Browsing by Author "Carignan, C"

Now showing 1 - 3 of 3
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    Open Access
    The dynamics of molecular gas in nearby galaxies
    (2013) Frank, Bradley Stanton; De Blok, W J G; Carignan, C
    Includes abstract. Includes bibliographical references.
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    Open Access
    Exploring the GalMer database: bar properties and non-circular motions
    (2016) Randriamampandry, T H; Deg, N; Carignan, C; Combes, F; Spekkens, K
    Context. We use Tree-SPH simulations from the GalMer database to characterize and quantify the non-circular motions induced by the presence of bar-like structures on the observed rotation curve of barred galaxies derived from empirical models of their line-of-sight velocity maps. The GalMer database consists of SPH simulations of galaxies spanning a wide range of morphological types and sizes.
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    Open Access
    HI observations of two new dwarf galaxies: Pisces A and B with the SKA Pathfinder KAT-7
    (2016) Carignan, C; Libert, Y; Lucero, D M; Randriamampandry, T H; Jarrett, T H; Oosterloo, T A; Tollerud, E J
    Context. Pisces A and Pisces B are the only two galaxies found via optical imaging and spectroscopy out of 22 HI clouds identified in the GALFAHI survey as dwarf galaxy candidates. Aims: We derive the HI content and kinematics of Pisces A and B. Methods. Our aperture synthesis H observations used the seven-dish Karoo Array Telescope (KAT-7), which is a pathfinder instrument for MeerKAT, the South African precursor to the mid-frequency Square Kilometre Array (SKA-MID). Results: The low rotation velocities of ∼5 km s−1 and ∼10 km s−1 in Pisces A and B, respectively, and their HI content show that they are really dwarf irregular galaxies (dIrr). Despite that small rotation component, it is more the random motions ∼9−11 km s−1 that provide most of the gravitational support, especially in the outer parts. The study of their kinematics, especially the strong gradients of random motions, suggest that those two dwarf galaxies are not yet in equilibrium. Conclusions. These HI- rich galaxies may be indicative of a large population of dwarfs at the limit of detectability. However, such gasrich dwarf galaxies will most likely never be within the virial radius of MW-type galaxies and become subhalo candidates. Systems such as Pisces A and B are more likely to be found at a few Mpc s from MW-type galaxies.