Search Publications
A study of rotating globular clusters. The case of the old, metal-poor globular cluster NGC 4372
Koch, A.; Kacharov, N.; Zijlstra, A. A. +7 more
Context. NGC 4372 is a poorly studied old, very metal-poor globular cluster (GC) located in the inner Milky Way halo.
Aims: We present the first in-depth study of the kinematic properties and derive the structural parameters of NGC 4372 based on the fit of a Plummer profile and a rotating, physical model. We explore the link between internal …
An Unorthodox X-Class Long-duration Confined Flare
Wang, Haimin; Wang, Yuming; Liu, Rui +3 more
We report the observation of an X-class long-duration flare which is clearly confined. It appears as a compact-loop flare in the traditional EUV passbands (171 and 195 Å), but in the passbands sensitive to flare plasmas (94 and 131 Å), it exhibits a cusp-shaped structure above an arcade of loops like other long-duration events. Inspecting images i…
Alignment in star-debris disc systems seen by Herschel
Olofsson, G.; Duchêne, G.; Eiroa, C. +28 more
Many nearby main-sequence stars have been searched for debris using the far-infrared Herschel satellite, within the DEBRIS, DUNES and Guaranteed-Time Key Projects. We discuss here 11 stars of spectral types A-M where the stellar inclination is known and can be compared to that of the spatially resolved dust belts. The discs are found to be well al…
Hiccup accretion in the swinging pulsar IGR J18245-2452
Campana, S.; Stella, L.; Rea, N. +7 more
The source IGR J18245-2452 is the fifteenth discovered accreting millisecond X-ray pulsar and the first neutron star to show direct evidence of a transition between accretion- and rotation-powered emission states. These swings provided the strongest confirmation to date of the pulsar recycling scenario. During the two XMM-Newton observations that …
Discovering extremely compact and metal-poor, star-forming dwarf galaxies out to z ~ 0.9 in the VIMOS Ultra-Deep Survey
Maccagni, D.; Cimatti, A.; Ilbert, O. +42 more
We report the discovery of 31 low-luminosity (-14.5 ≳ MAB(B) ≳ -18.8), extreme emission line galaxies (EELGs) at 0.2 ≲ z ≲ 0.9 identified by their unusually high rest-frame equivalent widths (100 ≤ EW[O iii] ≤ 1700 Å) as part of the VIMOS Ultra Deep Survey (VUDS). VIMOS optical spectra of unprecedented sensitivity (IAB ~ 25 m…
The SCUBA-2 Cosmology Legacy Survey: Ultraluminous Star-forming Galaxies in a z = 1.6 Cluster
Thomson, A. P.; Ivison, R. J.; Scott, D. +23 more
We analyze new SCUBA-2 submillimeter and archival SPIRE far-infrared imaging of a z = 1.62 cluster, Cl 0218.3-0510, which lies in the UKIRT Infrared Deep Sky Survey/Ultra-Deep Survey field of the SCUBA-2 Cosmology Legacy Survey. Combining these tracers of obscured star-formation activity with the extensive photometric and spectroscopic information…
Cassini observations reveal a regime of zonostrophic macroturbulence on Jupiter
Read, Peter L.; Young, Roland M. B.; Armstrong, David +4 more
In December 2000, the Cassini fly-by near Jupiter delivered high-resolution images of Jupiter’s clouds over the entire planet in a band between 50°N and 50°S. Three daily-averaged two-dimensional velocity snapshots extracted from these images are used to perform spectral analysis of jovian atmospheric macroturbulence. A similar analysis is also pe…
Astra: Interdisciplinary study on enhancement of the end-to-end accuracy for spacecraft tracking techniques
Iess, Luciano; Tortora, Paolo; Di Benedetto, Mauro +3 more
Navigation of deep-space probes is accomplished through a variety of different radio observables, namely Doppler, ranging and Delta-Differential One-Way Ranging (Delta-DOR). The particular mix of observations used for navigation mainly depends on the available on-board radio system, the mission phase and orbit determination requirements. The accur…
The Puzzling Chemical Composition of GJ 436b's Atmosphere: Influence of Tidal Heating on the Chemistry
Agúndez, Marcelino; Venot, Olivia; Iro, Nicolas +1 more
The dissipation of the tidal energy deposited on eccentric planets may induce a heating of the planet that affects its atmospheric thermal structure. Here we study the influence of tidal heating on the atmospheric composition of the eccentric (e = 0.16) "hot Neptune" GJ 436b, for which inconclusive chemical abundances are retrieved from multiwavel…
Observation of double layer in the separatrix region during magnetic reconnection
Zhang, Tielong; Li, Xing; Huang, Can +11 more
We present in situ observation of double layer (DL) and associated electron measurement in the subspin time resolution in the separatrix region during reconnection for the first time. The DL is inferred to propagate away from the X line at a velocity of about ion acoustic speed and the parallel electric field carried by the DL can reach -20 mV/m. …