EmbeddingGemma 2: an open, lightweight multimodal embedding model
deepmind.google·6d ago
AI Engineering
Hacker News·Aug 7·5 min read
An all-sky map of half a million supermassive black holes
TL;DR
The Sloan Digital Sky Survey's Data Release 20 introduces the Black Hole Mapper, revealing insights into 500,000 supermassive black holes through optical and X-ray observations. This milestone enhances our understanding of quasars and active galactic nuclei across the universe.
✦ Why It Matters
Explore the new data to enhance your research on supermassive black holes and their environments.
Key Takeaways
- Utilize the DR20 dataset for advanced black hole research.
- Leverage multi-wavelength data for comprehensive astrophysical studies.
- Investigate the implications of black hole growth in the early Universe.
- Engage with open data resources for collaborative research opportunities.
Full Summary
Data Release 20 (DR20) from the Sloan Digital Sky Survey (SDSS) marks a significant advancement in the study of supermassive black holes (SMBHs) through the Black Hole Mapper (BHM) program. It includes the first optical spectra from the southern hemisphere, alongside over 3.3 million optical spectra from 500,000 galaxies and 1.5 million stars.
A key feature is the SPIDERS program, which pairs optical data with X-ray observations from the eROSITA mission, providing identifications and distance measurements for around 200,000 X-ray sources. This dataset reveals that rapidly growing black holes were more common in the early Universe than previously thought, with 70% to 90% of black hole growth occurring obscured by dust and gas.
The findings challenge existing models of black hole evolution and highlight the importance of multi-wavelength observations in astrophysics.