Results 21 to 30 of about 53,848 (207)

New distance measures for classifying X-ray astronomy data into stellar classes [PDF]

open access: yes, 2018
The classification of the X-ray sources into classes (such as extragalactic sources, background stars, ...) is an essential task in astronomy. Typically, one of the classes corresponds to extragalactic radiation, whose photon emission behaviour is well ...
A Araujo   +31 more
core   +1 more source

The Supersonic Project: Star Formation in Early Star Clusters without Dark Matter

open access: yesThe Astrophysical Journal Letters, 2023
The formation mechanism of globular clusters (GCs) has long been debated by astronomers. It was recently proposed that supersonically induced gas objects (SIGOs)–which formed in the early Universe due to the supersonic relative motion of baryons and dark
William Lake   +9 more
doaj   +1 more source

Extragalactic Stellar Astronomy [PDF]

open access: yes, 2008
Despite their paucity, massive hot stars are real cosmic engines of fundamental importance in shaping our Universe, from its very early stages up to its current appearance. Understanding the physics of massive stars is then a key issue for many relevant astrophysical phenomena.
Urbaneja, Miguel A.   +2 more
openaire   +2 more sources

Status of the VERITAS Observatory [PDF]

open access: yes, 2008
VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for gammma-ray astronomy in the GeV-TeV range, has recently completed its first season of observations with a full array of four telescopes.
A. Cannon   +84 more
core   +3 more sources

Proton and neutrino extragalactic astronomy [PDF]

open access: yesPhysical Review D, 2008
The study of extragalactic sources of high energy radiation via the direct measurement of the proton and neutrino fluxes that they are likely to emit is one of the main goals for the future observations of the recently developed air showers detectors and neutrino telescopes. In this work we discuss the relation between the inclusive proton and neutrino
openaire   +2 more sources

Fixing the Reference Frame for PPMXL Proper Motions Using Extragalactic Sources [PDF]

open access: yes, 2014
We quantify and correct systematic errors in PPMXL proper motions using extragalactic sources from the first two LAMOST data releases and the Veron-Cetty & Veron Catalog of Quasars.
Beers, Timothy C.   +18 more
core   +2 more sources

TeV GAMMA RAYS: OBSERVATIONS VERSUS EXPECTATIONS & THEORY

open access: yesActa Polytechnica, 2013
The scope of this paper is to discuss two important questions relevant for TeV γ-ray astronomy; the pursuit to reveal the origin of cosmic rays in our galaxy, and the opacity of the universe in γ-rays.
Frank Krennrich
doaj   +1 more source

Probing the extragalactic fast transient sky at minute timescales with DECam [PDF]

open access: yes, 2019
Searches for optical transients are usually performed with a cadence of days to weeks, optimised for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on ...
Abbott, Timothy M. C.   +24 more
core   +3 more sources

Extragalactic Astronomy and IUE [PDF]

open access: yesHighlights of Astronomy, 1980
The first thing to say is that IUE has been a great success and we should all congratulate the agencies in the U.S.A., Europe and the U.K. and the many scientists and engineers involved in the project on making it possible. In surveying what has been achieved so far, it is important to remember that we may well have IUE with us for a further 3 or even ...
openaire   +1 more source

JADES Initial Data Release for the Hubble Ultra Deep Field: Revealing the Faint Infrared Sky with Deep JWST NIRCam Imaging

open access: yesThe Astrophysical Journal Supplement Series, 2023
JWST has revolutionized the field of extragalactic astronomy with its sensitive and high-resolution infrared view of the distant Universe. Adding to the new legacy of JWST observations, we present the first NIRCam imaging data release from the JWST ...
Marcia J. Rieke   +58 more
doaj   +1 more source

Home - About - Disclaimer - Privacy