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arXiv · 1905.08432

Formation of disc galaxies around z~2

Sonali Sachdeva·Rupjyoti Gogoi·Kanak Saha·Ajit Kembhavi·Somak Raychaudhury
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Abstract

We present combined evolution of morphological and stellar properties of galaxies on the two sides of z=2 (2.0 2 to ~70% for z<2, compensating for the fall in population of pure discs and pure spheroids. All quiescent outliers of our full sample on the main-sequence, are 2-component systems, belonging to the lower redshift range (z<2). The doubling of stellar mass of 2-component systems and decrease in their SFR by the same factor, suggests that mechanisms involved in morphological transformations are also responsible for the quenching of their star formation activity. Interestingly, while there is substantial increase in the size (~2.5 times) and mass (~5 times) of pure discs, from z>2 to z<2, pure spheroids maintain roughly the same values. Additionally, while bulge hosting discs witness an expansion in scale length (~1.3 times), their bulge sizes as well as bulge to total light ratio see no evolution, suggesting that z~2 is pre-dominantly a disc formation period.

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Sonali Sachdeva, Rupjyoti Gogoi, Kanak Saha, Ajit Kembhavi, Somak Raychaudhury. 2019-05-21. Formation of disc galaxies around z~2. https://doi.org/10.1093/mnras%2Fstz1417

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