iiinova — where your digital self keeps evolving

John Ilee @johnilee.bsky.social · 27/07/2026

Anastasia Topalidou with a great talk at #DiscsOnTheExe this morning about how we’ll be able to use the #SKAO to observe planet forming disks. A big stage and an even bigger array! 📡 #astronomy #radioastronomy @physicsleedsuni.bsky.social

Intro slide on why we want to study large dust grains

Comparison of the SKA Mid array to the local area. It is larger than most of Devon & Cornwall combined.

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John Ilee @johnilee.bsky.social · 20/07/2026

One of my favourite unexpected results is the connection between JWST outflows and their radio counterparts. In several systems, 10 GHz emission follows the outflow axis back to within a few au of the central source, linking large scale jets/outflows to where they are being launched.

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John Ilee @johnilee.bsky.social · 20/07/2026

Isaac models the full mm-cm SED to separate dust and ionised gas emission. Many disks seem to contain substantially more dust than millimetre observations alone would suggest, and there is evidence for millimetre-sized grains in young Class 0 systems. So, grain growth appears to start early!

SED and model of two targets from the survey.

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John Ilee @johnilee.bsky.social · 20/07/2026

Delighted that (new Dr!) Isaac Radley’s #JWST, #ALMA and #VLA survey of Ophiuchus is now on arXiv. By combining IR, mm and cm observations he traces disks, dust and outflows across the earliest stages of star formation. arxiv.org/abs/2607.15468 🔭 #starformation #planetformation #radioastronomy

Figure 1 from Radley et al. showing an overview of the targeted region with JWST NIRCam observations overlaid with ALMA and VLA data.

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John Ilee @johnilee.bsky.social · 08/07/2026

Very proud supervisor moment yesterday. Isaac Radley successfully defended his excellent PhD thesis - “A Multiwavelength Perspective of the ρ-Ophiuchus Star Forming Region” - with minor corrections and really nice compliments from both examiners. Well done Isaac! @physicsleedsuni.bsky.social

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John Ilee @johnilee.bsky.social · 22/04/2026

19 hours left and there’s only one thing for it… #ALMACycle13

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John Ilee @johnilee.bsky.social · 07/10/2025

The second surprising result is that even after throwing the chemical kitchen sink at the model (honestly, see Table 2) we could *not* reproduce the column density profile of methanol. We didn't have enough of it (short by ~1-2 orders of magnitude) and it was all in the wrong place (the outer disk).

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John Ilee @johnilee.bsky.social · 07/10/2025

TW Hya is great because it's so well studied and there is a wealth of information on the disk physical structure. We combined some pretty advanced chemical modelling (thanks to Catherine) with a really well benchmarked model of the disk (thanks to Jenny).

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John Ilee @johnilee.bsky.social · 07/10/2025

We can look at the relative intensities of each of these transitions to pull out physical information like excitation temperature and column density for the methanol gas, and since the observations were spatially resolved, we see how these change radially through the disk.

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John Ilee @johnilee.bsky.social · 07/10/2025

Methanol is the starting point for lots of important prebiotic chemistry. So far it has only been detected in a disk around one solar-type star, TW Hya. We used #ALMA to go back and get some very sensitive, high-resolution observations of multiple transitions for the first time.

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John Ilee @johnilee.bsky.social · 07/10/2025

The second surprising result is that, even after throwing the chemical kitchen sink at the model, we could *not* reproduce the column density profile of methanol. We didn’t have enough of it (short by ~1-2 orders of magnitude) and it was all in the wrong place (the outer disk).

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John Ilee @johnilee.bsky.social · 07/10/2025

TW Hya is great because it’s so well studied and there is a wealth of information on the disk physical structure. We combined some pretty advanced chemical modelling (Catherine) with a benchmarked model of the disk (Jenny).

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John Ilee @johnilee.bsky.social · 07/10/2025

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John Ilee @johnilee.bsky.social · 07/10/2025

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John Ilee @johnilee.bsky.social · 10/09/2025

Sending my apologies to the reviewer for this one… 😬

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John Ilee @johnilee.bsky.social · 14/07/2025

Lots of fun today at John Smeaton Academy talking all about science, art, radio astronomy & building planets onboard the amazing Moon Palace. Thanks for having us and for all the amazing questions!

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John Ilee @johnilee.bsky.social · 31/01/2025

Combining the ALMA & VLA observations revealed where the objects are optically thick at different wavelengths, and where ionised gas emission contaminates dust emission. Understanding this is really key to accurately measuring how much planet forming material is present in these young disks:

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John Ilee @johnilee.bsky.social · 31/01/2025

The ALMA observations also showed that B appears to be extremely unsettled (aren’t we all?) with millimetre dust emission originating from very high up in the disk:

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John Ilee @johnilee.bsky.social · 31/01/2025

The JWST observations revealed that the parsec-scale outflow in the region appears to originate from one member of the central binary AaAb, and were sensitive enough to pick up a faint outflow (or wind?) from its neighbour B:

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John Ilee @johnilee.bsky.social · 31/01/2025

Great to see Isaac Radley’s multi-wavelength study of some of the youngest protostars come out today - arxiv.org/abs/2501.18348 @physicsleedsuni.bsky.social

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John Ilee @johnilee.bsky.social · 31/01/2025

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John Ilee @johnilee.bsky.social · 31/01/2025

The ALMA observations also showed that B appears to be extremely unsettled (aren’t we all?) with millimetre dust emission originating from very high up in the disk:

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John Ilee @johnilee.bsky.social · 31/01/2025

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John Ilee @johnilee.bsky.social · 22/01/2025

Very nice to pop back to @cambridgeastro.bsky.social after far too long…

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