Search Publications
The environment of the SN-less GRB 111005A at z = 0.0133
Greiner, J.; Klose, S.; Schady, P. +5 more
The collapsar model has proved highly successful in explaining the properties of long γ-ray bursts (GRBs), with the most direct confirmation being the detection of a supernova (SN) coincident with the majority of nearby long GRBs. Within this model, a long GRB is produced by the core-collapse of a metal-poor, rapidly rotating, massive star. The de…
A likely planet-induced gap in the disc around T Cha
Pascucci, Ilaria; Henning, Thomas; Dong, Ruobing +7 more
We present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we…
Multiple star systems in the Orion nebula
Henning, Thomas; Lin, Chien-Cheng; Mérand, Antoine +132 more
This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for θ1 Ori B, θ2 Ori B, and θ2 Ori C. We determined a se…
Unambiguous Evidence of Filament Splitting-induced Partial Eruptions
Cheng, X.; Ding, M. D.; Kliem, B.
Coronal mass ejections are often considered to result from the full eruption of a magnetic flux rope (MFR). However, it is recognized that, in some events, the MFR may release only part of its flux, with the details of the implied splitting not completely established due to limitations in observations. Here, we investigate two partial eruption eve…
Galactic evolution of copper in the light of NLTE computations
Bonifacio, P.; Caffau, E.; Korotin, S. +5 more
We have developed a model atom for Cu with which we perform statistical equilibrium computations that allow us to compute the line formation of Cu I lines in stellar atmospheres without assuming local thermodynamic equilibrium (LTE). We validate this model atom by reproducing the observed line profiles of the Sun, Procyon and 11 metal-poor stars. …
Testing the X-ray reverberation model KYNREFREV in a sample of Seyfert 1 Active Galactic Nuclei
Papadakis, I. E.; Dovčiak, M.; Karas, V. +4 more
We present the first results obtained by the application of the KYNREFREV-reverberation model, which is ready for its use in XSPEC. This model computes the time-dependent reflection spectra of the disc as a response to a flash of primary power-law radiation from a point source corona located on the axis of the black hole accretion disc (lamp-post …
X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine
Capetti, A.; Grandi, P.; Torresi, E. +2 more
Fanaroff-Riley type 0 radio galaxies (FR0s) are compact radio sources that represent the bulk of the radio-loud active galactic nuclei (AGN) population, but they are still poorly understood. Pilot studies on these sources have been already performed at radio and optical wavelengths: here we present the first X-ray study of a sample of 19 FR0 radio…
A catalogue of dense cores and young stellar objects in the Lupus complex based on Herschel. Gould Belt Survey observations
Arzoumanian, D.; Könyves, V.; Palmeirim, P. +13 more
Context. How the diffuse medium of molecular clouds condenses in dense cores and how many of these cores will evolve in protostars is still a poorly understood step of the star formation process. Much progress is being made in this field, thanks to the extensive imaging of star-forming regions carried out with the Herschel Space Observatory.
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Revisiting CMB constraints on warm inflation
Arya, Richa; Dasgupta, Arnab; Goswami, Gaurav +2 more
We revisit the constraints that Planck 2015 temperature, polarization and lensing data impose on the parameters of warm inflation. To this end, we study warm inflation driven by a single scalar field with a quartic self interaction potential in the weak dissipative regime. We analyse the effect of the parameters of warm inflation, namely, the infl…
The magnetic environment of the Orion-Eridanus superbubble as revealed by Planck
Soler, J. D.; Bracco, A.; Pon, A.
Using the 353-GHz polarization observations by the Planck satellite we characterize the magnetic field in the Orion-Eridanus superbubble, a nearby expanding structure that spans more than 1600 square degrees in the sky. We identify a region of both low dispersion of polarization orientations and high polarization fraction associated with the outer…