Search Publications
Isotopic composition of CO2 in the coma of 67P/Churyumov-Gerasimenko measured with ROSINA/DFMS
Wurz, P.; Altwegg, K.; Balsiger, H. +15 more
Context. Measurements of isotopic abundances in cometary ices are key to understanding and reconstructing the history and origin of material in the solar system. Comets are considered the most pristine material in the solar system. Isotopic fractionation (enrichment of an isotope in a molecule compared to the initial abundance) is sensitive to env…
Mrk 71/NGC 2366: The Nearest Green Pea Analog
Jaskot, Anne E.; James, Bethan L.; Oey, M. S. +1 more
We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H II region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitat…
The MOSDEF Survey: The Prevalence and Properties of Galaxy-wide AGN-driven Outflows at z ∼ 2
Siana, Brian; Azadi, Mojegan; Aird, James +10 more
Using observations from the first 2 yr of the MOSFIRE Deep Evolution Field (MOSDEF) survey, we study 13 active galactic nucleus (AGN) driven outflows detected from a sample of 67 X-ray, IR, and/or optically selected AGNs at z∼ 2. The AGNs have bolometric luminosities of ∼ {10}44{--}{10}46 {erg} {{{s}}}-1, including…
Galactic bulge population II Cepheids in the VVV survey: period-luminosity relations and a distance to the Galactic centre
Minniti, D.; Rejkuba, M.; Zoccali, M. +7 more
Context. Multiple stellar populations of different ages and metallicities reside in the Galactic bulge that trace its structure and provide clues to its formation and evolution.
Aims: We present the near-infrared observations of population II Cepheids in the Galactic bulge from VISTA Variables in the Vía Láctea (VVV) survey. The JHKs
Catalogue of 55-80 MeV solar proton events extending through solar cycles 23 and 24
Heber, Bernd; Paassilta, Miikka; Raukunen, Osku +9 more
We present a new catalogue of solar energetic particle events near the Earth, covering solar cycle 23 and the majority of solar cycle 24 (1996-2016), based on the 55-80 MeV proton intensity data gathered by the Solar and Heliospheric Observatory/the Energetic and Relativistic Nuclei and Electron experiment (SOHO/ERNE). In addition to ERNE proton a…
Thermal Pressure in the Cold Neutral Medium of Nearby Galaxies
Smith, J. D.; Calzetti, D.; Galametz, M. +14 more
Dynamic and thermal processes regulate the structure of the multiphase interstellar medium (ISM), and ultimately establish how galaxies evolve through star formation. Thus, to constrain ISM models and better understand the interplay of these processes, it is of great interest to measure the thermal pressure (Pth) of the diffuse, neutral…
Simulation of VLF chorus emissions in the magnetosphere and comparison with THEMIS spacecraft data
Santolík, O.; Demekhov, A. G.; Taubenschuss, U.
We present results of numerical simulations of VLF chorus emissions based on the backward wave oscillator model and compare them with Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft data from the equatorial chorus source region on the early morning side at a radial distance of 6 Earth radii. Specific attenti…
Red nuggets grow inside-out: evidence from gravitational lensing
Treu, Tommaso; Fassnacht, Christopher D.; Auger, Matthew W. +7 more
We present a new sample of strong gravitational lens systems where both the foreground lenses and background sources are early-type galaxies. Using imaging from Hubble Space Telescope (HST)/Advanced Camera for Studies (ACS) and Keck/NIRC2, we model the surface brightness distributions and show that the sources form a distinct population of massive…
The properties of energetically unbound stars in stellar clusters
Gieles, Mark; Zocchi, Alice; Claydon, Ian
Several Milky Way star clusters show a roughly flat velocity dispersion profile at large radii, which is not expected from models with a tidal cut-off energy. Possible explanations for this excess velocity include the effects of a dark matter halo, modified gravity theories and energetically unbound stars inside of clusters. These stars are known …
Rapid Pitch Angle Evolution of Suprathermal Electrons Behind Dipolarization Fronts
Daly, P. W.; Cao, J. B.; Xu, Y. +4 more
The pitch angle distribution (PAD) of suprathermal electrons can have both spatial and temporal evolution in the magnetotail and theoretically can be an indication of electron energization/cooling processes there. So far, the spatial evolution of PAD has been well studied, leaving the temporal evolution as an open question. To reveal the temporal …