Search Publications
HST/STIS analysis of the first main sequence pulsar CU Virginis
Pigulski, A.; Trigilio, C.; Leto, P. +9 more
Context. CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period.
Aims: We…
Progenitor constraints on the Type Ia supernova SN 2014J from Hubble Space Telescope H β and [O III] observations
Graur, Or; Woods, Tyrone E.
Type Ia supernovae are understood to arise from the thermonuclear explosion of a carbon-oxygen white dwarf, yet the evolutionary mechanisms leading to such events remain unknown. Many proposed channels, including the classical single-degenerate scenario, invoke a hot, luminous evolutionary phase for the progenitor, in which it is a prodigious sour…
Observational Evidence for Summer Rainfall at Titan's North Pole
Sotin, Christophe; Barnes, Jason W.; Soderblom, Jason M. +13 more
Methane rain on Saturn's moon Titan makes it the only place, other than Earth, where rain interacts with the surface. When and where that rain wets the surface changes seasonally in ways that remain poorly understood. Here we report the discovery of a bright ephemeral feature covering an area of 120,000 km2 near Titan's north pole in ob…
NGTS-5b: a highly inflated planet offering insights into the sub-Jovian desert
Smalley, Barry; Jackman, James A. G.; Wheatley, Peter J. +32 more
Context. Planetary population analysis gives us insight into formation and evolution processes. For short-period planets, the sub-Jovian desert has been discussed in recent years with regard to the planet population in the mass/period and radius/period parameter space without taking stellar parameters into account. The Next Generation Transit Surv…
An efficient approach to extract parameters from star cluster CMDs: fitCMD
Bonatto, Charles
This work presents an approach (fitCMD) designed to obtain a comprehensive set of astrophysical parameters from colour-magnitude diagrams (CMDs) of star clusters. Based on initial mass function (IMF) properties taken from isochrones, fitCMD searches for the values of total (or cluster) stellar mass, age, global metallicity, foreground reddening, d…
The Stellar-to-halo Mass Ratios of Passive and Star-forming Galaxies at z ∼ 2-3 from the SMUVS Survey
Caputi, Karina I.; Le Fèvre, Olivier; Fazio, Giovanni G. +6 more
In this work, we use measurements of galaxy stellar mass and two-point angular correlation functions to constrain the stellar-to-halo mass ratios (SHMRs) of passive and star-forming galaxies at z ∼ 2-3, as identified in the Spitzer Matching Survey of the UltraVISTA ultra-deep Stripes. We adopt a sophisticated halo modeling approach to statisticall…
On the iron ionization balance of cool stars
Adibekyan, V.; Sousa, S. G.; Santos, N. C. +3 more
High-resolution spectroscopic studies of solar-type stars have revealed higher iron abundances derived from singly ionized species compared to neutral, violating the ionization equilibrium under the assumption of local thermodynamic equilibrium. In this work, we investigate the overabundances of Fe II lines reported in our previous work for a samp…
Chemical abundances in the metal-intermediate GC NGC 6723
Bono, Giuseppe; Alonso-García, Javier; Crestani, Juliana +2 more
We have performed a detailed spectral analysis of the inner halo Galactic globular cluster (GC) NGC 6723 using high-resolution (R{≈ } 22 000-48 000) spectra for for 11 red giant branch stars collected with MIKE (Magellan) and FEROS (MPG/ESO). This globular is located at the minimum of the bimodal metallicity distribution of GCs, which suggests tha…
Puzzling blue dips in the black hole candidate Swift J1357.2 - 0933, from ULTRACAM, SALT, ATCA, Swift, and NuSTAR
Altamirano, D.; Dhillon, V. S.; Charles, P. A. +13 more
We present rapid, multiwavelength photometry of the low-mass X-ray binary Swift J1357.2-0933 during its 2017 outburst. Using several sets of quasi-simultaneous ULTRACAM/NTT (optical), NuSTAR (X-ray), XRT/Swift (X-ray), SALT (optical), and ATCA (radio) observations taken during outburst decline, we confirm the frequent optical dipping that has prev…
A multiwavelength study of a massive, active galaxy at z ∼ 2: coupling the kinematics of the ionized and molecular gas
Loiacono, Federica; Cimatti, Andrea; Talia, Margherita +3 more
We report a multiwavelength study of the massive (M_{\star } ≳ 10^{11} {M}_{\odot }), z ∼ 2 star-forming galaxy GMASS 0953, which hosts an obscured AGN. We combined near-infrared observations of the GNIRS, SINFONI and KMOS spectrographs to study the kinematics of the [O III] λ5007 and H α emission lines. Our analysis shows that GMASS 0953 may host…