Search Publications
A Very High Energy γ-Ray Survey toward the Cygnus Region of the Galaxy
Abeysekara, A. U.; Archer, A.; Aune, T. +67 more
We present results from deep observations toward the Cygnus region using 300 hr of very high energy (VHE) γ-ray data taken with the VERITAS Cerenkov telescope array and over 7 yr of high-energy γ-ray data taken with the Fermi satellite at an energy above 1 GeV. As the brightest region of diffuse γ-ray emission in the northern sky, the Cygnus regio…
The CARMENES search for exoplanets around M dwarfs. A Neptune-mass planet traversing the habitable zone around HD 180617
Stahl, O.; Amado, P. J.; Bauer, F. F. +37 more
Despite their activity, low-mass stars are of particular importance for the search of exoplanets by the means of Doppler spectroscopy, as planets with lower masses become detectable. We report on the discovery of a planetary companion around HD 180617, a bright (J = 5.58 mag), low-mass (M = 0.45M⊙) star of spectral type M2.5 V. The star…
The Gaia-ESO Survey: properties of newly discovered Li-rich giants
Gilmore, G.; Bayo, A.; Recio-Blanco, A. +41 more
Aims: We report 20 new lithium-rich giants discovered within the Gaia-ESO Survey, including the first Li-rich giant with an evolutionary stage confirmed by CoRoT (Convection, Rotation and planetary Transits) data. We present a detailed overview of the properties of these 20 stars.
Methods: Atmospheric parameters and abundances were deriv…
Measurement of the primordial helium abundance from the intergalactic medium
Fumagalli, Michele; Cooke, Ryan J.
Almost every helium atom in the Universe was created just a few minutes after the Big Bang through a process commonly referred to as Big Bang nucleosynthesis1,2. The amount of helium that was made during Big Bang nucleosynthesis is determined by combining particle physics and cosmology3. The current leading measures of the pr…
LoCuSS: The infall of X-ray groups on to massive clusters
Finoguenov, A.; Smith, G. P.; Okabe, N. +10 more
Galaxy clusters are expected to form hierarchically in a Λ cold dark matter (ΛCDM) universe, growing primarily through mergers with lower mass clusters and the continual accretion of group-mass haloes. Galaxy clusters assemble late, doubling their masses since z ∼ 0.5, and so the outer regions of clusters should be replete with accreting group-mas…
Possible 1 hour quasi-periodic oscillation in narrow-line Seyfert 1 galaxy MCG-06-30-15
Ho, Luis C.; Gupta, Alok C.; Wiita, Paul J. +3 more
We found a possible 1 h quasi-periodic oscillation (QPO) in a 55 ks X-ray observation of the narrow-line Seyfert 1 galaxy MCG-06-30-15 made with the XMM-Newton EPIC/pn detector in the energy range 0.3-10 keV. We identify a total modulation of 16% in the light curve and find a ≃3670 s quasi-period using Lomb-Scargle periodogram (LSP) and weighted w…
Ubiquitous ram pressure stripping in the Coma cluster of galaxies
Boselli, A.; Gavazzi, G.; Consolandi, G. +2 more
We report the detection of Hα trails behind three new intermediate-mass irregular galaxies in the NW outskirts of the nearby cluster of galaxies Abell 1656 (Coma). Hints that these galaxies possess an extended component were found in earlier, deeper Hα observations carried out with the Subaru telescope. However the lack of a simultaneous r-band ex…
Molecular clouds in the NGC 6334 and NGC 6357 region: Evidence for a 100 pc-scale cloud-cloud collision triggering the Galactic mini-starbursts
Tachihara, Kengo; Fukui, Yasuo; Sano, Hidetoshi +7 more
We carried out new CO (J = 1-0, 2-1, and 3-2) observations with NANTEN2 and ASTE in the region of the twin Galactic mini-starbursts NGC 6334 and NGC 6357. We detected two velocity molecular components of 12 km s-1 velocity separation, which is continuous over 3° along the plane. In NGC 6334 the two components show similar two-peaked int…
Local growth of dust- and ice-mixed aggregates as cometary building blocks in the solar nebula
Blum, J.; Lacerda, P.; Lorek, S.
Context. Comet formation by gravitational instability requires aggregates that trigger the streaming instability and cluster in pebble-clouds. These aggregates form as mixtures of dust and ice from (sub-)micrometre-sized dust and ice grains via coagulation in the solar nebula. Aim. We investigate the growth of aggregates from (sub-)micrometre-size…
Impact of Type II Spicules in the Corona: Simulations and Synthetic Observables
Martínez-Sykora, Juan; De Pontieu, Bart; Carlsson, Mats +2 more
The role of type II spicules in the corona has been a much debated topic in recent years. This paper aims to shed light on the impact of type II spicules in the corona using novel 2.5D radiative MHD simulations, including ion-neutral interaction effects with the Bifrost code. We find that the formation of simulated type II spicules, driven by the …