This Week

Week Commencing 15 October 2018

Code Review Group

Code Review Group
Monday 15 October 2018, 11am, Physics West Library

Astrophysics & Space Research and HiROS Groups Seminar

Monday 15 October 2018, 1pm, Physics West Seminar Room 103
Speaker: Alexis Finoguenov, University of Helsinki
Title: High-z galaxy groups and their galaxies

ASR Management Group

Tuesday 16 October 2018, 1pm, Physics West 229

Astrophysics & Space Research and HiROS Groups Seminar

Wednesday 17 October 2018, 2.30pm, Physics West Lecture Theatre 117
Speaker: James Aird, University of Leicester
Title: X-rays across the galaxy population: tracing star formation and AGN

Abstract - I will present new work from a series of papers that combines large
samples of galaxies with deep Chandra X-ray data to measure the distribution
of X-ray luminosities across the galaxy population, using a sophisticated
Bayesian technique. Our measurements allow us to trace two origins of the
X-ray emission: star formation and AGN activity.
At low luminosities, we identify narrow peaks that we associate with star
formation processes (tracing the combined emission from X-ray binaries
throughout the galaxy). By tracking the position of these peaks as a
function of stellar mass and redshift we provide new, independent measurements
of the galaxy “star-forming main sequence”, based on the X-ray emission.

We also identify a tail in our distributions to higher X-ray luminosities that
allows us to trace the incidence of AGN. We use these data to measure the
distribution of AGN accretion rates across the galaxy population, as a
function of stellar mass, redshift and star formation rate. Our results reveal
a broad distribution of accretion rates in all galaxy types, reflecting the
flickering of AGN accretion on short timescales relative to the evolution of
galaxy properties. In star-forming galaxies, we find a broad correlation
between the star formation rate and the incidence of AGN (traced by the
fraction of galaxies with AGN and the average specific accretion rates),
indicating the key role of cold gas in AGN fuelling. We also measure the
AGN incidence in galaxies with a wider range of star formation rates at a
fixed stellar mass, spanning the star-forming main sequence and quiescent
galaxy populations. These measurements show enhancements in the incidence of
AGN and reveal the variety of mechanisms that drive black hole growth across
the galaxy population.

Physics Colloquium

Wednesday 17 October 2018, 4pm, Poynting Small Lecture Theatre S06
Speaker: Tim Bedding, University of Sydney
Title: A Golden Age of Asteroseismology with Kepler

Abstract - Stellar astrophysics has entered a new golden age, thanks to
wonderfully precise measurements being returned by NASA ’s Kepler mission.
Kepler is a 0.9-metre space telescope that has been monitoring the brightness
of more than 100,000 stars with extraordinary accuracy for more than four
years. Its main goal is to discover extra-solar planets by detecting the small
dips in light as they transit their parent stars. The mission has been
spectacularly successful, with thousands of candidates reported. Meanwhile,
Kepler’s observations of oscillations in thousands of stars have led to a
revolution in asteroseismology. I will review key results which include
detecting gravity modes in red giant stars and characterizing stars found
to host exoplanets. Results from ESA ’s Gaia mission will add to the
excitement, as has the launch of TESS , which is an all-sky follow-up mission
to Kepler .

Astronomy in the City

Wednesday 17 October 2018, 6pm, Poynting Large Lecture Theatre
The first event will include a talk by Dr Dorottya Szécsi about stars, their
sizes and how they are measured. Tickets
are now available from

Astronomy in the City is a series of free all-ticket public events, each
packed with astrophysics; stargazing, and tea and biscuits. Evenings begin
with talks covering astronomical highlights and recent research, and a
question-and-answer session (for everything from beginner's questions about
the night sky to the latest work done here in Birmingham). Afterwards, (if
the weather cooperates) we have observing with telescopes on campus, and a
lucky few will be taken out to the University’s Observatory.

Events are planned for

* Wednesday 17 October 2018
* Wednesday 21 November 2018
* Wednesday 23 January 2019
* Wednesday 6 March 2019

The first talk begins at 6:15 pm, in the Large Lecture Theatre of the
Poynting Physics Building on the University's Edgbaston campus. Please
arrive by 6:10 pm to be entered into the ballot for trips to the Observatory.

More details are on our website


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