with the PACS instrument on board the Herschel Space Observatory. The [C II] luminosities, L [C II], of the LIRGs in GOALS range from…
The Ultraviolet Radiation Environment around M dwarf Exoplanet Host Stars
Roberge, Aki; Désert, Jean-Michel; France, Kevin +8 more
The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis e…
Statistics of whistler mode waves in the outer radiation belt: Cluster STAFF-SA measurements
Breuillard, Hugo; Khotyaintsev, Yuri V.; Balikhin, Michael +5 more
ELF/VLF waves play a crucial role in the dynamics of the radiation belts and are partly responsible for the main losses and the acceleration of energetic electrons. Modeling wave-particle interactions requires detailed information of wave amplitudes and wave normal distribution over L-shells and over magnetic latitudes for different geomagnetic ac…
Spectrophotometric time series of SN 2011fe from the Nearby Supernova Factory
Aldering, G.; Fakhouri, H. K.; Kowalski, M. +36 more
We present 32 epochs of optical (3300-9700 Å) spectrophotometric observations of the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in the galaxy M101, extending from -15 to +97 d with respect to B-band maximum, obtained by the Nearby Supernova Factory collaboration. SN 2011fe is the closest (µ = 29.04) and brightest (B
Short versus Long and Collapsars versus Non-collapsars: A Quantitative Classification of Gamma-Ray Bursts
Piran, Tsvi; Bromberg, Omer; Nakar, Ehud +1 more
Gamma-ray bursts (GRBs) are traditionally divided into long and short according to their durations (lg2 s). It was generally believed that this reflects a different physical origin: collapsars (long) and non-collapsars (short). We have recently shown that the duration distribution of collapsars is flat, namely, independent of the duration, at shor…
Accretion Rates for T Tauri Stars Using Nearly Simultaneous Ultraviolet and Optical Spectra
Edwards, Suzan; Brown, Alexander; Calvet, Nuria +9 more
We analyze the accretion properties of 21 low-mass T Tauri stars using a data set of contemporaneous near-UV (NUV) through optical observations obtained with the Hubble Space Telescope Imaging Spectrograph and the ground-based Small and Medium Aperture Research Telescope System, a unique data set because of the nearly simultaneous broad wavelength…
Dust in the Polar Region as a Major Contributor to the Infrared Emission of Active Galactic Nuclei
Hönig, S. F.; Kishimoto, M.; Tristram, K. R. W. +7 more
Dust around active galactic nuclei (AGNs) is distributed over a wide range of spatial scales and can be observed in the infrared (IR). It is generally assumed that the distribution on parsec scales forms a geometrically and optically thick entity in the equatorial plane around the accretion disk and broad-line region—dubbed "dust torus"—that emits…
The Bimodal Metallicity Distribution of the Cool Circumgalactic Medium at z <~ 1
Lehner, N.; Prochaska, J. X.; Fox, A. J. +7 more
We assess the metal content of the cool (~104 K) circumgalactic medium (CGM) about galaxies at z <~ 1 using an H I-selected sample of 28 Lyman limit systems (LLS; defined here as absorbers with 16.2 <~ log N H I <~ 18.5) observed in absorption against background QSOs by the Cosmic Origins Spectrograph on board the H…
The extragalactic background light and the gamma-ray opacity of the universe
Dwek, Eli; Krennrich, Frank
The extragalactic background light (EBL) is one of the fundamental observational quantities in cosmology. All energy releases from resolved and unresolved extragalactic sources, and the light from any truly diffuse background, excluding the cosmic microwave background (CMB), contribute to its intensity and spectral energy distribution. It therefor…