Galaxy Redshifts - A hard thing to nail down. In this month’s episode, we interview Prof Joe Zuntz about his research into clustering galaxies for cosmology. Our next Jodbite comes from this year’s PhD cohort, Georgie, as she submits her thesis on molecular line fitting using ALMA.

The News

This month’s forecast: sunshine and rainbows

One of NASAs newly launched missions has delivered its first rainbow image along with the first images taken by two of its instruments. The Polarimeter to Unify the Corona and Heliosphere, or PUNCH, mission is aiming to unlock the mysteries of the solar atmosphere and how it streams out as the solar wind. PUNCH was launched back in March this year consists of four small satellites in a low Earth orbit.

These satellites are working together to create a three dimensional map of the corona, and solar wind, and their placement in a Sun-synchronous orbit allows them to constantly see the Sun. The satellites are creating images by measuring the polarisation of light and the polarisation is revealed via colour coding- resulting in the rainbow image. These early images help to confirm that the instruments are in focus and working as expected.

Results from PUNCH will help us to better understand the solar wind and how it is connected as a single system to the Earth and Sun. This knowledge will be able to help to make more accurate predictions about the arrival of space weather events so we can be better prepared for them on Earth, and prepare for their impact on the robotic explorers we have roaming the solar system.

On the menu this month: stellar spaghetti

This month, the first optical evidence of a rogue supermassive black hole was found using the Hubble space telescope (see paper here). Black holes of this mass have previously only been found in the centre of galaxies, so finding one that is not gravitationally bound to the galaxy’s core, but in fact 2,600 light years away from it has raised many questions about its history.

This black hole was found as it wandered close enough to a nearby star for it to stretch and tear it apart, or for the technical term spaghettified- in what’s known as an off-centre tidal disruption event (TDE). This was first detected as a sudden flare by the Zwicky Transient Facility and then further observations were then taken by Hubble, Chandra and the VLA to follow up this rareevent in optical, x-ray and radio wavelengths. These events are estimated to occur once every 30,000 years and allow us to see the roaming black holes. Without such an event, these black holes would be undetectable.

Interview with Prof. Joe Zuntz

Lily and Jonathan chat to Prof. Joe Zuntz about his work using photometric data to statistically sample clustering of galaxies. Joe is a professor in cosmology at the University of Edinburgh, but also an ex-Jodcaster (from 2013 - 2016)! We discuss the issues of this method such as correctly identifying the redshift these galaxies are in, different cosmological methods such as two-point functions and blinding (a method to reduce human bias when analysing large sets of data). .

Jodbite with Georgie Stroud

As JBCA’s final year PhD students submit their thesis and prepare to defend, we are putting together a series to celebrate their accomplishments and get the chance to chat to them about their research. In this Jodbite, Jessy talks to Georgie about her work in molecular line fitting using ALMA.

Feedback

Keep your eyes peeled next month for our next listeners feedback form. The survey will take only 5 minutes, but we love to hear what you enjoy about the show and your suggestions about what we could do in the future!

Until next time, Jod on!

Interview : Joe Zuntz and Lily Correa Magnus and Jonathan Wong
Jodbite : Georgie Stroud and Jessy Marin
Presenters : Jessy Marin and Phoebe Ryder
Editors : Jamie Incley, Louisa Mason and Jordan Norris
Show Lead : Louisa Mason
Website : Lilia Correa Magnus
Producer : Lily Correa Magnus
Cover Art : Einstein Ring LRG 3-757,imaged by NASA’s Hubble Space Telescope, one of a group of galaxies called the Luminous Red Galaxies. This blue horseshoe is a distant galaxy magnified and distorted by the strong gravitational pull of the massive foreground Luminous Red Galaxy. CREDIT:NASA, ESA.