Aayush Saxena

About

I am a Postdoctoral Researcher in Astrophysics at University of Oxford. The main focus of my research is to study the evolution of the onset of star and supermassive black hole formation in the very early Universe using James Webb Space Telescope (JWST) and other ground and space-based telescopes.

I am a member of the JWST NIRSpec Instrument Science team with Guaranteed Time Observations as well as the JADES survey, which is a collaboration between the NIRCam and NIRSpec galaxy assembly teams. By the way, check out my research.

I am a passionate science communicator with years of experience giving public lectures, setting up interactive activities suitable for all age groups, organizing multimedia exhibitions combining art, cinema and science, as well as giving interviews and acting as consultant to major newspapers and magazines around the world

In my spare time I enjoy playing football and tennis, watching all kinds of sports, gaming, listening to alternative/independent bands, cycling and bike maintenance, experimenting with coffee brewing techniques and travelling.

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Research

I am mainly interested in studying the stars and black holes in of some of the first galaxies that were formed in the Universe using the James Webb Space Telescope (JWST). I am a core member of the JWST NIRSpec instrument science team and the JWST Advanced Deep Extragalactic Survey (JADES). I am primarily using JWST's revolutionary capabilities to study the physical nature and chemical compositions of galaxies, the rapid assembly and growth of supermassive black holes and the interaction between galaxies and their supermassive black holes in the early Universe.

I am interested in solving the mystery of cosmic reionization, which represents a major phase transition of the intergalactic medium whereby it transformed from neutral to completely ionized within a billion years after the Big Bang. Very little is known about how and when the Universe was ionized, and what were its key drivers. I am using Lyman-alpha emitting galaxies as beacons of reionization, which can give insights into the production and escape of ionizing photons from distant galaxies, as well as how ionized "bubbles" grow around galaxies in the early Universe.

The figure above shows the revolutionary NIRSpec spectrum of the galaxy GN-z11, which was confirmed to lie at a redshift of z=10.6, showing a host of exciting emission line features that was previously unimaginable (Bunker, Saxena et al. 2023). The spectrum of GN-z11 shows some extremely exciting and strange features, that are challenging our understanding of the assembly of stars and supermassive black holes in some of the first galaxies that were formed. Within a year of the publication of this spectrum, over 50 papers speculating the nature of this object have already been published!

I am also researching the use of machine learning and artificial intelligence in identifying unbiased samples of distant galaxies and quasars from large and deep imaging datasets from current and future facilities (e.g. Euclid, LSST, Roman).

Below are some of the latest research papers that I have published. I also actively communicate my science to the general audience via popular science articles, media interviews, press releases and public lectures and more details about my public engagement/outreach work can be found on the Outreach page.

To know more about my research, projects and other requests regarding media interviews or public talks, please do not hesitate to get in touch using my Contact details.

Featured publications:

• JADES: Discovery of extremely high equivalent width Lyman-α emission from a faint galaxy within an ionized bubble at z = 7.3 (2023), published in Astronomy & Astrophysics (A&A)
• JADES NIRSpec Spectroscopy of GN-z11: Lyman-α emission and possible enhanced nitrogen abundance in a z = 10.60 luminous galaxy (2023), published in A&A
• No strong dependence of Lyman continuum leakage on physical properties of star-forming galaxies at 3.1 < z < 3.5 (2022), published in MNRAS
• Revealing new high-redshift quasar populations through Gaussian mixture model selection (2022), published in A&A
• The VANDELS Survey: new constraints on the high-mass X-ray binary populations in normal star-forming galaxies at 3 < z < 5.5 (2021), published in MNRAS
• The properties of He IIλ1640 emitters at z ∼ 2.5-5 from the VANDELS survey (2020), published in A&A
• The nature of faint radio galaxies at high redshifts (2019), published in MNRAS
• Discovery of a radio galaxy at z = 5.72 (2018), published in MNRAS
• Modelling the luminosities and sizes of radio sources: radio luminosity function at z = 6 (2017), published in MNRAS

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Outreach

I regularly give talks at amateur astronomy societies, schools and diploma clubs across the UK and internationally and engage with science journalists about the latest discoveries in the field. I have organised many public outreach events, most notably at the Science Museum in South Kensington, and am interested in bringing artists and scientists together, using innovative multimedia approaches to disseminate scientific knowledge and stimulate discussion. Listed below are some of the public engagement activities and media coverage about my work.

If you would like to know more about my availability for public engagement talks or discuss outreach events, please get in touch.

• Stargazing Lates at the Science Museum, September 2023
  Read more about it here!
• Pint of Science Festival London, May 2022
  Read more about this sold out event here!
• Astronomy on Tap London, UK, April 2020
  
• Astronomy on Tap Leiden, The Netherlands, August 2018
  
• JWST Spots Giant Black Holes All Over the Early Universe
  Quanta Magazine, 2023
• One year of James Webb Telescope: Earth's $10 billion time machine
  India Today, 2023
• 7 Easter eggs in the images from NASA's James Webb Space Telescope are totally new to astronomy
  Business Insider, 2022
• A message from the past: UK astronomers comment on the first JWST image
  RAS, 2022
• Why I am excited about first images from James Webb Space Telescope
  India Today, 2022
• $10bn James Webb telescope launched into space — watch video
  The Telegraph, 2021
• James Webb Telescope: We have built a time machine and it will launch on Christmas eve
  India Today, 2021
• Most distant radio galaxy, host to a voracious black hole, is found
  Astronomy Now, 2018

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Contact

Office address

Denys Wilkinson building,
University of Oxford,
Keble Road, Oxford OX1 3RH

Email

aayush [dot] saxena [at] physics [dot] ox [dot] ac [dot] uk

Socials

• Twitter
• Linkedin
• GitHub
• ORCID

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