Search Publications
Extinction in the 11.2 µm PAH band and the low L11.2/LIR in ULIRGs
Pérez-González, Pablo G.; Arribas, Santiago; Alonso-Herrero, Almudena +9 more
We present a method for recovering the intrinsic (extinction-corrected) luminosity of the 11.2 µm PAH band in galaxy spectra. Using 105 high S/N Spitzer/IRS spectra of star-forming galaxies, we show that the equivalent width ratio of the 12.7 and 11.2 µm PAH bands is independent on the optical depth (τ), with small dispersion (∼5 per c…
Turbulence and Energetic Particles in Radiative Shock Waves in the Cygnus Loop. II. Development of Postshock Turbulence
Blair, William P.; Slavin, Jonathan D.; Raymond, John C. +3 more
Radiative shock waves in the Cygnus Loop and other supernova remnants show different morphologies in [O III] and Hα emission. We use HST spectra and narrowband images to study the development of turbulence in the cooling region behind a shock on the west limb of the Cygnus Loop. We refine our earlier estimates of shock parameters that were based u…
Heavy-metal enrichment of intermediate He-sdOB stars: the pulsators Feige 46 and LS IV-14°116 revisited
Heber, U.; Latour, M.; Irrgang, A. +3 more
Hot subdwarf stars of spectral types O and B represent a poorly understood phase in the evolution of low-mass stars, in particular of close compact binaries. A variety of phenomena are observed, which make them important tools for several astronomical disciplines. For instance, the richness of oscillations of many subdwarfs are important for aster…
Eigengalaxies: describing galaxy morphology using principal components in image space
Kaviraj, Sugata; Geach, James E.; Uzeirbegovic, Emir
We demonstrate how galaxy morphologies can be represented by weighted sums of 'eigengalaxies' and how eigengalaxies can be used in a probabilistic framework to enable principled and simplified approaches in a variety of applications. Eigengalaxies can be derived from a Principal Component Analysis (PCA) of sets of single- or multiband images. They…
Processes governing the VIS/NIR spectral reflectance behavior of lunar swirls
Wöhler, C.; Grumpe, A.; Bhatt, M. +5 more
We investigated six bright swirls associated with magnetic anomalies of variable strength using Chandrayaan-1 Moon Mineralogy Mapper (M3) hyperspectral image data. We examined the 3 µm absorption band generally ascribed to solar wind-induced OH/H2O and spectral trends in the near-infrared wavelength range at on-swirl an…
Numerical Modeling of Suprathermal Electron Transport in the Solar Wind: Effects of Whistler Turbulence
Zank, Gary P.; Tang, Bofeng; Kolobov, Vladimir I.
The solar wind electron velocity distribution function deviates significantly from an equilibrium Maxwellian distribution and is composed of a Maxwellian core, a suprathermal halo, a field-aligned component strahl, and a higher-energy superhalo. Wave-particle interactions associated with whistler wave turbulence are introduced into the kinetic tra…
Significant Suppression of Star Formation in Radio-quiet AGN Host Galaxies with Kiloparsec-scale Radio Structures
Koss, Michael; Ricci, Claudio; Mushotzky, Richard +4 more
We conducted 22 GHz 1″ Jansky Very Large Array imaging of 100 radio-quiet X-ray-selected active galactic nuclei (AGN) from the Swift-Burst Array Telescope (Swift-BAT) survey. We find AGN-driven kiloparsec-scale radio structures inconsistent with pure star formation in 11 AGN. The host galaxies of these AGN lie significantly below the star-forming …
Predicting the dark matter velocity distribution in galactic structures: tests against hydrodynamic cosmological simulations
Lacroix, Thomas; Stref, Martin; Lavalle, Julien +2 more
Reducing theoretical uncertainties in Galactic dark matter (DM) searches is an important challenge as several experiments are now delving into the parameter space relevant to popular (particle or not) candidates. Since many DM signal predictions rely on the knowledge of the DM velocity distribution—direct searches, capture by stars, p-wave-suppres…
Origin of spin-orbit misalignments: the microblazar V4641 Sgr
Salvesen, Greg; Pokawanvit, Supavit
Of the known microquasars, V4641 Sgr boasts the most severe lower limit (>52°) on the misalignment angle between the relativistic jet axis and the binary orbital angular momentum. Assuming the jet and black hole spin axes coincide, we attempt to explain the origin of this extreme spin-orbit misalignment with a natal kick model, whereby an align…
Planet-induced spirals in the circumbinary disk of GG Tauri A
Chapillon, E.; Beck, T. L.; Guilloteau, S. +10 more
Context. ALMA high angular resolution observations of the dust and CO emission have already revealed signatures of protoplanets embedded in protoplanetary disks. These detections are around single T Tauri stars, while exoplanet surveys reveal that planets can also form in binary (or multiple) systems, either in circumstellar or circumbinary orbits…