The James Webb Space Telescope and stuff

[K^2]

4 hours ago, JoeSchmuckatelli said:

At work so I can't watch it.  Was the talk about problems with physics or the Crisis in Cosmology (Webb is seeing complex structures at a presumed age where many expected immature systems)? 

I've seen nothing credible that Webb is challenging physics, but several recent papers claiming our understanding of the early universe needs work. 

Crisis in Cosmology. Some of the assumptions that factor into both the red shift distance and the mass estimates are challenged, and with a more flexible approach, much more reasonable numbers are obtained.

3 hours ago, AckSed said:

will have to tweak the software that assumes the initial mass function of the Universe

Basically. The approach the research suggests is a bit manual.

1. Run the software to estimate red shift with standard IMF.
2. Get background radiation temperature for the relevant age of the universe.
3. Get adjusted IMF for the temperature.
4. Run the software with adjusted IMF, then repeat 2-4 if it the red shift changed significantly.
5. Get the mass from the adjusted IMF from the most recent run.

But this whole loop can, of course, be trivially automated once this process is accepted as standard.

There are concerns about overfitting, which is part of why the iterative method is being used, but the only real way to resolve that is going to be with recording more spectral information. I don't know if that's something we can get with JWST instrumentation, or if this is a note for the future observatories that are currently being developed.

[JoeSchmuckatelli]

On 5/8/2023 at 1:25 PM, K^2 said:

Crisis in Cosmology

Interestingly, there are TWO 'crisis' at the moment. 

https://www.google.com/amp/s/www.wired.com/story/is-cosmology-broken-atacama-telescope/amp

 

[K^2]

43 minutes ago, JoeSchmuckatelli said:

Interestingly, there are TWO 'crisis' at the moment. 

https://www.google.com/amp/s/www.wired.com/story/is-cosmology-broken-atacama-telescope/amp

There are always at least a few hanging about.

I wouldn't be surprised if one of the core assumptions of Lambda-CDM, that the dark matter to luminous matter ratio is uniform throughout the universe, is not valid. It's an assumption we're almost forced to make to produce useful results, and it's going to average out for a lot of things, like the rate of expansion. But an inhomogeneity can easily produce lensing anomalies not strictly consistent with Lambda-CDM. That's not as scary to me as, "JWST imaged multiple galaxies that are more than 100% of the mass of the matter in their neighborhoods."

Of course, it is still an inconsistency, and we have to track down where it comes from. Just because a boring plausible explanation exists, doesn't mean that's the actual explanation. We still have to get some measurements that confirm it.

[Spaceception]

I don't know if this deserves its own topic now (or an old thread revival), or soon given that there's a lot of interest on TRAPPIST-1 from Webb and elsewhere, but in case it simply belongs here, I'm just going to reply to this topic for the time being.

TRAPPIST-1c was not found to possess a thick atmosphere like Venus, with a dayside temperature of ~107 Celsius, just above the boiling point (anyone able to determine what the Terminator temperature should be?). If it has an atmosphere, it's more likely to be akin to Mars than Earth. https://webbtelescope.org/contents/news-releases/2023/news-2023-125 This is in spite of the planet being roughly the same size as Venus, with a similar insolation as Venus as well. Researchers believe this indicates the system has little water, or at least the planet itself.

That's 2/7 planets down, but researchers want to observe them again this year to see how the temperature changes from the day to night side, and constrain the possibility of an atmosphere further. https://www.stsci.edu/jwst/phase2-public/3077.pdf

Edited June 21, 2023 by Spaceception

[tater]

 

[JoeSchmuckatelli]

Happy Anniversary, JWST! 

 

Marking the one-year anniversary of science observations with the $10 billion James Webb Space Telescope, NASA released a spectacular new image Wednesday showing the closest star-forming region to Earth, a colorfully chaotic tapestry of swirling gas studded with sun-like stars.

 

The stellar nursery in the Rho Ophiuchi cloud complex features about 50 young stars, all similar to Earth's sun or smaller.

https://www.cbsnews.com/news/james-webb-space-telescope-image-nearby-stellar-nursery/

 

Edited July 12, 2023 by JoeSchmuckatelli

[Moritz Space]

Herbig-Haro 46/47

The James Webb Space Telescope has captured a tightly bound pair of actively forming stars, known as Herbig-Haro 46/47, in high-resolution near-infrared light. Look for them at the center of the red diffraction spikes. The stars are buried deeply, appearing as an orange-white splotch. They are surrounded by a disk of gas and dust that continues to add to their mass.

 

https://webbtelescope.org/contents/media/images/2023/131/01H53089T1FMZZN48VD4Z73FRC

[JoeSchmuckatelli]

Ring Nebula images, featuring a glowing halo and vibrant colors, also led to a surprising discovery, one astronomer said. 

these rings suggest that there must be a companion star in the system, orbiting about as far away from the central star as Pluto does from our Sun. As the dying star was throwing off its atmosphere, the companion star shaped the outflow and sculpted it. 

https://www.cbsnews.com/news/webb-telescope-makes-surprising-discovery-ring-nebula-halo/

 

[JoeSchmuckatelli]

 

Astronomers studying a famous supernova located 168,000 light-years from Earth have made new observations inside the structure that may help unlock the mysteries of exploding stars.

 

the unparalleled sensitivity and spatial resolution of Webb revealed a new feature in this supernova remnant – small crescent-like structures" that astronomers believe to be part of the "outer layers of gas shot out" by the explosion. 

[Vanamonde]

That's an amazing amount of detail to pick up on something that isn't even in our galaxy. 

[cubinator]

10 minutes ago, Vanamonde said:

That's an amazing amount of detail to pick up on something that isn't even in our galaxy. 

I'm more surprised that the thing grew to that size in 40 years.

[Spaceception]

Webb discovers Methane, Carbon Dioxide, in atmosphere of K2-18 b. https://www.nasa.gov/goddard/2023/webb-discovers-methane-carbon-dioxide-in-atmosphere-of-k2-18

This looks incredibly interesting.

"A new investigation with NASA’s James Webb Space Telescope into K2-18 b, an exoplanet 8.6 times as massive as Earth, has revealed the presence of carbon-bearing molecules including methane and carbon dioxide. Webb’s discovery adds to recent studies suggesting that K2-18 b could be a Hycean exoplanet, one which has the potential to possess a hydrogen-rich atmosphere and a water ocean-covered surface."

"The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. These initial Webb observations also provided a possible detection of a molecule called dimethyl sulfide (DMS). On Earth, this is only produced by life. The bulk of the DMS in Earth’s atmosphere is emitted from phytoplankton in marine environments.

The inference of DMS is less robust and requires further validation. “Upcoming Webb observations should be able to confirm if DMS is indeed present in the atmosphere of K2-18 b at significant levels,” explained Madhusudhan."

Edited September 11, 2023 by Spaceception
"adding quotes"

[Gargamel]

https://www.bbc.com/news/science-environment-66974738?app=news.science_and_environment.story.66974738.page
 

JWST finds binary rogue planets. 

[HebaruSan]

2 hours ago, Gargamel said:

JWST finds binary rogue planets. 

That article didn't answer my main question, so maybe someone here can:

How are such small, distant, isolated objects bright enough to be seen, even with JWST? No fusion, no reflected sunlight, tiny angular size... what's making those photons?

Edited October 2, 2023 by HebaruSan

[Minmus Taster]

12 minutes ago, HebaruSan said:

That article didn't answer my main question, so maybe someone here can:

How are such small, distant, isolated objects bright enough to be seen, even with JWST? No fusion, no reflected sunlight, tiny angular size... what's making those photons?

The nebula their in is quite bright, maybe there's s faint natural lighting?

[Piscator]

I suspect thermal radiation. Planets are slightly warmer than their surroundings due to radioactive decay, retained primordial heat etc so their infrared radiation should be detectable.

[cubinator]

1 hour ago, HebaruSan said:

That article didn't answer my main question, so maybe someone here can:

How are such small, distant, isolated objects bright enough to be seen, even with JWST? No fusion, no reflected sunlight, tiny angular size... what's making those photons?

I think they are probably still very hot, as these are probably < 1 million year old planets.

[HebaruSan]

2 hours ago, Minmus Taster said:

The nebula their in is quite bright, maybe there's s faint natural lighting?

1 hour ago, Piscator said:

I suspect thermal radiation. Planets are slightly warmer than their surroundings due to radioactive decay, retained primordial heat etc so their infrared radiation should be detectable.

1 hour ago, cubinator said:

I think they are probably still very hot, as these are probably < 1 million year old planets.

Thanks for the ideas, everyone! Can we check any of these hypotheses? Are there measurements that allow the ambient lighting or temperature to be deduced?

[cubinator]

I estimated the separation between the binary planets to be around 1 billion km.

[Spaceception]

Cycle 3 is coming up, and there's some interesting studies coming up. I'm admittedly more interested in the exoplanet science than the astrophysics it's designed for, but if you want to look through it, here's the link https://www.stsci.edu/jwst/science-execution/approved-programs/general-observers/cycle-3-go

Anyway, exomoons! David Kipping, who some of you know from the Cool Worlds channel is part of a team led by Ben Cassese to look for moons around the Jupiter analog Kepler 167e.

And there's more! Emily Pass is leading a program to search for large exomoons around the potentially habitable planets TOI-700 d and e.

Other highlights is another TRAPPIST-1 study to see if they can detect an atmosphere of TRAPPIST-1e by getting a double transit with TRAPPIST-1b (which should have little to no atmosphere), to get around stellar contamination (which makes me wonder if earlier studies for TRAPPIST-1e have been inconclusive, so they're trying to find a way around it).

As well as looking for the thermal emissions, and potential atmosphere of LP 791-18d, which is a roughly Earth-sized planet near the inner edge of the habitable zone, and is thought to be volcanically active like Io due to interactions with 2 planets larger than Earth (and the outer planet is a mini-Neptune).

Edited March 9 by Spaceception