Contents
Images
Upload your image
DSS Images Other Images
Related articles
The Counterarc to MS 1512-cB58 and a Companion Galaxy
We present near-infrared spectra of ``A2,'' the primary counterarc tothe gravitationally lensed galaxy MS 1512-cB58. The spectra showredshifted Hα, [N II], [O III], and Hβat z=2.729+/-0.001. We observe the same Hα/[O III]ratio as cB58, which together with the redshift confirms that A2 isindeed another image of a single background galaxy. Published lensingreconstruction reports that A2 is a magnification of the entire source,while cB58 is an image of only a part. At marginal significance, A2shows higher line-to-continuum ratios than cB58 (by a factor of ~2),suggesting a nonuniform ratio of young to old stars across the galaxy.We observe a second emission-line source in the slit. This object,``W5,'' is predicted to be a lensed image of another galaxy at aredshift similar to cB58. W5 is blueshifted from cB58 by ~400 kms-1 and has a significantly lower Hα/[O III]ratio, confirming that it is an image of a different background galaxyin a group with cB58. The Hα emission line in W5implies a star formation rate of 6 Msolar yr-1(H0=70 km s-1 Mpc-1,ΩM=0.3,ΩΛ=0.7), aftercorrecting for lensing magnification.Data presented herein were obtained at the W. M. Keck Observatory, whichis operated as a scientific partnership among the California Instituteof Technology, the University of California, and the NationalAeronautics and Space Administration. The Observatory was made possibleby the generous financial support of the W. M. Keck Foundation.
| Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
This work is the second part of the set of measurements of v sin i forA-type stars, begun by Royer et al. (\cite{Ror_02a}). Spectra of 249 B8to F2-type stars brighter than V=7 have been collected at Observatoirede Haute-Provence (OHP). Fourier transforms of several line profiles inthe range 4200-4600 Å are used to derive v sin i from thefrequency of the first zero. Statistical analysis of the sampleindicates that measurement error mainly depends on v sin i and thisrelative error of the rotational velocity is found to be about 5% onaverage. The systematic shift with respect to standard values fromSlettebak et al. (\cite{Slk_75}), previously found in the first paper,is here confirmed. Comparisons with data from the literature agree withour findings: v sin i values from Slettebak et al. are underestimatedand the relation between both scales follows a linear law ensuremath vsin inew = 1.03 v sin iold+7.7. Finally, thesedata are combined with those from the previous paper (Royer et al.\cite{Ror_02a}), together with the catalogue of Abt & Morrell(\cite{AbtMol95}). The resulting sample includes some 2150 stars withhomogenized rotational velocities. Based on observations made atObservatoire de Haute Provence (CNRS), France. Tables \ref{results} and\ref{merging} are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/393/897
| Near infrared observations of soft X-ray selected AGN
We report the results of near infrared observations of 19 soft X-rayselected AGN. The goal of the observations was to search for strong,narrow Paalpha or Brgamma emission lines, as a sign of nuclearstarbursts. We found Paalpha emission in the spectra of 11 sources andBrgamma in at least five. Strong NIR emission has been found in twosources, CBS 126 and Mkn 766, both objects with strong [OIII]lambda 5007emission, weak Fe II emission and wavelength dependent degree ofpolarization in the optical. Classical Narrow Line Seyfert 1 galaxies donot show exceptionally strong NIR emission lines. We present the resultsof our study and discuss how our findings fit into an evolutionaryscheme of AGN. Based on observations performed at the 2.7 m telescope ofthe McDonald Observatory, Texas.
| Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
| The Rest-Frame Optical Spectrum of MS 1512-CB58
Moderate-resolution, near-IR spectroscopy of MS 1512-cB58 is presented,obtained during commissioning of the near-infrared spectrometer(NIRSPEC) on the Keck II telescope. The strong lensing of this z=2.72galaxy by the foreground cluster MS 1512+36 makes it the best candidatefor detailed study of the rest-frame optical properties of Lyman-breakgalaxies. In 80 minutes of on-source integration, we have detectedHα, [N II] λλ6583, 6548, [O I] λ6300, He Iλ5876, [O III] λλ5007, 4959, Hβ, Hγ, [OII] λ3727, and a strong continuum signal in the range of1.29-2.46 μm. A redshift of z=2.7290+/-0.0007 is inferred from theemission lines, in contrast to the z=2.7233 calculated from UVobservations of interstellar absorption lines. Using the Balmer lineratios, we find an extinction of E(B-V) = 0.27. Using the linestrengths, we infer a star formation rate (SFR) of 620+/-18Msolar yr-1 (H0=75, q0=0.1,and Λ=0), which is a factor of 2 higher than that measured fromnarrowband imaging observations of the galaxy but is a factor of almost4 lower than the SFR inferred from the UV continuum luminosity. Thewidth of the Balmer lines yields a mass ofMvir=1.2x1010 Msolar. We find that theoxygen abundance is 1/3 solar, in good agreement with other estimates ofthe metallicity. However, we infer a high nitrogen abundance, which mayargue for the presence of an older stellar population. Data presentedherein were obtained at the W. M. Keck Observatory, which is operated asa scientific partnership among the California Institute of Technology,the University of California, and the National Aeronautics and SpaceAdministration. The Observatory was made possible by the generousfinancial support of the W. M. Keck Foundation.
| Nice observatory measurements of double stars (3rd series)
We present recent measurements of visual double stars made at the NiceObservatory (3rd series). We also report the discovery of a new doublestar: JCT 4. Moreover we give a more precise position of the double starDOO 35. Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| UvbyHbeta_ photometry of main sequence A type stars.
We present Stroemgren uvby and Hbeta_ photometry for a set of575 northern main sequence A type stars, most of them belonging to theHipparcos Input Catalogue, with V from 5mag to 10mag and with knownradial velocities. These observations enlarge the catalogue we began tocompile some years ago to more than 1500 stars. Our catalogue includeskinematic and astrophysical data for each star. Our future goal is toperform an accurate analysis of the kinematical behaviour of these starsin the solar neighbourhood.
| The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJS...99..135A&db_key=AST
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| A preliminary compilation of DS-programme star positions
A catalog is presented of the double-star-program (DS-program) starpositions, listing right ascensions for 930 DSs and declinations for1225 DSs of the program. The positions were compiled from the observedvalues obtained between 1980 and 1987 with the meridian circles of sixUSSR observatories (the Moscow, Kazan', Kiev, Khar'kov, Odessa, andTashkent Observatories) and the Belgrade Observatory. The measurementsand the treatment of the observational material were performed using therelative method, and the FK-4 system stars were used as reference stars.
| ICCD speckle observations of binary stars. IV - Measurements during 1986-1988 from the Kitt Peak 4 M telescope
One thousand five hundred and fifty measurements of 1006 binary starsystems observed mostly during 1986 through mid-1988 by means of speckleinterferometry with the KPNO 4-m telescope are presented. Twenty-onesystems are directly resolved for the first time, including newcomponents to the cool supergiant Alpha Her A and the Pleiades shellstar Pleione. A continuing survey of The Bright Star Catalogue yieldedeight new binaries from 293 bright stars observed. Corrections tospeckle measures from the GSU/CHARA ICCD speckle camera previouslypublished are presented and discussed.
| Micrometer Measures of Double Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJS....6....1K&db_key=AST
| Spectral Classification of 533 B8-A2 Stars and the Mean Absolute Magnitude of a0 V Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1959ApJ...130..159O&db_key=AST
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
| Constellation: | うしかい座 |
| Right ascension: | 14h55m58.70s |
| Declination: | +32°18'01.0" |
| Apparent magnitude: | 6.12 |
| Distance: | 96.061 parsecs |
| Proper motion RA: | -53.9 |
| Proper motion Dec: | -3 |
| B-T magnitude: | 6.252 |
| V-T magnitude: | 6.136 |
Catalogs and designations:
|
INHABITED SKY
