Семинар 133 – 23 декабря 2019 г.


Ольга Сильченко

Презентация

1912.08845 Formation of S0s in extreme environments I: clues from kinematics and stellar populations

Lodovico Coccato, Yara L. Jaffé, Arianna Cortesi, Michael Merrifield, Evelyn Johnston, Bruno Rodríguez del Pino, Boris Haeussler, Ana L. Chies-Santos, Claudia L. Mendes de Oliveira, Yun-Kyeong Sheen, Karín Menéndez-Delmestre

Published 2019-12-18, 18 pages, 11 figure, accepted for publication in MNRAS

Despite numerous efforts, it is still unclear whether lenticular galaxies(S0s) evolve from spirals whose star formation was suppressed, or formed troughmergers or disk instabilities. In this paper we present a pilot study of 21 S0galaxies in extreme environments (field and cluster), and compare theirspatially-resolved kinematics and global stellar populations. Our aim is toidentify whether there are different mechanisms that form S0s in differentenvironments. Our results show that the kinematics of S0 galaxies in field andcluster are, indeed, different. Lenticulars in the cluster are morerotationally supported, suggesting that they are formed through processes thatinvolve the rapid consumption or removal of gas (e.g. starvation, ram pressurestripping). In contrast, S0s in the field are more pressure supported,suggesting that minor mergers served mostly to shape their kinematicproperties. These results are independent of total mass, luminosity, ordisk-to-bulge ratio. On the other hand, the mass-weighted age, metallicity, andstar formation time-scale of the galaxies correlate more with mass than withenvironment, in agreement with known relations from previous work such as theone between mass and metallicity. Overall, our results re-enforce the idea thatthere are multiple mechanisms that produce S0s, and that both mass $and$environment play key roles. A larger sample is highly desirable to confirm orrefute the results and the interpretation of this pilot study.