Search Publications
Star formation in a stellar mass-selected sample of galaxies to z= 3 from the GOODS-NICMOS Survey
Conselice, C. J.; Pérez-González, P. G.; Buitrago, F. +4 more
We present a study of the star-forming properties of a stellar mass-selected sample of galaxies in the GOODS (Great Observatories Origins Deep Survey) NICMOS Survey (GNS), based on deep Hubble Space Telescope (HST) imaging of the GOODS North and South fields. Using a stellar mass-selected sample, combined with HST/ACS and Spitzer data to measure b…
The rapid X-ray variability of NGC 4051
Nandra, K.; Vaughan, S.; Uttley, P. +2 more
We present an analysis of the high-frequency X-ray variability of NGC 4051 (MBH∼ 1.7 × 106 M⊙) based on a series of XMM-Newton observations taken in 2009 with a total exposure of ∼570 ks (EPIC pn). These data reveal the form of the power spectrum over frequencies from 10-4 Hz, below the previously detect…
Two-dimensional Hα kinematics of bulgeless disc galaxies
Böker, Torsten; Neumayer, Nadine; Rix, Hans-Walter +3 more
We present two-dimensional Hα velocity fields for 20 late-type, disc-dominated spiral galaxies, the largest sample to date with high-resolution Hα velocity fields for bulgeless discs. From these data, we derive rotation curves and the location of the kinematic centres. The galaxy sample was selected to contain nucleated and non-nucleated galaxies …
NGC 2419: a large and extreme second generation in a currently undisturbed cluster
Milone, A. P.; D'Antona, F.; Ventura, P. +6 more
We analyse complementary Hubble Space Telescope and Subaru data for the globular cluster NGC 2419. We make a detailed analysis of the horizontal branch (HB), which is composed of two main groups of stars: the luminous blue HB stars, which extend by evolution into the RR Lyrae and red HB region, and a fainter, extremely blue population. We examine …
Luminosity functions of local infrared galaxies with AKARI: implications for the cosmic star formation history and AGN evolution
Goto, Tomotsugu; Inami, Hanae; Nakagawa, Takao +15 more
Infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and active galactic nuclei (AGN) evolution, since their most intense stages are often obscured by dust. However, local IR luminosity function estimates today are still based on the IRAS survey in the 1980s, with wavelength coverage only up to 100 µm. T…
Multi-epoch X-ray observations of the Seyfert 1.2 galaxy Mrk 79: bulk motion of the illuminating X-ray source
Guainazzi, M.; Fabian, A. C.; Miller, J. M. +4 more
Multi-epoch X-ray spectroscopy (0.3-25 keV) of the Seyfert 1.2 galaxy Mrk 79 (UGC 3973) spanning nearly 8 yr and a factor of 3 in broad-band flux are analysed. The data are obtained at seven epochs with either XMM-Newton or Suzaku. Comparison with contemporaneous RXTE monitoring indicates that all flux states of Mrk 79 are represented by the data.…
New constraints on the X-ray spectral properties of type 1 active galactic nuclei
Alexander, D. M.; Mateos, S.; Ward, M. J. +3 more
We present a detailed characterization of the X-ray spectral properties of 761 type 1 active galactic nuclei (AGN), selected from a cross-correlation of the SDSS DR5 quasar catalogue and the incremental version of the second XMM-Newton serendipitous X-ray source catalogue 2XMMi-DR2. The X-ray spectrum of each source has been fitted with models bas…
Carbon chemistry in Galactic bulge planetary nebulae
Zijlstra, A. A.; Lagadec, E.; Gesicki, K. +4 more
Galactic bulge planetary nebulae show evidence of mixed chemistry with emission from both silicate dust and polycyclic aromatic hydrocarbons (PAHs). This mixed chemistry is unlikely to be related to carbon dredge-up, as third dredge-up is not expected to occur in the low-mass bulge stars. We show that the phenomenon is widespread and is seen in 30…
Assessing black hole spin in deep Suzaku observations of Seyfert 1 AGN
Porquet, D.; Reeves, J. N.; Lobban, A. P. +2 more
We present a broad-band analysis of deep Suzaku observations of nearby Seyfert 1 active galactic nuclei (AGN): Fairall 9, MCG-6-30-15, NGC 3516, 3783 and 4051. The use of deep observations (exposures >200 ks) with high signal-to-noise ratio allows the complex spectra of these objects to be examined in full, taking into account features such as …
Charge-exchange X-ray emission of M82: Kα triplets of O VII, Ne IX and Mg XI
Wang, Q. Daniel; Liu, Jiren; Mao, Shude
Starburst galaxies are primary feedback sources of mechanical energy and metals, which are generally measured from associated X-ray emission lines, assuming that they are from the thermal emission of the outflowing hot gas. Such line emission, however, can also arise from the charge-exchange X-ray emission (CXE) between highly ionized ions and neu…