Ryan Trainor

60,000 Gazans have been killed. 18,500 were children. These are their names. Palestinian children have been killed at a rate of more than one per hour since the war began.

www.washingtonpost.com/world/intera...

Stay tuned for more soon as we figure out what this means for chemical abundances in low-mass galaxies at early times!

An N2-BPT diagram similar to the previous post but with additional points for individual galaxies. CECILIA Faint sources are in pink, and two of the points lie in the lower-left corner, far from the gray points and contours that represent previous large surveys of galaxies.

Another N2-BPT diagram, but this one has color-coded points (blue to yellow) from Cloudy photoionization models showing that [OIII]/Hb declines at low Zneb (low O/H, blue points). The CECILIA points in pink trace a range of model points, but the two in the lower left are consistent with O/H < 10% solar.

However, the analysis of individual objects shows that we have a few galaxies at low [OIII]/Hb *and* low [NII]/Ha, a region of parameter space that is extremely rare in local galaxies, but which photoionization models predict traces a turnover in [OIII]/Hb toward extremely low O/H (<<10% solar).

An N2-BPT diagram with black axes and a white background showing that the stacked CECILIA Faint spectrum (pink) sits in the upper-left corner, indicating relatively low oxygen abundance compared to local galaxies (dashed lines) and more massive/more luminous galaxies in the early Universe (grey points with error bars).

With that said, we find that the stack and typical galaxy have high [OIII]/Hb and low [NII]/Ha, as expected for low-mass, low-metallicity galaxies (O/H ~ 20% solar, similar to the Trainor+16 Keck/MOSFIRE stack).

The paper presents some physical properties of the galaxies such as star-formation rates and dust reddening, but we defer quantitative analysis of their masses and chemical abundances for a forthcoming paper that Menelaos is also leading.

A multi-panel figure showing the spectrum of a single “dwarf” galaxy (NB2929) at 2=2.55. Top panel is the full 2D spectrum, middle panel is the full 1D spectrum, and the lower panel shows inset regions of specific emission lines.

The stacked 1D spectrum of 9 faint “dwarf” galaxies at z=2-3. Top panel shows the full spectrum, and inset and lower boxes show zoom-in regions around specific emission lines from H, O, N, and S.

With that in mind, check out this beautiful spectrum of a single galaxy in 2D and 1D, as well as a stacked 1D spectrum of the 9 objects:

These galaxies have stellar masses 10^7-10^9 Msun (1000x smaller than the Milky Way), and we’re measuring light from z=2-3 (a few billion years after the Big Bang), so it has been extremely difficult to detect relatively faint emission lines from Nitrogen and Sulfur even with hours on Keck/MOSFIRE.

Most of the analysis is based on ultra-deep (~30hr) JWST/NIRSpec spectra of 9 of the most continuum-faint galaxies from the CECILIA program (PI: Allison Strom).

Today is a paper day! We present some of the most sensitive measurements of the nebular emission lines for “dwarf” galaxies at Cosmic Noon.

This study is the culmination of three years of work by Menelaos Raptis, a rising senior undergraduate student at @fandmcollege.bsky.social!

A page from Shel Silverstein's book "A Light in the Attic". The featured rhyme is titled "The Homework Machine" and it's about a big, awkward contraption powered by a small child that gives incorrect answers to math questions, like "nine plus four equals three".

It's amazing to look back through history and discover that this was prophesized back in 1981.

This is insanely dystopian. LLM-powered bots impersonating people with completely fake personas in order to change people's viewpoints on reddit.

I cannot believe an IRB approved this "experiment"

Map of the continental USA in orange with black dots at the locations of all universities where visas have been revoked.

This @insidehighered.com website is tracking visa revocations of students across the US, >600 at >100 colleges as of today, April 10. www.insidehighered.com/news/global/...

We hang together or we hang separately. Could not be clearer what is happening and how universities must respond.

This pointless stunt by Cory Booker is accomplishing nothing but drawing attention to the Trump administration’s wrongdoing and delaying the work of the Senate and energizing the Democratic base and, wait, hang on, let me come in again

He did it!

Just got an email from the Fulbright Association. As of right now, funding has been cut off to 12,500 US citizens currently abroad and and more than 7,400 foreigner scholars and students in the United States

Day 2 of SK8plotlib development completed 💪🛹👩‍💻

Today I did a complete rewrite of the physics engine - it is now MUCH more stable, supports user input, and can rotate the board to match the line below it!

All you need to do is pass a matplotlib figure to sk8plot() - it sets itself up automatically!

Hey y'all - A reminder that the smoke and ash down in LA/Pasadena is.... really toxic.
Some folks didn't track it, but the Camp Fire has killed people for multiple years after the fact because of their interactions with the toxic byproducts of the fire. Stay safe. Gloves and masks.

Hey bluesky! Do you want to develop your own open-source software in Python? Apply to attend Code/Astro!

Website: semaphorep.github.io/codeastro/
Scroll all the way down for the application link. :) Apps are due Feb 1! (1/2)

A light blue grid on a white background.

A red isometric grid on a pink background.

A brown grid with major and minor lines, on a pale yellow background.

A green hex grid on a light green background.

Occasional PSA, 2025 edition: @duetosymmetry.com and I made a graph paper package for LaTeX.

Various grid styles (graph, quadrille, hex, iso, dot grid, etc), custom and pre-defined colors. Print out or make templates for your tablet.

Github: github.com/mcnees/LaTeX...
CTAN: ctan.org/pkg/gridpapers

It’s Getting Hot in Here, So Take Off All Your H2O Was Venus always a formidable hellscape, or did it once have a temperate climate with liquid water on its surface?

From Tori Bonidie: Was Venus always a formidable hellscape, or did it once have a temperate climate with liquid water on its surface? 🔭✨
astrobites.org/2024/12/24/i...

Awesome!! Congratulations, and of course so deserved!

Really impressive work here

For Survivors of Forced Sterilization in California Prisons, a Rushed Shot at Justice A state board deciding reparations for women sterilized against their will rejected most applications. Advocates are now racing against a January deadline for victims to appeal.

California forcibly sterilized hundreds of women. Then, it 'allowed' them to apply for compensation.

But only ≈15% of the affected women have gotten compensation so far. Many were denied.

And the deadline to apply/appeal is in just 10 days, leading to an unfair rush many don't know about:

Same! I’ve been waiting for the rush to die down since 2020, but I think it’ll be any time now…

Great! Are you in Garching or Santiago?

Holy cow, look at that primary mirror! It's the same size as Hubble's (2.4m) but 4x lighter. And its field of view is 100x wider than Hubble (compare the small box versus the full color image in the picture below), with Hubble's resolution.

It’s ok, our time will come!

*shorter 😢

Thanks, Paul! I appreciate your thoughtfulness—both in your approach to letters and in your response here. I hope you’re doing well and that we can chat in Lancaster, Indiana, or elsewhere again soon!