תוכן
תמונות
הוסף תמונה שלך
DSS Images Other Images
מאמרים קשורים
Open clusters in the Third Galactic Quadrant. II. The intermediate age open clusters NGC 2425 and NGC 2635
We analyse CCD broad band (UBV(RI)_C) photometric data obtained in thefields of the poorly studied open clusters NGC 2425and NGC 2635. Both clusters are found to be ofintermediate age thus increasing the population of open clusters knownto be of the age of, or older than, the Hyades. More explicitly, we findthat NGC 2425 is a 2.2 Gyr old cluster, probably ofsolar metallicity, located at 3.5 kpc from the Sun. NGC2635 is a Hyades age (600 Myr) cluster located at a distanceof 4.0 kpc from the Sun. Its Colour Magnitude Diagram reveals that it isextremely metal poor for its age and position, thus making it a veryinteresting object in the context of Galactic Disk chemical evolutionmodels.
| Mass function study of six open clusters Be 10, Be 67, To 5, Be 15, Be 71 and King 1
In the present study, we have used the CCD data to determine theluminosity and mass function of six open clusters. Members of clustersare identified using photometric and statistical criteria. From thesemembers, we have derived luminosity functions and determined the massfunction slopes for the clusters under study. The mass function slopesfor clusters Be 10, Be 67, To 5, Be 15, Be 71 and King 1 are1.39(+/-)0.73, 3.41(+/-)0.98, 1.32(+/-)0.47, 1.35(+/-)0.46,3.02(+/-)0.81 and 1.46(+/-)0.71 respectively. These slopes agree withthe Salpeter value (x=1.35) within errors except for clusters Be 67 andBe 71 which have steeper slopes. The clusters Be 10, Be 67, To 5 and Be15 show mass segregation while King 1 gives weak evidence of masssegregation and Be 71 does not show the ects of mass segregation. Allthe clusters under study are dynamically relaxed.
| NGC 2580 and NGC 2588. Two open clusters in the Third Galactic Quadrant
We present CCD broad band photometric observations in the fields of theThird Galactic Quadrant open clusters NGC 2580 and NGC 2588(V(I)C and UBV(RI)C respectively). From theanalysis of our data we found that NGC 2580 is located at a distance ofabout 4 kpc and its age is close to 160 Myr. As for NGC 2588, it isplaced at about 5 kpc from the Sun and is 450 Myr old. This means thatNGC 2588 belongs to the extension of the Perseus arm, whereas NGC 2580is closer to the local arm structure. The luminosity functions (LFs)have been constructed for both clusters down to V ˜ 20 togetherwith their initial mass functions (IMFs) for stars with masses above M˜ 1-1.5 Mȯ. The IMF slopes for the most massivebins yielded values of x ≈ 1.3 for NGC 2580 and x ≈ 2 for NGC2588. In the case of this latter cluster we found evidence of acore-corona structure produced probably by dynamical effect. In the mainsequences of both clusters we detected gaps, which we suggest could bereal features.Based on observations c ollected at ESO, CASLEO and CTIO.Table 3 is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/417/961
| Open clusters in the third galactic quadrant. I. Photometry
We have performed a photometric survey of open clusters in the thirdGalactic quadrant in order to study the star formation history andspatial structure in the Canis Major-Puppis-Vela region. In this paperwe describe a catalogue of CCD U BV RI photometry of approximately 65000 stars in the fields of 30 open clusters. The data were obtained andreduced using the same telescope, the same reduction procedures, and thesame standard photometric system, which makes this catalogue the largesthomogeneous source of open cluster photometry so far. In subsequentpapers of this series, colour-colour and colour-magnitude diagrams willbe presented which, amongst other uses, will allow the determination ofan homogeneous set of cluster reddenings, distances, and ages that willconstitute the observational basis for our studies of the spatialstructure and star formation history in the third Galactic quadrant.
| Uniform survey of clusters in the southern Milky Way.
Abstract image available at:http://adsabs.harvard.edu/abs/1975AJ.....80...11V
|
הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
|
תצפית ומידע אסטרומטרי
קטלוגים וכינוים:
|
