高频射电源中的类星体

研究表明，高频射电源与低频射电源相比，前者中的类星体比例更大。３ＣＲ低频射电源（Ｓ１７８ＭＨｚ＞９Ｊｙ）中有１７．８％是类星体，而在２．７ＧＨｚ亮射电源样本中（Ｓ２．７ＧＨｚ≥２．０Ｊｙ），有３５．６％是类星体。更有趣的是，５１８个５ＧＨｚ亮射电源中（Ｓ５ＧＨｚ≥１．０Ｊｙ），至少有２９１个（≥５６％）是类星体。因此，我们认为高频亮射电源的证认是发现类星体的有效手段。     

贫金属星的重元素丰度Ⅱ.细致的光谱分析

本文确定了贫金属矮星和亚巨星的重元素丰度，基于高分辨率高信噪比光谱得到２７颗样本星的锶，钇，锆，钡，镧，铈和铕丰度，主要结果为：（１）第一峰区元素锶－钇－锆显示了奇偶效应，在晕族星中钇相对于锶和锆过贫。（２）对［Ｆｅ／Ｈ］＞－２．５的恒星钇丰度为常数。（３）［Ｆｅ／Ｈ］＜１．７的样本星，随金属丰度减小钡过贫增加。（４）镧和铈相对于铁过贫。（５）在金属丰度－１．０＞［Ｆｅ／Ｈ］＞－２．０区间，铕表现     

10颗近赤道弱源MK2VLBI观测结果

本文给出利用中国、意大利、南非射电望远镜对一个近赤道源样本在５ＧＨｚ频率上进行ＭＫ２ＶＬＢＩ普测中１０颗弱源的相关流量和其中部分源用ＨａｒｔＲＡＯ望远镜观测的总流量值，作为进一步的ＭＫ３或ＶＬＢＡ记录系统的ＶＬＢＩ观测依据．     

两个底片天区的依巴谷星自行

利用上海天文台佘山４０ 厘米折射望远镜拍摄的２ 个底片天区１５ 张照相底片上的３１ 次观测,以ＡＣＴ 星表作为初始参考星表,按中心重叠法进行归算处理,得到了１６ 颗依巴谷星和３８ 颗场星的高精度位置和自行结果,其中依巴谷星的赤经和赤纬标准误差的平均值分别为１０ ．５ ｍａｓ 和７ ．５ ｍａｓ,赤经自行和赤纬自行标准误差的平均值分别为０ ．７０ ｍａｓ／ｙｒ 和０ ．５９ ｍａｓ／ｙｒ     

盾牌座δ型变星4CVn的多重非径向脉动振幅变化

对非径向脉动δＳｃｕｔｉ（盾牌座δ）型变星４ＣＶｎ的最新光电测光观测，证实了其振幅和周期的长期缓慢变化．两种多重频率分析方法都一致确认出已知７个频率中的５个（ｆ１，ｆ２，ｆ３，ｆ５，ｆ７）．观测还发现三个可疑频率．目前主频的振幅和十几年前的一样，基本保持不变，可能正处于向最大振幅变化的增加阶段或者处于刚过极大的下降段．其它四个频率的振幅都不同程度地变大．ｆ２，ｆ３和ｆ５的振幅增幅分别为６３％，２５％和１２０％，尤其是ｆ７，从上次的０变为０．００９ｍａｇ．频率分析显示除主频ｆ１几乎未变外，其它频率缓慢变化：ｆ２和ｆ７约减小０．０８％；ｆ３减小０．１４％；ｆ５增加０．０３％．用Ｂｌａｚｈｋｏ效应和不同非径向脉动模式之间的共振解释振幅和周期变化的合理性，尚需进一步从观测上检验．     

恒星形成区NGC7538中的分子氢发射

报告在ＮＧＣ７５３８中利用Ｈ２（２．１２μｍ）发射线测新发现的两个喷流和１８个近红外ＨＨ天体,在ＩＲＳ１－３星云中观测到了强Ｈ２发射壳层结构环绕在星云的北边。星云中红外源的ＵＶ辐射场的外流活动都可能导致这一Ｈ２发射。在ＨＲＳ１－３星云的南边和东边探测到了５个Ｈ２ｋｎｏｔｓ．在ＩＲＳ１南边发现的Ｈ２喷流暗示该区域有一个南北向的外流,在ＩＲＳ１１星团的周围发现了９个Ｈ２ｈｎｏｔｓ．在西北－东南方向和东     

北京天文台发现新的BL型天体和类星体

今年５月２８～３１日,北京天文台的两个天文学家小组在兴隆观测站用２１６米望远镜对从密云２３２ＭＨｚ巡天源表精选的１８个光谱源进行观测,获得了它们的低色散光谱。证认出５个蝎虎座ＢＬ型天体和类星体。其中３个蝎虎座ＢＬ型天体和５个类星体属于世界上首次发现...     

一次特大微波IV型爆发事件的分析研究

云南天文台快速采样射电望远镜（１．４２ＧＨｚ，２．８４ＧＨｚ，４．００ＧＨｚ）于１９８８年１２月１６日观测到一次特大微波ＩＶ型爆发。爆发从世界时０８＾ｈ３１＾ｍ结束。在７０分钟的持续期内，爆发出现了五个主峰段，呈现出１２．５分钟的长周期振荡和１．２分钟的短周期振荡。其中两个频率上出现了丰富的快速精细结构。根据爆发源区的扭斜磁场位形，本文提出振荡是ＭＨＤ调制磁流管的磁场强度产生的，爆发是高能电子在磁     

8个ROSAT X射线源和5G射电源被证认为类星体

１９９５年５月，使用２．１６ｍ望远镜对ＲＯＳＡＴ Ｘ射线源进行光学证认期间，发现８个ＲＯＳＡＴ Ｘ射线源和５Ｇ射电源的光学对应体是以前未发现的类星体，其红移范围从０．３３３至１．０９１。本文给出了这些类星体的多波段特性。     

乌鲁木齐天文站25m天线18cm脉冲星脉冲到达时间观测系统

脉冲星脉冲到达时间观测系统建立在２５ｍ射电天线的１８ｃｍ波段上,消色散采用了２ｘ１２８ｘ２．５ＭＨｚ多通过滤波器和数字化器,数据采集系统由ＰＣ机完成．１９９９年５月至６月间建立了基于常温接收机的到达时间观测系统．观测到的最弱源的平均流量密度为４ｍＪｙ．     

Eléments Orbitaux de cinq Etoiles Doubles Visuelles

We have calculated the orbital elements, the dynamical parallax, and the total mass of the binary stars ADS 1615, 3341, 3472, 3573, and 5464.     

Analysis of a sample of RC catalog objects in the region overlapping with the areas covered by FIRST and SDSS surveys. II: Optical identification with the SDSS survey and USNO-B1 and 2MASS catalogs

We report the results of optical identification of a sample of RC catalog radio sources with the FIRST and SDSS surveys. For 320 sources identified with NVSS and FIRST objects we perform optical identification with the SDSS survey. When selecting optical candidates we make maximum use of the information about the structure of radio sources as provided by the FIRST survey images. We find optical candidates for about 70% of all radio sources.     

Identification of emission sources of umbral flashes using phase congruency

The emission sources of umbral flashes(UFs) are believed to be closely related to running umbral and penumbral waves,and are concluded to be associated with umbral dots in the solar photosphere. Accurate identification of emission sources of UFs is crucial for investigating these physical phenomena and their inherent relationships. A relatively novel model of shape perception,namely phase congruency(PC),uses phase information in the Fourier domain to identify the geometrical shape of the region of interest in different intensity levels,rather than intensity or gradient.Previous studies indicate that the model is suitable for identifying features with low contrast and low luminance. In the present paper,we applied the PC model to identify the emission sources of UFs and to locate their positions. For illustrating the high performance of our proposed method,two time sequences of Ca II H images derived from the Hinode/SOT on 2010 August 10 and 2013 August 20 were used. Furthermore,we also compared these results with the analysis results that are identified by the traditional/classical identification methods,including the gray-scale adjusted technique and the running difference technique. The result of our analysis demonstrates that our proposed method is more accurate and effective than the traditional identification methods when applied to identifying the emission sources of UFs and to locating their positions.     

Spectroscopic and photometric observations of unidentified ultraviolet variable objects in the GUVV-2 Catalog

An NUV-optical diagram composed from sources from the second Galaxy Evolution Explorer(GALEX) Ultraviolet Variability(GUVV-2) Catalog provides us with a method to tentatively classify the unknown GUVV-2 sources by their NUV-optical magnitudes.For the purpose of testing the correctness and generality of the method,we carry out a program on the spectroscopic observations of the unidentified GUVV-2 sources.The spectroscopic identification of these 37 sources are 19 type-A to-F stars,10 type-G to-K stars and 7 ...     

Radio and optical identification of giant radio galaxies from NVSS radio survey

We investigate giant radio galaxy candidates that were selected based on the components cataloged as separate sources in the NVSS survey. The radio and optical identification is done for fifty radio galaxies using the CATS, NED, and SkyView databases.     

OH/IR脉泽源的空间运动

本文在“OH/IR脉泽源的空间分布和光度函数”一文的基础上,对其所用的127个已有光学或红外证认的OH脉泽源的空间运动特性进行了分析,找到各类OH/IR脉泽源的视向速度与银河系较差自转运动的偏离以及各种速度分离下源的运动特点,同时利用文[1]所得的已证认OH/IR源的空间真实密度分布,导出了它们的速度分布模型N(l,v)。对与新证认的非IRC红外源(通常是在更长波长上观测到的)成协的OH/IR源发现有一以银心为心的约为50km/s的径向膨胀运动。文章最后对已证认和未证认的OH/IR脉泽源的差别和联系进行了讨论。     

Asteroid Confusions with Extremely Large Telescopes

Asteroids can be considered as sources of contamination of point sources and also sources of confusion noise, depending whether their presence is detected in the image or their flux is under the detection limit. We estimate that at low ecliptic latitudes, ≈10,000–20,000 asteroids/sq. degree will be detected with an E-ELT like telescope, while by the end of Spitzer and Herschel missions, infrared space observatories will provide ≈100,000 serendipitous asteroid detections. The detection and identification of asteroids is therefore an important step in survey astronomy.     

Radio identification of decameter-wave sources. II: The 30°< <Emphasis Type="Italic">δ</Emphasis> <40° declination interval

This paper is dedicated to the identification of decameter-wave sources of the UTR catalog within declination interval 30°< δ <40°. UTR sources are cross-identified with CATS database catalogs within 40′ × 40′ error boxes. The sources are deblended using the data on the coordinates of the objects and the behavior of their continuum radio spectra. The spectra of 875 sources are derived and fitted by standard analytical functions. Of these sources, 221 objects have straight-line spectra with spectral indices α < ?1.0. All objects are catalogued and stored in the CATS database.     

A deep radio survey in the ISO-ELAIS fields: optical identification with the APM catalogue/atl>

The optical identification programme is presented for a complete sample of 867 radio sources that were observed with the Very Large Array (VLA) within 4.22 deg² to S _{1.4 GHz} ≥ 0.135 mJy (5 σ). The area covered by the VLA survey is part of the regions of the sky that have been surveyed in the mid and far Infrared over the wavelength range 6.7–175 μmwith ISO as part of the European Large Area ISO Survey (ELAIS). Optical identifications are made using the Automatic Plate-measuring Machine (APM) optical catalogue in E (∼ R) and O (∼ B) bands with approximate limiting magnitudes of ∼ 20.0 and 21.5 mag, respectively. For 220 out of the 867 radio sources, likely identifications are proposed with an a posteriori identification percentage of 25%. The sample of identification has a reliability of 96% and a completeness of 80%. This revised version was published online in July 2006 with corrections to the Cover Date.     

Periodicity Search in the X-ray Data of RX J0007.0+7302

Some unidentified EGRET sources have been reported to have probable X-ray counterparts. Periodicities in the X-ray data of those sources, if found, may help to strengthen the identification and to reveal their nature. We performed a detailed search of periodicities with a photon-counting method, the H-test, in the XMM and ASCA data of RX J0007.0+7302, which is the most probable X-ray counterpart to the EGRET source 3EG J0010+7309. Although no periods with enough significance were found, a possible one, at 0.1275433± 0.0000001 s (MJD 52327.03399), is quite intriguing based on results of cross-checking the two data sets. We suggest future analysis with other data to search the vicinity of this period.