Deepest Ever Deep Field. Where Are The Limits of James Webb?
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- Опубліковано 21 тра 2024
- We all know the Hubble Deep Field as one of the most important astronomy images of all time. But when will we get a similar attempt from Webb? What will we be able to get from it and what are the limits of JWST? Finding out with Dr Viraj Pandya from NASA.
👉 Nobel Prize Winner Explains JWST vs The Crisis in Cosmology
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00:00 Intro
01:43 Galaxy classification
08:20 Hubble's observations and biases
19:53 Breadstick galaxies
31:07 Wen JWST Deep Field
43:58 What is the limit of Webb
52:03 Final thoughts
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You are free to use my work for any purpose you like, just mention me as the source and link back to this video. - Наука та технологія
A note from Viraj,
"I just saw your video from our interview and think it's fantastic! Thank you so much again. It seems many of your viewers were interested in the planning of future JWST deep field surveys (based on the video title) but that is not my current interest/expertise -- it is something I'd like to help with in a few years after I get a permanent faculty-level position (fingers crossed). But right now, as an early career researcher, thanks to the work of many others who dedicated lots of time to the planning of surveys like CEERS, I have the privilege of focusing my time on thinking deeply about galaxy formation using these amazing observations and by developing new theoretical models (like what we discussed in the first half of the video).
I highly recommend getting someone from the JADES team on your podcast -- they are at the current frontier of JWST deep fields so will know much more than me about what is and isn't possible over the next few years (as I said, I'm focused on the science itself). They've already surveyed areas including and surrounding the Hubble Deep Fields North and South. As discussed in section 4.1 and Table 1 of Eisenstein+23 (arXiv:2306.02465), some of their deepest imaging in any particular pointing and in any single filter is of order ~10 hours which is a factor of ~5 lower than the deepest single pointing (in a single filter) from the latest "Hubble Legacy Field" (Whitaker+19). And yet as Figure 5 from Eisenstein+23 beautifully shows, this ~10 hour JWST imaging is already much more sensitive than the deepest single ~65 hour Hubble Legacy Field imaging (at a similar wavelength). There is also another "JADES Origins Deep Field" (Eisenstein+23, arXiv:2310.12340) whose deepest single pointing (in a single filter) may approach or even exceed the deepest single-pointing, single-filter HDF images with 50+ hours. On top of this, they are investing a significant chunk of time on spectroscopy -- I discussed the importance of spectroscopy in the first half of the video for, e.g., constraining the kinematics of stars/gas in low-mass high-redshift elongated galaxies. You can probably extrapolate what will be possible for JWST Deep Fields over the ~15-20 year lifetime of JWST based on the incredible work that JADES has done.
I also wanted to clarify that I mis-spoke at ~37:30. The HST-CANDELS program was ~2 months total of observing time but that was split among 5 fields, and there is nuance in the depth of individual pointings (in individual filters) in any individual field. In other words, not all tiles for the mosaic in a single field have the same exposure time. For GOODS-S and GOODS-N (which contain the HDF-S and HDF-N, respectively), some of the deepest imaging is indeed ~50+ hours in a single pointing (in a single filter). For the wider (shallower) parts of CANDELS in the UDS, EGS and COSMOS fields, the depth drops to a few hours at most in a single tile with a single filter. This nuance is important because it can be confusing to say that a deep field was "100s or 1000s" of hours -- indeed, the latest Hubble Legacy Field in GOODS-S (containing HUDF) has a total exposure time of 6.3 Megasec ~ 1750 hours, but what's more useful from a practical point of view is to quote the *range* of exposure times in a single filter over the full survey area (as nicely shown in Figure 1 of Whitaker+19). For example, the original Hubble Deep Field was 140 hours (Table 5 of Williams+96) but that was split into ~30-40 hour images in four different filters -- this was unprecedentedly deep in individual filters and only feasible because they didn't do a mosaic (effectively just a single tile/pointing)."
Sincerely,
Viraj
I am in awe with what JWST has already achieved, but I share the disappointment that JWST has not yet fully exploited its potential to produce a step-change in deep field observation. The original discussion suggested that JWST can achieve more in 50 minutes (on one tile of the sky) than Hubble did in 50 days (72000 minutes per tile). I understand that this was a mistake, but that JWST is about 7-10 times faster than Hubble, so could achieve better results to Hubble in a week.
This is publicly funded science, and so should pay attention to what will interest the public. Thus it is disappointing also that diminishing returns on longer deep field observations are not widely discussed. Why not imagine what JWST could achieve in 2 months of deep field observations? That still leaves 10 months for other observations.
Normally interviews like these don't really captivate me but, Fraser does a really good job with the questions that he asks that I can't stop listening, it also helps when you have really interesting guests like Dr Pandya. I can't wait for the next one.
I thought his guest was one of the most likeable and interesting people I've heard... and that's from a field of often articulate and interesting people (imo, ofc), despite the stereotype of the "antisocial scientist." I really hope to see more of the good Dr. in the years to come.
That's the first time I've heard somebody being interviewed saying "thanks. It's been a lot of fun." For an esteemed scientist to say that to you greatly impresses me. Congratulations Fraser!! And greetings from Thailand.
He paid homage to my favorite food, 🍕 pizza. Hes alright in my book.
The exposure length limits due to background light is addressed in a JWST Science Working Group paper titled The Scientific Capabilities of the James Webb Space Telescope. It is available on-line as a pdf.
This was a fantastic interview. You can tell Dr. Pandya loves and is excited about his work.
These recent interviews are awesome and your questions and reasoning are great. Well done Fraser.
You are hitting home run after home run with your interviews. The guests are highly knowledgeable, are great communicators, topics are very interesting, and you're asking high quality questions. I think you're doing a wonderful job and sincerely thank you for bringing such high quality Science for presentation on YT. 👏
Thanks a lot, I'm glad you're enjoying them. They're very fun and easy for me to do too. :-)
Couldn't agree more.
@frasercain they are only easy because you have gained the background to know what to ask. It allows you to avoid the disgustingly dumbed down versions that unscientific interviewers get.
Dr. Pandya sucks! He don't know weather he is coming or going. He dances around deep field topics and just says, "I'm not thinking about that". Well tough sht, that's what people want to know, is the deep field info. How long will jwst be spent staring at one spot? He just says I don't think about that. Terrible guest. The way he looks down and away when asked about deep field shows he is totally incompetent when it comes to this subject
@@Mr.DeleteriousYou’re in such a minority with that comment that you’re probably going to have to start hating yourself
The Hubble Deep field, as wonderful as it is, only took 100 hrs, not thousands.
However, I love these interviews. Great to get the insights of experts actually working on and with these projects. 👍
I thought that sounded wrong...
Dr. Pandya's food analogies absolutely work for me! 🤣
Thanks for these interviews, Fraser. Please, never get tired of doing them!
Great interview and interviewee, yes. Impressive when someone successfully conveys their visualisation of dynamics.
I liked Viraj's attitude... just straight up admitted when he didn't know something, and then demonstrated interest in the question?
Another great interview, "Deepest Ever Deep Field", that I could not stop listening to! It would be most helpful to my limited, linear mind, to see pictures flashed up on objects being discussed, e.g. Hubble deep field view, bread stick galaxies, 15 red shift galaxies, and even such 'mundane' things as Red Dwarf, Blue stars?, edge on elliptical galaxy, etc, etc....
I also have a limited, linear mind. Throughout the video I couldn't help but think that the occasional visual representation of what was being discussed would have helped me understand it so much better. I know what a breadstick looks like, but I have no idea what a breadstick shaped galaxy looks like.. I also know that it may not be that easy to portray such complex concepts in visual form. Also someone has to create these images and insert them into the video which I'm sure is a monumental task in itself. However I still appreciate these men for doing the best they could to explain what they could. Great interview like you said.
I agree with Fraser.
If waiting for Roman to come online and having that ability to do a wider range view prior to a James Webb deep field, this will allow for a better targeting range for Webb to deep field and whether a longer/shorter exposure is needed.
JW has plenty of science to do before that decision is needed. Besides, they can do both w/a shorter exposure now and after Roman is alive, proceed w/a longer more targeted exposure then.
It would be wild if the JWST did like 100 hours like Hubble and it just came back solid light...so many galaxies that they became one light in the survey...
I've never commented before, but had to for this. Viraj was far and away one of the best interviews I've seen - wonderfully knowledgeable, thoughtful, and so interesting. And Fraser excellent as always. Thanks for all you do, and hoping for a follow-up interview with Viraj someday!
Great you tube with a great subject. Definitely the best work on Galaxies I have seen so far
This discussion with Viraj is so interesting . Cain is a GREAT Interviewer, and the discussion is deep but so clear. Thank you for doing this!
I'm in the middle of watching this interesting video, and the discussion of the breadstick shape evolving to the spirals we're familiar with has ended. Probably no one knows, but I'm wondering whether the bar in barred spirals is a remnant of that breadstick.
Just what I am thinking at the same part of the interview.
Loved it as usual. It's sometimes hard to click on these instead of some anger-inducing drama. But I'm always happy that I clicked
Great interview. You guys did a great job of painting a pictures for me. Thank you!
Great interview, thanks both of you.
This is a great interview. Thank you Fraser and Dr. Pandya.
Fraser Cain is such a great choice for explaining the Hubble and James Webb ultra deep field images. His sentences are clear and informative. I’m glad he is our guide!
Absolutely fascinating...again! Thanks to all involved.
Honestly I would have expected your guest to know the answer to the limits question as it’s something I’ve wondered myself and seems fundamental to the field. The fact that it hadn’t even occurred to him is surprising.
Maybe it'll turn into a paper. :-)
43:41 i think this was a perfect answer Fraser, the diminishing returns starts with the overlap of ROMAN. There is no point in wasting JamesWEB time on something that newer telescopes will be able to do exponentially faster.
Fascinating insights into the cosmos! Thank you for sharing, I thoroughly enjoyed the information. Sending love from Ontario Canada. ❤️🎶🍁
Great topic, thanks for the interview! Also this is one of few interviews I need to rewatch becsuse the ammount of new information and thought experiments. I think the large structure of the universe should get more time on this channel, it's so fascinating!
Captivating interview, well done, that was fascinating.
Absolutely loved this discussion. Fascinating! ❤️
Perfect for a Sunday mornings viewing
This discussion is SO cool!!
Thank you for a plethora of great content
Great interview, great interviewee
great interview
I learned soooo much on this one! Ty ty ty Fraser!
Interviews are my favorites
Thanks Fraser. You could tell that he loves what he does.
So often, my hobby - aspiring to be an autodidact, polymath, polyglot, Renaissance man, and natural philosopher - makes me feel stupid. Like when I set my curtains on fire with a laser or blow the door off my shed making rocket motors. In fact, feeling daft is a good thing, as the Dunning-Kruger effect tells me. Yet, it is always a joy to feel clever after watching Mr. Cain's video content. His penetrating questions and fantastic subject matter are much appreciated. Thanks.
What a great read
Great video. Also, your only video that has made me hungry haha.
Last week astronomers dreamt of pool noodles and frisbees. This week it's bread sticks and pizza. Humans are wonderful.
Excellent informative and interesting interview. I enjoyed the insightful questions and the straightforward answers. Fraser, your questions do a great job of helping guests with painting the big picture as well as extracting meaningful, supportive details. And your steady stream of articulate leaders in each field is also superb. Best interview so far. I am amazed that there are breadstick galaxies. Keep up the excellent work.
I found this very useful and informative. The "breadsticks" speculation is a useful testable concept.
Awesome interview!!
Bless you to the person in the background.
Thank you for a wonderful discussion.
Amazing interview
omg is this guy pleasant and chill 😎👍
We want more and soon.
Thanks to Vijar 😊😊
Dude that was great!
You're amazing Fraser, the stuff you know is scary.
Awesome topic and guest. How was this not one of the first things JWST did? It would be the most incredible thing ever. Really interesting discussion
Well done. Thank you.
I've used the ultra-deep field Hubble image for years as my desktop wallpaper!
You and Viraj both have infectious passion and this has been great to watch and listen to! Also agreeing with a comment below, Dr. Pandya's analogies are perfect lmaoo
I just want to thank you all for the knowledge shared and insights in the journey so far with JWTS along with the gifts from the images and what we know so far. I appreciate the educational aspects too by the bucket load along with the additional comments from Viraj and others commenting on what is really needed to get understandable information.
I am not educated in any way but only want to say thank you for what you share as I still catch my breath at moments in my life time.
I confess I was aching for a visual of a breadstick galaxy.
Fraser, the satellite galaxies are the peperami flying off the rotating pizza 🥴
42:00 What is the noise floor on the sensors? Would ten 100 hour exposures look different than 100 ten hour exposures?
What about EUCLID? Seems to have a similar mission to Roman. How will they work together, and with webb?
When or wen?!!
Yeah, wth. I looked fairly extensively for "wen" as a scientific term or acronym related to JWST or astronomy, but did he really just misspell "when" repeatedly and in the thumbnail?
So through the direction of those early breadstick shaped galaxies, you can map the dark matter filaments. It’s quite a feat to be able to map these filaments and intersections that we can’t even see. You guys are doing extraordinary stellar work!
p.s. Just stumbled upon your channel, it’s doing a great job at explaining this information in a comprehensible manner to novices, like me. Thank you! I also enjoyed listening to Dr Viraj Pandiya.
Incredible! Ty
Im not much for interviews but that was great.
The Hubble deep feild was a little over 100 hours of exposure time. Not thousands of hours.
exciting times, especially with the studies being done on the age of universe being twice as old as we thought!
God bless you **(to the sneeze)
here for the bread sticks, pizza and doughballs! 😂
So do we have any galaxies that we *know* are breadstick galaxies, and if so, what is the closest one? Is there any reason we should be finding these in the distant past but not in contemporaneous time?
Very interesting. Have you read Time Waves on the Shores of Forever, lots of similar ideas..
The "breadstick" observation feels so much like an artifact of the way we're observing, in a universe with lensing, expansion, time dilation, etc.
But experts would know a lot better than I would.
Oh man I'm looking forward to this. Also is like like matter and the void or dark matter are like oil and water in a way?
Pardon? Sorry, this question is rather incomprehensible. :/
That is amazing! All the Astronomy details and searches that are planned!. All this time I was shaking my head at the U.S. Military for using so many Acronyms . And then here comes C.e.e.r.s. lol I guess we will never be without tons of acronyms in our life lol. Thank you Fraser.
The popping in to existence is the key to the wavelength of a mass ejection points they lost there energia but continue on with the barometric pressure that no vibration system that electrons flows through from point to point interactions
Hey Frasier, the moon regolith is known to be really rough on space equipment, plants, and lungs. Is there some kind of device like a rock polisher that could be used to make it safer for things like plants?
The Universe is endless ... it just goes on, and on, and on.
I would like to see an ultra deep field view 180 deg from Hubbles original...!
Actually, I had assumed that by now a JWST deep field had already been done. Please do some in pairs, 180 degrees from each other so comparisons can be made. I would like to know if there are similarities at opposite sides of the universe - or are they wildly different?
It should have already been done. My assumption. The 1st year of images was required by law to be public domain. After that the images can be held for up to 1 year. While they write their Nobel prize, having exclusive rights to the image.
Great!
This guy comes across as a first year undergraduate at first. Then you listen for awhile and realize he knows more than almost every phd astronomer.
Not doing a deep field with WEB is like not looking for the Higgs particle with the LHC.
Bless you 😊 18:00
I was startled when Dr Pandya suggested dark matter in a filament was responsible for the breadstick shape of some early galaxies. In my astronomy study the cosmic web was a filamentary network composed of filaments, sheets, knots and voids. I understood voids are vast empty regions, knots are massive galaxy clusters, and filaments and sheets connect the knots. Filaments were highways or transport channels that channelled mass and galaxies into higher density cluster regions. It makes sense that the cosmic web can outline and reveal the locations of dark matter. If merging dwarf galaxies are drawn into a filament this may explain the breadstick shape of the resulting galaxy. But filaments are present in the early and late universe, why are breadsticks only seen in the early universe?
I have a naïve question about the distance ladder. I gather that the first rung of the ladder is dependent on parallax measures of distances to Cepheid variables to get the absolute luminosities of the stars and these measurements are limited by the size of the base line constituted by opposite sides of the earth’s orbit around the sun. I’ve wondered whether astronomers have also tried comparing current star fields to historical photographs from say 100 years ago to get a longer baseline constituted by the distance traveled by the earth around the center of the Milky Way during that time. If that were doable, it would seem that it would refine the distances to the stars already measured by the standard method, and would extend the sphere in which Cepheid variable distances could be measured. Is that something that just hasn’t been done because it’s not practicable due to the difference in technique over time, or due to the fact that you could only get one measurement, rather than repeated measurements as you could using the earths orbit, or are such measurements part of the current understanding of the first rung of the latter?
A object with a redshift of 15 (at an age, the time since the Big Bang, of only 272 million years) has an interesting cosmological effect. While these objects will have a luminosity distance (D_L) is 547 billion light years, and so will be very dim, their angular size distance (D_A) is only 2.14 billion light years. This means a 10,000 parsec long galaxy will have an angular size of about ½ an arc minute, an easy target for the Webb to resolve.
I think that the 15 min with JWST vs. 50 days Hubble is mostly explained by the fact that the far away galaxies are seen in great part in infrared that JWST is designed for, Hubble being designed for visible (and ultra v)..
Question, can there be a correlation with the bar in the center of the pizzas and your breadstick?
This channel is out of control. A new episode every day for 2 weeks now?!
It's like Groundhog's Day but every day is Christmas with different and exciting gifts.
I literally considered going out for pizza when he mentioned the analogy, then I wanted to go to the supermarket to get breadsticks…
I thought that they already did a comparison of the Hubble's Deep Field and the Webb's Deep Field! No?
Our galaxy is moved around by the massive black hole in it's center. The "black matter" halo around it is the radiation that has escaped from the black hole, which consists of non-reality particles. They turn on/off so fast we see their surroundings as lightparticles, mostly light blue.
I like this video so so much its incredible
Glad you enjoyed it.
What’s the maximum red shift factor beyond which we need to start questioning current understanding of the age of the universe❓
We generally can't see anything beyond the CMB, which has a redshift of over 1000. If we could one day detect the neutrino background radiation, that has a redshift of 10 billion and corresponds to about 1 second after the big bang!
But to be more helpful, if we detect fully formed galaxies beyond a redshift of 20 to 30 (180 to 100 million years after BB) the big bang model would be in trouble.
I'm curious if these observed "breadstick" shaped galaxies may have started out as the "contrails" of old quasar streams?
🧐good idea!
Yeah someone already made that prediction. They took away his telescope time. Seriously. Edit: Now i am confused if you already knew that.
Really? No, I’m not familiar with that.
@@Hal_McKinney i won't mention his name the community would go nuts. But If you happened to searched for "quasars birth galaxies."You will most likely will find it.
Are you accounting for the time lapse factor? Is it even significant at those distances? A doughnut could stretch out to a breadstick depending on orientation…
Very interesting.
But, wat is with the wen?
Sorry, what is with the when?
47:00 I never thought about leaving the aperture open for 50 hours on JWST like we did on the Hubble that gave us the most mind blowing astronomical discovery of our life time that there are 20 million galaxies behind a postage stamp held at arms length in every direction. Facepalm!
It's actually somewhat perplexing and disappointing that they send this marvelous new telescope and don't even know how deep/far back can they look and what is the detection limit / diminishing returns boundary.
I mean like isn't this one of the most important things to know about a telescope? Shouldn't it be somehow at least estimated before the launch and then tested once in orbit?
It's bizarre to me that people using the telescope do not know the answers to those basic questions. I hope that this isn't universal and at least some people in the scientific community know the theoretical limits of the telescope and if they don't then they are keen on finding them out by just looking at the empty sky for at least the same amount of time the Hubble did.
Not gonna lie this reminded me of the Elon/SpaceX interview where the interviewer literally got Musk thinking of something he hadnt yet thought of live on camera in sort of a natural and wholesome way.
What gives with the "WEN" acronym? I see it in the thumbnail and in the chapter title, but the explanation escapes me, am I missing something?
It's a reference to a meme.
I would not put anything past looking longer at something. In other words, they may not be a point of diminishing returns.
When the Hubble Deep Field was done, I'm sure everyone figured there would be little to nothing there, but then, bonk!
I don't see why the same wouldn't be true for holding the Webb looking at the same spot as Hubble for the same amount of time and being further wowed by what is observed!
When I first saw the Hubble Deep Field photo, I was just sitting at my desk alone and my jaw hit the ground as I realized I was looking at hundreds of galaxies!!! Hubble for me proved its worth in that moment!
Nice interview, thanks!
If we actually discover this empty space (behind the edge of our universe) with an advanced telescope that reaches and observes even further than the JWST or Hubble ST, it will only be because the general collapse of matter of the previous universe took place there, the so-called Big Rip or Big Freeze. However, this period would be limited, depending on how long the predecessor's dying process took...
Even in the Voids there are far fewer or hardly any stars and galaxies or clusters than in other areas of the universe - I think the reason is that at the very beginning of the cosmos there were many small pocket universes, or rather small bubble multiverses, which later all merged into one single gigantic universe, so these are unfilled spaces from a previous border zone...
Then to the mysterious dark matter - the “glue” that holds galaxies together.
I'm not so sure whether it really exists. At least I think the word “dark matter” is wrongly chosen; I would call these phenomena or force "space-connecting gravity"... 🌀