Search Publications
The role of secular evolution in the black hole growth of narrow-line Seyfert 1 galaxies
Marconi, A.; Komossa, S.; Tacconi, L. +5 more
Narrow-line Seyfert 1 (NLS1) galaxies show extreme properties with respect to the other Seyfert galaxies. Indeed, they are thought to be accreting at Eddington rates and to possess low-mass black holes. Therefore, they may represent a key class of objects for understanding the co-evolution of black holes and their host galaxies. We propose that NL…
The Hubble Space Telescope GOODS NICMOS Survey: overview and the evolution of massive galaxies at 1.5< z< 3
Daddi, E.; Lucas, Ray A.; Chary, R. -R. +27 more
We present the details and early results from a deep near-infrared survey utilizing the NICMOS instrument on the Hubble Space Telescope centred around massive M* > 1011 M⊙ galaxies at 1.7 < z < 2.9 found within the Great Observatories Origins Deep Survey (GOODS) fields North and South. The GOODS NICMOS Sur…
Effects of grain size distribution on the interstellar dust mass growth
Hirashita, Hiroyuki; Kuo, Tzu-Ming
Grain growth by the accretion of metals in interstellar clouds (called 'grain growth') could be one of the dominant processes that determine the dust content in galaxies. The importance of the grain size distribution for the grain growth is demonstrated in this paper. First, we derive an analytical formula that gives the grain size distribution af…
Gemini/GMOS imaging of globular cluster systems in five early-type galaxies*
Forbes, Duncan A.; Zepf, Stephen E.; Gebhardt, Karl +7 more
In this paper, we present deep high-quality photometry of globular cluster systems (GCSs) belonging to five early-type galaxies, covering a range of mass and environment. Photometric data were obtained with the Gemini North and Gemini South telescopes in the filter passbands g', r' and i'. The combination of these filters with good seeing conditio…
A tale of two GRB-SNe at a common redshift of z=0.54
Im, M.; Melandri, A.; Pian, E. +71 more
We present ground-based and Hubble Space Telescope optical observations of the optical transients (OTs) of long-duration Gamma Ray Bursts (GRBs) 060729 and 090618, both at a redshift of z= 0.54. For GRB 060729, bumps are seen in the optical light curves (LCs), and the late-time broad-band spectral energy distributions (SEDs) of the OT resemble tho…
On the origin of variable gamma-ray emission from the Crab nebula
Lyutikov, M.; Komissarov, S. S.
The oblique geometry of the pulsar wind termination shock ensures that the Doppler beaming has a strong impact on the shock emission. We illustrate this using the recent relativistic magnetohydrodynamic (MHD) simulations of the Crab nebula and the analysis of oblique shocks. We also show that the observed size, shape and distance from the Crab pul…
The OGLE view of microlensing towards the Magellanic Clouds - III. Ruling out subsolar MACHOs with the OGLE-III LMC data
Soszyński, I.; Udalski, A.; Szymański, M. K. +8 more
In the third part of the series presenting the Optical Gravitational Lensing Experiment (OGLE) microlensing studies of the dark matter halo compact objects (MACHOs), we describe results of the OGLE-III monitoring of the Large Magellanic Cloud (LMC). This unprecedented data set contains almost continuous photometric coverage over 8 years of about 3…
Hubble Space Telescope Paschen α survey of the Galactic Centre: data reduction and products
Calzetti, D.; Morris, M. R.; Wang, Q. D. +7 more
Our Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer (HST/NICMOS) Paschen α survey of the Galactic Centre, first introduced by Wang et al., provides a uniform, panoramic, high-resolution map of stars and an ionized diffuse gas in the central 416 arcmin2 of the Galaxy. This survey was carried out with 144 HST orb…
Little change in the sizes of the most massive galaxies since z = 1
Smith, G. P.; Burke, C.; Collins, C. A. +2 more
Recent reports suggest that elliptical galaxies have increased their size dramatically over the last ∼8 Gyr. This result points to a major rethink of the processes dominating the late-time evolution of galaxies. In this paper we present the first estimates for the scale sizes of brightest cluster galaxies (BCGs) in the redshift range 0.8 < z &l…
Modelling the high-mass accretion rate spectra of GX 339-4: black hole spin from reflection?
Done, Chris; Kolehmainen, Mari; Díaz Trigo, María
We extract all the XMM-Newton European Photon Imaging Camera (EPIC) pn burst mode spectra of GX 339-4, together with simultaneous/contemporaneous RXTE data. These include three disc-dominated and two soft intermediate spectra, and the combination of broad bandpass/moderate spectral resolution gives some of the best data on these bright soft states…