- ID:
- ivo://CDS.VizieR/J/MNRAS/402/1005
- Title:
- Stellar cluster dynamical masses in NGC3310
- Short Name:
- J/MNRAS/402/1005
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gas and star velocity dispersions have been derived for eight circumnuclear star-forming regions (CNSFRs) and the nucleus of the spiral galaxy NGC 3310 using high-resolution spectroscopy in the blue and far red. Stellar velocity dispersions have been obtained from the CaII triplet in the near-IR, using cross-correlation techniques, while gas velocity dispersions have been measured by Gaussian fits to the H{beta} {lambda}4861{AA} and [OIII] {lambda}5007{AA} emission lines.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/542/A3
- Title:
- Stellar clusters from UKIDSS Galactic Plane Survey
- Short Name:
- J/A+A/542/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data mining techniques must be developed and applied to analyse the large public data bases containing hundreds to thousands of millions entries. We develop methods for locating previously unknown stellar clusters from the UKIDSS Galactic Plane Survey (GPS) catalogue data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/310/210
- Title:
- Stellar composition of CMa R1
- Short Name:
- J/MNRAS/310/210
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This directory contains movies in mpeg format which show models for the time evolution of the Hertzsprung-Russell diagram of a very young open cluster between 0 and 30Myr. Four different star formation scenario's are considered, (a) instantaneous star formation, (b) constant rate of star formation with time, (c) increasing rate of star formation, and (d) decreasing rate of star formation. For the latter three scenario's, models for a duration of the star formation episode {delta}t of 0.1, 1.0 and 10Myr are computed.
- ID:
- ivo://CDS.VizieR/J/AJ/103/1205
- Title:
- Stellar Content of LH 9 and 10 in the LMC
- Short Name:
- J/AJ/103/1205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry and spectroscopy for stars in Lucke-Hodge 9 and 10, two adjacent OB association in the northwest corner of the LMC. Our catalog contains UBV photometry (complete to ~18mag in all three filters) for 795 stars and BV-only photometry (complete to ~19mag in both filters) for an additional 434 stars.
- ID:
- ivo://CDS.VizieR/J/AJ/144/182
- Title:
- Stellar groups in IC 2574
- Short Name:
- J/AJ/144/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dissolving stellar groups are very difficult to detect using traditional surface photometry techniques. We have developed a method to find and characterize non-compact stellar systems in galaxies where the young stellar population can be spatially resolved. By carrying out photometry on individual stars, we are able to separate the luminous blue stellar population from the star field background. The locations of these stars are used to identify groups by applying the HOP algorithm, which are then characterized using color-magnitude and stellar density radial profiles to estimate age, size, density, and shape. We test the method on Hubble Space Telescope Advanced Camera for Surveys archival images of IC 2574 and find 75 dispersed stellar groups. Of these, 20 highly dispersed groups are good candidates for dissolving systems. We find few compact systems with evidence of dissolution, potentially indicating that star formation in this galaxy occurs mostly in unbound clusters or groups. These systems indicate that the dispersion rate of groups and clusters in IC 2574 is at most 0.45pc/Myr. The location of the groups found with HOP correlate well with HI contour map features. However, they do not coincide with HI holes, suggesting that those holes were not created by star-forming regions.
- ID:
- ivo://CDS.VizieR/J/ApJS/254/20
- Title:
- Stellar groups in Taurus field from Gaia DR2 & LAMOST
- Short Name:
- J/ApJS/254/20
- Date:
- 17 Jan 2022 14:18:37
- Publisher:
- CDS
- Description:
- In this work, we present a systematic search for stellar groups in the Taurus field by applying the DBSCAN algorithm to the data from Gaia DR2. We find 22 groups, consisting of 8 young groups (Groups 1-8) at ages of 2-4Myr and distances of ~130-170pc, and 14 old groups (Groups 9-22) at ages of 8-49Myr and distances of ~110-210pc. We characterize the disk properties of group members and find 19 new disk-bearing stars, 8 of which are in the young groups with 11 others belonging to the comparatively old groups at the ages of 8-11Myr. We characterize the accretion properties of the group members with H{alpha} emission lines in their Large Sky Area Multi-Object Fibre Spectroscopic Telescope spectra, and discover one source in Group 10 at an age of 10Myr which still shows accretion activity. We investigate the kinematic relations among the old groups, find that Group 9 is kinematically related to the known Taurus members, and exclude any kinematic relations between Groups 10-22 and the known Taurus members.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A148
- Title:
- Stellar populations towards Orion with Gaia DR1
- Short Name:
- J/A+A/608/A148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we use the first data release of the Gaia mission to explore the three-dimensional arrangement and age ordering of the many stellar groups toward the Orion OB association, aiming at a new classification and characterization of the stellar population not embedded in the Orion A and B molecular clouds. We make use of the parallaxes and proper motions provided in the Tycho Gaia Astrometric Solution (TGAS) subset of the Gaia Data Release 1 (DR1) catalog and of the combination of Gaia DR1 and 2MASS photometry. In TGAS, we find evidence for the presence of a young population at a parallax {varpi}~2.65mas, which is loosely distributed around the following known clusters: 25 Ori, {epsilon} Ori, and {sigma} Ori, and NGC 1980 ({iota} Ori) and the Orion Nebula Cluster (ONC). The low mass counterpart of this population is visible in the color magnitude diagrams constructed by combining Gaia DR1 G-band photometry and 2MASS. We study the density distribution of the young sources in the sky using a kernel density estimation (KDE). We find the same groups as in TGAS and also some other density enhancements that might be related to the recently discovered Orion X group, Orion dust ring, and {lambda} Ori complex. The maps also suggest that the 25 Ori group presents a northern elongation.We estimated the ages of this population using a Bayesian isochronal fitting procedure assuming a unique parallax value for all the sources, and we inferred the presence of an age gradient going from 25 Ori (13-15Myr) to the ONC (1-2Myr). We confirmed this age ordering by repeating the Bayesian fit using the Pan-STARRS1 data. Intriguingly, the estimated ages toward the NGC 1980 cluster span a broad range of values. This can either be due to the presence of two populations coming from two different episodes of star formation or to a large spread along the line of sight of the same population. Some confusion might arise from the presence of unresolved binaries, which are not modeled in the fit, and usually mimic a younger population. Finally, we provisionally relate the stellar groups to the gas and dust features in Orion. Our results form the first step toward using Gaia data to unravel the complex star formation history of the Orion region in terms of the various star formation episodes, their duration, and their effects on the surrounding interstellar medium.
- ID:
- ivo://CDS.VizieR/J/MNRAS/476/114
- Title:
- Stellar properties of Kron 3 stars
- Short Name:
- J/MNRAS/476/114
- Date:
- 02 Nov 2021 11:26:14
- Publisher:
- CDS
- Description:
- We present the results of a spectroscopic study of the intermediate age (~=6.5Gyr) massive cluster Kron 3 in the Small Magellanic Cloud. We measure CN and CH band strengths (at ~=3839 and 4300{AA}, respectively) using VLT FORS2 spectra of 16 cluster members and find a sub-population of five stars enriched in nitrogen. We conclude that this is evidence for multiple populations in Kron 3, the fourth intermediate age cluster, after Lindsay 1, NGC 416 and NGC 339 (ages 6-8Gyr), to display this phenomenon originally thought to be a unique characteristic of old globular clusters. At ~=6.5Gyr this is one of the youngest clusters with multiple populations, indicating that the mechanism responsible for their onset must operate until a redshift of at least 0.75, much later than the peak of globular cluster formation at redshift ~3.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/2427
- Title:
- Structural parameters of M33 star clusters
- Short Name:
- J/MNRAS/426/2427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the morphological properties of 161 star clusters in M33 using the Advanced Camera for Surveys Wide Field Channel on-board the Hubble Space Telescope using observations with the F606W and F814W filters. We obtain, for the first time, ellipticities, position angles and surface brightness profiles for a significant number of clusters. On average, M33 clusters are more flattened than those of the Milky Way (MW) and M31, and more similar to clusters in the Small Magellanic Cloud (SMC). The ellipticities do not show any correlation with age or mass, suggesting that rotation is not the main cause of elongation in the M33 clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A137
- Title:
- Structure and kinematics of the Taurus region
- Short Name:
- J/A+A/630/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We take advantage of the second data release of the Gaia space mission and the state-of-the-art astrometry delivered from very long baseline interferometry observations to revisit the structure and kinematics of the nearby Taurus star-forming region. We apply a hierarchical clustering algorithm for partitioning the stars in our sample into groups (i.e., clusters) that are associated with the various molecular clouds of the complex, and derive the distance and spatial velocity of individual stars and their corresponding molecular clouds. We show that the molecular clouds are located at different distances and confirm the existence of important depth effects in this region reported in previous studies. For example, we find that the L~1495 molecular cloud is located at d=129.9^+0.4^_-0.3_pc, while the filamentary structure connected to it (in the plane of the sky) is at d=160.0^+1.2^_-1.2_pc. We report B215 and L1558 as the closest (d=128.5^+1.6^_-1.6_pc) and most remote (d=198.1^+2.5^_-2.5_pc) substructures of the complex, respectively. The median inter-cloud distance is 25pc and the relative motion of the subgroups is on the order of a few km/s. We find no clear evidence for expansion (or contraction) of the Taurus complex, but signs of the potential effects of a global rotation. Finally, we compare the radial velocity of the stars with the velocity of the underlying ^13^CO molecular gas and report a mean difference of 0.04+/-0.12km/s (with r.m.s. of 0.63km/s) confirming that the stars and the gas are tightly coupled.
