200,541 research outputs found
Optical and near-infrared observations of the GRB 970616 error box
We report on near-infrared and optical observations of the GRB 970616 error
box and of the X-ray sources discovered by ASCA and ROSAT in the region. No
optical transient was found either within the IPN band or in the X-ray error
boxes, similarly to other bursts, and we suggest that either considerable
intrinsic absorption was present (like GRB 970828) or that the optical
transient displayed a very fast decline (like GRB 980326 and GRB 980519).Comment: 2 pages with one encapsulated PostScript figure included. Uses
Astronomy & Astrophysics LaTeX macros. Accepted for publication in Astronomy
& Astrophysics Supplement Serie
E-prints and Journal Articles in Astronomy: a Productive Co-existence
Are the e-prints (electronic preprints) from the arXiv repository being used
instead of the journal articles? In this paper we show that the e-prints have
not undermined the usage of journal papers in the astrophysics community. As
soon as the journal article is published, the astronomical community prefers to
read the journal article and the use of e-prints through the NASA Astrophysics
Data System drops to zero. This suggests that the majority of astronomers have
access to institutional subscriptions and that they choose to read the journal
article when given the choice. Within the NASA Astrophysics Data System they
are given this choice, because the e-print and the journal article are treated
equally, since both are just one click away. In other words, the e-prints have
not undermined journal use in the astrophysics community and thus currently do
not pose a financial threat to the publishers. We present readership data for
the arXiv category "astro-ph" and the 4 core journals in astronomy
(Astrophysical Journal, Astronomical Journal, Monthly Notices of the Royal
Astronomical Society and Astronomy & Astrophysics). Furthermore, we show that
the half-life (the point where the use of an article drops to half the use of a
newly published article) for an e-print is shorter than for a journal paper.
The ADS is funded by NASA Grant NNG06GG68G. arXiv receives funding from NSF
award #0404553Comment: 8 pages, 4 figures, submitted to Learned Publishin
The A&A Experience With Impact Factors
There is a widespread impression that the scientific journal "Astronomy &
Astrophysics" (A&A) has a smaller impact, as measured by citations to articles,
than some of the other major astronomy journals. This impression was apparently
supported - and probably created - by the Journal Citation Report (JCR), which
is prepared annually by the Institute of Scientific Information (ISI) Web of
Knowledge. The published poor impact factor of A&A was in fact wrong and was
due to a serious flaw in the method used by ISI Web of Knowledge to determine
it. The resulting damage inflicted upon A&A by the JCR is incalculable.Comment: 4 pages, to be published in A. Heck (ed.) "Organizations and
Strategies in Astronomy, Vol. 5" (Kluwer, 2004
Near-Earth Supernova Explosions: Evidence, Implications, and Opportunities
There is now solid experimental evidence of at least one supernova explosion within 100 pc of Earth within the last few million years, from measurements of the short-lived isotope ⁶⁰Fe in widespread deep-ocean samples, as well as in the lunar regolith and cosmic rays. This is the first established example of a specific dated astrophysical event outside the Solar System having a measurable impact on the Earth, offering new probes of stellar evolution, nuclear astrophysics, the astrophysics of the solar neighborhood, cosmic-ray sources and acceleration, multi-messenger astronomy, and astrobiology. Interdisciplinary connections reach broadly to include heliophysics, geology, and evolutionary biology. Objectives for the future include pinning down the nature and location of the established near-Earth supernova explosions, seeking evidence for others, and searching for other short-lived isotopes such as ²⁶Al and ²⁴⁴Pu. The unique information provided by geological and lunar detections of radioactive ⁶⁰Fe to assess nearby supernova explosions make now a compelling time for the astronomy community to advocate for supporting multi-disciplinary, cross-cutting research programs
The Universe on a Desktop: Observational Astronomy Simulations in the Instructional Laboratory
Though the value of hands-on learning has long been recognised by educators, it is difficult to design laboratories in astronomy classes that present realistic astrophysical techniques to undergraduate students. Unlike most other sciences, astronomy is largely observational, not experimental, and making useful observations involves expensive equipment over time scales inconvenient for pedagogy. In recent years, however, astronomy has gone almost completely digital, and the advent of large on-line databases and fast personal computers has made it possible to realistically simulate the experience of research astrophysics in the laboratory. Since 1992, Project CLEA (Contemporary Laboratory Experiences in Astronomy) has been developing computer-based exercises aimed primarily at the introductory astronomy laboratory. These exercises simulate important techniques of astronomical research using digital data and Windows-based software. Each of the nine exercises developed to date consists of software, technical guides for teachers, and student manuals for the exercises. CLEA software is used at many institutions in all the United States and over 60 countries worldwide, in a variety of settings from middle school to upper-class astronomy classes. The current design philosophy and goals of Project CLEA are discussed along with plans for future development
Frontiers of Astrophysics - Workshop Summary
We summarize recent results presented in the astrophysics session during a
conference on ``Frontiers of Contemporary Physics''. We will discuss three main
fields (High-Energy Astrophysics, Relativistic Astrophysics, and Cosmology),
where Astrophysicists are pushing the limits of our knowledge of the physics of
the universe to new frontiers. Since the highlights of early 1997 were the
first detection of a redshift and the optical and X-ray afterglows of gamma-ray
bursts, as well as the first well-documented flares of TeV-Blazars across a
large fraction of the electromagnetic spectrum, we will concentrate on these
topics. Other topics covered are black holes and relativistic jets, high-energy
cosmic rays, Neutrino-Astronomy, extragalactic magnetic fields, and
cosmological models.Comment: Proceedings of the Workshop "Frontiers in Contemporary Physics",
Nashville, May 11-16, 1997, AIP-conference series, Ed. T. Weiler & R.
Panvini, LaTex(aip2col), 13 pages, preprint also available at
http://www.astro.umd.edu/~hfalcke/publications.html#frontier
SPAN: Astronomy and astrophysics
The Space Physics Analysis Network (SPAN) is a multi-mission, correlative data comparison network which links science research and data analysis computers in the U.S., Canada, and Europe. The purpose of this document is to provide Astronomy and Astrophysics scientists, currently reachable on SPAN, with basic information and contacts for access to correlative data bases, star catalogs, and other astrophysic facilities accessible over SPAN
- …