Search Publications
Polycyclic aromatic hydrocarbon emission model in photodissociation regions - II. Application to the polycyclic aromatic hydrocarbon and fullerene emission in NGC 7023
Cami, Jan; Tielens, A. G. G. M.; Peeters, Els +1 more
We present a charge distribution-based emission model that calculates the infrared spectrum of fullerenes (C60). Analysis of the modelled spectrum of C60 in various charge states shows that the relative intensity of the features in the 5-10 µm versus 15-20 µm can be used to probe the C60 charge state in…
The radial profile of dust grain size in the protoplanetary disc of DS Tau
Wang, Hongchi; Ma, Yuehui; Liu, Yao +2 more
How do dust grains in protoplanetary discs overcome rapid radial drift and grow from micron size particles to planets is not well understood. The key is to search for evidence of dust accumulation and growth as a function of radius in the disc. We investigate the radial profile of grain size in the DS Tau disc by fitting multiband ALMA observation…
Secular light curves of comets 60P/Tsuchinshan 2 and 62P/Tsuchinshan 1
Li, Juncen; Shi, Jianchun; Ma, Yuehua
The activity of Jupiter family comets, 60P/Tsuchinshan 2 and 62P/Tsuchinshan 1, is analysed by creating their Secular light curves (SLCs). We collected 850 observations in apparitions 1995, 2005, 2012, and 2018 for 60P/Tsuchinshan 2 and 471 observations in apparitions 1998, 2004, and 2017 for 62P/Tsuchinshan 1. We obtained the main activity parame…
An X-rays-to-radio investigation of the nuclear polarization from the radio-galaxy Centaurus A
Wu, Kinwah; Lopez-Rodriguez, Enrique; Marin, Frédéric +5 more
Centaurus A is one of the closest radio galaxies to Earth. Its proximity allowed us to extensively study its active galactic nucleus but the core emission mechanism remains elusive because of local strong dust and gas obscuration. The capability of polarimetry to shave-off contaminating emission has been exploited without success in the near-infra…
The broadening of the main sequence in the open cluster M38
Salaris, M.; Bedin, L. R.; Cassisi, S. +1 more
Our recent multiband photometric study of the colour width of the lower main sequence of the open cluster M37 has revealed the presence of a sizeable initial chemical composition spread in the cluster. If initial chemical composition spreads are common amongst open clusters, this would have major implications for cluster formation models and the f…
Magnetic topologies of two weak-line T Tauri stars TAP 4 and TAP 40
Donati, J. -F.; Collier Cameron, A.; Hussain, G. A. J. +3 more
We present a Zeeman-Doppler imaging study of two weak-line T Tauri stars TAP 4 and TAP 40, based on the high-resolution spectropolarimetric observations with ESPaDOnS at the Canada-France-Hawaii Telescope in November 2013, in the framework of the Magnetic Topologies of Young Stars and Survival of close-in giant Exoplanets large programme. We apply…
Testing quasi-linear modified Newtonian dynamics theory with Galactic globular clusters in a weak external field
Calura, F.; Baumgardt, H.; Sollima, A. +2 more
We developed self-consistent dynamical models of stellar systems in the framework of quasi-linear modified Newtonian dynamics (QUMOND). The models are constructed from the anisotropic distribution function of Gunn and Griffin, combined with the modified Poisson equation defining this gravitation theory and take into account the external field effe…
Digging a little deeper: characterizing three new extreme ULX candidates
Scaringi, S.; Roberts, T. P.; Walton, D. J. +2 more
A prime motivation for compiling catalogues of any celestial X-ray source is to increase our numbers of rare subclasses. In this work, we take a recent multimission catalogue of ultraluminous X-ray sources (ULXs) and look for hitherto poorly-studied ULX candidates that are luminous ($L_{\rm X} \ge 10^{40}\,{\rm erg\,s}^{-1}$), bright ($f_{\rm X} \…
On the origin of the anomalous gas, non-declining rotation curve, and disc asymmetries in NGC 253
Meurer, Gerhardt R.; Lyu, Xuanyi; Westmeier, T. +1 more
We present a multiwavelength (from far-ultraviolet to ${\rm H}\, \rm {\small I}$ emission) study of star formation feedback on the kinematics of the interstellar medium in the Sculptor galaxy, NGC 253. Its three well-known features (a disrupted stellar disc, a previously reported declining rotation curve, and anomalous ${\rm H}\, \rm {\small I}$ g…
Discovery of a magnetar candidate X-ray pulsar in the Large Magellanic Cloud
Haberl, F.; Tiengo, A.; Stella, L. +11 more
During a systematic search for new X-ray pulsators in the XMM-Newton archive, we discovered a high amplitude ($PF\simeq 86~{{\ \rm per\ cent}}$) periodic ($P\simeq 7.25\, \mathrm{s}$) modulation in the X-ray flux of 4XMM J045626.3-694723 (J0456 hereafter), a previously unclassified source in the Large Magellanic Cloud (LMC). The period of the modu…