Search Publications
Kinematics and simulations of the stellar stream in the halo of the Umbrella Galaxy
Zibetti, S.; Martínez-Delgado, D.; Strader, J. +9 more
We study the dynamics of faint stellar substructures around the Umbrella Galaxy, NGC 4651, which hosts a dramatic system of streams and shells formed through the tidal disruption of a nucleated dwarf elliptical galaxy. We elucidate the basic characteristics of the system (colours, luminosities, stellar masses) using multiband Subaru/Suprime-Cam im…
Cold electron heating by EMIC waves in the plasmaspheric plume with observations of the Cluster satellite
Dandouras, Iannis; Yuan, Zhigang; Huang, Shiyong +7 more
We report in situ observations by the Cluster spacecraft of plasmaspheric electron heating in the plasmaspheric plume. Electron heating events were accompanied by enhancements of electromagnetic ion cyclotron (EMIC) waves in the increased density ducts on the negative density gradient side for two substructures of the plasmaspheric plume. Electron…
Self-calibration of BICEP1 three-year data and constraints on astrophysical polarization rotation
Ade, P. A. R.; Bock, J. J.; Chiang, H. C. +33 more
Cosmic microwave background (CMB) polarimeters aspire to measure the faint B-mode signature predicted to arise from inflationary gravitational waves. They also have the potential to constrain cosmic birefringence, rotation of the polarization of the CMB arising from parity-violating physics, which would produce nonzero expectation values for the C…
The VLT-FLAMES Tarantula Survey. XIII: On the nature of O Vz stars in 30 Doradus
Herrero, A.; Simón-Díaz, S.; Puls, J. +13 more
Context. O Vz stars, a subclass of O-type dwarfs characterized by having He ii λ4686 stronger in absorption than any other helium line in their blue-violet spectra, have been suggested to be on or near the zero-age main sequence (ZAMS). If their youth were confirmed, they would be key objects with which to advance our knowledge of the physical pro…
Star Formation Rates from [C II] 158 µm and Mid-infrared Emission Lines for Starbursts and Active Galactic Nuclei
Lebouteiller, V.; Sargsyan, L.; Samsonyan, A. +5 more
A summary is presented for 130 galaxies observed with the Herschel Photodetector Array Camera and Spectrometer instrument to measure fluxes for the [C II] 158 µm emission line. Sources cover a wide range of active galactic nucleus to starburst classifications, as derived from polycyclic aromatic hydrocarbon strength measured with the Spitzer…
Optical Spectroscopic Observations of Blazars and γ-Ray Blazar Candidates in the Sloan Digital Sky Survey Data Release Nine
Masetti, N.; Funk, S.; Massaro, F. +2 more
We present an analysis of the optical spectra available in the Sloan Digital Sky Survey data release nine (SDSS DR9) for the blazars listed in the ROMA-BZCAT and for the γ-ray blazar candidates selected according to their IR colors. First, we adopt a statistical approach based on Monte Carlo simulations to find the optical counterparts of the blaz…
Methane depletion in both polar regions of Uranus inferred from HST/STIS and Keck/NIRC2 observations
Sromovsky, L. A.; Fry, P. M.; Karkoschka, E. +3 more
From Space Telescope Imaging Spectrograph (STIS) observations of Uranus in 2012, when good views of its north polar regions were available, we found that the methane volume mixing ratio declined from about 4% at low latitudes to about 2% at 60-80°N. This depletion in the north polar region of Uranus in 2012 is similar in magnitude and depth to tha…
A Solar Type II Radio Burst from Coronal Mass Ejection-Coronal Ray Interaction: Simultaneous Radio and Extreme Ultraviolet Imaging
Feng, Li; Li, Gang; Chen, Yao +5 more
Simultaneous radio and extreme ultraviolet (EUV)/white-light imaging data are examined for a solar type II radio burst occurring on 2010 March 18 to deduce its source location. Using a bow-shock model, we reconstruct the three-dimensional EUV wave front (presumably the type-II-emitting shock) based on the imaging data of the two Solar TErrestrial …
Accelerated post-AGB evolution, initial-final mass relations, and the star-formation history of the Galactic bulge
Zijlstra, A. A.; Hajduk, M.; Gesicki, K. +1 more
Aims: We study the star-formation history of the Galactic bulge, as derived from the age distribution of the central stars of planetary nebulae that belong to this stellar population.
Methods: The high resolution imaging and spectroscopic observations of 31 compact planetary nebulae are used to derive their central star masses. We use th…
The Herschel Exploitation of Local Galaxy Andromeda (HELGA). IV. Dust scaling relations at sub-kpc resolution
Blommaert, J. A. D. L.; Ciesla, L.; Boquien, M. +18 more
Context. Dust and stars play a complex game of interactions in the interstellar medium and around young stars. The imprints of these processes are visible in scaling relations between stellar characteristics, star formation parameters, and dust properties.
Aims: In the present work, we aim to examine dust scaling relations on a sub-kpc resolu…