Spectroscopy of the brightest optical counterparts of X-ray sources in the direction of M 31 and M 33
Context.Recent surveys of the Local Group spiral Galaxies M 31 and M 33with XMM-Newton yielded a large number of X-ray sources. Aims.Aspart of the effort to identify and classify the objects responsible forthis X-ray emission, we have obtained optical spectra of the brightestoptical counterparts of the identified X-ray sources, using the 1.3 mSkinakas Telescope. Most of these objects are foreground starcandidates. The purpose of the present study is to confirm thisidentification and to explore the compatibility between the opticalspectral classification and the observed X-ray properties of thesources. Methods.We have obtained optical spectra for the 14brightest optical counterparts of X-ray sources identified by XMM-Newtonin the direction of M 31 and for 21 optical counterparts in thedirection of M 33, using the 1.3 m Skinakas telescope in Crete, Greece.Results.All of the M 31 sources and all but one of the M 33sources were confirmed to be foreground stars, of spectral types betweenA and M. One of the stars is a late M dwarf with Hα emission, aflare star, also displaying strong X-ray variability. One of the M 33sources (lying within the D25 ellipse) corresponds to a previously knownbackground galaxy, LEDA 5899.
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XMM-Newton survey of the Local Group galaxy M 33
In an XMM-Newton raster observation of the bright Local Group spiralgalaxy M 33 we study the population of X-ray sources(X-ray binaries, supernova remnants) down to a 0.2-4.5 keV luminosity of1035 erg s-1 - more than a factor of 10 deeperthan earlier ROSAT observations. EPIC hardness ratios and optical andradio information are used to distinguish between different sourceclasses. The survey detects 408 sources in an area of 0.80 squaredegree. We correlate these newly detected sources with earlierM 33 X-ray catalogues and information from optical,infra-red and radio wavelengths. As M 33 sources wedetect 21 supernova remnants (SNR) and 23 SNR candidates, 5 super-softsources and 2 X-ray binaries (XRBs). There are 267 sources classified ashard, which may either be XRBs or Crab-like SNRs in M33 or background AGN. The 44 confirmed and candidate SNRs morethan double the number of X-ray detected SNRs in M33. 16 of these are proposed as SNR candidates from the X-raydata for the first time. On the other hand, there are several sourcesnot connected to M 33: five foreground stars, 30foreground star candidates, 12 active galactic nucleus candidates, onebackground galaxy and one background galaxy candidate. Extrapolatingfrom deep field observations we would expect 175 to 210 backgroundsources in this field. This indicates that about half of the sourcesdetected are within M 33.XMM-Newton is an ESA Science Mission with instruments and contributionsdirectly funded by ESA Member States and the USA (NASA).Full Table \ref{master} is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/426/11
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Non-radial pulsation of the δ Scuti star UV Trianguli
We present the results of a three-year photometric study of the δScuti star UV Trianguli. Our data sets consist of 9378 differentialmeasurements in Johnson V together with a few data collected into theStrömgren uvbyβ system. UV Tri is at least a biperiodicvariable. The two best-fitting frequencies, f1= 9.3298d-1 and f2= 10.8513 d-1, are still notthe complete set of pulsation frequencies representing the lightvariations of the star. A suspected third frequency might present in thestar. Several `anomalous cycles' are observed in the light curves. Theyseem real, but are aperiodic. We derive the colour indices and physicalparameters for the variable and conclude that it is a Population Iδ Sct star with normal metal abundance ([Me/H]= 0.0 +/- 0.1 dex)evolving on its main-sequence stage at an early evolutionary phasebefore the turn-off point. Finally, we compare the observed oscillationfrequencies with theoretical models. The two pulsation modes of UV Triare likely to be non-radial gravity modes.
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Photometric Observations of the δ Scuti Star UV Trianguli and its Evolutionary Status
UV Tri was observed photometrically from 1999 to 2000 at the XinglongStation of the National Astronomical Observatories, Chinese Academy ofSciences, and was also observed with Strömgren uvbyHβ filter system at the Sierra Nevada Observatory(Spain) in 2000. From period analyses of the data, three pulsationfrequencies, 9.3299 c d-1, 10.8483 c d-1 and3.6035 c d-1 were obtained. We derived color indices: b-y =0.215, m1 = 0.169, c1 = 0.783, and β = 2.775.With these indices and some calibrations, we obtain: Mv =2.44, Mbol = 2.27, logL /Lȯ = 0.99, and logTeff = 3.875. Evolutionary sequences of stellar models with1.00-2.00 solar masses, at steps of 0.05 Msun, are computed. Eachsequence consists of 220 evolutionary intervals. From a comparisonbetween the observed and calculated physical parameters we conclude thatUV Tri is in an early evolutionary phase before the turn-off point.
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Observations of Galaxies with the Midcourse Space Experiment
We have imaged eight nearby spiral galaxies with the SPIRIT III infraredtelescope on the Midcourse Space Experiment (MSX) satellite in themid-infrared at 18" resolution at 8.3, 12.1, 14.7, and 21.3 μm. Eachof the eight shows interesting structure not previously detected witholder, lower resolution infrared data sets, such as a resolved nucleusor spiral structure. The MSX data are compared with existing data setsat ultraviolet, optical, and infrared wavelengths, including recentobservations from the Infrared Space Observatory. The infraredstructures in M83 and NGC 5055 show a striking similarity to theultraviolet emission but are less similar to the optical emission.Several point sources with no identified counterparts at otherwavelengths are found near M31, NGC 4945, M83, and M101. Over 200previously known objects are also detected at 8 μm.
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The X-ray view of M 33 after ROSAT
We present a catalogue of 184 X-ray sources within 50' of the nucleus ofthe local group spiral galaxy M 33. The catalogue is derived from ananalysis of the complete set of ROSAT archival data pointed in thedirection of M 33 and contains X-ray position, existence likelihood,count rates and PSPC spectral hardness ratios. To identify the sourcesthe catalog was correlated with previous X-ray catalogues, optical andradio catalogues. In addition sources were classified according to theirX-ray properties. We find seven candidates for supersoft X-ray sources,of which two may be associated with known planetary nebulae in M 33. Themajority of X-ray detected supernova remnants is also detected at radiofrequencies and seen in optical lines. The low overall X-ray detectionrate of optically selected SNRs can probably be attributed to theirexpansion into interstellar matter of low density. Table~2 is onlyavailable 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/qcat?J/A+A/373/438
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Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
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The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
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GPM - compiled catalogue of absolute proper motions of stars in selected areas of sky with galaxies.
Not Available
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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.
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The distribution of the ultraviolet emission in the disk of Messier 33
Ultraviolet (2000 A) observations of Messier 33 at a resolution of 20arcsec are used to study the repartition of the UV emission in the diskof this galaxy. The relative contribution of discrete sources anddiffuse areas to the UV emission are estimated: sources are found todominate the UV emission. The fraction of the UV flux arising fromdiffuse regions would not exceed 20%, the exact value depending on thecorrections for dust extinction applied to the UV emission. Implicationsof these results on the recent star formation activity in Messier 33 aswell as on the evaluation of the dust extinction affecting the UVemission in galactic disks are discussed.
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Fifth fundamental catalogue. Part 2: The FK5 extension - new fundamental stars
The mean positions and proper motions for 3117 new fundamental starsessentially in the magnitude range about 4.5 to 9.5 are given in thisFK5 extension. Mean apparent visual magnitude is 7.2 and is on average2.5 magnitudes fainter then the basic FK5 which has a mean magnitude of4.7. (The basic FK5 gives the mean positions and proper motions for theclassical 1535 fundamental stars). The following are discussed: theobservational material, reduction of observations, star selection, andthe system for the FK5 extension. An explanation and description of thecatalog are given. The catalog of 3117 fundamental stars for the equinoxand epoch J2000.0 and B1950.0 is presented. The parallaxes and radialvelocities for 22 extension stars with large forecasting effects aregiven. Catalogs used in the compilation of the FK5 fundamental catalogare listed.
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UBV photometry of stars whose positions are accurately known. VI
Results are presented from UBV photometric observations of 1000 stars ofthe Bright Star Catalogue and the faint extension of the FK5.Observations were carried out between July 1987 and December 1990 withthe 40-cm Cassegrain telescope of the Kvistaberg Observatory.
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Spectral types of 80 early-type stars of variable radial velocity
MK spectral types are given for 80 normal early-type stars of variableradial velocity. These spectral types were determined from spectrogramstaken with the Lick Observatory 0.9-m refractor during the years1957-58.
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Not Available
Not Available
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The galactic foreground reddening in the direction of the nearby triangulum galaxy M33
Observations of 314 stars with the uvby-beta photometric system are usedto establish the reddening in the direction of the nearby Triangulumgalaxy M33. Color excesses are obtained for 151 A and F type stars in a1 deg radius centered around the galaxy. A color excess of E(b-y) =0.057 mag /E(B-V) = 0.077 mag/ is obtained for a distance modulus m - M= 10. A secondary result of this investigation is the discovery of sixsuspected variable stars, as well as ten observations of V Triangulum, aBeta Lyrae eclipsing variable.
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New delta Scuti Type Variable in Triangulum
Not Available
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The cluster system of M33
A catalog of more than 250 nonstellar objects found on high resolutiondirect plates of M33 has been compiled. Additional classificationcriteria were derived from low dispersion 4 m grism plates andmulticolor photographs. BVR photometry of 60 of these objects, believedto be star clusters, is presented, especially in comparison to similarobservations of clusters in other Local Group galaxies. The M33 clusterspopulate a fairly uniform region for B-V between 0.0-0.8 mag and for Vbetween 17.0-19.5 mag in an integrated color-magnitude diagram. Inparticular, there appears to be a sizable population of blue andintermediate color objects. An obvious resemblance of these clusters tothe populous clusters found in the Large Magellanic Cloud was noted. Asmall class of red objects, presumably including true globulars isevident.
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UBV photometry of eclipsing binaries with visual companions
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83...69H&db_key=AST
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Catalog of Indidual Radial Velocities, 0h-12h, Measured by Astronomers of the Mount Wilson Observatory
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJS...19..387A&db_key=AST
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INHABITED SKY
