We present deep UBVI photometry for Trumpler 20, a rich, intermediate-age open cluster located at l=301.47, b=+2.22 (RA=12:39:34, DEC=-60:37:00, J2000.0) in the fourth Galactic quadrant. In spite of its interesting properties, this cluster has received little attenti on, probably because the line of sight to it crosses twice the Carina spiral arm, which causes a significant contamination of its color-magnitude diagram (CMD) by field stars, therefore complicating seriously its interpretation. We provide more robust estimates of the fundamental parameters of Trumpler 20, and investigate the most prominent features of its CMD: a rich He-burning star clump, and a vertical sequence of stars above the turnoff, which can be either blue stragglers or field stars. Our precise photometry has allowed us to derive updated values of the age and heliocentric distance of Trumpler 20, which we estimate to be 1.4 $\pm$ 0.2 Gyr and 3.0 $\pm$ 0.3 kpc, respectively. As predicted by models, at this age the clump has a tail towards fainter magnitudes and bluer colors, thus providing further confirmation of the evolutionary status of stars in this particular phase. The derived heliocentric distance places the cluster in the inter-arm region between the Carina and Scutum arms, which naturally explains the presence of the vertical sequence of stars (which was originally interpreted as the cluster itself) observed in the upper part of the CMD.Most of these stars would therefore belong to the general galactic field, while only a few of themwould be bona fide cluster blue stragglers. Our data suggest that the cluster metallicity is solar, and that its reddening is \textit{E(B-V)} = 0.35 $\pm$ 0.04.
Context. Sulfur (S) is one of the lesser-studied $α$-elements. Published investigations of its behavior have so far focused on local stars, and only a few clusters of the Milky Way have been considered to study this topic. We aim to study the S content of the globular cluster Ruprecht 106 -- which has never before been studied for this purpose, but is known to present low levels of the [$α$/Fe] abundance ratio -- and the open cluster Trumpler 5. The only star studied so far in Trumpler 5 shows an unexpectedly low abundance of S. Aims. With this work, we aim to provide the first S abundance in …
We carried out UBVRcIc photometric study of three poorly studied young open clusters IC 1442, King 21, and Trumpler 7 (Tr 7). We obtained 263, 244, and 128 member stars using Gaia DR2 proper motions and parallaxes in IC 1442, King 21, and Tr 7, respectively. The reddening, E(B-V), was derived to be 0.54+/-0.04, 0.76+/-0.06, and 0.38+/-0.04 mag for these clusters. The comparison of observed colour-magnitude diagrams (CMDs) with solar metallicity isochrones yields log(Age) = 7.40+/-0.30, 7.70+/-0.20, and 7.85+/-0.25 yr and corresponding distances 2847+/-238, 2622+/-156, and 1561+/-74 pc for IC 1…
Open clusters are central elements of our understanding of the Galactic disk evolution, as an accurate determination of their parameters leads to an unbiased picture of our Galaxy's structure. Extending the analysis towards fainter magnitudes in cluster sequences has a significant impact on the derived fundamental parameters, such as extinction and total mass. We perform a homogeneous analysis of six open stellar clusters in the Galactic disk using kinematic and photometric information from the Gaia DR2 and VVV surveys: NGC6067, NGC6259, NGC4815, Pismis18, Trumpler23, and Trumpler20. We implem…
We investigate the physical conditions of the CO gas near the young star cluster, Trumpler 14 of the Carina Nebula. The observations presented in this work are taken with the Fourier Transform Spectrometer (FTS) of the Spectral and Photometric Imaging REceiver (SPIRE) onboard the Herschel Space Observatory. Our field of view covers the edge of a cavity carved by Trumpler 14 about $1\,\mathrm{Myr}$ ago and marks the transition from HII regions to photo-dissociation regions. With the state-of-the-art Meudon PDR code, we successfully derive the physical conditions, which include the thermal press…
For application to surveys of interstellar matter and Galactic structure, we compute new spectrophotometric distances to 139 OB stars frequently used as background targets for UV spectroscopy. Many of these stars have updated spectral types and digital photometry with reddening corrections from the Galactic O-Star (GOS) spectroscopic survey. We compare our new photometric distances to values used in previous IUE and FUSE surveys and to parallax distances derived from Gaia-DR2, after applying a standard (0.03 mas) offset from the quasar celestial reference frame. We find substantial differences…
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）
We present and discuss photometric optical data in the area of the OB association Sco OB1 covering about 1 squared degree. UBVI photometry is employed in tandem with Gaia DR2 data to investigate the 3 dimensional structure and the star formation history of the region. By combining parallaxes and proper motions we identify 7 physical groups located between the young open cluster NGC 6231 and the bright nebula IC4628. The most prominent group coincides with the sparse open cluster Trumpler 24. We confirm the presence of the intermediate age star cluster VdB-Hagen 202, which is unexpected in this…
Passing through the Galactic disk, a massive object such as a globular cluster, can trigger star formation process leading to the birth of open clusters. Here, we analyze such possible evolutionary relationship between globular and open clusters. To search for the closest rapprochement between objects we computed backwards the orbits of 150 Galactic globular and 232 open clusters (younger than 100 Myr) with proper motions, derived from the Gaia DR2 Catalog. The orbits were computed using the recently modified three-component (disk, bulge and halo) axisymmetric Navarro-Frenk-White potential, wh…
We present the results of long-term photometric monitoring of two active galactic nuclei, 2MASX J08535955+7700543 (z $\sim$ 0.106) and VII Zw 244 (z $\sim$ 0.131), being investigated by the reverberation mapping method in medium-band filters. To estimate the size of the broad line region, we have analyzed the light curves with the JAVELIN code. The emission line widths have been measured using the spectroscopic data obtained at the 6-m BTA telescope of SAO RAS. We give our estimates of the supermassive black hole masses $\lg (M/M_{\odot})$, $7.398_{-0.171}^{+0.153}$, and $7.049_{-0.075}^{+0.06…
We present a novel infrared spectral energy distribution (SED) modeling methodology that uses likelihood-based weighting of the model fitting results to construct probabilistic H-R diagrams (pHRD) for X-ray identified, intermediate-mass (2-8 $M_{\odot}$), pre-main sequence young stellar populations. This methodology is designed specifically for application to young stellar populations suffering strong, differential extinction ($ΔA_V > 10$ mag), typical of Galactic massive star-forming regions. We pilot this technique in the Carina Nebula Complex (CNC) by modeling the 1-8 $μ$m SEDs of 2269 like…
University of Split, Faculty of Science（斯普利特大学理学院）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，天体物理与行星学研究所）；Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa（里斯本大学理学院，空间与天体物理研究所）；European Southern Observatory（欧洲南方天文台）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Istituto Nazionale di Astrofisica (INAF) - Osservatorio Astronomico di Palermo（意大利国家天体物理研究所（INAF）- 巴勒莫天文台）
Total infrared fluxes are estimated for 99 HII regions around massive stars. The following wavebands have been used for the analysis: 8 and 24 $μ$m, based on data from Spitzer space telescope (IRAC and MIPS, respectively); 70, 160, 250, 350, and 500 $μ$m, based on data from Herschel Space Observatory (PACS and SPIRE). The estimated fluxes are used to evaluate the mass fraction of polycyclic aromatic hydrocarbons ($q_{\rm PAH}$) and the intensity of the ultraviolet emission in the studied objects. It is shown that the PAH mass fraction, $q_{\rm PAH}$, is much lower in these objects than the ave…
GALACTICNUCLEUS: A high angular resolution JHKs imaging survey of the Galactic centre. V. Toward the GNS Second Data Release: Methodology, Photometric and Astrometric Performance
Instituto de Astrofísica de Andalucía (CSIC)（安达卢西亚天体物理学研究所）；Laboratoire d’Astrophysique de Bordeaux (LAB), Université de Bordeaux（波尔多大学天体物理实验室）
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…
The astrophysical parameters of the open star cluster Mayer 3 have been estimated using the Newtonian focus (f/4.84) of the 1.88 m Telescope of Kottamia Observatory in Egypt. The VRI observations have been carried out down to a limiting magnitude of V ~ 20 mag. To emphasize the main astrophysical parameters, Near-Infra Red, Two Micron All Sky Survey (2MASS-JHK) database has been used. Analyzing the color-magnitude diagrams and radial density distribution of Mayer 3, the cluster's age, reddening, distance from the Sun, the limited border, core and tidal radii are evaluated. The photometrical me…
Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68°> l > -70°
（节略）我们首次公开发布了Hi-GAL的高质量数据产品（DR 1），即{ \em Herschel}红外银道面巡天。Hi-GAL是从近红外到射电的一系列连续星系面调查的基石，覆盖70，160，250，350和500微米的五个波段，包括8 < T <50 K的冷尘埃光谱能量分布的峰值。这是第一次Hi-GAL数据发布，涵盖了|b| <1°纬度带内68° > 1> -70°经度范围内的银河系。ROMAGAL管道利用{ \em Herschel} PACS和SPIRE测光相机的测辐射热计阵列的出色灵敏度和稳定性制作了测光图，以提供高质量和动态范围的图像，并使用{ \em Planck}和{ \em IRAS}进行绝对校准，并恢复所有波长和所有空间尺度的扩展发射。紧凑的源目录已生成的CuTEx算法，专门开发，以优化源检测和提取的极端条件下的激烈和空间变化的背景，发现在银河平面的热红外。Hi-GAL DR 1图像可通过专门的基于网络的图像剪切服务访问。DR 1紧凑型源目录以单波段光度列表的形式提供，除了源位置、峰值和积分通量以及源大小之外，还包含各种用于评估所提取源的质量和可靠性的参数，并提供了有助于评估的注意事项和提示。所有波段的通量完整性极限是由广泛的合成源实验确定的，并取决于沿银道面的特定视线。Hi-GAL DR 1星表在五个波段分别包含123210、308509、280685、1609…
Photometric metallicity for 694233 Galactic giant stars from Gaia DR3 synthetic Stromgren photometry. Metallicity distribution functions of halo sub-structures
Photometric redshifts for active galactic nuclei with LePHARE for the Vera C. Rubin Observatory
Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；Exzellenzcluster ORIGINS（ORIGINS卓越集群）；Université Clermont-Auvergne（克莱蒙奥弗涅大学）；Aix-Marseille Université（艾克斯-马赛大学）；Université Paris-Saclay（巴黎萨克雷大学）；Université Paris-Cité（巴黎 Cité 大学）；Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales（迭戈帕拉莱斯大学工程学院天文学中心）；School of Physics and Astronomy, University of Southampton（南安普顿大学物理与天文学院）；INAF-Osservatorio Astronomico di Roma（罗马国家天体物理研究所天文台）；Institute for Gravitation and the Cosmos, The Pennsylvania State University（宾夕法尼亚州立大学引力与宇宙学研究所）
本研究针对Vera C. Rubin天文台的LSST巡天，用LePHARE分析AGN测光红移的影响因素，提供AGN处理配置及COSMOS天区AGN测光红移数据，优化AGN测光红移计算。
We have started automatized photometric monitoring of active galactic nuclei using the 46 cm telescope of the Wise Observatory in Israel. The telescope is specially equipped with narrow-band filters to perform high-fidelity photometric reverberation mapping of the accretion disk in V < 17 mag sources up to z ~ 0.1. Here, we describe the capability and accuracy of the experiment, and present the first science verification data obtained for the Seyfert 1 galaxy Mrk 279. With sub-diurnal sampling over more than two months, and typical flux measurement uncertainties of $1\%$, we are able to measur…
We obtained new multicolour photometry of close binary stars in the young open cluster M35, the solar-age open cluster M67, and the globular cluster M71. New observations have been carried out at the TÜBİTAK National Observatory (TUG) by using the 100cm (T100) telescope. We present observational results for eclipsing binary systems in the selected Galactic clusters. New accurate light curves for 2MASS J19532554 + 1851175, 2MASS J19533427 + 1844047, 2MASS J06092044 + 2415155, and AH Cnc were obtained. The light curves were analysed and we derived some of the orbital parameters of the systems.
Based on Sloan Digital Sky Survey (SDSS) photometric data, Gu developed a new Monte-Carlo-based method for estimating the stellar metallicity distribution functions (MDFs). This method enables a more reliable determination of MDFs compared with the conventional polynomial-based methods. In this work, MDF determined from the method are well fit by three-Gaussian model, with peaks at ${\rm [Fe/H]}$=$-0.68$, $-1.38$, and $-1.90$, associated with the thick disk, inner halo, and outer halo, respectively. The vertical metallicity gradient within $1<Z<5\,{\rm kpc}$ is ${\rm d}\langle{\rm [Fe/H]}\rang…
The photometric properties that we could observe for Extra-Galactic Globular Clusters (EGGCs) are the integrated light of the system and for nearby EGGCs it also is possible to measure both half-light radii and the color spatial distribution, e.g. for areas smaller and larger than the half-light radius. No information about the internal dynamical state of the system could be directly obtained from observations. On the other hand, simulations of Globular Clusters (GCs) can provide detailed information about the dynamical evolution of the system. We present a preliminary study of EGGCs' photomet…
We present the discovery of 32 new double periodic variables (DPVs) located toward the Galactic bulge. We found these objects among the nearly half a million binary stars published by the Optical Gravitational Lensing Experiment project. With this discovery, we increase the number of known DPVs in the Milky Way by a factor of 2. The new set of DPVs contains 31 eclipsing binaries and one ellipsoidal variable star. The orbital periods cover the range from 1.6 to 26 days, while long periods are detected between 47 and 1144 days. Our analysis confirms a known correlation between orbital and long p…
Astrometry and spectroscopy of the S-stars in the Galactic Center provide a unique way to probe the properties of the central supermassive black hole, as well as the post-Newtonian effects caused by its gravity, e.g. gravitational redshift and general relativistic precession. It has also been suggested that the photometry of S-stars can be used for studying the properties of gaseous environment of Sgr A$^*$. Due to the high velocities of the S-stars, sometimes approaching $~0.1c$, their photometric signal should be considerably affected by the Doppler boosting. We calculate this relativistic e…
