Search Publications
Dwarf spheroidal J-factors without priors: A likelihood-based analysis for indirect dark matter searches
Cohen-Tanugi, J.; Conrad, J.; Anderson, B. +3 more
Line-of-sight integrals of the squared density, commonly called the J-factor, are essential for inferring dark matter (DM) annihilation signals. The J-factors of DM-dominated dwarf spheroidal satellite galaxies (dSphs) have typically been derived using Bayesian techniques, which for small data samples implies that a choice of priors constitutes a …
High-resolution spectroscopy of the extended narrow-line region of IC 5063 and NGC 7212
La Mura, G.; Ciroi, S.; Cracco, V. +6 more
We studied the properties of the gas of the extended narrow-line region (ENLR) of two Seyfert 2 galaxies: IC 5063 and NGC 7212. We analysed high-resolution spectra to investigate how the main properties of this region depend on the gas velocity. We divided the emission lines in velocity bins and we calculated several line ratios. Diagnostic diagra…
The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters - XI. The horizontal branch in NGC 6388 and NGC 6441
Salaris, M.; Di Criscienzo, M.; Anderson, J. +12 more
The Hubble Space Telescope UV Legacy survey of Galactic globular clusters (GC) is characterizing many different aspects of their multiple stellar populations. The `Grundahl-jump' (G-jump) is a discontinuity in ultraviolet brightness of blue horizontal branch (HB) stars, signalling the onset of radiative metal levitation. The HB Legacy data confirm…
Kinematics of Subluminous O and B Stars by Surface Helium Abundance
Jeffery, C. S.; Woolf, V. M.; Martin, P. +1 more
The majority of hot subdwarf stars are low-mass core-helium-burning stars. Their atmospheres are generally helium deficient; however, a minority have extremely helium-rich surfaces. An additional fraction have an intermediate surface-helium abundance, occasionally accompanied by peculiar abundances of other elements. We have identified a sample of…
HST and ground-based spectroscopy of quasar outflows: from mini-BALs to BALs
Shields, J. C.; Hamann, F.; Capellupo, D. M. +3 more
Quasar outflows have been posited as a mechanism to couple supermassive black holes to evolution in their host galaxies. We use multi-epoch spectra from the Hubble Space Telescope (HST) and ground-based observatories to study the outflows in seven quasars that have C IV outflow lines ranging from a classic broad absorption line (BAL) to weaker/nar…
Photometric behaviour of 67P/Churyumov-Gerasimenko and analysis of its pre-perihelion diurnal variations
Mottola, S.; Erard, S.; Capaccioni, F. +14 more
Spectral parameters measured by the Rosetta/VIRTIS imaging spectrometer on the nucleus of comet 67P/Churyumov-Gerasimenko were studied as a function of incidence, emission and phase angles. A statistical analysis was undertaken for a number of spectral parameters: reflectance at seven wavelengths (0.55, 0.75, 1.2, 1.7, 2.0, 2.8 and 4.0 µm), …
A strongly truncated inner accretion disc in the Rapid Burster
Degenaar, N.; Fabian, A. C.; van den Eijnden, J. +4 more
The neutron star (NS) low-mass X-ray binary (LMXB) the Rapid Burster (RB; MXB 1730-335) uniquely shows both Type I and Type II X-ray bursts. The origin of the latter is ill-understood but has been linked to magnetospheric gating of the accretion flow. We present a spectral analysis of simultaneous Swift, NuSTAR and XMM-Newton observations of the R…
Weighing in on the masses of retired A stars with asteroseismology: K2 observations of the exoplanet-host star HD 212771
Vanderburg, Andrew; Chaplin, William J.; Davies, Guy R. +12 more
Doppler-based planet surveys point to an increasing occurrence rate of giant planets with stellar mass. Such surveys rely on evolved stars for a sample of intermediate-mass stars (so-called retired A stars), which are more amenable to Doppler observations than their main-sequence progenitors. However, it has been hypothesized that the masses of su…
Warm and cold molecular gas conditions modelled in 87 galaxies observed by the Herschel SPIRE Fourier transform spectrometer
Glenn, J.; Kamenetzky, J.; Rangwala, N.
We have conducted two-component, non-local thermodynamic equilibrium modelling of the CO lines from J = 1-0 through J = 13-12 in 87 galaxies observed by the Herschel SPIRE Fourier Transform Spectrometer (FTS). We find the average pressure of the cold molecular gas, traced especially by CO J = 1-0, is ∼105.0±0.5 K cm-3. The mi…
Supernova remnants in M33: X-ray properties as observed by XMM-Newton
Williams, Benjamin F.; Blair, William P.; Haberl, Frank +8 more
We have carried out a study of the X-ray properties of the supernova remnant (SNR) population in M33 with XMM-Newton, comprising deep observations of eight fields in M33 covering all of the area within the D25 contours, and with a typical luminosity of 7.1 × 1034 erg s-1 (0.2-2.0 keV). Here, we report our work to c…