Live data from Hacker News

An all-sky map of half a million supermassive black holes

sdss.org

1–10 of 44 posts

Re: An all-sky map of half a million supermassive black holes

#4

Interesting how anisotropic it is. Naively I would have assumed it would be roughly symmetrical

Interesting indeed but might be an artifact of regions being surveilled and Milky Way disk both containing more easily detectable holes and obscuring some areas with the dust clouds (I am not an astrophysicist or astronomer)

Re: An all-sky map of half a million supermassive black holes

#6
The number of massive maps of the universe in recent years are absoultely fascinating, and have reignited my childhood interest in astronomy and cosmology.

These maps consist of a large number of statistical observations derived from images, and that lines up with all the data analysis I've used in the past decades in genomics. (Most DNA sequencing data comes from image analysis, coincidentally!). And the plots I see in these papers are looking increasingly like the plots I've produced over the past 20 years, so I'm thinking maybe it would be fun to download a few TB of atlas and see if I can reproduce their plots...

Thanks for everyone who works in this field, it's fantastic work that's reshaping our very understanding of reality.

Re: An all-sky map of half a million supermassive black holes

#7
Anyone ever worked with data from SDSS? What have you done with it? I imagine it's a gold mine for university students. I took an astronomy class and was able to plot the largest structures in the universe from their data, which was cool but pretty basic. I've loved astronomy all my life and I've always wondered if there was anything more one person or a small team could do with SDSS data. I took the class in 2010 so I imagine there are more possibilities now with AI?

Re: An all-sky map of half a million supermassive black holes

#9
post #3

Interesting how anisotropic it is. Naively I would have assumed it would be roughly symmetrical

I think that's more a result of our incomplete/inconsistent scanning.

On the other hand, the ancients assumed there had to be big continents in the southern and western hemispheres to "balance" the land in their own quadrant.

They turned out to be right, but not quite for the reasons they put forth.

As a non-cosmologist, I'm unwilling to speculate on what "should" be out there, because my mental model is probably very wrong (keeping in mind that our best models of what's happening out there are also probably quite wrong).

Re: An all-sky map of half a million supermassive black holes

#10

Interesting how anisotropic it is. Naively I would have assumed it would be roughly symmetrical

As others say, this is probably mostly artifacts from the survey design (e.g. eROSITA data rights), but the Galactic plane definitely limits things too.

This video of the DESI galactic map shows the directions that are possible to survey with optical light, in a very cool way:

https://www.youtube.com/watch?v=VSTGiRLWzS4

Post reply on HN