Search Publications
Dynamical histories of the IC 348 and NGC 1333 star-forming regions in Perseus
Parker, Richard J.; Alves de Oliveira, Catarina
We present analyses of the spatial distributions of stars in the young (1-3 Myr) star-forming regions IC 348 and NGC 1333 in the Perseus giant molecular cloud. We quantify the spatial structure using the Q-parameter and find that both IC 348 and NGC 1333 are smooth and centrally concentrated with Q-parameters of 0.98 and 0.89, respectively. Neithe…
Large decay of X-ray flux in 2XMM J123103.2+110648: evidence for a tidal disruption event
Ho, Luis C.; Lin, Dacheng; Godet, Olivier +3 more
The X-ray source 2XMM J123103.2+110648 was previously found to show pure thermal X-ray spectra and an ∼3.8 h periodicity in three XMM-Newton X-ray observations in 2003-2005, and the optical spectrum of the host galaxy suggested it as a type 2 active galactic nucleus candidate. We have obtained new X-ray observations of the source, with Swift and C…
Dipolar modulation in the size of galaxies: the effect of Doppler magnification
Bacon, David; Bonvin, Camille; Andrianomena, Sambatra +4 more
Objects falling into an overdensity appear larger on its near side and smaller on its far side than other objects at the same redshift. This produces a dipolar pattern of magnification, primarily as a consequence of the Doppler effect. At low redshift, this Doppler magnification completely dominates the usual integrated gravitational lensing contr…
Connecting X-ray absorption and 21 cm neutral hydrogen absorption in obscured radio AGN
Callingham, J. R.; Heywood, I.; Soria, R. +22 more
Many radio galaxies show the presence of dense and dusty gas near the active nucleus. This can be traced by both 21 cm H I absorption and soft X-ray absorption, offering new insight into the physical nature of the circumnuclear medium of these distant galaxies. To better understand this relationship, we investigate soft X-ray absorption as an indi…
Probing the interstellar dust towards the Galactic Centre: dust-scattering halo around AX J1745.6-2901
Haberl, Frank; Jin, Chichuan; Ponti, Gabriele +1 more
AX J1745.6-2901 is an X-ray binary located at only 1.45 arcmin from Sgr A⋆, showcasing a strong X-ray dust-scattering halo. We combine Chandra and XMM-Newton observations to study the halo around this X-ray binary. Our study shows two major thick dust layers along the line of sight (LOS) towards AX J1745.6-2901. The LOS position and N
Breaking news from the HST: the central star of the Stingray Nebula is now returning towards the AGB
Rauch, T.; Werner, K.; Todt, H. +2 more
SAO 244567 is a rare example of a star that allows us to witness stellar evolution in real time. Between 1971 and 1990, it changed from a B-type star into the hot central star of the Stingray Nebula. This observed rapid heating has been a mystery for decades, since it is in strong contradiction with the low mass of the star and canonical post-asym…
H2O and O2 absorption in the coma of comet 67P/Churyumov-Gerasimenko measured by the Alice far-ultraviolet spectrograph on Rosetta
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +10 more
We have detected H2O and O2 absorption against the far-UV continuum of stars located on lines of sight near the nucleus of Comet 67P/Churyumov-Gerasimenko using the Alice imaging spectrograph on Rosetta. These stellar appulses occurred at impact parameters of ρ = 4-20 km, and heliocentric distances ranging from Rh …
Multiband photometry and spectroscopy of an all-sky sample of bright white dwarfs
Geier, S.; Hermes, J. J.; Gänsicke, B. T. +11 more
The upcoming NASA Transiting Exoplanet Survey Satellite (TESS) will obtain space-based uninterrupted light curves for a large sample of bright white dwarfs distributed across the entire sky, providing a very rich resource for asteroseismological studies and the search for transits from planetary debris. We have compiled an all-sky catalogue of ult…
On the statistics of proto-cluster candidates detected in the Planck all-sky survey
Danese, L.; Dole, H.; Montier, L. +8 more
Observational investigations of the abundance of massive precursors of local galaxy clusters ('proto-clusters') allow us to test the growth of density perturbations, to constrain cosmological parameters that control it, to test the theory of non-linear collapse and how the galaxy formation takes place in dense environments. The Planck collaboratio…
Multicolour modelling of SN 2013dx associated with GRB 130702A★
Minaev, P. Yu.; Pozanenko, A. S.; Ehgamberdiev, Sh. A. +13 more
We present optical observations of SN 2013dx, related to the Fermi burst GRB 130702A, which occurred at red shift z = 0.145. It is the second-best sampled gamma-ray burst (GRB)/supernova (SN) after SN 1998bw. The observational light curves contain more than 280 data points in the uBgrRiz filters until 88 d after the burst, and the data were collec…