相关论文: A Statistical Estimation of the Occurrence of Extr…
As a guide for astronomers new to the field of technosignature search (i.e. SETI), I present an overview of some of its observational and theoretical approaches. I review some of the various observational search strategies for SETI,…
Reconstructing the mass assembly history of the Milky Way relies on obtaining detailed measurements of the properties of many stars in the Galaxy, especially in the stellar halo. One of the most constraining quantities is stellar age, as it…
We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}|…
I review the scientific and technical history of the Search for Extraterrestrial Intelligence (SETI), discuss the impact of the political involvement, and speculate on the nature of a successful detection and its potential social and…
In ecological systems, be it a petri dish or a galaxy, populations evolve from some initial value (say zero) up to a steady state equilibrium, when the mean number of births and deaths per unit time are equal. This equilibrium point is a…
This study examines the hypothesis that the rapid development of Artificial Intelligence (AI), culminating in the emergence of Artificial Superintelligence (ASI), could act as a "Great Filter" that is responsible for the scarcity of…
We present stellar population parameters of twelve early-type galaxies (ETGs) in the Coma Cluster based on spectra obtained using the Low Resolution Imaging Spectrograph on the Keck II Telescope. Our data allow us to examine in detail the…
"Traditional SETI is not part of astrobiology" declares the NASA Astrobiology Strategy 2015 document. This is incorrect. In this white paper, I argue that SETI$-$seen as the search for technosignatures characteristic of the future of life…
We discuss experiments achievable via monitoring of stellar dynamics near the massive black hole at the Galactic center with a next generation, extremely large telescope (ELT). Given the likely observational capabilities of an ELT and…
In a series of recent papers and in a book, this author put forward a mathematical model capable of embracing the search for extra-terrestrial intelligence (SETI), Darwinian Evolution and Human History into a single, unified statistical…
Using our rich observations within the Milky Way to better understand galaxy evolution requires understanding what the Milky Way looks like "as a galaxy" -- that is, its "true" shape and abundance profiles (unskewed by observational…
The data recently accumulated by the Kepler mission have demonstrated that small planets are quite common and that a significant fraction of all stars may have an Earth-like planet within their Habitable Zone. These results are combined…
In this article an analysis of the fundamentals used to search for extraterrestrial artificial signals in the galaxy, which have been developing for more than five decades, is presented. It is shown that the key factor for the success of…
The knowledge of the ages of stars hosting exoplanets allows us to obtain an overview on the evolution of exoplanets and understand the mechanisms affecting their life. The measurement of the ages of stars in the Galaxy is usually affected…
An astrophysical model is proposed to answer Fermi's question. Gamma-ray bursts have the correct rates of occurrence and plausibly the correct energetics to have consequences for the evolution of life on a galactic scale. If one assumes…
The development of civilisations like ours into spacefaring, multi-planet entities requires significant raw materials to construct vehicles and habitats. Interplanetary debris, including asteroids and comets, may provide such a source of…
Stellar populations and their distribution differ widely across the Galaxy, which is likely to affect planet demographics. Our local neighbourhood is dominated by young, metal-rich stars in the galactic thin disc, while the stellar halo and…
Current observational results show that both late-and-early-type galaxies follow tight mass-size planes, on which physical properties such as age, velocity dispersion and metallicities correlate with the scatter on the plane. We study the…
JWST and HST observations have revealed numerous elongated, pickle-shaped galaxies at high to intermediate redshifts, with masses close to those expected for Milky Way progenitors. Here we use reduced-mass eigentensors to quantify the…
We explore the structure of the element abundance--age--orbit distribution of the stars in the Milky Way's low-$\alpha$ disk, by (re-)deriving precise [Fe/H], [X/Fe] and ages, along with orbits, for red clump stars from the APOGEE survey.…