Search Publications
On the origin of X-ray oxygen emission lines in obscured AGN
Bianchi, S.; Guainazzi, M.; García, F. +4 more
We present the Catalogue of High Resolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray O VII (f) and O VIII Lyα emission lines to shed light on to the p…
Evidence for coupling of evolved star atmospheres and spiral arms of the Milky Way
Barmby, Pauline; Gorski, Mark D.
It is imperative to map the strength and distribution of feedback in galaxies to understand how feedback affects galactic ecosystems. H2O masers act as indicators of energy injection into the interstellar medium. Our goal is to measure the strength and distribution of feedback traced by water masers in the Milky Way. We identify optical…
AT 2016dah and AT 2017fyp: the first classical novae discovered within a tidal stream
Kasliwal, M. M.; Darnley, M. J.; Williams, S. C. +7 more
AT 2016dah and AT 2017fyp are fairly typical Andromeda galaxy (M 31) classical novae. AT 2016dah is an almost text book example of a 'very fast' declining, yet uncommon, Fe II'b' (broad-lined) nova, discovered during the rise to peak optical luminosity, and decaying with a smooth broken power-law light curve. AT 2017fyp is classed as a 'fast' nova…
The near-infrared polarization of the pre-planetary nebula Frosty Leo
Luna, A.; Sabin, L.; Mayya, Y. D. +3 more
We present a near-infrared imaging polarimetric study of the pre-planetary nebula: Frosty Leo. The observations were carried out in J, H, and K' bands using the new polarimeter POLICAN mounted on the 2.1-m telescope of the Guillermo Haro Astrophysical Observatory, Sonora, Mexico. The most prominent result observed in the polarization maps is a lar…
Measuring the mass of the supermassive black hole of the lenticular galaxy NGC 4546
Ricci, T. V.; Steiner, J. E.
Most galaxies with a well-structured bulge host a supermassive black hole (SMBH) in their centre. Stellar kinematics models applied to adaptive optics (AO) assisted integral field unit observations are well-suited to measure the SMBH mass (MBH) and also the total mass-to-light ratio [(M/L)TOT] and possible anisotropies in the…
The fate of binary stars hosting planets upon interaction with Sgr A* black hole
Capuzzo-Dolcetta, R.; Davari, N.
Our Galaxy hosts a very massive object at its centre, often referred to as the supermassive black hole Sgr A*. Its gravitational tidal field is so intense that it can strip apart a binary star passing its vicinity and accelerate one of the components of the binary as hypervelocity star (HVS) and grab the other star as S-star. Taking into considera…
X-ray study of the double source plane gravitational lens system Eye of Horus observed with XMM-Newton
Lee, Chien-Hsiu; Sonnenfeld, Alessandro; Oguri, Masamune +19 more
A double source plane (DSP) system is a precious probe for the density profile of distant galaxies and cosmological parameters. However, these measurements could be affected by the surrounding environment of the lens galaxy. Thus, it is important to evaluate the cluster-scale mass for detailed mass modelling. We observed the Eye of Horus, a DSP sy…
Fast-rotating giant stars behind the Coma Berenices star cluster
Fernández, Matilde; Alfaro, Emilio J.; Casanova, Víctor +2 more
In the frame of a study of the empirical isochrones of young stellar clusters, we have carried out BVIc Johnson-Cousins photometry of a sample of K and M stars of the Coma Berenices star cluster. All these stars have known rotational periods. Our main goal is to get a valuable reference on the colour-magnitude diagram, Mv ver…
Concerning the Li-rich status of KIC 9821622: a Kepler field RGB star reported as a Li-rich giant
Aoki, Wako; Reddy, Bacham E.; Singh, Raghubar +1 more
Given the implications for the origin of Li enhancement in red giants, we have reviewed the Li-rich classification of KIC 9821622, the only bonafide red giant branch (RGB) giant with a He inert core to date, reported as a Li-rich giant by reanalysing the high-resolution spectra. We have obtained A(Li)LTE = 1.42 ± 0.05 dex. After correct…
Pulsation mode switching in the pulsating star HD 81589 and a proposed classification as a field FaRPB star
Martinez, P.; van Heerden, P.; Engelbrecht, C. A.
Extensive multicolour photometry and low-resolution spectroscopy obtained for HD 81589 place the star in the gap between δ Scuti and slowly pulsating B pulsators on the main sequence. A clear episode of pulsation mode switching has apparently occurred in HD 81589, with its primary pulsation frequency switching from 4.57 to 3.71 c d-1 in…