Bulletin of the American Astronomical Society最新文献_第5页

Obituary: Earle B. Mayfield (1923-2007) 讣告:厄尔·b·梅菲尔德(1923-2007)

Bulletin of the American Astronomical Society Pub Date : 2011-01-01 DOI: 10.3847/BAASOBIT2011018

Gary Chapman

引用次数: 0

Dynamics of Jupiter's Atmosphere 木星大气动力学

Bulletin of the American Astronomical Society Pub Date : 1998-01-01 DOI: 10.1007/978-94-011-4778-1_134

A. Ingersoll, A. Vasavada

引用次数: 115

The effect of velocity gradients on Cepheid spectra: models. 速度梯度对造父变星光谱的影响:模型。

Bulletin of the American Astronomical Society Pub Date : 1995-12-01 DOI: 10.1086/177064

R. Paul Butler, Roger A. Bell, R. Hindsley

引用次数: 20

Map-based trigonometric parallaxes of open clusters: Coma 基于地图的疏散星团三角视差:彗差

Bulletin of the American Astronomical Society Pub Date : 1995-06-01 DOI: 10.1086/175733

G. Gatewood

{"title":"Map-based trigonometric parallaxes of open clusters: Coma","authors":"G. Gatewood","doi":"10.1086/175733","DOIUrl":"https://doi.org/10.1086/175733","url":null,"abstract":"This is the fourth study in a series to determine the direct trigonometric parallaxes of four of the nearest open star clusters, the Hyades, the Pleiades, the Praesepe, and the nearby cluster in Coma (Gatewood et al. 1990; Gatewood et al. 1992); Gatewood & Kiewiet de Jonge 1994). The results for the open star cluster in Coma are compared with those of the other three clusters, and the members are found to be significantly subluminous. The trigonometric parallax of the cluster is estimated from that of three members studied with the Multichannel Astrometric Photometer (MAP) at the Thaw Refractor of the University of Pittsburgh's Allegheny Observatory. The weighted mean parallax of the cluster is +13.53 +/- 0.54 mass (0.00054 min), corresponding to a distance modulus of 4.34 +/- 0.09 mag. The U-B excess of the Coma cluster members may be used to adjust the observed absolute magnitudes and the B-V measurements as suggested by Sandage & Eggen (1959). The agreement obtained in this manner suggests that, like subdwarf stars, the stars of the Coma cluster appear subluminous because of line blanketing. One of the three members observed in this study was recognized as a member by its parallax and is the faintest known member of the cluster.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"80 1","pages":"1330"},"PeriodicalIF":0.0,"publicationDate":"1995-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83952163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Precision Vs. Accuracy in Star Catalogs 星表中的精确与精确

Bulletin of the American Astronomical Society Pub Date : 1995-01-01 DOI: 10.1007/978-94-011-0069-4_81

L. Taff, J. Morrison, R. Smart

引用次数: 0

High-redshift radio galaxies 高红移射电星系

Bulletin of the American Astronomical Society Pub Date : 1995-01-01 DOI: 10.1007/BFB0102579

G. Miley

引用次数: 0

THE DISCOVERY OF THE BINARY PULSAR 双星脉冲星的发现

Bulletin of the American Astronomical Society Pub Date : 1994-07-01 DOI: 10.1103/revmodphys.66.699

R. Hulse, R. Hulse

引用次数: 113

A kinematic search for supernova remnants in giant extragalactic H II regions 在巨大的河外H II区对超新星残骸的运动学搜索

Bulletin of the American Astronomical Society Pub Date : 1994-02-01 DOI: 10.1086/116885

Hui Yang, E. Skillman, R. Sramek

{"title":"A kinematic search for supernova remnants in giant extragalactic H II regions","authors":"Hui Yang, E. Skillman, R. Sramek","doi":"10.1086/116885","DOIUrl":"https://doi.org/10.1086/116885","url":null,"abstract":"We have obtained velocity fields of the Giant H II complexes NGC 5471 in M101, NGC 2363 in NGC 2366, and the largest H II region in NGC 2403 from H-alpha observations using the TAURUS imaging Fabry-Perot interferometer. We have detected five H-alpha sources with velocity profiles which are broad when compared with the surrounding H II region. Region B in NGC 5471 has been previously determined to contain a supernova remnant by the presence of nonthermal radio continuum radiation and enhanced (O I) and (S II) emission (Skillman 1985) and broad H-alpha emission (Chu & Kennicutt 1986). Two broad H-alpha sources in NGC 2363 coincide with regions where strong splitting has been found in the (O III) line (Roy et al. 1991). Two more broad H-alpha sources have been identified in the largest H II region in NGC 2403. Very Large Array (VLA) radio continuum observations with a resolution of 2 sec at lambda(6) and lambda(20) cm of all 3 H II complexes are presented. In addition, high resolution (subarcsecond) VLA images of NGC 5471 were made at lambda(2) and lambda(6) cm. The presence of a nonthermal source in region NGC 5471 B was confirmed while region NGC 5471 A appears to be dominated by thermal emission. The nonthermal spectral index in NGC 2363 A indicates the existence of none or more supernova remnants at the position of a large velocity width source detected in H-alpha emission. No similar nonthermal sources were detected in NGC 2403 #1. Supernovae explosions and stellar winds are considered as causes for these large velocity width sources (LVWS). If the emission from the LVWSs is attributed to single supernova remnants, they are unusually luminous in both nonthermal radio continuum and H-alpha emision. The very large H-alpha luminosities could be a result of high velocity gas being ionized by the neighboring stellar cluster.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"86 1","pages":"1410"},"PeriodicalIF":0.0,"publicationDate":"1994-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78098531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Elemental abundances of the supernova remnant G292.0+1.8: evidence for a massive progenitor 超新星遗迹G292.0+1.8的元素丰度:大质量祖先的证据

Bulletin of the American Astronomical Society Pub Date : 1994-02-01 DOI: 10.1086/173710

J. Hughes, K. P. Singh

{"title":"Elemental abundances of the supernova remnant G292.0+1.8: evidence for a massive progenitor","authors":"J. Hughes, K. P. Singh","doi":"10.1086/173710","DOIUrl":"https://doi.org/10.1086/173710","url":null,"abstract":"We present a comprehensive nonequilibrium ionization (NEI) analysis of X-ray spectral data from the Einstein Observatory and EXOSAT for the supernova remnant G292.0+1.8. The spectra are well described by a single-temperature, single-timescale NEI model with kT = 1.64(sub -0.19)(sup +0.29) keV and n(sub e)t = (5.55(sub -1.12)(sup +1.2) x 10(exp 10)s/cu cm, which establishes that this remnant is indeed young and in the ionizing phase of evolution of its X-ray spectrum. We determine the abundances of the elements O, Ne, Mg, Si, S, Ar, and Fe and examine their variation over the allowed range of column density, kT, and n(sub e)t. Numerical calculations of the nucleosynthesis expected for a 25 solar mass progenitor agree best with the fitted abundances; in fact the minimum rms percent difference between this model and the derived abundances is only 15%. From the fitted emission measure and a simple geometric model of the remnant we estimate the mass of X-ray-emitting plasma to be 9.3(sub -6.2)(sup +1.19) solar mass, for an assumed distance of 4.8 +/- 1.6 kpc. Additional errors on this mass estimate, from clumping of the ejecta, for example, may be substantial. No evidence was found for a difference in the thermodynamic state of the plasma as a function of elemental composition based on analysis of the individual ionization timescales of the various species. In this sense then, G292.0+1.8 resembles the remnant Cas A (another product of a massive star supernova), while it is different from the remnants of SN 1572 (Tycho) and SN 1006, both of which are believed to be from Type Ia supernovae.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"36 1","pages":"918"},"PeriodicalIF":0.0,"publicationDate":"1994-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90706277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 44

The Ages of Elliptical Galaxies 椭圆星系的时代

Bulletin of the American Astronomical Society Pub Date : 1994-01-01 DOI: 10.1007/978-94-011-0752-5_34

R. O’Connell

引用次数: 6