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1.
1997－1998年期间,使用2．16m望远镜对ROSATX射线源进行光学证认,证认出4个ROSATX射线源是新发现的类星体,2个ROSATX射线源是新发现的赛弗特星系． 相似文献
2.
We present results of optical identifications of six hard X-ray sources from the INTEGRAL and Swift all-sky surveys (IGR J03249+4041,
SWIFT J1449.5+8602, SWIFT J1542.0-1410, IGR J17009+3559, IGR J18151-1052, IGR J18538-0102). Our optical observations were
performed in 2009–2011 with the 6-m BTA telescope (Special Astrophysical Observatory, Nizhnii Arkhyz, Russia) and the 1.5-m
RTT-150 telescope (Turkish National Observatory, Antalya, Turkey). The optical spectra obtained for each of the program sources
have allowed us to establish the nature of the objects and to measure their redshifts from the positions of emission and absorption
lines. Five sources are shown to be extragalactic—four of them are identified with Seyfert 1 or 2 galaxies and the fifth source
belongs to the class of X-ray-bright, optically normal galaxies (XBONGs). The sixth object (IGR J18151-1052) is located in
our Galaxy and is an X-ray binary (XRB), a suspected cataclysmic variable. Apart from the optical spectra, we provide the
X-ray spectra for five sources in the 0.6–10 keV energy band obtained from XRT/Swift data. 相似文献
3.
Observations of the X-ray pulsar Vela X-1 with the ART-P telescope onboard the Granat Observatory are presented. Variability on a time scale of several thousand seconds was detected; intensity variations are shown to be accompanied by changes in the source’s spectrum. The hardness was also found to be highly variable on a scale of one pulsation period. The source’s spectrum exhibits an absorption feature at energy ～7 keV, which is apparently attributable to cyclotron scattering/absorption in the neutron-star magnetic field. Weak persistent emission was detected during an X-ray eclipse, which probably resulted from the scattering of pulsar emission in the stellar wind from an optical star. 相似文献
4.
利用北京天文台具有ＣＣＤ终端的６０ｃｍ光学望远镜（Ｖ波段）观测射电源的光学对应体，得到了０７１６＋７１４和０８３９＋１８７精确的光学位置。参考星表采用拉帕尔玛（ＬａＰａｌｍａ）的１８ｃｍ全自动子午环观测资料编制的ＣＡＭＣ星表，该星表是ＦＫ５星表系统。两颗源位置的内符精度约为０．″１９，与其他作者给出的光学和射电位置观测结果分别进行了比较 相似文献
5.
V. L. Afanasiev S. N. Dodonov A. V. Moiseev V. Chavushyan R. Mujica Y. Juarez A. G. Gorshkov V. K. Konnikova M. G. Mingaliev 《Astronomy Letters》2003,29(9):579-586
We present the classification of optical identifications and radio spectra of six radio sources from a complete (in flux density) sample in the declination range 10° to 12°30′ (J2000.0). The observations were carried out with the 6-m Special Astrophysical Observatory telescope (Russia) in the wavelength range 3600–10000 Å, the 2.1-m GHAO telescope (Mexico) in the range 4200–9000 Å, and the RATAN-600 radio telescope in the frequency range 0.97–21.7 GHz. Three of the six objects under study are classified as quasars, one is a BL Lac object, one is an absorption-line radio galaxy, and one is an emission-line radio galaxy. Five objects have flat radio spectra, and one object has a power-law radio spectrum. All of the radio sources identified as quasars or BL Lac objects show variable radio flux densities. The spectra of three objects were separated into extended and compact components. 相似文献
6.
We present the results of optical spectroscopy for 19 quasar candidates at photometric redshifts z phot ? 3, 18 of which enter into the Khorunzhev et al. (2016) catalog (K16). This is a catalog of quasar candidates and known type 1 quasars selected among the X-ray sources of the 3XMM-DR4 catalog of the XMM-Newton serendipitous survey. We have performed spectroscopy for a quasi-random sample of new candidates at the 1.6-m AZT-33IK telescope of the Sayan Solar Observatory and the 6-m BTA telescope of the Special Astrophysical Observatory. The spectra at AZT-33IK were taken with the new low- and medium-resolution ADAM spectrograph that was produced and installed on the telescope in 2015. Fourteen of the 18 candidates actually have turned out to be quasars; 10 of them are at spectroscopic redshifts z spec > 3. The high purity of the sample of new candidates suggests that the purity of the entire K16 catalog of quasars is probably 70–80%. One of the most distant (z spec = 5.08) optically bright (i′ ? 21) quasars ever detected in X-ray surveys has been discovered. 相似文献
7.
M. G. Revnivtsev R. A. Sunyaev D. A. Varshalovich V. V. Zheleznyakov A. M. Cherepashchuk A. A. Lutovinov E. M. Churazov S. A. Grebenev M. R. Gilfanov 《Astronomy Letters》2004,30(6):382-389
From August 23 through September 24, 2003, the INTEGRAL Observatory conducted a deep survey of the Galactic-Center region with a record-breaking sensitivity at energies above 20 keV. We have analyzed the images of the Galactic-Center region obtained with the ISGRI detector of the IBIS telescope (15–200 keV) and give a catalog of detected sources. We detected a total of 60 sources with fluxes above 1.5 mCrab, 44 and 3 of which were previously identified as binary systems of different classes in our Galaxy and as extragalactic objects, respectively. We discovered one new source. 相似文献
8.
We present the results of optical identifications and spectroscopic redshift measurements for galaxy clusters from the second Planck catalogue of Sunyaev–Zeldovich sources (PSZ2) located at high redshifts, z ≈ 0.7?0.9. We used the data of optical observations with the Russian–Turkish 1.5-mtelescope (RTT-150), the Sayan Observatory 1.6-m telescope, the Calar Alto 3.5-m telescope, and the 6-m SAO RAS telescope (BTA). The spectroscopic redshift measurements were obtained for seven galaxy clusters, including one cluster, PSZ2 G126.57+51.61, from the cosmological sample of the PSZ2 catalogue. In the central regions of two clusters, PSZ2 G069.39+68.05 and PSZ2 G087.39?34.58, we detected arcs of strong gravitational lensing of background galaxies, one of which is at redshift z = 4.262. The data presented below roughly double the number of known galaxy clusters in the second Planck catalogue of Sunyaev–Zeldovich sources at high redshifts, z ≈ 0.8. 相似文献
9.
S. S. Tsygankov A. A. Lutovinov S. A. Grebenev M. R. Gilfanov R. A. Sunyaev 《Astronomy Letters》2004,30(8):540-548
The variability of the X-ray flux from the pulsar GX 301-2 is analyzed by using data from the ART-P telescope of the GRANAT Observatory. The intensity variations with time scales of several thousand seconds are studied at various orbital phases. The high-state flux from the source exceeds its low-state flux by as much as a factor of 10. The hardness and spectrum of the source are shown to change greatly with its intensity. These intensity variations are most likely caused by substantial inhomogeneities in the stellar wind from the companion star. 相似文献
10.
During the ROSAT All-Sky Survey (RASS; Voges 1992, 1997) about 80,000 X-ray sourceswith a detection likelihood 2 10 were detected, from which 18,811 sources having a PSPC countrate larger than 0.05 ets s--1 and detection likelihood 3 15 were compiled in the RASS-BSC(VOges et al. 1996a). More than 65% RASS sources remain unidentified (Voges et al. 1996b).The optical spectroscopic study of these RASS sources is essential for understanding them moreclearly.The idelltification of X-… 相似文献
11.
The spectroscopic red shifts of seven optical objects whose coordinates coincide with those of radio sources in the IVS (International
VLBI Service for Geodesy and Astrometry) program list are determined from observations with the 6-m BTA telescope at the Special
Astrophysical Observatory (SAO) of the Russian Academy of Sciences. A comparison of these spectra and red shifts with data
in the radio frequency range shows that four of the objects discussed here are correctly identified, while the other three
require further study. The distances to the radio sources derived from our measurements yield more accurate estimates of the
cosmological model parameters than those based on the proper motions of these objects derived from geodesic VLBI observations. 相似文献
12.
R. A. Burenin A. V. Mescheryakov M. G. Revnivtsev S. Yu. Sazonov I. F. Bikmaev M. N. Pavlinsky R. A. Sunyaev 《Astronomy Letters》2008,34(6):367-374
We present the results of our optical identifications of a set of X-ray sources from the INTEGRAL and SWIFT all-sky surveys. The optical data have been obtained with the 1.5-m Russian-Turkish Telescope (RTT-150). Nine X-ray sources have been identified with active galactic nuclei (AGNs). Two of them are located in the nearby spiral galaxies MCG-01-05-047 and NGC 973 seen almost edge-on. One source, IGR J16562-3301, is probably a BL Lac object (blazar). The remaining AGNs are observed as the starlike nuclei of spiral galaxies whose spectra exhibit broad emission lines. The relation between the hard X-ray (17–60 keV) luminosity and the [O III] 5007 line luminosity, log L x/L [O III] ≈ 2.1, holds good for most of the AGNs detected in hard X rays. However, the luminosities of some AGNs deviate from this relation. The fraction of such objects can reach ～20%. In particular, the [O III] line flux is lower for two nearby edge-on spiral galaxies. This can be explained by the effect of absorption in the galactic disks. 相似文献
13.
获得完备的样本一直是类星体统计分析工作中至关重要的第一步。类星体巡天选择候选体的方法主要有射电波段筛选、色指数筛选、无缝光谱筛选、X射线波段筛选、对红外源或变源进行筛选和零自行的方法。单独运用任一方法都有选择效应,采用多波段方法可以极大地提高样本的完备性。阐述了使用多波段方法选择活动星系核样本的研究现状,提出多波段类星体巡天方法和选源判据,给出ROSAT巡天中F.1002,F.Coma,F.836和F.Leo 4个天区以及空源的15年来X射线选活动星系核的选源和光学新证认的AGN结果,表明多波段类星体巡天方法能有效地提高观测效率。 相似文献
14.
A. A. Lutovinov R. A. Burenin M. G. Revnivtsev S. Yu. Sazonov O. N. Sholukhova A. F. Valeev 《Astronomy Letters》2012,38(5):281-289
We present the results of our optical identifications of four hard X-ray sources from the Swift all-sky survey. We obtained optical spectra for each of the program objects with the 6-m BTA telescope (Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz), which allowed their nature to be established. Two sources (SWIFT J2237.2+6324 and SWIFT J2341.0+7645) are shown to belong to the class of cataclysmic variables (suspected polars or intermediate polars). The measured emission line width turns out to be fairly large (FWHM ?? 15?C25 ?), suggesting the presence of extended, rapidly rotating (v ? 400?C600 km s?1) accretion disks in the systems. Apart from line broadening, we have detected a change in the positions of the line centroids for SWIFT J2341.0+7645, which is most likely attributable to the orbital motion of the white dwarf in the binary system. The other two program objects (SWIFT J0003.3+2737 and SWIFT J0113.8+2515) are extragalactic in origin: the first is a Seyfert 2 galaxy and the second is a blazar at redshift z = 1.594. Apart from the optical spectra, we provide the X-ray spectra for all sources in the 0.6?C10 keV energy band obtained from XRT/Swift data. 相似文献
15.
The observations of 34 extragalactic radio sources with the 22-m Crimean Astrophysical Observatory radio telescope at 36 GHz in 1985–1994 are presented. Intensity variations were detected in 27 objects, which may result from the appearance of new components in their cores. 相似文献
16.
5个新发现的X选BL Lac天体 总被引：1，自引：0，他引：1
利用ＲＯＳＡＴＶＬＡ方法筛选，从ＲＯＳＡＴＸ射线源中选出了一批新的ＢＬＬａｃ天体和类星体的候选体．１９９６年１２月８日至１７日，利用北京天文台２．１６ｍ望远镜和新从美国引进的ＯＭＲ摄谱仪，对这批新候选体进行了光谱认证．经ＳＵＮ工作站处理，又发现了５个新的Ｘ选ＢＬＬａｃ天体．此外，还对去年作者在ＯＭＲ引进之前发现的ＢＬＬａｃ天体进行了检验，结果发现，去年发现的７个ＢＬＬａｃ天体中，２３２２＋３４３的ＣａＩＩＨ＆Ｋ“Ｂｒｅａｋｓｔｒｅｎｇｔｈ”为２６．９％，稍大于判据２５％，因此，２３２２＋３４３到底是ＢＬＬａｃ天体还是射电星系还有待于进一步测光及偏振观测的验证． 相似文献
17.
R. A. Burenin A. L. Amvrosov M. V. Eselevich V. M. Grigor’ev V. A. Aref’ev V. S. Vorob’ev A. A. Lutovinov M. G. Revnivtsev S. Yu. Sazonov A. Yu. Tkachenko G. A. Khorunzhev A. L. Yaskovich M. N. Pavlinsky 《Astronomy Letters》2016,42(5):295-306
The capabilities of the new medium- and low-resolution spectrograph installed recently on the 1.6-m AZT-33IK telescope at the Sayan Observatory of the Institute of Solar–Terrestrial Physics to solve the problems of ground-based optical support for the future all-skyX-ray survey of the SRGobservatory are discussed. Results of the test observations of galaxy clusters, active galactic nuclei (AGNs) and quasars, and cataclysmic variables performed immediately after the installation of the spectrograph on the telescope are presented. The results of these observations show that the AZT-33IK telescope equipped with the new medium- and low-resolution spectrograph can provide a substantial fraction of the necessary optical observations in the program of ground-based optical support for the all-sky survey of the SRG observatory. 相似文献
18.
Andrew Fittingoff J. Xavier Prochaska Jasonjot S. Kalirai Jay Strader † Puragra Guhathakurta Kyle F. Kaplan 《Monthly notices of the Royal Astronomical Society》2009,399(2):728-736
We have performed a wide-area ultraviolet (UV) imaging survey using the GALaxy Evolution eXplorer to search for bright, point-like UV sources behind M31's extended halo. Our survey consisted of 46 pointings covering an effective area of ≈50 deg2 , in both the far-UV and near-UV channels. We combined these data with optical R -band observations acquired with the WIYN Mosaic-1 imager on the Kitt Peak National Observatory 0.9-m WIYN telescope. An analysis of the brightness and colours of sources matched between our photometric catalogues yielded ≈100 UV-bright quasar candidates. We have obtained discovery spectra for 76 of these targets with the Kast spectrometer on the Lick 3-m telescope and confirmed 30 active galactic nuclei and quasars, 29 galaxies at z > 0.02 including several early-type systems, 16 Galactic stars (hot main-sequence stars) and one featureless source previously identified as a BL Lac object. Future UV spectroscopy of the brightest targets with the Cosmic Origins Spectrograph on the Hubble Space Telescope will enable a systematic search for diffuse gas in the extended halo of M31. 相似文献
19.
V. S. Vorobyev R. A. Burenin I. F. Bikmaev I. M. Khamitov S. N. Dodonov R. Ya. Zhuchkov E. N. Irtuganov A. V. Mescheryakov S. S. Melnikov A. N. Semena A. Yu. Tkachenko N. Aghanim R. A. Sunyaev 《Astronomy Letters》2016,42(2):63-68
We present the results of spectroscopic redshift measurements for the galaxy clusters from the first all-sky Planck catalogue that have been mostly identified based on the optical observations performed previously by our team (Planck Collaboration 2015a). Data on 13 galaxy clusters at redshifts from z ≈ 0.2 to z ≈ 0.8, including the improved identification and redshift measurement for the cluster PSZ1 G141.73+14.22 at z = 0.828, are provided. We have performed the measurements based on data from the Russian–Turkish 1.5-m telescope (RTT-150), the 2.2-m Calar Alto Observatory telescope, and the 6-m SAO RAS telescope (Bolshoy Teleskop Azimutalnyi, BTA). 相似文献
20.
V. R. Amirkhanyan V. L. Afanas'ev S. N. Dodonov A. V. Moiseev V. P. Mikhailov 《Astronomy Letters》2004,30(12):834-842
We performed spectroscopic observations of 22 radio sources from the Zelenchuk survey (Sternberg Astronomical Institute) using the 6-m and 1-m Special Astrophysical Observatory telescopes. For 18 objects, we determined the redshifts. Ten, seven, and one of these objects were identified with quasars, elliptical galaxies, and a Seyfert galaxy, respectively. Four radio sources have a continuum spectrum, and three of them are BL Lac objects. We failed to classify one object. 相似文献