[Astronomy seminar] Astronomy Department Seminar - September 10th Sara Saracino

[Astronomy seminar announcements]

Reminder - Sara's seminar in 35 minutes!

Thanks
Chris

On 06/09/2021 12:08, Chris Usher wrote:
>
> Hello
>
> On Friday the 10th we have the second astronomy seminar of the year 
> with Sara Saracino (Liverpool John Moores University) speaking via 
> Zoom at 10:30.
>
> *Stellar-mass black holes in young star clusters: exciting news*
>
> Black holes (BHs) are among the most mysterious and elusive objects in 
> the Universe. The recent discovery through gravitational waves of very 
> massive BHs has challenged our understanding of stellar evolution in 
> massive stars, moving the focus to high-density environments like star 
> clusters, where merger cascades are most likely to happen. In this 
> context, a systematic search for stellar mass BHs in star clusters 
> would be crucial to add important pieces of information in this 
> complicated puzzle.
>
> Exploiting the technique developed by Giesers et al. 2018, 2019, we 
> have recently started a large spectroscopic campaign with MUSE, to 
> search for these objects in clusters of different ages. For two very 
> young clusters in the Large Magellanic Clouds (NGC 1850, ~100Myr and 
> NGC1846, ~1.5Gyr) we have recently secured ~15 epochs of observations 
> spanning almost 2 years. First results show that a fair amount of 
> stars in the clusters are in binary systems, with some of them showing 
> evidence of orbit around BHs.
>
> I will spend some time discussing the first BH directly detected in 
> NGC 1850, which is in a binary system with a B main sequence star. The 
> simultaneous modelling of both radial velocity and OGLE light curves 
> allowed us to derive the main physical properties of the system, as 
> well as a first BH mass measurement.
>
> Such a detection is very important for clusters as young as 100 Myr, 
> as this is the first step in constructing the initial mass function of 
> BHs, which represents a long standing open question in astrophysics.
>
> We are trying something new this year with leaving the Zoom call open 
> after the formal hour of the seminar is up to allow the speaker, if 
> they wish, to chat informally with anyone who is interested.
>
> Thanks
>
> Chris and Tine
>
> Christopher Usher is inviting you to a scheduled Zoom meeting.
>
> Topic: Christopher Usher's Zoom Meeting
> Time: Sep 10, 2021 10:30 AM Stockholm
>
> Join Zoom Meeting
> https://stockholmuniversity.zoom.us/j/63399256477?pwd=U2RPNzY1Ry8wNFU4blFRYWZQeEVYZz09 
>
>
> Meeting ID: 633 9925 6477
> Passcode: niChInat
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.su.se/pipermail/seminars-announce.astro-at-su.se/attachments/20210910/b62a4773/attachment.html>