- ID:
- ivo://CDS.VizieR/J/AJ/159/246
- Title:
- WIYN open cluster study. LXXX. Photometry of NGC 7142
- Short Name:
- J/AJ/159/246
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry of 8702 stars in a 0.5x0.5{deg} field in the direction of NGC7142, taken with the Half Degree Imager at the WIYN 0.9m telescope, to improve knowledge of this cluster's basic parameters. Our photometry spans the ranges 10.6-20.4mag in U, 10.6-22.0mag in B, 10.0-21.8mag in V, 9.2-20.7mag in R, and 8.5-19.9mag in I. Using color-color diagrams that employ all four color combinations that include U, versus B-V, we derive a reddening-metallicity relation for the cluster, with preferred values E(B-V)=0.338{+/-}0.031mag for the left-edge fiducial of the main sequence and [Fe/H]=0.0{+/-}0.1dex, where the Hyades cluster has been used as an unreddened reference cluster, the extinction relations of Cardelli have been employed, and the metallicity dependence of the Yonsei-Yale (Y^2^) isochrones has been assumed. Comparison of our data to the Y^2^ isochrones in multiple color-magnitude diagrams (CMDs) yields distance-metallicity and age-metallicity relations, with preferred values of m-M=12.65{+/-}0.23 mag and age=4.0_+1.3_^-0.7^Gyr. Re-evaluation of the parameters of M67 using Stetson's UBVI photometry yields [Fe/H]=-0.02{+/-}0.05dex, E(B-V)=0.04{+/-}0.01mag, m-M=9.75{+/-}0.03mag, and age=3.85{+/-}0.17Gyr; we thus find the metallicity and age of the two clusters to be indistinguishable. A semi-independent analysis adopting the parameters of M67 and shifting the fiducials of the two clusters in six CMDs until they match strongly corroborates the values listed above. The differences between our inferred parallaxes and the Gaia DR2 values are 87{+/-}60{mu}as for NGC7142 and 48{+/-}15{mu}as for M67, consistent with previous studies.
Number of results to display per page
Search Results
2782. W3 Main JHKs photometry
- ID:
- ivo://CDS.VizieR/J/A+A/561/A12
- Title:
- W3 Main JHKs photometry
- Short Name:
- J/A+A/561/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Embedded clusters like W3 Main are complex and dynamically evolving systems that represent an important phase in the star formation process. We aim to characterize of the entire stellar content of W3 Main in a statistical sense, which will then identify possible differences in evolutionary phase of the stellar populations and find clues about the formation mechanism of this massive embedded cluster. Deep JHKs imaging is used to derive the disk fraction, Ks-band luminosity functions, and mass functions for several subregions in W3 Main. A two-dimensional completeness analysis using artificial star experiments is applied as a crucial ingredient for assessing realistic completeness limits for our photometry. We find an overall disk fraction of 7.7+/-2.3%, radially varying from 9.4+/-3.0 in the central 1pc to 5.6+/-2.2% in the outer parts of W3 Main. The mass functions derived for three subregions are consistent with a Kroupa and Chabrier mass function. The mass function of IRSN3 is complete down to 0.14M_{sun}_ and shows a break at M~0.5M_{sun}_. We interpret the higher disk fraction in the center as evidence that the cluster center is younger. We find that the evolutionary sequence observed in the low-mass stellar population is consistent with the observed age spread among the massive stars. An analysis of the mass function variations does not show evidence of mass segregation. W3 Main is currently still actively forming stars, showing that the ionizing feedback of OB stars is confined to small areas (~0.5pc). The FUV feedback might be influencing large regions of the cluster as suggested by the low overall disk fraction.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A63
- Title:
- W51 OB stars NIR spectroscopy
- Short Name:
- J/A+A/624/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The interplay between the formation of stars, stellar feedback and cloud properties strongly influences the star formation history of giant molecular clouds. The formation of massive stars leads to a variety of stellar clusters, ranging from low stellar density OB associations to dense, gravitationally bound starburst clusters. We aimed at identifying the massive stellar content and reconstructing the star formation history of the W51 giant molecular cloud. We performed near-infrared imaging and K-band spectroscopy of the massive stars in W51. We analysed the stellar populations using colour-magnitude and colour-colour diagrams and compared the properties of the spectroscopically identified stars with stellar evolution models. We derive the ages of the different sub-clusters in W51 and, based on our spectroscopy derive an age for W51 of 3Myrs or less. The age of the P Cygni star LS1 and the presence of two still forming proto- clusters suggests that the star formation history of W51 is more complex than a single burst. We did not find evidence for triggered star formation and we concluded that the star formation in W51 is multi seeded. We finally concluded that W51 is a OB association where different sub-clusters form over a time span of at least 3-5Myrs.
- ID:
- ivo://CDS.VizieR/J/A+A/568/A5
- Title:
- XDCP J0044.0-2033 J and Ks images
- Short Name:
- J/A+A/568/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent observational progress has enabled the detection of galaxy clusters and groups out to very high redshifts and for the first time allows detailed studies of galaxy population properties in these densest environments in what was formerly known as the "redshift desert" at z>1.5. We aim to investigate various galaxy population properties of the massive X-ray luminous galaxy cluster XDCP J0044.0-2033 at z=1.58, which constitutes the most extreme currently known matter-density peak at this redshift. We analyzed deep VLT/HAWK-I near-infrared data with an image quality of 0.5" and limiting Vega magnitudes (50% completeness) of 24.2 in J- and 22.8 in the Ks band, complemented by similarly deep Subaru imaging in i and V, Spitzer observations at 4.5um, and new spectroscopic observations with VLT/FORS 2.
- ID:
- ivo://CDS.VizieR/J/A+A/459/199
- Title:
- XMM-Newton survey of two Upper Scorpius regions
- Short Name:
- J/A+A/459/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied X-ray emission from young stars by analyzing the deep XMM-Newton observations of two regions of the Upper Scorpius association with an age of 5Myr. Based on near infrared and optical photometry we identified 22 Upper Scorpius photometric members among the 224 detected X-ray sources. We derived coronal properties of Upper Scorpius stars by performing X-ray spectral and timing analyses. The study of four strong and isolated stellar flares allowed us to derive the length of the flaring loops.
- ID:
- ivo://CDS.VizieR/J/AJ/145/143
- Title:
- XMM observations of {alpha} Per
- Short Name:
- J/AJ/145/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the analysis of an archival observation of part of the {alpha} Persei cluster obtained with XMM-Newton. We detected 102 X-ray sources in the band 0.3-8.0 keV, of which 39 of them are associated with the cluster as evidenced by appropriate magnitudes and colors from Two Micron All Sky Survey photometry. We extend the X-ray luminosity distribution (XLD) for M dwarfs, to add to the XLD found for hotter dwarfs from spatially extensive surveys of the whole cluster by ROSAT. Some of the hotter stars are identified as a background, possible slightly older group of stars at a distance of approximately 500 pc.
- ID:
- ivo://CDS.VizieR/J/A+A/530/A150
- Title:
- XMM observations of {lambda} Ori cluster
- Short Name:
- J/A+A/530/A150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the X-ray properties of the young (~1-8Myr) open cluster around the hot (O8 III) star {lambda} Ori and compared them with those of the similarly-aged sigma Ori cluster to investigate possible effects of the different ambient environment. We analysed an XMM-Newton observation of the cluster using EPIC imaging and low-resolution spectral data. We studied the variability of detected sources, and performed a spectral analysis of the brightest sources in the field using multi-temperature models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/781
- Title:
- XMM observations of NGC 2547
- Short Name:
- J/MNRAS/367/781
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The following tables describe the results of a survey for X-ray (0.3-3 keV) sources in the young (30Myr) NGC 2547 open cluster using the XMM-Newton EPIC instrument. Table 1 lists the details of X-ray sources which are correlated with optical cluster members. Table 2 catalogues the cross-identifications with optical catalogues for the sources in Table 1 and derives their X-ray luminosities and X-ray to bolometric flux ratios. Table 3 lists the X-ray properties of sources which are uncorrelated with cluster members. Table 7 lists the correlations between cluster members detected by XMM-Newton and those detected 7 years earlier by the ROSAT HRI instrument, along with the X-ray luminosities and flux ratios as determined by the HRI.
- ID:
- ivo://CDS.VizieR/J/A+A/456/977
- Title:
- XMM observations of NGC 2516 stars
- Short Name:
- J/A+A/456/977
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the characteristics of the X-ray variability of stars in the cluster NGC 2516 as derived from XMM-Newton/EPIC/pn data. The X-ray variations on short (hours), medium (months), and long (years) time scales have been explored. We detected 303 distinct X-ray sources by analysing six EPIC/pn observations; 194 of them are members of the cluster. Stars of all spectral types, from the early-types to the late-M dwarfs, were detected.
- ID:
- ivo://CDS.VizieR/J/A+A/446/501
- Title:
- XMM observations of sigma Ori cluster
- Short Name:
- J/A+A/446/501
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an XMM-Newton observation of the young (~2-4Myr) cluster around the hot star sigma Orionis. In a previous paper (Sanz-Forcada et al., 2004A&A...421..715S) we presented the analysis of the RGS spectrum of the central hot star; here we discuss the results of the analysis of the full EPIC field. We have detected 175 X-ray sources, 88 of which have been identified with cluster members, including very low-mass stars down to the substellar limit. We detected eleven new possible candidate members from the 2MASS (Cat. <II/246>) catalogue.
