Search Publications
OGLE Study of the Sagittarius Dwarf Spheroidal Galaxy and its M54 Globular Cluster
Soszyński, I.; Udalski, A.; Szymański, M. K. +9 more
We use the fundamental-mode RR Lyr-type variable stars (RRab) from OGLE-IV survey to draw a 3D picture of the central part of the tidally disrupted Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. We estimate the line-of-sight thickness of the Sgr dSph stream to be FWHMcen=2.42 kpc. Based on OGLE-IV observations collected in seasons 2011…
Imprints of a high-velocity wind on the soft X-ray spectrum of PG1211+143
Vaughan, S.; Reeves, J. N.; Pounds, K. A. +2 more
An extended XMM-Newton observation of the luminous narrow-line Seyfert galaxy PG1211+143 in 2014 has revealed a more complex high-velocity wind, with components distinguished in velocity, ionization level, and column density. Here we report soft X-ray emission and absorption features from the ionized outflow, finding counterparts of both high-velo…
Deciphering the embedded wave in Saturn's Maxwell ringlet
Nicholson, Philip D.; French, Richard G.; McGhee-French, Colleen A. +5 more
The eccentric Maxwell ringlet in Saturn's C ring is home to a prominent wavelike structure that varies strongly and systematically with true anomaly, as revealed by nearly a decade of high-SNR Cassini occultation observations. Using a simple linear "accordion" model to compensate for the compression and expansion of the ringlet and the wave, we de…
Two Eclipsing Ultraluminous X-Ray Sources in M51
Soria, R.; Urquhart, R.
We present the discovery, from archival Chandra and XMM-Newton data, of X-ray eclipses in two ultraluminous X-ray sources (ULXs), located in the same region of the galaxy M51: CXOM51 J132940.0+471237 (ULX-1, for simplicity) and CXOM51 J132939.5+471244 (ULX-2). Three eclipses were detected for ULX-1 and two for ULX-2. The presence of eclipses puts …
Effects of the crustal magnetic fields on the Martian atmospheric ion escape rate
Barabash, Stas; Nilsson, Hans; Holmström, Mats +2 more
Eight years (2007-2015) of ion flux measurements from Mars Express are used to statistically investigate the influence of the Martian magnetic crustal fields on the atmospheric ion escape rate. We combine all Analyzer of Space Plasmas and Energetic Atoms/Ion Mass Analyzer (ASPERA-3/IMA) measurements taken during nominal upstream solar wind and sol…
Magnetic reconnection in Saturn's magnetotail: A comprehensive magnetic field survey
Thomsen, M. F.; Jackman, C. M.; Smith, A. W.
Reconnection within planetary magnetotails is responsible for locally energizing particles and changing the magnetic topology. Its role in terms of global magnetospheric dynamics can involve changing the mass and flux content of the magnetosphere. We have identified reconnection related events in spacecraft magnetometer data recorded during Cassin…
GRB 980425 host: [C II], [O I], and CO lines reveal recent enhancement of star formation due to atomic gas inflow
Le Floc'h, E.; Sollerman, J.; Hunt, L. K. +18 more
Context. Accretion of gas from the intergalactic medium is required to fuel star formation in galaxies. We have recently suggested that this process can be studied using host galaxies of gamma-ray bursts (GRBs).
Aims: Our aim is to test this possibility by studying in detail the properties of gas in the closest galaxy hosting a GRB (980425). …
Using ForeCAT Deflections and Rotations to Constrain the Early Evolution of CMEs
Vourlidas, A.; Kay, C.; Opher, M. +1 more
To accurately predict the space weather effects of the impacts of coronal mass ejection (CME) at Earth one must know if and when a CME will impact Earth and the CME parameters upon impact. In 2015 Kay et al. presented Forecasting a CME’s Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic forces from the background sola…
Herschel detects oxygen in the β Pictoris debris disk
Heras, A. M.; Walker, H. J.; Ivison, R. J. +28 more
The young star β Pictoris is well known for its dusty debris disk produced through collisional grinding of planetesimals, kilometre-sized bodies in orbit around the star. In addition to dust, small amounts of gas are also known to orbit the star; this gas is likely the result of vaporisation of violently colliding dust grains. The disk is seen edg…
Chain Reconnections Observed in Sympathetic Eruptions
Joshi, Navin Chandra; Magara, Tetsuya; Aulanier, Guillaume +2 more
The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multiwavelength observations of sympathetic eruptions, associated flares, and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close active regions. Two filaments, I.e., F1 and F2, are observed in betwe…