Using offset-corrected Gaia-EDR3 parallax measurements and spectrophotometric methods, we have determined distances for 69 massive stars in the Carina OB1 association and associated clusters: Trumpler 16 (21 stars), Trumpler 14 (20 stars), Trumpler 15 (3 stars), Bochum 11 (5 stars), and South Pillars region (20 stars). Past distance estimates to the Carina Nebula range from 2.2 to 3.6 kpc, with uncertainties arising from photometry and anomalous dust extinction. The EDR3 parallax solutions show considerable improvement over DR2, with typical errors $σ_{\varpi}/\varpi \approx$~3-5%. The O-type stars in the Great Carina Nebula lie at essentially the same distance ($2.35\pm0.08$ kpc), quoting mean and rms variance. The clusters have distances of $2.32\pm0.12$ kpc (Tr 16), $2.37\pm0.15$ kpc (Tr 14), $2.36\pm0.09$ kpc (Tr 15), and $2.33\pm0.12$ kpc (Bochum 11) in good agreement with the $η$ Car distance of around 2.3 kpc. O-star proper motions suggest internal (2D) velocity dispersions $\sim4$ km/s for Tr 14 and Tr 16. Reliable distances allow estimates of cluster sizes, stellar dynamics, luminosities, and fluxes of photoionizing radiation incident on photodissociation regions in the region. We estimate that Tr 14 and Tr 16 have half-mass radii $r_h = 1.5-1.8$ pc, stellar crossing times $t_{\rm cr} = r_h/v_m \approx 0.7-0.8$ Myr, and two-body relaxation times $t_{rh} \approx 40-80$ Myr. The underlying velocity dispersion for Tr 14, if a bound cluster, would be $v_m \approx 2.1^{+0.7}_{-0.4}$ km/s for $N = 7600^{+5800}_{-2600}$ stars. With the higher dispersions of the O-stars, mass segregation might occur slowly, on times scales of 3-6~Myr.
We present a study, based on Gaia DR2, of the population of blue straggler stars (BSS) in the open clusters Trumpler 5, Trumpler 20, and NGC 2477. All candidates were selected according to their position in the color-magnitude diagram, to their proper motion components, and to their parallax. We also looked for yellow stragglers, i.e., possible evolved blue stragglers. We found that Trumpler 5 hosts a large BSS population, which allowed us to analyze their radial distribution as a probe of the cluster's dynamical status. The BSS distribution was compared with that of red giant branch stars (RG…
This paper presents a comprehensive analysis of two pairs of binary clusters (NGC 5617 and Trumpler 22) and (NGC 3293 and NGC 3324) located in the fourth quadrant of our Galaxy. For this purpose we use different data taken from VVV survey, WISE, VPHAS, APASS, GLIMPSE along with Gaia~EDR3 astrometric data. We identified 584, 429, 692 and 273 most probable cluster members with membership probability higher than 80 % towards the region of clusters NGC 5617, Trumpler 22, NGC 3293 and NGC 3324. We estimated the value of R as ~ 3.1 for clusters NGC 5617 and Trumpler 22, which indicates normal extinc…
We present ALMA observations of the continuum and line emission of $^{12}$CO, $^{13}$CO, C$^{18}$O, and [C I] for a portion of the G287.38-0.62 (Car 1-E) region in the Carina star-forming complex. The new data record how a molecular cloud responds on subarcsecond scales when subjected to a powerful radiation front, and provide insights into the overall process of star formation within regions that contain the most massive young stars. The maps show several molecular clouds superpose upon the line of sight, including a portion of the Western Wall, a highly-irradiated cloud situated near the you…
Context: The Carina Nebula complex (CNC) is one of the most massive and active star-forming regions in our Galaxy and it contains several large young star clusters. The distances of the individual clusters and their physical connection were poorly known up to now, with strongly discrepant results reported in the literature. Aims: We want to determine reliable distances of the young stellar clusters in the central Carina Nebula region (in particular, Tr 14, 15, and 16) and the prominent clusters NGC 3324 and NGC 3293 in the northwestern periphery of the CNC. Methods: We analyzed the parallaxes …
No country for old stars -Spectroscopic confirmation of the first intermediate-age RR Lyrae in the open cluster Trumpler 5
University of Rome Tor Vergata（罗马托尔维加塔大学）；INAF – Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Universidad de la República（乌拉圭共和国大学）；Universitat de Barcelona（巴塞罗那大学）；Monash University（蒙纳士大学）；European Southern Observatory（欧洲南方天文台）；Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文学中心）；INAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天体物理学与空间科学观测站）；Institute of Astronomy, Russian Academy of Sciences（俄罗斯科学院天文学研究所）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Leibniz-Institut für Astrophysik Potsdam（波茨坦莱布尼茨天体物理研究所）
A number of stellar open cluster (OC) pairs in the Milky Way occupy similar positions in the phase space (coordinates, parallax and proper motions) and therefore may constitute physically interacting systems. The characterization of such objects based on observational data is a fundamental step towards a proper understanding of their physical status and to investigate cluster pair formation in the Galaxy. In this work, we employed Gaia EDR3 data to investigate a set of 16 OCs distributed as seven stellar aggregates. We determined structural parameters and applied a decontamination technique th…
Aims. We aim to map the 3D distribution of the interstellar extinction of the Milky Way disk up to distances larger than those probed with the Gaia parallax alone. Methods. We apply the FEDReD (Field Extinction-Distance Relation Deconvolver) algorithm to the 2MASS near-infrared photometry together with the Gaia DR2 astrometry and photometry. This algorithm uses a Bayesian deconvolution approach, based on an empirical HR-diagram representative of the local thin disk, in order to map the extinction as a function of distance of various fields of view. Results. We analysed more than 5.6 million st…
[Abridged] Luminous hot stars dominate the stellar energy input to the interstellar medium throughout cosmological time, they are laboratories to test theories of stellar evolution and multiplicity, and they serve as luminous tracers of star formation in the Milky Way and other galaxies. Massive stars occupy well-defined loci in colour-colour and colour-magnitude spaces, enabling selection based on the combination of Gaia EDR3 astrometry and photometry and 2MASS photometry, even in the presence of substantive dust extinction. In this paper we devise an all-sky sample of such luminous OBA-type …
