Stars and gas in the very large interacting galaxy NGC 6872 (2007)
Horellou, Cathy, Koribalski, Baerbel
The dynamical evolution of the large (> 100 kpc), barred spiral galaxy NGC 6872 and its small companion IC 4970 in the southern group Pavo is investigated. We present N-body simulations with stars...
Probing the cosmic microwave background temperature using the Sunyaev-Zeldovich effect (2005)
Horellou, Cathy, Nord, Martin, Johansson, Daniel, Levy, Anna
We discuss the possibility to constrain the relation between redshift and temperature of the cosmic microwave background (CMB) using multifrequency Sunyaev-Zeldovich (SZ) observations. We have...
Dark energy and the evolution of spherical overdensities (2005)
We use the non-linear spherical model in cold dark matter (CDM) cosmologies with dark energy to investigate the effects of dark energy on the growth of structure and the formation of virialised...
The signature of dark energy on the local Hubble flow (2004)
Maccio', Andrea V., Governato, Fabio, Horellou, Cathy
Using N-body simulations of flat, dark energy dominated cosmologies, we show that galaxies around simulated binary systems resembling the Local Group (LG) have low peculiar velocities, in good...
A wavelet add-on code for new-generation N-body simulations and data de-noising (JOFILUREN) (2004)
Romeo, Alessandro B., Horellou, Cathy, Bergh, Joeran
Wavelets are a new and powerful mathematical tool, whose most celebrated applications are data compression and de-noising. In Paper I (Romeo, Horellou & Bergh 2003, astro-ph/0302343), we have shown...
Assessing the galaxy population out to z ~ 2 using the Hubble Deep Field South (2004)
Wiegert, Theresa, De Mello, Duilia F., Horellou, Cathy
In this work we use the Hubble Deep Field South (HDF-S) version 2 images to assess the galaxy population out to z ~ 2. We have used two methods of templates fitting of the spectral energy...
N-body simulations with two-orders-of-magnitude higher performance using wavelets (2003)
Romeo, Alessandro B., Horellou, Cathy, Bergh, Joeran
Noise is a problem of major concern for N-body simulations of structure formation in the early Universe, of galaxies and plasmas. Here for the first time we use wavelets to remove noise from N-body...
Horellou, Cathy, Booth, Roy, Karlsson, Bruno
We present the analysis of a survey of atomic and molecular gas in interacting and merging galaxies (Horellou & Booth 1997). The sample is optically selected and contains all interacting galaxies (~...
Collisional Ring Galaxies in Small Groups (1999)
The probability of plunging orbits is enhanced in groups of galaxies and indeed, observations show that ring galaxies, which are believed to form when a galaxy passes through the center of a larger...