XMM‐Newton publication statistics

We assessed the scientific productivity of XMM‐Newton by examining XMM‐Newton publications and data usage statistics. We analyse 3272 refereed papers, published until the end of 2012, that directly use XMM‐Newton data. The SAO/NASA Astrophysics Data System (ADS) was used to provide additional information on each paper including the number of citations. For each paper, the XMM‐Newton observation identifiers and instruments used to provide the scientific results were determined. The identifiers were used to access the XMM‐Newton Science Archive (XSA) to provide detailed information on the observations themselves and on the original proposals. The information obtained from these sources was then combined to allow the scientific productivity of the mission to be assessed. Since around three years after the launch of XMM‐Newton there have been around 300 refereed papers per year that directly use XMM‐Newton data. After more than 13 years in operation, this rate shows no evidence that it is decreasing. Since 2002, around 100 scientists per year become lead authors for the first time on a refereed paper which directly uses XMM‐Newton data. Each refereed XMM‐Newton paper receives around four citations per year in the first few years with a long‐term citation rate of three citations per year, more than five years after publication. About half of the articles citing XMM‐Newton articles are not primarily X‐ray observational papers. The distribution of elapsed time between observations taken under the Guest Observer programme and first article peaks at 2 years with a possible second peak at 3.25 years. Observations taken under the Target of Opportunity programme are published significantly faster, after one year on average. The fraction of science time taken until the end of 2009 that has been used in at least one article is ∼90%. Most observations were used more than once, yielding on average a factor of two in usage on available observing time per year. About 20 % of all slew observations have been used in publications. The scientific productivity of XMM‐Newton measured by the publication rate, number of new authors and citation rate, remains extremely high with no evidence that it is decreasing after more than 13 years of operations.     

Productivity and impact of astronomical facilities: A statistical study ofpublications and citations

In calendar years 2001 and 2002, 20 journals of astronomy and astrophysics published 7768 papers that reported or analyzed observations at wavelengths from meter radio to ultrahigh energy gamma rays. In the three calendar years after publication, these papers were cited more than 97 000 times, according to the Science Citation Index/Web of Science data base (the most complete, we believe, available), for an average rate of 4.19 citations per paper per year.We slice these data up several ways, by subject matter, wavelength band, and the telescopes (etc.) used. Most of the results will not surprise: There are hot topics (cosmology, exoplanets) and not so hot topics (binary stars, planetary nebulae). Papers reporting spacebased data are cited a bit more often and radio papers a bit less often than optical papers, but multi‐wavelength studies do the best. The total number of telescopes involved is surprisingly large, about 330 optical and infrared (mostly ground based but including HST), 109 radio (including COBE and VSOP satellites), and 90 space based (including satellites, interplanetary probes, things carried on rockets, balloons, the Shuttle, and so forth). The superstar telescopes are (mostly) the ones you would expect, though having the most papers does not always go with largest ratios of citations per paper. HST produces the largest number of optical papers, but SDSS the most highly‐cited ones, while the VLA is responsible for the largest number of radio papers and the most highly cited (apart from balloon‐borne CMB observatories), and among things that fly, the most recent tend to dominate both paper and citation numbers. If you have to choose, it is probably better to opt for a small telescope on a well‐supported site than a larger one with less support, and service to the community, in the form of catalogues and mission definitions, is rewarded, at least in citation counts, if not always in other ways. A few comparisons are made with other studies. The main difference is that we have included all the papers and all the telescopes for the years chosen, rather than focussing on one or a few observatories or skimming the cream of most‐cited papers or ones from the highest‐profile journals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Productivity and impact of astronomical facilities: A recent sample

The papers published in 11 key astronomical journals in 2008, and a year of citations to those from the first half of the year, have been associated with the telescopes, satellites, and so forth where the data were gathered using a form of fractional counting. Some numbers are also given by journal, by subfield, and by wavelength band. The largest numbers of papers, and generally also quite highly cited ones, in their respective wavelength bands come from the Very Large Array, the Hubble Space Telescope, the Sloan Digital Sky Survey, the Spitzer Space Telescope, and the Chandra X‐ray Telescope. Optical astronomy is still the largest sector; and papers about cosmology and exoplanets are cited more often than papers about binary stars and planetary nebulae. The authors conclude that it is of equal importance to recognize (a) that a very large number of papers also come from less famous facilities, (b) that a very large fraction of papers (and their authors) are concerned with the less highly‐cited topics, (c) that many facilities are quite slow in achieving their eventual level of influence, and (d) that one really needs at least three years of citation data, not just one or two, to provide a fair picture of what is going on (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Telescopes in the mirror of scientometrics

Counting papers and citations is one way to estimate the significance of particular astronomical telescopes and other facilities in the long time gap between the verdict of history and the referee’s report on your most recent proposal. This has been done for 2,184 observational astronomy papers published between 1960 and 1964 (with 14,237 citations in 1965–1969) and the numbers looked at in various ways. The extreme dominance of California in optical astronomy and of the UK and Australia in radio astronomy provides the background against which ESO, NOAO, NRAO, and A&A were founded, with equality of access to facilities having increased enormously in the intervening 40 years, but inequality of results having increased slightly. A number of other factoids about astronomical publications, the community, and their environments surfaced during the counting process, and a subset reported here, including a few pertaining to the more distant past.     

An anomalous journal impact factor

The impact factor (average number of citations per paper) for the Astrophysical Journal Supplement Series jumped between 2003 and 2004 from 6.247 to 15.231, giving it the world's second highest impact factor for an astronomical journal in 2004. Was this change due to a computing error or to an unusual occurrence? It is shown that it was due to the extremely high citation rates (average of 160 citations per year) for 13 papers in the special issue devoted to the WilkinsonMicrowave Anisotropy Probe. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Ernst Julius Öpik's (1916) note on the theory of explosion cratering on the Moon's surface—The complex case of a long‐overlooked benchmark paper

High‐velocity impact as a common phenomenon in planetary evolution was ignored until well into the twentieth century, mostly because of inadequate understanding of cratering processes. An eight‐page note, published in Russian by the young Ernst Julius Öpik, a great Estonian astronomer, was among the key selenological papers, but due to the language barrier, it was barely known and mostly incorrectly cited. This particular paper is here intended to serve as an explanatory supplement to an English translation of Öpik's article, but also to document an early stage in our understanding of cratering. First, we outline the historical–biographical background of this benchmark paper, and second, a comprehensive discussion of its merits is presented, from past and present perspectives alike. In his theoretical research, Öpik analyzed the explosive formation of craters numerically, albeit in a very simple way. For the first time, he approximated relationships among minimal meteorite size, impact energy, and crater diameter; this scaling focused solely on the gravitational energy of excavating the crater (a “useful” working approach). This initial physical model, with a rational mechanical basis, was developed in a series of papers up to 1961. Öpik should certainly be viewed as the founder of the numerical simulation approach in planetary sciences. In addition, the present note also briefly describes Nikolai A. Morozov as a remarkable man, a forgotten Russian scientist and, surprisingly, the true initiator of Öpik's explosive impact theory. In fact, already between 1909 and 1911, Morozov probably was the first to consider conclusively that explosion craters would be circular, bowl‐shaped depressions even when formed under different impact angles.     

上海天文台天体物理研究室近10年科学论文产出及其分析

对我台天体物理研究室 1992 - 2 0 0 1年期间科学论文产出情况进行了定量统计和分析 ,对已发表的论文总数、国内外SCI论文数、学报及台刊 (包括会议集等 )文章、青年作者论文数及论文引用情况的变化 ,分类归纳并进行讨论。结果表明该研究室科学论文产出的数量和质量逐年提高 ,并已形成了一支以青年天文工作者为主的天体物理基础研究队伍     

Cover

Fragments of the Sutter's Mill meteorite fall collected by NASA Ames and SETI Institute meteor astronomer Dr. Peter Jenniskens in the evening of Tuesday April 24, 2012, two days after the fall, before rain hit the area. Given the number SM2, these fragments were found in Henningsen‐Lotus Park (38.8029 N, 120.9085 E), one of 78 reported fi nds from this fall. Photo: NASA/Eric James..     

Presence of an iron‐rich nanophase material in the upper layer of the Cretaceous‐Tertiary boundary clay

Abstract— We report new geochemical evidence from ten Cretaceous‐Tertiary (K‐T) boundary sites in North America and Europe, indicating the presence of a material remnant of a large asteroid or comet that struck the Earth at 65.0 Ma. Mössbauer spectroscopic data reveals that a ubiquitous iron‐rich nanophase material exists at the uppermost part of the K‐T boundary layer in the Western Hemisphere and in Europe in marine and continental fine‐grained sedimentary rock. The high surface‐to‐volume ratio of nanophase material suggests that it may be the carrier of the iridium abundance enhancement that marks the K‐T boundary. Even more provocative is the possibility that the discovered nanophase material is, for the most part, composed of the vaporized impactor after the impact‐generated high‐temperature vapor plume rose and cooled above the atmosphere.     

光污染和光学天文台址保护

讨论了天光背景对光学天文台的背景，综述了造成光污染的主要途径，介绍了防止光污染的几个主要国际组织和国际上对天文台址的保护立法，提出了减少污染的主要措施。为国内进行光学天文台址保护采取措施以至（国家的或者地方的）立法提供参考。     

第24届国际天文学联合会大会简况

2000年8月7－18日在英国曼彻斯特如开了第24届国际天这联合会（IAU）大会，会议期间同时召开了5个学术讨论会，14个联合组讨论会，一个发展中国家天文学的专门讲座会和34个专业委员会及其所属工作组的工作会义，还在第29和第45专业委员会之间的联组会议以及三个大会邀请的科普讲座。简要介绍了会议概况，有关天体测量的联组讨论会JD2，JD6，JD12，JD13以及天体物理领域中的学术讨论会S201，S202，JD10等的讨论情况，并扼要介绍了这次大会通过的决议。     

Astrotomography

Even in the new millenium, many astronomical objects cannot be resolved spatially with any available telescope. Most stars are too small and galaxies are too far away to be imaged directly or in detail in the foreseeable future. However, advances in data‐analysis techniques allow us now to create detailed indirect images using tomographic methods. These images provide unprecedented insights into fundamental processes that drive the evolution of stars and galaxies, such as accretion and magnetic‐field generation, on length scales that are of great physical importance but which are otherwise inaccessible. Here we present a collection of papers on recent progress in astrotomography, all of which were presented at Joint Discussion 09 of the XXV General Assembly of the IAU in Sydney, during July 2003. The online edition of the journal contains several illustrative movies for free download. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

行星天文学的重要地位及其热点

对1995年至2001年《Natue》和《Science》上发表的天文学论文的统计表明，行星天文学领域的论文数量明显超过天文学的其它分支学科，占天文学总论文数的1/3左右。从这个角度来看，行星天文学是天文学最活跃和重要的分支学科之一。对这些论文具体内容的分析可以给出当前行星天文学领域的若干热点问题。相比之下，我国对这一重要领域的关注和投入还远远不够。     

New emission-line galaxies identified from an objective prism survey

As a part of an ongoing objective prism survey, 107 emission line galaxy candidates have been identified from three selected fields. We present a preliminary analysis of some of them based on spectroscopic observations with moderate spectral resolution and CCD images. From these data the nature of the observed objects is discussed. In almost all the cases the candidates emerge as star-burst nuclei. The four sample objects which have been also detected by IRAS follow the IR-H luminosity relationship observed in extragalacticHII regions.Paper presented at the 11th European Regional Astronomical meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The Citation Impact of Digital Preprint Archives for Solar Physics Papers

Papers that are posted to a digital preprint archive are typically cited twice as often as papers that are not posted. This has been demonstrated for papers published in a wide variety of journals, and in many different subfields of astronomy. Most astronomers now use the arXiv.org server (astro-ph) to distribute preprints, but the solar physics community has an independent archive hosted at Montana State University. For several samples of solar physics papers published in 2003, I quantify the boost in citation rates for preprints posted to each of these servers. I show that papers on the MSU archive typically have citation rates 1.7 times higher than the average of similar papers that are not posted as preprints, while those posted to astro-ph get 2.6 times the average. A comparable boost is found for papers published in conference proceedings, suggesting that the higher citation rates are not the result of self-selection of above-average papers. Editors’ Note: This paper lies outside the normal purview of Solar Physics papers, however the editors feel that the content is of sufficient importance for all Solar Physics authors and readers to merit its publication.     

FLAIR observations of planetary nebulae in the Large Magellanic Cloud

This paper presents new observations of 97 planetary nebulae in the Large Magellanic Cloud (LMC) obtained using the FLAIR system on the UK 1.2-m Schmidt Telescope. These nebulae are mostly at the fainter end of the known population, and about 75 per cent have not been observed before in spectroscopic mode. Radial velocities have been measured using cross-correlation techniques, and represent an increase of 66 per cent in the sample of LMC planetary nebulae with known radial velocities. The major line ratios are given, and are analysed in conjunction with published data. One-quarter of the faint nebulae are Type I objects with very strong [N II ] and [S II ] lines; most of the other faint nebulae have low density, low excitation and relatively strong [S II ] lines.     

An Overview of the Veritas Prototype Telescope and Camera

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is the next-generation ground-based gamma-ray observatory that is being built in southern Arizona by a collaboration of 10 institutions in Canada, Ireland, the UK and the USA. VERITAS is designed to operate in the range from 50 GeV to 50 TeV with optimal sensitivity near 200 GeV; it will effectively overlap with the next generation of space-based gamma-ray telescopes. The first phase of VERITAS, consisting of four telescopes of 12 m aperture, will be operational by the time of the GLAST launch in 2007. Eventually, the array will be expanded to include the full array of seven telescopes on a filled hexagonal grid of side 80 m. A prototype VERITAS telescope with a reduced number of mirrors and signal channels has been built. Its design and performance is described here. The prototype is scheduled to be upgraded to a full 499 pixel camera with 350 mirrors during the autumn of 2004. The VERITAS collaboration consists of universities and institutions from Ireland, UK, USA and Canada. See for a full listing.     

Variable Star Signature Classification using Slotted Symbolic Markov Modeling

With the advent of digital astronomy, new benefits and new challenges have been presented to the modern day astronomer. No longer can the astronomer rely on manual processing, instead the profession as a whole has begun to adopt more advanced computational means. This paper focuses on the construction and application of a novel time-domain signature extraction methodology and the development of a supporting supervised pattern classification algorithm for the identification of variable stars. A methodology for the reduction of stellar variable observations (time-domain data) into a novel feature space representation is introduced. The methodology presented will be referred to as Slotted Symbolic Markov Modeling (SSMM) and has a number of advantages which will be demonstrated to be beneficial; specifically to the supervised classification of stellar variables. It will be shown that the methodology outperformed a baseline standard methodology on a standardized set of stellar light curve data. The performance on a set of data derived from the LINEAR dataset will also be shown.