Search Publications
The period-luminosity relation of red supergiants with Gaia DR2
Bedding, Timothy R.; Murphy, Simon J.; Dobie, Dougal +3 more
We revisit the K -band period-luminosity (P-L) relations of Galactic red supergiants using Gaia Data Release 2 parallaxes and up to 70 yr of photometry from AAVSO and ASAS campaigns. In addition, we examine 206 LMC red supergiants using 50 yr of photometric data from the digitized Harvard Astronomical Plate Collection. We identified periods by com…
Experimental phase function and degree of linear polarization of cometary dust analogues
Bertini, I.; Cremonese, G.; Lazzarin, M. +12 more
We present experimental phase function and degree of linear polarization curves for seven samples of cometary dust analogues namely: ground pieces of Allende, DaG521, FRO95002, and FRO99040 meteorites, Mg-rich olivine and pyroxene, and a sample of organic tholins. The experimental curves have been obtained at the IAA Cosmic Dust Laboratory at a wa…
Evidence for short ∼ 1 Myr lifetimes from the He II proximity zones of z ∼ 4 quasars
Hennawi, Joseph F.; Worseck, Gábor; Khrykin, Ilya S.
The duration of quasar accretion episodes is a key quantity for distinguishing between models for the formation and growth of supermassive black holes, the evolution of quasars, and their potential feedback effects on their host galaxies. However, this critical time-scale, often referred to as the quasar lifetime, is still uncertain by orders of m…
MOVES - II. Tuning in to the radio environment of HD189733b
Moutou, C.; Vidotto, A. A.; Bourrier, V. +7 more
We present stellar wind modelling of the hot Jupiter host HD189733, and predict radio emission from the stellar wind and the planet, the latter arising from the interaction of the stellar wind with the planetary magnetosphere. Our stellar wind models incorporate surface stellar magnetic field maps at the epochs 2013 June/July, 2014 September, and …
Triage of astrometric binaries - how to find triple systems and dormant black hole secondaries in the Gaia orbits
Mazeh, T.; Holl, B.; Faigler, S. +1 more
Preparing for the expected wealth of Gaia detections, we consider here a simple algorithm for classifying unresolved astrometric binaries with main-sequence (MS) primary into three classes: binaries with a probable MS secondary, with two possible values for the mass ratio; probable hierarchical triple MS systems with an astrometric secondary as a …
The mass-loss, expansion velocities, and dust production rates of carbon stars in the Magellanic Clouds
Goldman, Steven R.; Boyer, Martha L.; van Loon, Jacco Th +5 more
The properties of carbon stars in the Magellanic Clouds (MCs) and their total dust production rates are predicted by fitting their spectral energy distributions (SED) over pre-computed grids of spectra reprocessed by dust. The grids are calculated as a function of the stellar parameters by consistently following the growth for several dust species…
The impact of stellar feedback from velocity-dependent ionized gas maps - a MUSE view of Haro 11
Östlin, G.; Hayes, M.; Adamo, A. +6 more
We have used the capability of the Multi-Unit Spectroscopic Explorer (MUSE) instrument to explore the impact of stellar feedback at large scales in Haro 11, a galaxy under extreme starburst condition and one of the first galaxies where Lyman continuum (LyC) has been detected. Using H α, [O III] λ5007, and [O I] λ6300 emission lines from deep MUSE …
NuSTAR and XMM-Newton broad-band spectrum of SAX J1808.4-3658 during its latest outburst in 2015
Sanna, A.; Papitto, A.; Di Salvo, T. +4 more
The first discovered accreting millisecond pulsar, SAX J1808.4-3658, went into X-ray outburst in 2015 April. We triggered a 100 ks XMM-Newton ToO, taken at the peak of the outburst, and a 55 ks NuSTAR ToO, performed 4 d apart. We report here the results of a detailed spectral analysis of both the XMM-Newton and NuSTAR spectra. While the XMM-Newton…
Close-up view of an ongoing merger between the NGC 4839 group and the Coma cluster - a post-merger scenario
Churazov, E.; Forman, W.; Jones, C. +5 more
We study a merger of the NGC 4839 group with the Coma cluster using X-ray observations from the XMM-Newton and Chandra telescopes. X-ray data show two prominent features: (i) a long (∼600 kpc in projection) and bent tail of cool gas trailing (towards south-west) the optical centre of NGC 4839, and (ii) a `sheath' region of enhanced X-ray surface b…
On the Oosterhoff dichotomy in the Galactic bulge: I. Spatial distribution
Smolec, R.; Grebel, E. K.; Catelan, M. +3 more
We present a study of the Oosterhoff (Oo) dichotomy in the Galactic bulge using 8141 fundamental-mode RR Lyrae stars. We used public photometric data from the Optical Gravitational Lensing Experiment and the Vista Variables in the Vía Láctea survey. We carefully selected fundamental-mode stars without modulation and without association with any gl…