DDO 68: A FLEA WITH SMALLER FLEAS THAT PREY ON HIM
| Autor: | Annibali, Francesca, Nipoti, Carlo, Ciotti, Luca, Tosi, Monica, Aloisi, Alessandra, Bellazzini, Michele, Cignoni, Michele, Cusano, Felice, Paris, Diego, Sacchi, Elena |
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| Přispěvatelé: | Annibali, Francesca, Nipoti, Carlo, Ciotti, Luca, Tosi, Monica, Aloisi, Alessandra, Bellazzini, Michele, Cignoni, Michele, Cusano, Felice, Paris, Diego, Sacchi, Elena |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
galaxies: kinematics and
DWARF GALAXIES M31 galaxies: dwarf galaxies: formation galaxies: individual (DDO 68) galaxies: interactions galaxies: irregular dynamics MILKY-WAY NGC 4449 STREAMS SATELLITES STARS DARK HALO SUBSTRUCTURES galaxies: dwarf – galaxies: formation – galaxies: individual (DDO 68) – galaxies: interactions – galaxies: irregular – galaxies: kinematics and dynamics |
| Popis: | We present new photometry of the dwarf irregular galaxy DDO68, one of the most metal-poor and least massive dwarfs, located in the Lynx-Cancer Void. The images were acquired with the Large Binocular Telescope in the g and r passbands and show unequivocally that DDO68 has previously unknown stellar streams related to the accretion of at least two smaller companions: a flea with smaller fleas biting it, to put it in Jonathan Swift’s words (from Jonathan Swift’s On Poetry: a Rhapsody: So, naturalists observe, a flea/has smaller fleas that on him prey/and these have smaller still to bite em/and so proceed ad infinitum). Our data provide direct observational evidence of multiple galaxy merging occurring at very low galactic mass scales. We present the results of an N-body simulation of the interaction of three dwarf galaxies that reproduce well the main morphological features of DDO68. |
| Databáze: | OpenAIRE |
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