The evolutionary sequence of sub-mm galaxies: from diffuse discs to massive compact ellipticals - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




The evolutionary sequence of sub-mm galaxies: from diffuse discs to massive compact ellipticals - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The population of compact massive galaxies observed at z > 1 arehypothesised, both observationally and in simulations, to be merger remnants ofgas-rich disc galaxies. To probe such a scenario we analyse a sample of 12gas-rich and active star forming sub-mm galaxies SMGs at 1.8 < z < 3. Wepresent a structural and size measurement analysis for all of these objectsusing very deep ACS and NICMOS imaging in the GOODS-North field. Our analysisreveals a heterogeneous mix of morphologies and sizes. We find that fourgalaxies 33% \pm 17% show clear signs of mergers or interactions, which weclassify as early-stage mergers. The remaining galaxies are divided into twocategories: five of them 42% \pm 18% are diffuse and regular disc-likeobjects, while three 25% \pm 14% are very compact, spheroidal systems. Weargue that these three categories can be accommodated into an evolutionarysequence, showing the transformation from isolated, gas-rich discs with typicalsizes of 2-3 kpc, into compact < 1 kpc galaxies through violent major mergerevents, compatible with the scenario depicted by theoretical models. Ourfindings that some SMGs are already dense and compact provides strong supportto the idea that SMGs are the precursors of the compact, massive galaxies foundat slightly lower redshift.



Author: E. Ricciardelli, I. Trujillo, F. Buitrago, C. J. Conselice

Source: https://arxiv.org/



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