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Dear all,<br>
<br>
The next SU astronomy departmental seminar will take place on
Friday March 8 at 10:30am in room FC61 (AlbaNova building, 6th
floor) and on zoom (<a
href="https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09"
class="moz-txt-link-freetext">https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09</a>).<br>
___________________<br>
<br>
Speaker: Jack William Edmund Mallinson (Stockholm University)<br>
Title: Non-LTE effects on titanium in late-type stars.<br>
Event: <a class="moz-txt-link-freetext" href="https://indico.fysik.su.se/e/jack_mallinson">https://indico.fysik.su.se/e/jack_mallinson</a> <br>
<br>
Abstract:<br>
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.<br>
___________________<br>
<br>
We look forward to seeing many of you there. Thanks!<br>
<br>
Adur, Adélaïde, and Sanja<br>
<br>
Upcoming Events:<br>
<br>
2024-03-15 Joe Lewis<br>
2024-03-22 Khaled Al Moulla<br>
2024-03-29 ** No seminar **<br>
2024-04-05 Simon Ringqvist<br>
2024-04-12 Alex Riley<br>
2024-04-19 Arthur Choplin<br>
2024-04-26 Dominique Petit<br>
2024-05-03 Gang Li<br>
<br>
You can subscribe to the seminars calendar in: <br>
<a href="https://ttt.astro.su.se/ical/astro-seminars.ics"
class="moz-txt-link-freetext">https://ttt.astro.su.se/ical/astro-seminars.ics</a><br>
(Please note that calendar can be subject to updates)<br>
___________________<br>
<br>
Join Zoom Meeting:<br>
<a
href="https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09"
class="moz-txt-link-freetext">https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09</a><br>
Meeting ID: 622 1126 9644; Password : 593083<br>
<br>
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