Stephen A Walker

Associate Professor of Physics and Astronomy @UAHuntsville. Formerly @NASAGoddard, @Cambridge_Uni and @UniofOxford. Researching #galaxyclusters

[Andrea Botteon @and_botteon]

The central region of A3667 in hard X-rays, by @MSMirakhor+@astroswalker
A @NASANuSTAR observation of the cluster is presented. The spectrum is better described by a 2T thermal model. An updated limit of B > 0.2 muG is provided from the lack of IC emission
https://t.co/5eVuOnR1wB

[Phys.org @physorg_com]

#A distant #SpiralGalaxy with colossal radio jets challenges our understanding of galaxy evolution. This anomaly suggests the #MilkyWay might one day produce similar jets, impacting life on Earth. @RoyalAstroSoc https://t.co/N8D3DUR5VV https://t.co/a4PZnEsJNZ

[astrobites @astrobites]

From Lindsey Gordon: Bundle up – we’re taking a look at some cool simulations of cluster cold fronts. 🔭✨️

https://t.co/Im1b9Oq4DS

[NASA Universe @NASAUniverse]

On the largest scales, our universe looks like a giant web. 🕸 Clusters and superclusters of galaxies form along giant thread-like structures with voids in between. #MondayMotivation #NASAHalloween

[AXIS X-ray Probe @AXISprobe]

We are thrilled that AXIS has been selected to advance to Phase A. Our team is eager to continue supporting AXIS and the remarkable scientific discoveries it will deliver. #AXISTheXrayUniverse

https://t.co/H6KdQLpZKe

[Grant Tremblay @astrogrant]

#SaveChandra worked 👀👀👀👀❤️❤️❤️❤️❤️🫡🫡🫡🫡🚀🚀🚀🚀

[Chandra Observatory @chandraxray]

Are we alone? X-ray observations of nearby stars are helping astronomers identify the best targets to search for exoplanets with conditions suitable for life. Explore more at: https://t.co/C2h255rSh2 #AAS244 🪐

[NASA Webb Telescope @NASAWebb]

The world’s most powerful space telescope has done it again.

Webb has discovered what appears to be a new record-holder for the most distant known galaxy — shattering its own previous record. This galaxy existed only 290 million years after the big bang: https://t.co/6JN3L2CvRG

[Chandra Observatory @chandraxray]

Today Chandra is studying a galaxy in the constellation Canes Venatici (Latin for "hunting dogs"). Nearby in the sky is M63, also known as the Sunflower Galaxy. Similar in size to our own Milky Way Galaxy, this celestial bloom contains over 400 billion stars! 🌻✨

[Chandra Observatory @chandraxray]

Can we vent?
Scientists have discovered an "exhaust vent" releasing hot gas from a region around Sagittarius A*, the supermassive black hole at the center of our galaxy. It could help reveal how Sagittarius A* ingests & rejects material: https://t.co/UTMmngyO4c #BlackHoleWeek⚫

[University of Alabama in Huntsville (UAH) @UAHuntsville]

Congratulations UAH class of 2024! 🫶

[Dr Affelia Wibisono @AffeliaW]

There’s no doubt that Chandra has revolutionised our understanding of the planets, dwarf planets, moons and comets in our Solar System. It’s not just for far-away astronomy! Chandra is also essential for planetary and Solar System science.

[Chandra Observatory @chandraxray]

Celebrate the 25th anniversary of @NASA's Chandra X-ray Observatory with us this year!🎉 Chandra is at the forefront of so many discoveries — what wonders will come next? Learn more at: https://t.co/eYi7zsFXO5

[Grant Tremblay @astrogrant]

#SaveChandra https://t.co/tvYfkzq76c

[Ming Sun @MingSun_astro]

XRISM spectrum of the Perseus cluster just released!

[ARCHIVED - Dr. Nicky Fox @NASAScienceAA]

We’ve selected a new @NASAUniverse mission! UVEX — UltraViolet Explorer — will conduct a deep survey of the whole sky in two bands of ultraviolet light, providing new insights into galaxy evolution and the lifecycles of stars. Congratulations to Principal Investigator, Fiona Harrison and her team! https://t.co/H9nNIb37rV

[Chandra Observatory @chandraxray]

We hate to burst your bubble on #BubbleGumDay, but you'll never blow a bubble bigger than the one an O-type star is blowing in RCW 120. This big, beautiful, expanding bubble of hydrogen gas is more than 12 light-years across! (Yes, we'd like to watch it pop too.)

[Athena X-ray observatory @AthenaXobs]

Congratulations to the @eROSITA_SRG consortium on the first #eROSITA #AllSkySurvey data release 👇🏽

[ESA Webb Telescope @ESA_Webb]

🆕 Spiral galaxies galore! Webb has snapped portraits of 19 spiral galaxies, showing stars, gas, and dust on the smallest scales ever seen beyond our own galaxy ⭐. Read more: https://t.co/3UG784pIc1 or 🧵👇

[European Space Agency @esa]

How do you measure something that the human eye can't see?

JAXA’s @XRISM_jp X-ray telescope has done just this in its 'first light' observations released today.

XRISM’s images reveal a cluster of galaxies and a supernova remnant plus more hidden behind the Universe's hot gas.