![Schematic diagram of our spectral line stacking and matched filtering procedures. First, (a) shows relevant spectral regions of the (synthetic) observational data (black) and an initial spectral simulation (red). Each spectral window is then weighted based on the signal-to-noise ratio of each region to create a velocity stack of all relevant molecular rotational transitions (b). Finally, the stacked simulation is used as a matched filter and is cross-correlated with the stacked data to visualize the statistical significance of a given detection (c). -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Exploring-the-Limits.png?resize=1200%2C720&ssl=1)
[astro-ph.GA] The formation history of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium remains a topic of active debate, with proposed mechanisms ranging from high-temperature stellar ejecta processes to low-temperature […]
Interstellar
![Helicity asymmetries of the primordial (left panel) and late-time (right panel) density fields for parity asymmetric (blue curves) and symmetric (red curves) simulations. The shaded regions indicate the standard deviation (1σ) of the ensemble-average. The red markers highlight the asymmetries exceeding a statistical significance of 3σ. - [astro-ph.CO]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Probing.png?resize=1200%2C718&ssl=1)
Posted inAstrochemistry
Probing Primordial Chirality in the Matter Distribution
[astro-ph.CO] Whether parity symmetry was violated in the early universe remains one of the fundamental open questions in cosmology. If so, it may leave an intrinsic handedness in the large-scale […]
![Three-dimensional thermal phase architecture of the local ISM. (a) Three-dimensional rendering of the cold (blue) and unstable (yellow) isosurfaces, with warm gas shown transparent. The transparent warm volume traces WNM together with unmodelled hot ionised gas, which carries negligible mass (Methods). An interactive version is available at https://sb2580.github.io/phases 3d/. (b) Slices through the Galactic plane (𝑧 = 0) of gas density 𝑛 (left), FUV radiation intensity 𝐼UV (middle), and phase classification (right). Concentric circles mark heliocentric radii of 150, 300, and 450 pc. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-first-three.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry
The First Three-dimensional Map Of Thermal Phases In The Local Interstellar Medium
[astro-ph.GA] The thermal state of interstellar gas controls whether it remains warm and diffuse or cools into dense clouds. Twentyone centimetre observations have established a statistical picture of neutral-gas phases, […]
Posted inAstrochemistry
An Interstellar Energetic And Non-aqueous Pathway To Peptide Formation
[astro-ph.SR] The origin of the molecular building blocks of life is a central question in science. A few α-amino acids such as glycine, the simplest proteinogenic amino acid, have been […]
![Molecular structure of the two conformational isomers that are connected through a single bond rotation,syn and anti CH2CHCHS. The numbers represent the zero-point energy corrected energy separation in kcal mol−1 at the CCSD(T)-F12/cc-pVTZ-F12//SCS-MP2/aug-cc-pVTZ, described later in the text. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Laboratory-spectroscopy.png?resize=1200%2C723&ssl=1)
Posted inAstrochemistry
Laboratory Spectroscopy, Theoretical Characterization, And Astronomical Search For Syn-propenethial (CH2CHCHS)
[astro-ph.GA] We report the laboratory characterization of the higher-energy isomer of propenethial, syn-CH2CHCHS. While the lower-energy isomer, anti-CH2CHCHS, was detected in the interstellar medium during the QUIJOTE line survey of […]
![Snapshots of the system 1 ps after the initial contact of the nanograins for different initial velocities. Atom colour key indicates hydrogen: white; carbon: dark gray; oxygen: red; silicon: beige; and magnesium: green. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/When-Two-Worlds.png?resize=1200%2C715&ssl=1)
Posted inAstrochemistry
When Two Worlds Collide: How Collisions Between Silicate and Carbonaceous Nanograins can Drive Complex Chemistry
[astro-ph.GA] Our overall objective is to determine how collision velocity governs the interactions between silicate and carbonaceous nanograins. (astrochemistry)
Posted inSETI & Technosignatures
Could Alien Signals Be Hiding On A Different Radio Channel?
[RAS] Astronomers searching for signs of extraterrestrial intelligence may have been missing alien signals in part of the radio spectrum that has not recently been explored.
![Simulated light curve for a periodic laser beacon at fpulse = 413 Hz at d = 15 pc observed with a Dtel = 1 m telescope at a cadence of 10 µs. The upper panels show a short segment of the noiseless pulse signal (left) and the corresponding signal including the estimated noise contributions (right). The bottom panel shows the integrated folded pulse profile after combining 108 pulses, resulting in an expected SNR of approximately 5.99. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-Interstellar-Laser.png?resize=1200%2C716&ssl=1)
Posted inSETI & Technosignatures
The Interstellar Laser Beacons Hypothesis and the Cosmic Lighthouses Project
[astro-ph.IM] In this paper, we argue that in a realistic, resource-limited scenario senders whose intent is to maximize successful communication at the lowest cost will utilize very long-lived, pulsed beacons.
![DFT-computed anharmonic absorption spectra of 1-cyanonaphthalene in its neutral (1-CNN0 , top panel), cation (1-CNN+ , middle panel), and anion (1-CNN− , bottom panel) charge states. The calculated vibrational transitions are convolved with a Lorentzian profile using a FWHM of 4 cm−1 to simulate realistic spectral profiles. Numerical labels near the major peaks represent their respective wavelengths. Key vibrational bands, including the CN stretch at ∼ 4.4–4.6 µm and the CH stretch at ∼ 3.2–3.3 µm, are explicitly highlighted.-- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Anharmonic-Infrared-Emission.png?resize=1200%2C718&ssl=1)
Posted inAstrochemistry
Anharmonic Infrared Emission Of Cyano-Substituted Polycyclic Aromatic Hydrocarbon Molecules: Cyanonaphthalenes As A Case Study
[astro-ph.GA] Recent detections of cyano-substituted polycyclic aromatic hydrocarbons (cyano-PAHs) highlight them as key tracers of nitrogen heterocycles in the interstellar medium (ISM).
![Conservative CW mitigation demonstrated on a fully synthetic wideband radio dataset with realistic detector features. (a) Frequency spectrum before and after mitigation. Red shaded regions indicate the three cataloged anthropogenic CW tones at 137, 405, and 450 MHz (representing satellite downlinks, weather balloon telemetry, and South Pole station communications, respectively). These tones are removed via least-squares time-domain sine subtraction as described in the text. The orange dotted line marks an uncataloged narrowband feature at 285 MHz that is successfully preserved. (b) Time domain trace of the same waveform shown in panel (a), zoomed in to show the effect of mitigation around an injected nanosecond-scale broadband transient (dashed black line). The raw simulated trace before mitigation (light red line) is heavily obscured by CW interference. After subtraction of the cataloged tones, the mitigated trace (solid green line) shows significantly reduced coherent CW contamination, successfully recovering the underlying broadband impulsive signal and preserving both its original shape and temporal structure. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Methodological-Synergies.png?resize=1200%2C720&ssl=1)
Posted inSETI & Technosignatures
Methodological Synergies Between Technosignature And UHE Neutrino Searches
[astro-ph.IM] Radio technosignature searches and radio-based ultra-high energy (UHE) neutrino experiments address different scientific questions, but share a closely related data analysis problem: identifying rare signals of unknown morphology within […]