SDSS-V Maps 500,000 Supermassive Black Holes in All-Sky Survey
An all-sky map of half a million supermassive black holes
The Sloan Digital Sky Survey's Data Release 20 (DR20) unveils the first southern hemisphere optical observations from the Black Hole Mapper program, paired with eROSITA X-ray data to identify and study hundreds of thousands of accreting supermassive black holes. The survey reveals that the most luminous quasars were more common in the early universe than expected, and that 70–90% of black hole growth occurred behind dust and gas, hidden from optical and even X-ray view. With over 3.3 million spectra, DR20 provides the largest uniform spectroscopic follow-up of X-ray sources to date, enabling precise black hole mass measurements and new insights into their evolution.
“This release marks the culmination of more than a decade of joint planning and scientific exchange between the German eROSITA Consortium and the Sloan Digital Sky Survey,” said Dr. Andrea Merloni, eROSITA Principal Investigator and BHM Survey Scientist.
- xioxox
We also released the 2nd half sky catalogue of the eROSITA X-ray survey at the same time, for 1.5 years of operations, in collaboration with SDSS. Here is a sky map and 3D plot with redshift: https://www.mpe.mpg.de/8215311/news20260731
This almost doubled the number of known X-ray sources to 2 million.
- epistasis
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.
- RagnarD
I tend to assume that the obvious gridded point pattern is a sky sampling artifact - but it would be far more interesting if it's a real thing.
- csallen
How different is "mapping supermassive black holes" from "mapping galaxies"?
- gwerbin
What are the "gridded" regions in the middle? Is that some kind of measurement artifact?