Results 21 to 30 of about 57,383 (218)
Discovery of Pulsed OH Maser Emission Stimulated by a Pulsar [PDF]
, 2005 Stimulated emission of radiation has not been directly observed in astrophysical situations up to this time. Here we demonstrate that photons from pulsar B1641-45 stimulate pulses of excess 1720 MHz line emission in an interstellar OH cloud.
Johnston, Simon +3 more
core +4 more sources
δ Orionis: Further temporal variability and evidence for small-scale structure in the interstellar medium [PDF]
, 2001 We report here the detection of both spatial and temporal variations in interstellar absorption in the line of sight to δ Orionis. First, we present new high-resolution (R≈110 000) observations of the interstellar D lines of Na i towards both δ Ori A and
Crawford, IA, Howarth, ID, Price, RJ
core +1 more source
Interstellar Matter Structure along the Line of Sight to Cyg X-1
Open Astronomy, 2015 High-resolution spectra (R = 60 000) of Cyg X-1 = V1357 Cyg obtained with the NES echelle spectrograph of the Russian 6 meter telescope (3950–6690 Å) were used to study narrow interstellar absorption lines.
Bochkarev N. G. +3 more
doaj +1 more source
Interstellar absorption lines toward gamma Arae
The Astrophysical Journal, 1975 The available data on interstellar absorption lines in the spectrum of gamma Ara observed from the ground and with the Copernicus telescope have been analyzed to give column densities of various ion stages of H, C, N, O, Na, Mg, Si, P, S, Ar, Ca, Mn, and Fe.
D. C. Morton, E. M. Hu
openaire +1 more source
BD-22 3467, a DAO-type star exciting the nebula Abell 35 [PDF]
, 2012 Spectral analyses of hot, compact stars with NLTE (non-local thermodynamical equilibrium) model-atmosphere techniques allow the precise determination of photospheric parameters.
Koeppen, J. +4 more
core +1 more source
New 3-D gas density maps of NaI and CaII interstellar absorption within 300pc [PDF]
, 2009 We present new high resolution (R>50,000) absorption measurements of the NaI doublet (5889 - 5895A) along 482 nearby sight-lines, in addition to 807 new measurements of the CaII K (3933A) absorption line.
Lallement, Rosine +3 more
core +7 more sources
The Astrophysical Journal, 2023 Molecules and particles make up ∼40%–70% of carbon in the interstellar medium, yet the exact chemical structure of these constituents remains unknown. We present carbon K-shell absorption spectroscopy of the Galactic interstellar medium obtained with the
John Staunton, Frits Paerels
doaj +1 more source
A survey of ultraviolet interstellar absorption lines
The Astrophysical Journal Supplement Series, 1983 A telescope-spectrometer on the Copernicus spacecraft made possible the measurement of many ultraviolet absorption lines produced by the interstellar gas. The present survey provides data on ultraviolet absorption lines in the spectra of 88 early-type stars.
R. C. Bohlin +6 more
openaire +1 more source
X‐Ray Absorption Line Spectroscopy of the Galactic Hot Interstellar Medium [PDF]
The Astrophysical Journal, 2005 This is the pre-published version harvested from ArXiv. The published version is located at http://iopscience.iop.org/0004-637X/624/2/751/
Yao, Y, Wang, QD
openaire +3 more sources
Modelling ultraviolet-line diagnostics of stars, the ionized and the neutral interstellar medium in star-forming galaxies [PDF]
, 2017 We combine state-of-the-art models for the production of stellar radiation and its transfer through the interstellar medium (ISM) to investigate ultraviolet-line diagnostics of stars, the ionized and the neutral ISM in star-forming galaxies.
Bruzual, G. +3 more
core +2 more sources