Galaxy Archives

(Left) The N2H +/HCN ratio toward the central region of M83 shown in the color scale. The black contours show 3-mm continuum intensities with 0.5 mJy beam−1 increments. The beam size is shown at the bottom left corner. (Right) The same figure as Figure 2(a), but including data points from the galactic center region. The grey dashed lines have slopes of 1, and show the lines of constant N2H +/HCN ratios. -- [astro-ph.GA]

ALMA Observations Towards M83 Reveal N2H+ Tracing Dense Gas

by Keith CowingOctober 20, 2026October 20, 2026

[astro-ph.GA] Galactic observations have shown that N2H+ intensities preferentially trace star-forming dense molecular gas compared with HCN or HCO+, which are conventionally used as dense-gas tracers in extragalactic studies.

Example slope (BPAH) measurement for galaxy

Astrochemistry

Variations in the 3.3 µm Polycyclic Aromatic Hydrocarbon Feature Across Nearby Galaxies Driven by Metallicity and Radiation Field Spectrum

by Keith CowingAugust 8, 2026August 8, 2026

[astro-ph.GA] We use JWST NIRCam imaging to investigate the 3.3 μm polycyclic aromatic hydrocarbon (PAH) feature in nearby galaxies. NIRCam observations of the 3.3 μm feature are emerging as a […]

SFR as a function of stellar mass for equilibrium (left) and non-equilibrium (right) galaxies. The solid red line indicates the SFMS from Renzini & Peng (2015), with dashed lines showing the adopted scatter. Colour maps indicate the number of galaxies per bin in each panel; note that the colour scales differ between the equilibrium and non-equilibrium panels, reflecting the different sample sizes. -- astro-ph.GA

Astrochemistry, Habitable Zones, Status Report

The Habitability Trade-off: Chemical Decoupling And Quenching In Massive Galaxies

by Keith CowingMay 26, 2026May 26, 2026

Massive galaxies experience complex evolutionary processes, including mergers and gas accretion, which can disrupt the chemical equilibrium between their stellar and gaseous components.

This composite image combines observations from the NASA/ESA/CSA James Webb Space Telescope of the Phantom Galaxy (M74) with a high-resolution simulation of galactic turbulence. The simulation from this study — zoomed into a small patch of the galaxy’s interstellar medium — reveals extremely high-resolution chaotic motions of plasma that regulate star formation, structure formation, and the magnetic field across the galactic scales. -- Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team; Acknowledgement: J. Schmidt; Simulation: J. Beattie.

Astronomy & Telescopes, Imaging & Spectroscopy, Interstellar, Press Release

Simulating Turbulence In A Galaxy

by Keith CowingMay 29, 2025May 26, 2025

From the ocean’s rolling swells to the bumpy ride of a jetliner, turbulence is everywhere. It breaks large waves into smaller ones, cascading energy across scales. It is ubitquitous throughout […]

Limits of danger to various species, a differential flux Fν in erg s−1 cm−2 Hz−1 , as a function of frequency in Hz. Human keratinocyte data comes from Aoki et al. (2011), rat PC12 cell data from Masuma et al. (2013), and E. Coli and D. Radiodurans from Krisko & Radman (2010). The left panel shows the original data, and the right panel shows our extrapolated version. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Habitable Zones, Microbiology & Virology, Radiation, Status Report

Impacts of UV Radiation From An AGN On Planetary Atmospheres And Consequences For Galactic Habitability

by Keith CowingNovember 26, 2024November 26, 2024

We present a study of the effects of ultraviolet (UV) emission from active galactic nuclei (AGN) on the atmospheric composition of planets and potential impact on life. It is expected […]

An international team of astronomers has used the NASA/ESA/CSA James Webb Space Telescope to detect the first brown dwarf candidates outside the Milky Way in the star cluster NGC 602. larger image - ESA/NASA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

The First Young Brown Dwarfs Found Outside Our Home Galaxy?

by Keith CowingOctober 23, 2024October 23, 2024

Picture the outskirts of the Small Magellanic Cloud, a satellite galaxy of our Milky Way, roughly 200 000 light-years from Earth: here lies the young star cluster NGC 602. The […]

Gigantic infrared map of the Milky Way, ESO Larger images

Astronomy & Telescopes, Imaging & Spectroscopy, Press Release, Stellar Cartography

ESO Telescope Captures The Most Detailed Infrared Map Ever Of Our Home Galaxy

by Keith CowingSeptember 27, 2024September 27, 2024

Astronomers have published a gigantic infrared map of the Milky Way containing more than 1.5 billion objects ― the most detailed one ever made. Using the European Southern Observatory’s VISTA […]

A 2D visual comparison of the filaments identified by DisPerSE from the DTFE density field (left) and the MCPM density field (right) in the same 10 Mpc thick slices in TNG100 at z = 0. In both panels, the underlying DM overdensity along the line of sight is represented by the blue–white color bar, and gray circles represent galaxies. The individual filament segments from DTFE and MCPM are curves colored by the average persistence value of a segment (red is less persistent, yellow is more persistent). The MCPM density field identifies the filamentary structure with significantly higher fidelity, including the less prominent filaments that the DTFE density field method misses. -- The Astronomical Journal

Astronomy & Telescopes, Gaia - Planetary Perspectives, Interstellar, Microbiology & Virology, Science Fiction, Status Report, Stellar Cartography

Filaments Of The Slime Mold Cosmic Web and How They Affect Galaxy Evolution

by Keith CowingSeptember 17, 2024September 17, 2024

We present a novel approach for identifying cosmic web filaments within the DisPerSE structure identification framework, using cosmic density field estimates from the Monte Carlo Physarum Machine (MCPM), inspired by […]

Artist’s impression of the center of the starburst galaxy, NGC 253. Credit: ALMA (ESO/NAOJ/NRAO)

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

A Molecular Production Line Inside a Busy Star Factory in a Starburst Galaxy

by Keith CowingMay 11, 2024May 11, 2024

An international research team led by Sergio Martín of the European Southern Observatory/Joint ALMA Observatory, Nanase Harada of the National Astronomical Observatory of Japan, and Jeff Mangum of the National […]

Galaxy NGC 4383 evolving strangely. Gas is flowing from its core at a rate of over 200 km/s. This mysterious gas eruption has a unique cause: star formation. Credit: ESO/A. Watts et al

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

Galaxy NGC 4383 Explosions Release Various Elements Into Interstellar Space

by Keith CowingApril 23, 2024April 23, 2024

A team of international researchers studied galaxy NGC 4383, in the nearby Virgo cluster, revealing a gas outflow so large that it would take 20,000 years for light to travel […]