내용
사진
사진 업로드
DSS Images Other Images
관련 글
The Chandra Small Magellanic Cloud Wing Survey - the search for X-ray binaries
We have detected 523 sources in a survey of the Small Magellanic Cloud(SMC) Wing with Chandra. By cross-correlating the X-ray data withoptical and near-infrared catalogues, we have found 300 matches. Using atechnique that combines X-ray colours and X-ray to optical flux ratios,we have been able to assign preliminary classifications to 265 of theobjects. Our identifications include four pulsars, one high-mass X-raybinary (HMXB) candidate, 34 stars and 185 active galactic nuclei (AGN).In addition, we have classified 32 sources as `hard' AGN which arelikely absorbed by local gas and dust, and nine `soft' AGN whose natureis still unclear. Considering the abundance of HMXBs discovered so farin the Bar of the SMC the number that we have detected in the Wing islow.
| A ROSAT PSPC catalogue of X-ray sources in the SMC region
We present a catalogue of 517 discrete X-ray sources in a 6°x6°\field covering the Small Magellanic Cloud (SMC). The catalogue wasderived from the pointed ROSAT PSPC observations performed betweenOctober 1991 and May 1994 and is complementary to the Large MagellanicCloud (LMC) catalogue published by \cite[Haberl & Pietsch(1999).]{H99} We followed the same identification scheme and used, amongother information, X-ray hardness ratios and spatial extent to classifyunknown sources as candidates for active galactic nuclei (AGN),foreground stars, supernova remnants (SNRs), supersoft sources (SSSs)and X-ray binaries. For 158 sources a likely source type is given, fromwhich 46 sources are suggested as background AGN (including candidatesresulting from a comparison of X-ray and radio images). Nearly all ofthe X-ray binaries known in the SMC were detected in ROSAT PSPCobservations; most of them with luminosities below \ergs{36} suggestingthat the fraction of high luminosity X-ray binary systems in theMagellanic Clouds (MCs) is not significantly larger than in our galaxy.Seventeen X-ray sources are associated with SNRs found in earlier workand we suggest here two additional extended sources as SNR candidates.Three very soft sources are newly classified as SSSs from which one isidentified with the symbiotic star LIN 358 in the SMC. Table 2 is onlyavailable in electronic form at CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| A ROSAT PSPC X-ray survey of the Small Magellanic Cloud
We present the results of a systematic search for point-like andmoderately extended soft (0.1-2.4 keV) X-ray sources in a raster of ninepointings covering a field of 8.95\ deg(2) and performed with the ROSATPSPC between October 1991 and October 1993 in the direction of the SmallMagellanic Cloud (SMC). We detect 248 objects which we include in thefirst version of our SMC catalogue of soft X-ray sources. We set upseven source classes defined by selections in the count rate, hardnessratio and source extent. We find five high luminosity super-soft sources(1E 0035.4-7230, 1E 0056.8-7146, RX J0048.4-7332, RX J0058.6-7146 and RXJ0103-7254), one low-luminosity super-soft source RX J0059.6-7138correlating with the planetary nebula L357, 51 candidate hard X-raybinaries including eight bright hard X-ray binary candidates, 19supernova remnants (SNRs), 19 candidate foreground stars and 53candidate background active galactic nuclei (and quasars). We give alikely classification for ~ 60% of the catalogued sources. The totalcount rate of the detected point-like and moderately extended sources inour catalogue is 6.9 +/- 0.3 s(-1) , comparable to the backgroundsubtracted total rate from the integrated field of ~ 6.1+/-0.1 s(-1) .Table 1 is also available in electronic from at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Positional reference stars in the Magellanic Clouds
The equatorial coordinates are determined of 926 stars (mainly ofgalactic origin) in the direction of the Magellanic Clouds at the meanepoch T = 1978.4 with an overall accuracy characterized by the meanvalues of the O-C coordinates, Sa = 0.35 arcsec and Sd = 0.38 arcsec,calculated from the coordinates of the Perth reference stars. Thesevalues are larger than the accuracy expected for primary standard stars.They allow the new positions to be considered as those of reliablesecondary standard stars. The published positions correspond to anunquestionable improvement of the quality of the coordinates provided inthe current catalogs. This study represents an 'astrometric step' in thestarting of a 'Durchmusterung' of the Magellanic Clouds organized by deBoer (1988, 1989).
| Search for Variability of the Sr-Cr-Eu Star HD 8783
Not Available
| Sir John Herschel's Observations of Stars in the Small Magellanic Cloud
Not Available
| Photometry of bright stars in the Small Magellanic Cloud.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&A.....9...95D&db_key=AST
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
