Dr. Ignacio Mendigutia
CAB, INTA-CSIC, Spain
Accretion rates as a link between different astronomical scales
Abstract:
The mass accretion rate is a fundamental parameter as it determines the growth and evolution of the astrophysical objects under analysis. During the first part of the talk I will focus on the smallest -planetary- scales. Despite of the fact that the number of known exoplanets around stars different than the Sun has increased exponentially during the last decades, the detection of forming -accreting- planets in protoplanetary disks around young stars remains merely anecdotal, with only a few candidates proposed to date. The pre-main sequence stars HD 100546 and LkCa 15 are two of the most representative, given that their circumstellar disks may host (proto-) planetary systems with several planets each. I will show some of the main properties of HD 100546 as we inferred from different instrumentation and observational techniques. I will also discuss the potential of spectro-astrometry to detect planets in formation based on recently obtained ISIS/WHT data of LkCa 15. The intermediate -stellar- scales will be the topic of the second part of the talk. I will summarize some of our related work, focusing on the observational evidence that suggests that the accretion mechanism could change from “magnetospheric accretion” in young, low-mass T-Tauri and Herbig Ae stars to direct disk-to-star “boundary layer” accretion in Herbig Be and more massive young stellar objects. Finally, the third part of the talk will be devoted to link individual young stars with larger scales. We have recently found a statistically significant, roughly linear correlation between the rate of gas transformed into stars and the mass of dense gas directly involved on star formation, ranging 16 orders of magnitude and encompassing au-size circumstellar disks, pc-size protostellar-hosting clouds within our Galaxy, and kpc-size cloud-hosting galaxies. I will describe the “bottom-up” hypothesis we propose to explain this finding, according to which the protostellar accreting population drives the correlation for all scales.
Location:To be confirmed (31 Fitzwilliam Place/ Burlington Road)
Upcoming seminars:
https://www.dias.ie/2018/03/07/astronomy-and-astrophysics-seminar-schedule-2018/
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Last Updated: 6th November 2018 by Rebeca Garcia
2018-11-14, 11:00, Dr. Ignacio Mendigutia (CAB, INTA-CSIC, Spain), Accretion rates as a link between different astronomical scales
Dr. Ignacio Mendigutia
CAB, INTA-CSIC, Spain
Accretion rates as a link between different astronomical scales
Abstract:
The mass accretion rate is a fundamental parameter as it determines the growth and evolution of the astrophysical objects under analysis. During the first part of the talk I will focus on the smallest -planetary- scales. Despite of the fact that the number of known exoplanets around stars different than the Sun has increased exponentially during the last decades, the detection of forming -accreting- planets in protoplanetary disks around young stars remains merely anecdotal, with only a few candidates proposed to date. The pre-main sequence stars HD 100546 and LkCa 15 are two of the most representative, given that their circumstellar disks may host (proto-) planetary systems with several planets each. I will show some of the main properties of HD 100546 as we inferred from different instrumentation and observational techniques. I will also discuss the potential of spectro-astrometry to detect planets in formation based on recently obtained ISIS/WHT data of LkCa 15. The intermediate -stellar- scales will be the topic of the second part of the talk. I will summarize some of our related work, focusing on the observational evidence that suggests that the accretion mechanism could change from “magnetospheric accretion” in young, low-mass T-Tauri and Herbig Ae stars to direct disk-to-star “boundary layer” accretion in Herbig Be and more massive young stellar objects. Finally, the third part of the talk will be devoted to link individual young stars with larger scales. We have recently found a statistically significant, roughly linear correlation between the rate of gas transformed into stars and the mass of dense gas directly involved on star formation, ranging 16 orders of magnitude and encompassing au-size circumstellar disks, pc-size protostellar-hosting clouds within our Galaxy, and kpc-size cloud-hosting galaxies. I will describe the “bottom-up” hypothesis we propose to explain this finding, according to which the protostellar accreting population drives the correlation for all scales.
Location:To be confirmed (31 Fitzwilliam Place/ Burlington Road)
Upcoming seminars:
https://www.dias.ie/2018/03/07
Category: Astronomy and Astrophysics Section News & Events, Seminars
Happy Birthday! twitter.com/thecelticist/s…
The papers were 1) Affine Field Theory: conservation identitites and relation to Weyl and Eddington 2)The Union of the three fundamental fields (Gravitation, Menson, Electromagnetism) Which went on to secure worldwide acclaim. #DIASdiscovers
Date: 01 December 1943 Paper: The Irish Press Headline: Two Papers by Dr. Schroedinger Synopsis: 1943 was a busy year for Schroedinger. Not only did he deliver the "What is Life?" Lectures in @tcddublin in February in November he delivered two papers in the @RIAdawson (1/2)
Available to buy on the DIAS bookshop: books.dias.ie/index.php?main… (5/5) #DIASdiscovers #celtic #studies #twopatricks
"In the lives of St. Patrick, the two saints are invariably fused into one", said Prof. O'Rahilly in his lecture. The lecture was a condensation from O’Rahilly’s book “The two Patricks: a lecture on the history of Christianity in fifth-century Ireland”. (4/5)
He was known by his first name Patricius, which in later times would lead to confusion as he was succeeded by another apostle of the same name (Saint Patrick or Patricius in Latin). (3/5)
He spoke on "Palladius and Patrick". Palladius was the first bishop of the Christians of Ireland. (2/5)
Date: 21st March 1942 Paper: The Irish Press Headline: Palladius and Patrick | School Of Celtic Studies Lecture Synopsis: The first public lecture under the auspices of the School of Celtic Studies was delivered in Trinity College by Professor T. F. O'Rahilly in 1942. (1/5)
As part of our ongoing participation in the @HistFest we decided to take a look into the Irish Newspaper Archives and see where DIAS made it into print over the last 80 years. There were so many articles, the hardest part was selecting what we would post. We hope you enjoy!
@AReillyFailte @CultureNight @VisitDublin Thanks Antoinette! Glad you enjoyed 😊
Big thank you to @MartinaPQuinn of @helloalicepr for moderating the discussion, and of course to our panel @NeasaMcG @CormacORafferty and @laoneill111
@CormacORafferty "to cut yourself off from fundamental research means you could miss out on some of the biggest ideas"
@laoneill "it's our job as researchers to keep reminding governments how important basic research is" "For Dev basic research being carried out in Ireland was a badge of pride"
@NeasaMcG Schrödinger's work in causality was not well received by the religious authorities at the time At the same time DIAS did have Catholic priests working on research projects in the early days, so there was not the conflict you might think between science and religion
@laoneill111 Schrödinger was very popular in social circles in Dublin, a bit of a renaissance man
@CormacORafferty Schrödinger was gifted at explaining difficult concepts
@CormacORafferty on how unsuccessful work, in Schrödinger's case, unified field theory, is just as important part of science. And no one has managed to crack it yet! And not forgetting the cat
@laoneill111 how Schrödinger's book inspired scientists to change fields and result in the finding of the double helix.