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تسجيل مستخدم جديدTidal Dwarf Galaxies, Accretion Tails, and `Beads on a String in the `Spirals, Bridges, and Tails Interacting Galaxy Survey
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تأليف
Beverly J. Smith
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We have used the GALEX ultraviolet telescope to study stellar populations and star formation morphology in a well-defined sample of more than three dozen nearby optically-selected pre-merger interacting galaxy pairs. We have combined the GALEX NUV and FUV images with broadband optical maps from the Sloan Digitized Sky Survey to investigate the ages and extinctions of the tidal features and the disks. We have identified a few new candidate tidal dwarf galaxies in this sample, as well as other interesting morphologies such as accretion tails, `beads on a string, and `hinge clumps. In only a few cases are strong tidal features seen in HI maps but not in GALEX.
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We present Spitzer mid-infrared images from a survey of three dozen pre-merger strongly interacting galaxy pairs selected from the Arp Atlas. The global mid-infrared colors of these galaxies and their tidal tails and bridges are similar to those of n
ormal spiral galaxies, thus this optically selected sample of interacting galaxies does not have strongly enhanced normalized star formation rates in their disks or tidal features. Despite distortion and disturbance these systems continue to form stars at a normal rate on average. The morphology of these galaxies is generally smoother in the shorter wavelength IRAC bands than at 8 $mu$m, where dozens of clumps of star formation are detected.
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he early Universe than in the present, thus our study provides a nearby well-resolved comparison sample for high redshift studies. We have combined the GALEX NUV and FUV images with broadband optical maps from the Sloan Digitized Sky Survey to investigate the ages and extinctions of the tidal features and the disks. The distributions of the UV/optical colors of the tidal features and the main disks of the galaxies are similar, however, the tidal features are bluer on average in NUV - g when compared with their own parent disks, thus tails and bridges are often more prominent relative to the disks in UV images compared to optical maps. This effect is likely due to enhanced star formation in the tidal features compared to the disks rather than reduced extinction, however, lower metallicities may also play a role. We have identified a few new candidate tidal dwarf galaxies in this sample. Other interesting morphologies such as accretion tails and `beads on a string are also seen in these images. We also identify a possible `Taffy galaxy in our sample, which may have been produced by a head-on collision between two galaxies. In only a few cases are strong tidal features seen in HI maps but not in GALEX.
We present Spitzer mid-infrared imaging of a sample of 35 tidally-distorted pre-merger interacting galaxy pairs selected from the Arp Atlas. We compare their global mid-infrared properties with those of normal galaxies from the SINGS Spitzer Legacy s
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