astrophysics Archives

Primordial SN explosions. One kpc images of the 13 M⊙ CC SN in the 1.1 × 106 M⊙ halo 1.2 Myr after the explosion (a) and the 200 M⊙ PI SN in the 2.2 × 107 M⊙ halo 0.7 Myr after the explosion (b). The relic H II regions of the stars are visible as the 2000 K - 10,000 K gas and the CC and PI ejecta are visible as the 104 and 105 K shocked gas with radii of ∼ 50 and 100 pc, respectively. At the end of the simulations both SN remnants are still trapped within their respective H II regions. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Status Report

Abundant Water From Early Supernovae At Cosmic Dawn

by Keith CowingJanuary 9, 2025January 9, 2025

Primordial (or Pop III) supernovae were the first nucleosynthetic engines in the Universe, forging the heavy elements required for the later formation of planets and life.

Brightness distribution of the 13CO J=2−1 lines integrated over the velocity interval corresponding to the full width at zero intensity of the C18O J=2−1 lines. The contours show levels at 3, 5, 10, and 20 times the root mean square noise level of the image. -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Interstellar, Status Report, Stellar Cartography

ALMA Observations of CO Isotopologues Towards Six Obscured post-AGB Stars

by Keith CowingJanuary 9, 2025January 9, 2025

Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB), when an efficient mass-loss process removes a significant fraction of their initial mass.

Illustration of the main modalities included in the Multimodal Universe, along with typical associated machine learning tasks. In addition, the Multimodal Universe also includes a small amount of hyperspectral images and tabular data, not shown here. -- astro-ph.IM

AI - Data - Apps - Cybernetics, Apps - Games, Astronomy & Telescopes, Status Report

The Multimodal Universe: Enabling Large-Scale Machine Learning with 100TB of Astronomical Scientific Data

by Keith CowingDecember 6, 2024December 6, 2024

We present the MULTIMODAL UNIVERSE, a large-scale multimodal dataset of scientific astronomical data, compiled specifically to facilitate machine learning research.

Upper panels: Cosmic star formation rate density, as computed with our extension of the SP21 model (dashed black line) and as given by the original SP21 model (dot-dashed red line). In the left panel, we further show with the empirical fit (dotted black line) to a compilation of observational data provided by Madau & Dickinson (2014) (grey data points). The right panel shows the behaviour of the SP21 model and our extended formalism in the future of the universe. As future times correspond to negative redshifts, and the cosmic star formation rate density becomes asymptotically null at arbitrarily large times, both axes switch from logarithmic to linear scale when moving from the left to the right panel. The grey hatched shaded area in the right panel excludes the non-physical region corresponding to 𝜌¤∗ < 0. Lower panels: Relative difference between the two models showed above (dashed black line), and between our formalism and the fit from Madau & Dickinson (2014) (dotted black line). The latter comparison is available only for positive redshifts (i.e., past cosmic times), as the fit represents a purely empirical fit to the data, and not a predictive theoretical model. The SP21 model agrees well with the improved method introduced in this work at high redshift, but overestimates the cosmic star formation rate density at lower redshift and in the future. In the redshift range 0 < 𝑧 < 10, both the original SP21 model and our updated formalism agree with the empirical fit within a factor of ∼ 2. -- astro-ph.CO

Astronomy & Telescopes, Status Report, Stellar Cartography

The Impact Of The Cosmological Constant On Past And Future Star Formation

by Keith CowingNovember 23, 2024November 23, 2024

We present an extended analytic model for cosmic star formation, with the aim of investigating the impact of cosmological parameters on the star formation history within the ΛCDM paradigm.

Modeling stellar winds and star–planet interactions: TRAPPIST-1 system (upper left; Garraffo et al., 2017), TOI-700 system (lower left; Dong et al., 2020), and for Proxima c (right; Alvarado-Gómez et al., 2020a) (from Lynch et al., 2022) -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Space Weather & Heliophysics, Status Report, Stellar Cartography

Physics of mid- and Low-mass Stars with Solar-type Activity and Their Impact on Exoplanetary Environments

by Keith CowingNovember 20, 2024November 20, 2024

In the monograph, the authors systematize and generalize the results of studying solar-type activity that is characteristic of a significant part of mid- and low-mass stars of the Galaxy, outline […]

This Hubble Space Telescope image captures a triple-star system, which can host potentially-habitable planets. Our nearest stellar neighbour, the Alpha Centauri system, includes three stars. Credit NASA, ESA, G. Duchene (Universite de Grenoble I); Image Processing: Gladys Kober (NASA/Catholic University of America)

Astronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Interstellar, Origin & Evolution of Life, People Of Astrobiology, Press Release, SETI & Technosignatures, Stellar Cartography

A New Model Calculates The Chances Of Intelligent Life Elsewhere

by Keith CowingNovember 13, 2024November 13, 2024

The chances of intelligent life emerging in our Universe – and in any hypothetical ones beyond it – can be estimated by a new theoretical model which has echoes of […]

Astrobiology (general), Astrochemistry, Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Press Release

NASA SMD Town Hall for Planetary Science Research Programs on October 15

by Keith CowingOctober 15, 2024October 15, 2024

On October 15, 2024, at 3 PM Eastern Time, NASA’s Planetary Science Division (PSD) will host a webinar to discuss changes made to select upcoming Research Opportunities in Space and […]

[C/Fe], [N/Fe], and [O/Fe] abundances and C/O and N/O ratios as functions of [Fe/H] for observed dwarfs (left panel) and giants (right panel). Thin disc planet-hosting stars are represented by green circles, while pink circles indicate stars from the thick disc. Circles filled with both colours represent "in between stars" to thin and thick discs. The (coloured) diamond symbols represent the planets-hosts from Tautvaišiene et al. ˙ (2022). The comparison sample results are taken from Stonkute et al. (2020); Tautvaišien ˙ e et al. (2022) and indicated by empty grey squares (thin ˙ disc) and triangles (thick disc). -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report, Stellar Cartography

Chemical Composition of Planetary Hosts: C, N, and a-element Abundances

by Keith CowingOctober 12, 2024

Accurate atmospheric parameters and chemical composition of planet-hosting stars are crucial for characterising exoplanets and understanding their formation and evolution.

Voyager 2 Interstellar Probe Heads Outward -- NASA

Astronomy & Telescopes, Interstellar, Missions & Hardware, Press Release, Radiation

Voyager 2 Interstellar Probe Science Instrument Turned Off To Save Power

by Keith CowingOctober 2, 2024October 2, 2024

The Voyager 2 mission has been working to postpone the shut-off as long as possible. Four other instruments aboard the interstellar spacecraft continue to operate.

The configuration of stellar associations in and around the LB. Left panel: Shown is a map of today’s LB and the locations of the nearby stellar associations. The shape of the LB is taken from (Zucker et al. 2022). Right panel: Shown are the positions in Galactic coordinates of the nearby stellar associations Tuc-Hor and Sco-Cen’s subgroups: Lower Centaurus Crux (LCC), Upper Centaurus Lupus (UCL), and Upper Scorpius (US). Also shown (bubble) is the new Galactic bubble discovered by Robitaille et al. (2018), which is likely the remnant of a supernova that took place in UCL. We anticipate an anisotropy in the distribution of arrival directions of cosmic rays that results from SN explosions hosted by these nearby stellar associations. -- astro-ph.HE

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Origin & Evolution of Life, Press Release, Radiation, Stellar Cartography

Life in the Bubble: How A Nearby Supernova Left Ephemeral Footprints On The Cosmic-ray Spectrum And Indelible Imprints On Life

by Keith CowingSeptember 20, 2024September 20, 2024

The Earth sits inside a 300pc-wide void that was carved by a series of supernova explosions that went off tens of millions of years ago, pushing away interstellar gas and […]