[Astronomy seminar] Reminder: Astronomy departmental seminar Friday March 8 at 10:30am - Jack William Edmund Mallinson (Stockholm University)

[Astronomy seminar announcements]

Dear all,

This is a reminder of the weekly SU astronomy departmental seminar that 
will take place in about 95 minutes, at 10:30am in room FC61 (AlbaNova 
building, 6th floor) and on zoom 
(https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09). 
As usual, we encourage you to attend in person if possible.
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Speaker: Jack William Edmund Mallinson (Stockholm University)
Title: Non-LTE effects on titanium in late-type stars.
Event: https://indico.fysik.su.se/e/jack_mallinson

Abstract:
Iron peak elements are vital tracers of Galactic chemical evolution due 
to their formation in both Type Ia and core-collapse supernovae, and are 
analysed in large scale surveys such as GALAH and WEAVE. While iron is 
arguably the most important of them, titanium is also a powerful 
indicator in Galactic formation history. Its unique behaviour as both an 
iron peak and alpha element leads it to be one of the most useful 
elements in stellar spectroscopy and separating Galactic stellar 
populations. However, despite this interest and the multitude of its 
lines across all wavelengths, investigations often limit themselves to 
just its ionised form: Ti II. This is due to the historical inability to 
correctly model titanium in older, metal-poor stars because of the 
common assumption of local thermodynamic equilibrium (LTE) that leads to 
a large ionisation imbalance, |Ti I - Ti II| > 0. By investigating over 
70,000 GALAH stars in non-LTE, we determine, for the first time, a large 
set of accurate non-LTE titanium abundances across a range of stellar 
parameters. This results in a departure coefficient grid to allow any 
survey to easily apply non-LTE corrections at little extra computational 
cost.
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We look forward to seeing many of you there. Thanks!

Adur, Adélaïde, and Sanja

Upcoming Events:

2024-03-15 Joe Lewis
2024-03-22 Khaled Al Moulla
2024-03-29 ** No seminar **
2024-04-05 Simon Ringqvist
2024-04-12 Alex Riley
2024-04-19 Arthur Choplin
2024-04-26 Dominique Petit
2024-05-03 Gang Li

You can subscribe to the seminars calendar in:
https://ttt.astro.su.se/ical/astro-seminars.ics
(Please note that calendar can be subject to updates)
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Join Zoom Meeting:
https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09
Meeting ID: 622 1126 9644; Password : 593083