Search Publications
Hubble Space Telescope Detection of the Millisecond Pulsar J2124-3358 and its Far-ultraviolet Bow Shock Nebula
van Kerkwijk, M. H.; Pavlov, G. G.; Guillot, S. +4 more
We observed the nearby millisecond pulsar J2124-3358 with the Hubble Space Telescope in broad far-UV (FUV) and optical filters. The pulsar is detected in both bands with fluxes F(1250-2000 Å) = (2.5 ± 0.3) × 10-16 erg s-1 cm-2 and F(3800-6000 Å) = (6.4 ± 0.4) × 10-17 erg s-1 cm-2, w…
Nitrogen-to-carbon atomic ratio measured by COSIMA in the particles of comet 67P/Churyumov-Gerasimenko
Langevin, Yves; Fischer, Henning; Briois, Christelle +24 more
The COmetary Secondary Ion Mass Analyzer (COSIMA) on board the Rosetta mission has analysed numerous cometary dust particles collected at very low velocities (a few m s-1) in the environment of comet 67P/Churyumov-Gerasimenko (hereafter 67P). In these particles, carbon and nitrogen are expected mainly to be part of the organic matter. W…
Compact solar UV burst triggered in a magnetic field with a fan-spine topology
Peter, H.; Chitta, L. P.; Young, P. R. +1 more
Context. Solar ultraviolet (UV) bursts are small-scale features that exhibit intermittent brightenings that are thought to be due to magnetic reconnection. They are observed abundantly in the chromosphere and transition region, in particular in active regions.
Aims: We investigate in detail a UV burst related to a magnetic feature that is adv…
The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during γ-ray events
Rouillard, A. P.; Plotnikov, I.; Share, G. H.
Context. The observation of >100 MeV γ-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions when γ-rays are detected even when the solar eruptions occurred beyond the solar limb as viewed from Earth provid…
A Model of the Hα and Na Transmission Spectrum of HD 189733b
Arras, Phil; Li, Zhi-Yun; Christie, Duncan +1 more
This paper presents a detailed hydrostatic model of the upper atmosphere of HD 189733b, with the goal of constraining its temperature, particle densities, and radiation field over the pressure range 10-4 to 10 µbar, where the observed Hα transmission spectrum is produced. The atomic hydrogen level population is computed including …
Statistical simulations of the dust foreground to cosmic microwave background polarization
Boulanger, F.; Aumont, J.; Ghosh, T. +6 more
The characterization of the dust polarization foreground to the cosmic microwave background (CMB) is a necessary step toward the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate maps of polarized dust emission on the sphere that is similar to the approach used for CMB anisotropies. This…
Spectroscopy and Photometry of Multiple Populations along the Asymptotic Giant Branch of NGC 2808 and NGC 6121 (M4)
Milone, A. P.; Marino, A. F.; Bedin, L. R. +8 more
We present a photometric and spectroscopic study of multiple populations along the asymptotic giant branch (AGB) of the intermediate-metallicity globular clusters (GCs) NGC 2808 and NGC 6121 (M4). Chemical abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, Zn, Y, and Ce in AGB stars from high-resolution FLAMES+UVES@VLT spectra are rep…
Evidence for multiple populations in the intermediate-age cluster Lindsay 1 in the SMC
Rejkuba, M.; Bastian, N.; Lardo, C. +6 more
Lindsay 1 is an intermediate-age (≈8 Gyr) massive cluster in the Small Magellanic Cloud. Using VLT FORS2 spectra of 16 probable cluster members on the lower red giant branch of the cluster, we measure CN and CH band strengths (at ≃ 3883 and 4300 Å, respectively), along with carbon and nitrogen abundances and find that a sub-population of stars has…
Near-infrared MOSFIRE Spectra of Dusty Star-forming Galaxies at 0.2 < z < 4
Casey, Caitlin M.; Sanders, D. B.; Capak, Peter +6 more
We present near-infrared and optical spectroscopic observations of a sample of 450 and 850 µm-selected dusty star-forming galaxies (DSFGs) identified in a 400 arcmin2 area in the COSMOS field. Thirty-one sources of the 114 targets were spectroscopically confirmed at 0.2< z< 4, identified primarily in the near-infrared with K…
Evolution of the reverberation lag in GX 339-4 at the end of an outburst
Ponti, G.; Tomsick, J. A.; Rodriguez, J. +13 more
We studied X-ray reverberation lags in the Black hole X-ray binary (BHXRB) GX 339-4 at the end of the 2014-2015 outburst. We analysed data from an XMM-Newton campaign covering the end of the transition from the soft to hard state, and the decrease of luminosity in the hard state. During all the observations we detected, at high frequencies, signif…