Search Publications
Missions
Journals
Publication Years
The Possible Detection of a Binary Companion to a Type Ibn Supernova Progenitor
Maund, J. R.; Mattila, S.; Pastorello, A. +2 more
We present late-time observations of the site of the Type Ibn supernova (SN) 2006jc, acquired with the Hubble Space Telescope Advanced Camera for Surveys. A faint blue source is recovered at the SN position, with brightness {m}F435W=26.76+/- 0.20, {m}F555W=26.60+/- 0.23 and {m}F625W=26.32+/- 0.19 mag, although ther…
The Nature and Frequency of the Gas Outbursts in Comet 67P/Churyumov-Gerasimenko Observed by the Alice Far-ultraviolet Spectrograph on Rosetta
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +7 more
Alice is a far-ultraviolet imaging spectrograph on board Rosetta that, among multiple objectives, is designed to observe emissions from various atomic and molecular species from within the coma of comet 67P/Churyumov-Gerasimenko. The initial observations, made following orbit insertion in 2014 August, showed emissions of atomic hydrogen and oxygen…
Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456
Behar, E.; Turner, T. J.; Tombesi, F. +5 more
High-resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton reflection grating spectrometer spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of five observations of approximately 100 ks in length. During the last observation (OBS. E), the quasar is at…
The cause of spatial structure in solar He I 1083 nm multiplet images
Joshi, Jayant; Carlsson, Mats; Leenaarts, Jorrit +2 more
Context. The He I 1083 nm is a powerful diagnostic for inferring properties of the upper solar chromosphere, in particular for the magnetic field. The basic formation of the line in one-dimensional models is well understood, but the influence of the complex three-dimensional structure of the chromosphere and corona has however never been investiga…
Ultra-narrow Negative Flare Front Observed in Helium-10830 Å Using the 1.6 m New Solar Telescope
Xu, Yan; Cao, Wenda; Liu, Chang +10 more
Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope …
Detection of Lyman-alpha Emission from a Triply Imaged z = 6.85 Galaxy behind MACS J2129.4-0741
Fontana, Adriano; Pentericci, Laura; Schmidt, Kasper B. +13 more
We report the detection of Lyα emission at ∼9538 Å in the Keck/DEIMOS and Hubble Space Telescope WFC3 G102 grism data from a triply imaged galaxy at z=6.846+/- 0.001 behind galaxy cluster MACS J2129.4-0741. Combining the emission line wavelength with broadband photometry, line ratio upper limits, and lens modeling, we rule out the scenario that th…
Effect of data gaps: comparison of different spectral analysis methods
Mursula, Kalevi; Echim, Marius; Munteanu, Costel +1 more
In this paper we investigate quantitatively the effect of data gaps for four methods of estimating the amplitude spectrum of a time series: fast Fourier transform (FFT), discrete Fourier transform (DFT), Z transform (ZTR) and the Lomb-Scargle algorithm (LST). We devise two tests: the single-large-gap test, which can probe the effect of a single da…
Estimation of bounce resonant scattering by fast magnetosonic waves
Shprits, Yuri Y.
In this study we present calculation of bounce resonant scattering of near equatorially mirroring electrons by fast magnetosonic waves. We first explore the sensitivity of the scattering rates and estimated time scales to a different number of resonances included into calculations. We then explore the sensitivity of calculated rates to the assumed…
The Impact of Accurate Extinction Measurements for X-Ray Spectral Models
Smith, Randall K.; Valencic, Lynne A.; Corrales, Lia
Interstellar extinction includes both absorption and scattering of photons from interstellar gas and dust grains, and it has the effect of altering a source's spectrum and its total observed intensity. However, while multiple absorption models exist, there are no useful scattering models in standard X-ray spectrum fitting tools, such as XSPEC. Non…
A textbook example of ram-pressure stripping in the Hydra A/A780 cluster
Rossetti, M.; Molendi, S.; De Grandi, S. +7 more
In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the viri…