Topic: Galaxies & Cosmology
DESI Takes Census of Black Holes in More Than One Million Galaxies

DESI Takes Census of Black Holes in More Than One Million Galaxies

Artist's illustration depicting a dwarf galaxy that hosts an active galactic nucleus (credit: NOIRLab) Back when I started astronomy in the 1990s, folks joked that a sample of 6 was big enough to do statistics. In those early days of digital cameras and multi-meter telescopes, it still took a night or more to observe a single galaxy.  I bring this up because a recent press release casually failed to mention that a new publication using the Dark Energy Survey Instrument started with a sample of 1,385,177 galaxy spectra… and this is just galaxies from their Early Data Release. There are...

read more
Gas Ripples Shake Up Ancient Galaxies

Gas Ripples Shake Up Ancient Galaxies

FIR image of BRI 1335–0417 overlaid with our identified bar ellipses (blue ellipse) and two-armed spiral structure identified in Tsukui & Iguchi (2021, black solid line). Contours start at 2σ but are logarithmically spaced in powers of 2 (2σ, 4σ, 8σ,...)....

One Theory Puts Us Somewhere Special

One Theory Puts Us Somewhere Special

The image shows the distribution of matter in space (blue; the yellow dots represent individual galaxies). The Milky Way (green) lies in an area with little matter. The galaxies in the bubble move in the direction of the higher matter densities (red arrows). The...

More Theory-Changing Old Galaxies

More Theory-Changing Old Galaxies

Credit: Cluster image: NASA, UNCOVER (Bezanson et al., DIO: 10.48550/arXiv.2212.04026). Insets: Nasa, UNCOVER (Wang et al., 2023); Composition: Dani Zemba/Penn State Ok, I have to admit, the JWST is finding objects so exceedingly weird that my first reaction is to...

Dark “Stars” or galaxies?

Dark “Stars” or galaxies?

JWST initially identified these three objects (JADES-GS-z13-0, JADES-GS-z12-0 and JADES-GS-z11-0) as galaxies in December 2022. Now a team suggests they might be “dark stars,” theoretical objects powered by particles of dark matter annihilating. Credit: NASA/ESA We...