Search Publications
Herschel-ATLAS: the connection between star formation and AGN activity in radio-loud and radio-quiet active galaxies
Ivison, R. J.; Fritz, J.; Hardcastle, M. J. +6 more
We examine the relationship between star formation and active galactic nuclei (AGN) activity by constructing matched samples of local (0 < z < 0.6) radio-loud and radio-quiet AGN in the Herschel-Astrophysical Terahertz Large Area Survey fields. Radio-loud AGN are classified as high-excitation and low-excitation radio galaxies using their emi…
Helium and multiple populations in the massive globular cluster NGC 6266 (M 62)
Milone, A. P.
Recent studies suggest that the helium content of multiple stellar populations in globular clusters (GCs) is not uniform. The range of helium varies from cluster to cluster with more massive GCs having, preferentially, large helium spread. GCs with large helium variations also show extended-blue horizontal branch (HB). I exploit Hubble Space Teles…
The systematic search for z ≳ 5 active galactic nuclei in the Chandra Deep Field South
Schawinski, Kevin; Koss, Michael; Weigel, Anna K. +3 more
We investigate early black hole (BH) growth through the methodical search for z ≳ 5 active galactic nuclei (AGN) in the Chandra Deep Field South. We base our search on the Chandra 4-Ms data with flux limits of 9.1 × 10-18 (soft, 0.5-2 keV) and 5.5 × 10-17 erg s-1 cm-2 (hard, 2-8 keV). At z ∼ 5, this corr…
Revisiting the rigidly rotating magnetosphere model for σ Ori E - II. Magnetic Doppler imaging, arbitrary field RRM, and light variability
Owocki, S. P.; Wade, G. A.; Kochukhov, O. +6 more
The initial success of the Rigidly Rotating Magnetosphere (RRM) model application to the B2Vp star σ Ori E by Townsend, Owocki & Groote triggered a renewed era of observational monitoring of this archetypal object. We utilize high-resolution spectropolarimetry and the magnetic Doppler imaging (MDI) technique to simultaneously determine the mag…
The nature and origin of substructure in the outskirts of M31 - II. Detailed star formation histories
Lewis, Geraint F.; McConnachie, Alan W.; Ibata, Rodrigo A. +9 more
While wide-field surveys of M31 have revealed much substructure at large radii, understanding the nature and origin of this material is not straightforward from morphology alone. Using deep Hubble Space Telescope/Advanced Camera for Surveys data, we have derived further constraints in the form of quantitative star formation histories (SFHs) for 14…
The evolving relation between star formation rate and stellar mass in the VIDEO survey since z = 3
Vaccari, Mattia; Häußler, Boris; Jarvis, Matt +4 more
We investigate the star formation rate (SFR) and stellar mass, M*, relation of a star-forming (SF) galaxy (SFG) sample in the XMM-LSS field to z ∼ 3.0 using the near-infrared data from the VISTA Deep Extragalactic Observations (VIDEO) survey. Combining VIDEO with broad-band photometry, we use the SED fitting algorithm CIGALE to derive S…
The reversal of the SF-density relation in a massive, X-ray-selected galaxy cluster at z = 1.58: results from Herschel.
Altieri, B.; Elbaz, D.; Valtchanov, I. +8 more
Dusty, star-forming galaxies have a critical role in the formation and evolution of massive galaxies in the Universe. Using deep far-infrared imaging in the range 100-500 µm obtained with the Herschel telescope, we investigate the dust-obscured star formation (SF) in the galaxy cluster XDCP J0044.0-2033 at z = 1.58, the most massive cluster …
SN 2009ib: a Type II-P supernova with an unusually long plateau
Inserra, C.; Smartt, S. J.; Kankare, E. +18 more
We present optical and near-infrared photometry and spectroscopy of SN 2009ib, a Type II-P supernova in NGC 1559. This object has moderate brightness, similar to those of the intermediate-luminosity SNe 2008in and 2009N. Its plateau phase is unusually long, lasting for about 130 d after explosion. The spectra are similar to those of the subluminou…
Iron K and Compton hump reverberation in SWIFT J2127.4+5654 and NGC 1365 revealed by NuSTAR and XMM-Newton
Harrison, F. A.; Stern, D.; Zhang, W. W. +13 more
In the past five years, a flurry of X-ray reverberation lag measurements of accreting supermassive black holes have been made using the XMM-Newton telescope in the 0.3-10 keV energy range. In this work, we use the NuSTAR (Nuclear Spectroscopic Telescope Array) telescope to extend the lag analysis up to higher energies for two Seyfert galaxies, SWI…
Tracing the conversion of gas into stars in Young Massive Cluster Progenitors
Bastian, N.; Longmore, S. N.; Kruijssen, J. M. D. +5 more
Whilst young massive clusters (YMCs; M ≳ 104 M⊙, age ≲ 100 Myr) have been identified in significant numbers, their progenitor gas clouds have eluded detection. Recently, four extreme molecular clouds residing within 200 pc of the Galactic Centre have been identified as having the properties thought necessary to form YMCs. Her…