Holiday science gifts, JWST confirms REALLY far away galaxies

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With the holidays coming up soon, here are a few sciencey gift ideas for you and yours, because we all need more reality in our lives.

Every year, the European Southern Observatory — a world-class international astronomical consortium that is the caretaker of phenomenal telescopes across the globe — puts out a wall calendar featuring amazing astronomical images and photos of their observatories. They send me one annually and I love it.

As you can see it’s big and beautifully printed, and it also has info on the images for each month. They’ve put the images online, too.

They sell these for € 9,50 (plus shipping/handling), which is a bargain — the shop is not-for-profit so they can keep prices low. I see they are closing the shop starting December 22, so if you want something there better order now! They do have quite a bit of merch, so take a look.

I’ve known scientist and science communicator Emily Lakdawalla forever, it seems. She has given wide-ranging public talks, wrote a reference guide for the Mars Curiosity rover, and is just a great scicommer.

She creates solar-system-themed jewelry that she sells at her Etsy store, too. And on top of that she maintains a carefully curated list of science books for kids, which I highly recommend taking a look at. Every kid — every kid — should have science books around, and Emily’s suggestions will be a huge help in buying some for the wee protoscientists in your life.

She has a newsletter, too.

My friend Cathrin Machin is a wonder. She is a space artist with phenomenal talent, painting astronomical objects with a deft combination of photoreality and artistic interpretation.

She ran the highest crowd-funded painting project in the world and holds the record as Australia's highest crowd-funded artist of all time. She’s created art for scientists, science communicators, and chief officers from top Fortune 500 companies, all because she loves space and wants more people to be able to see it all the time.

She created The Fabric of Space store where you can find her beautiful artwork on desk mats, blankets, tapestries, puzzles, and of course hangable prints.

You can also follow her on Twitter and Instagram.

Long-time BANners may remember me writing about my dear friend Amy Roth, a science and critical thinking artist who makes science- and critical-thinking-based jewelry and paintings. She also makes her own ceramics including plates, mugs, bowls, and more.

Her store is on Etsy, and I urge you to check it out.

I would be remiss not to mention that my daughter Zoe also knits beanies with lots of fun designs!

Astronomy News

It’s a big Universe. Here’s a thing about it.

One of the biggest and most important things the space-based JWST observatory will do is seek out and characterize the most distant galaxies in the Universe we’ve seen so far. This is absolutely critical work for astronomy: Light travels at a finite speed, so the farther away a galaxy is the longer it takes its light to reach us. Because of that, we see more distant galaxies when they were young, closer to the time they formed.

If we can see galaxies far enough away, we’ll be able to spot the first ones that ever formed in the early cosmos. This will tell us a lot about the galaxies themselves, but also conditions in the Universe back then, about which we don’t know a whole lot.

Because of how important this is, JWST was pointed at several different spots in the sky to look for distant galaxies as soon as it was able to. One of these observations looks at the area in and near the incredible Hubble Ultra Deep Field, a series of observations taken in 2003/2004, at the time the longest and deepest ever taken of the Universe.

In July 2022 a huge splash was made by the news that JWST may have detected four of the most distant galaxies ever in that region, one of which, called GLASSz13, we see as it was when the Universe itself was only a little over 300 million years old.

I wrote about this at the time, expressing scientific skepticism. Why? Because the method used to determine the distance to the galaxy, called photometric redshift, has a lot of uncertainty in it. You might think a given galaxy is really far away, but it might be a weird galaxy much closer. That method can’t distinguish between the two, so at best these new findings were candidate large-distance galaxies.

Welp. That’s changed now. Two papers have just been released showing that the four galaxies seen in the original data have now had their distances confirmed using a far more reliable technique! And yes, one of them is now the record holder for the most distant galaxy ever confirmed, an incredible 13.5 billion light years away (or, more properly, its light has traveled 13.5 billion years to get to us).

Here’re the links to the first paper and the second paper. Now I still have to be a bit of a wet blanket here: Neither of these papers has been peer-reviewed, so we should still exercise a bit of caution! Once they have been reviewed by other astronomers and accepted for publication then we can firmly celebrate. Still, reading them over, I’m pretty well convinced of their accuracy.

I described the photometric redshift method in my original blog post about these galaxies (another slightly more technical description can be found here; hat tip to BANner John Simpson for that link). Basically, hydrogen clouds in galaxies absorb any ultraviolet light with a wavelength shorter than 121.6 nanometers. If you look at the light of a nearby galaxy, you’ll see a big dropoff in brightness at that wavelength and shorter. This is called the Lyman break. Because the Universe is expanding, light from distant galaxies has its wavelength stretched, called its redshift. If we can measure that redshift we can get the galaxy’s distance.

The photometric method looks for the Lyman break in a galaxy’s light by observing it in a bunch of different filters. The galaxy may appear bright in a red filter, but disappear in ones with shorter wavelengths (yellow, blue, UV). Seeing which filter that happens in tells you how much the Lyman break has redshifted, and from there you get the distance. However, as I said earlier, this method is prone to uncertainty. Each filter covers a broad range of wavelengths, so the measurement is clunky.

What you need are spectroscopic observations, where the light from the galaxy is broken up into hundreds or thousands of individual wavelengths, like having thousands of filters instead of just, say, a dozen. This is a much finer parsing of the galaxy light, so you get a much more accurate handle on the Lyman break and the redshift.

And that’s the big news here: Using the NIRSpec camera on JWST, the spectroscopic observations of the four galaxies originally seen confirmed the photometric redshifts. The light from the galaxies were indeed redshifted by huge amounts so these galaxies truly are incredibly far away.

We use the letter z to denote redshift, where a z = 1 means the galaxy’s light has been redshifted by a factor of 2, z = 3 means it’s redshifted by a factor of 4, and so on. GLASSz13 has a confirmed redshift of 13.2, so its light has been redshifted by a staggering 14.2 times, which in turn means the light we see left it 13.5 billion years ago (depending on what models you use for how the Universe is expanding; a complicated idea especially at these distances).

That means we see this galaxy when the Universe was only 325 million years old, or when it was only 2% of its present 13.8 billion year age.

Holy yikes. I’ve been doing astronomy a long time, and when I worked on Hubble getting z = 6 galaxies was a Very Big Deal. This blows that away.

Mind you, these observations were taken in literally the first few months of JWST’s operational use! There will be many, many more done, some even deeper and with better spectra. The more of these galaxies we find the better we’ll understand what our Universe was like when it was a toddler, just taking its first steps into becoming what we see around us today.

Et alia

You can email me at [email protected] (though replies can take a while), and all my social media outlets are gathered together at about.me. Also, if you don’t already, please subscribe to this newsletter! And feel free to tell a friend or nine, too. Thanks!