"Hubble can't photograph the AT2022dsb tidal event's mayhem up close, since the munched-up star is nearly 300 million light-years away at the core of the galaxy ESO 583-G004. But astronomers used Hubble's powerful ultraviolet sensitivity to study the light from the shredded star, which include hydrogen, carbon, and more. The spectroscopy provides forensic clues to the black hole homicide." - TFA
Reading the article I figured this event was in our galaxy but it’s 22 million light years away! Makes sense that other telescopes couldn’t resolve it.
" To capture the large portion of the galaxy seen here — over 40 000 light-years across — Hubble took 411 images which have been assembled into a mosaic image."
"The image featured here has 69 536 x 22 230 pixels and is a cropped version of the full uncropped image which has 3.9 billion pixels and covers a length of almost 60 000 light years."
I was blown away in particular by sheer luminescence difference between galactic core and edge of the galaxy. Imagine the brightness of night sky in galactic core. That reminded me of the paper that estimated number of GRB's that would hit a planet based on where it was located - galactic core is not a hospitable place.
Someone else linked an gif comparing against our previous best photo of that star: https://twitter.com/gbrammer/status/1504369779540480002 . Presumably astronomers knew those blobs were galaxies, but no details could be resolved.
The article says they attributed it to HB9, which I was able to find in a catalog of supernova remnants (warning, PDF: http://www.mrao.cam.ac.uk/surveys/snrs/table-IV-l.pdf). On page 63, it gives the coordinates for the remnant to be 5h01m, +46°40', which would put it right around the brightest star in Auriga in this sky chart: https://en.wikipedia.org/wiki/File:Perseus_IAU.svg. The catalog gives the size as 140x120 arcmin (2.3x2.0°), which is huge and probably means its very faint by now, which explains why it wouldn't be included in the sky chart by S&T. Curious if any astrophotographers have managed to capture it, I searched astrobin.com and found one photo: https://www.astrobin.com/229090/B/ (edit: and a second: https://www.astrobin.com/73794/B/).
Edit: Looks like another designation for HB9 is Sh2-221, which turns up much more results in a search engine.
How far away is it? There appear to be some odd-shaped objects in the background that look like some galaxies from the Hubble Deep-space images. But HDS is optical, and this is radio.
What RF frequencies are represented by the blue-grey haze? That info would make it possible for a layman to speculate about what material was doing the radiating.
It does seem mysterious. If that thing's really a million ly across, then it's surely hard to explain. Any event at the centre most probably happened in a galaxy, and I would expect the galaxy itself to have captured most of the energy from the event.
Have they tried to look at the central galaxy in optical? Does it look like an watermelon that's been blasted with a 12-bore?
So we're talking about an event that occurred 1 million years ago, plus the time light took to get here. Perhaps it's a hugely energetic event that has illuminated and ionised intergalactic gas? But I can't imagine what kind of event that could be (the merger of two black holes doesn't seem to me to be right, but what do I know).
> This image of galaxy cluster SMACS 0723 has been constructed from blue, green, and red filters aboard Hubble, along with four infrared filter views of the cluster’s central regions. Hubble viewed this object to wavelengths of ~1600 nanometers; [1]
I'm not sure I understand the significance. Is it observation of something we'd expect anyway or something more.
All stars in the galaxy are orbiting a supermassive black hole at the center. So this is similar but on a much smaller scale. Maybe the find is illuminating early black hole interaction with nearby stars, idk.
"The team looked at a binary star system at the edge of the Milky Way known as VFTS 243, comprising of a main sequence O star and a black hole orbiting each other every 10.4 days" - sounds intense!
It is a bit suspicious looking, but there's a lot of very red objects that the Hubble image doesn't catch. Presuming that the red colors in the images are the deeper infrared wavelengths (and thus the most heavily-redshifted objects) I would guess that Hubble just didn't have the detectors to see those.
it's a photometric redshift derived from the lyman break. rest-frame ultra-violet emission less than 912 A is "completely" absorbed by intervening neutral hydrogen, and between 912 and 1216 A partially, in lines. so objects are dark at shorter wavelengths than 1216 A (in the frame of the galaxy). their observations show that in our frame there's no emission short of 1.46 um (infra-red). and 1.46e-6 / 1216e-10 ~ 12 = 1+z, so redshift is approx 11.
if it's correct (photometric redshifts are not as reliable as those obtained from spectra, but are technically easier to achieve, and this is really pushing the limits of what is possible - my partner, who is still in astronomy, is sceptical that this is real), then it's the most distant object known.
i guess the above isn't very clear. i'll try again. hydrogen gas just floating around in space absorbs ultra-violet (UV) light. so you don't see much UV from galaxies.
now distant galaxies are redshifted so much (by expansion of the universe) that the UV ends up in the infra-red (IR). so what you observe are things that are only visible in the IR - everything shorter (optical and UV) in our frame was absorbed (UV) in the galaxy's frame.
so one way to find extremely distance objects is to find things that can only be seen in the IR. what you're actually seeing is the redshifted optical; what you don't see in the optical is what, in the galaxy's frame, is absorbed UV.
but these galaxies are very faint, so they are hard to detect. using a gravitational lens boosts the brightness and so makes this technique more powerful.
i'm not sure that helps (a diagram would make things much clearer). the technique, well, the resulting objects, are called "lyman break galaxies". but i haven't found a good reference googling.
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