Search Publications
Densities Probed by Coronal Type III Radio Burst Imaging
Cairns, Iver H.; McCauley, Patrick I.; Morgan, John
We present coronal density profiles derived from low-frequency (80 - 240 MHz) imaging of three Type III solar radio bursts observed at the limb by the Murchison Widefield Array (MWA). Each event is associated with a white-light streamer at larger heights and is plausibly associated with thin extreme-ultraviolet rays at lower heights. Assuming harm…
Abell 1367: a high fraction of late-type galaxies displaying H I morphological and kinematic perturbations
Boselli, A.; Cortese, L.; Scott, T. C. +2 more
To investigate the effects the cluster environment has on late-type galaxies (LTGs), we studied H I perturbation signatures for all Abell 1367 LTGs with H I detections. We used new Very Large Array H I observations combined with AGES single-dish blind survey data. Our study indicates that the asymmetry between the high- and low-velocity wings of t…
Ultra-red Galaxies Signpost Candidate Protoclusters at High Redshift
Ivison, R. J.; Omont, A.; Clements, D. L. +20 more
We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870 µm survey covers an area of ≈1 deg2 down to an average rms of 3.9 {mJy} {beam}}-1, with …
High-resolution Observations of Flares in an Arch Filament System
Cao, Wenda; Liu, Rui; Ahn, Kwangsu +3 more
We study five sequential solar flares (SOL2015-08-07) occurring in Active Region 12396 observed with the Goode Solar Telescope (GST) at the Big Bear Solar Observatory, complemented by Interface Region Imaging Spectrograph and SDO observations. The main flaring region is an arch filament system (AFS) consisting of multiple bundles of dark filament …
First results from the LIFE project: discovery of two magnetic hot evolved stars
Fossati, L.; Wade, G. A.; Neiner, C. +6 more
We present the initial results of the Large Impact of magnetic Fields on the Evolution of hot stars (LIFE) project. The focus of this project is the search for magnetic fields in evolved OBA giants and supergiants with visual magnitudes between 4 and 8, with the aim to investigate how the magnetic fields observed in upper main-sequence (MS) stars …
Testing the accuracy of reflection-based supermassive black hole spin measurements in AGN
Nardini, E.; Kammoun, E. S.; Risaliti, G.
Context. X-ray reflection is a very powerful method to assess the spin of supermassive black holes (SMBHs) in active galactic nuclei (AGN), yet this technique is not universally accepted. Indeed, complex reprocessing (absorption, scattering) of the intrinsic spectra along the line of sight can mimic the relativistic effects on which the spin measu…
Signatures of Solar Cycle 25 in Subsurface Zonal Flows
Thompson, M. J.; Howe, R.; Komm, R. +5 more
The pattern of migrating zonal flow bands associated with the solar cycle, known as the torsional oscillation, has been monitored with continuous global helioseismic observations by the Global Oscillations Network Group (GONG), together with those made by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) and…
Characteristics and Energy Dependence of Recurrent Galactic Cosmic-Ray Flux Depressions and of a Forbush Decrease with LISA Pathfinder
Mendes, L.; Russano, G.; Lloro, I. +82 more
Galactic cosmic-ray (GCR) energy spectra observed in the inner heliosphere are modulated by the solar activity, the solar polarity and structures of solar and interplanetary origin. A high counting rate particle detector (PD) aboard LISA Pathfinder, meant for subsystems diagnostics, was devoted to the measurement of GCR and solar energetic particl…
Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids
Geier, S.; Siwak, M.; Cikota, A. +40 more
Context. The available set of spin and shape modelled asteroids is strongly biased against slowly rotating targets and those with low lightcurve amplitudes. This is due to the observing selection effects. As a consequence, the current picture of asteroid spin axis distribution, rotation rates, radiometric properties, or aspects related to the obje…
A Multiwavelength View of the Neutron Star Binary 1FGL J1417.7-4402: A Progenitor to Canonical Millisecond Pulsars
Strader, Jay; Bahramian, Arash; Cheung, C. C. +6 more
The Fermi γ-ray source 1FGL J1417.7-4407 (J1417) is a compact X-ray binary with a neutron star primary and a red giant companion in a ∼5.4 days orbit. This initial conclusion, based on optical and X-ray data, was confirmed when a 2.66 ms radio pulsar was found at the same location (and with the same orbital properties) as the optical/X-ray source.…