[Astronomy seminar] SU astronomy departmental seminar Friday April 28th - Biwei Jiang (Beijing Normal University)

[Astronomy seminar announcements]

Dear all,

It is our pleasure to announce that this week we will have Biwei Jiang visiting us here at Stockholm University, all the way from Beijing Normal University, and giving this Friday's SU astronomy departmental seminar on April 28th at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352).

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Speaker: Biwei Jiang (Beijing Normal University, BNU)
Title: The sample and mass loss rate of red supergiants in M31 and M33
<https://www.albanova.se/event/astronomy-departmental-seminar-tadafumi-matsuno-groningen/>https://www.albanova.se/event/7310/

Abstract:
Red supergiants (RSGs) are important contributors to interstellar medium through massive winds. Due to serious interstellar extinction, the complete sample of RSGs is  extremely difficult to obtain in our Galaxy. As  two of the largest  spiral galaxies in the Local Group, M31 and M33 can serve as references to analyze the global contribution of RSGs to the galactic medium. By using evident branching of red dwarfs and red (super)giants in the near-infrared color-color (J-H/H-K) diagram, the foreground dwarf stars are excluded efficiently with the UKIRT observational data, The most complete and pure sample of RSGs in M31 and M33, specifically, 5498 and 3055 RSGs respectively, are obtained from the color-magnitude ( J-K/K) diagram of the member stars. The dust radiative transfer model, the DUSTY code, is run to calculate the mass loss rate of RSGs. The average mass loss rate of RSGs is found to be around 2.0 × 10-5 M☉ yr-1 with a  gas-to-dust ratio of 100, which yields a total contribution to the interstellar dust of about 1.1 × 10-3 M☉ yr-1  in M31 and 6.0 × 10-4 M☉ yr-1 in M33, a non-negligible source in comparison with evolved low-mass stars.

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We look forward to seeing many of you there. Thanks!

Eliot and Kris

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Note, there will also be an additional seminar this week on Wednesday April 26th at 14:30 in room FC61 by our own Alexandra Lereste (SU).
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Upcoming Events:

2023-04-26 Alexandra Lereste (SU) <— Note this is on a Wednesday (time 14:30 - followed by Fika)
2023-05-05 Natalia Lahen (MPA Garching)
2023-05-12 Jin Koda (Stony Brooke University)

The calendar for later planned seminars is available here<https://ebox.su.se/owa/calendar/75d76b284ca84db1a85c4e021d1133e8@astro.su.se/22bc11d486d04afaa009a9730dd065d65524176602456481514/calendar.html>.
(Please note that calendar can be subject to updates)

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Join Zoom Meeting:
https://stockholmuniversity.zoom.us/s/61002076352
Meeting ID: 610 0207 6352

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