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- ID:
- ivo://CDS.VizieR/J/MNRAS/353/1025
- Title:
- JHK photometry of 4 W51 star clusters
- Short Name:
- J/MNRAS/353/1025
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present sub-arcsecond (0.35-0.9"), near-infrared J-, H- and K-band photometric observations of six fields along the W51 giant molecular cloud (W51 GMC). Our observations reveal four new, embedded clusters and provide a new high-resolution (0.35") view of the W51 IRS2 (G49.5-0.4) region. The cluster associated with G48.9-0.3 is found to be a double cluster enclosed in a nest of near-infrared nebulosity. We construct stellar surface density maps for four major clusters in the W51 GMC. These unveil the underlying hierarchical structure.
- ID:
- ivo://CDS.VizieR/J/AJ/126/1916
- Title:
- JHK photometry of young clusters near the Sun
- Short Name:
- J/AJ/126/1916
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of near-infrared surveys of young (<~a few 10^6^yr) stellar groups and clusters within 1kpc from the Sun, based on an extensive search of the literature from the past ten years. We find 143 surveys from 69 published articles, covering 73 different regions. The number distribution of stars in a region has a median of 28 and a mean of 100. About 80% of the stars are in clusters with at least 100 members. By a rough classification of the groups and clusters based on the number of their associated stars, we show that most of the stars form in large clusters. The spatial distribution of catalogued regions in the Galactic plane shows a relative lack of observed stellar groups and clusters in the range 270{deg}<l<60{deg} of Galactic longitude, reflecting our location between the Local and Sagittarius arms. This compilation is intended as a useful resource for future studies of nearby young regions of multiple star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/472/835
- Title:
- JHKs and GLIMPSE photometry of RCW 120
- Short Name:
- J/A+A/472/835
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the process of star formation triggered by the expansion of an HII region, we present a multi-wavelength analysis of the Galactic HII region RCW 120 and its surroundings. The collect and collapse model predicts that the layer of gas and dust accumulated between the ionization and shock fronts during the expansion of the HII region collapses and forms dense fragments, giving rise to potential sites of massive-star formation. The aim of our study is to look for such massive fragments and massive young stars on the borders of RCW 120. We mapped the RCW 120 region in the cold dust continuum emission at 1.2 mm to search for these fragments. We supplemented this study with the available near- (2MASS) and mid-IR (GLIMPSE) data to locate the IR sources observed towards this region and to analyse their properties. We then compared the observational results with the predictions of Hosokawa & Inutsuka's model (2005ApJ...623..917H; 2006ApJ...646..240H).
- ID:
- ivo://CDS.VizieR/J/A+A/496/177
- Title:
- JHKs and GLIMPSE photometry of RCW 120
- Short Name:
- J/A+A/496/177
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study deals with the star formation triggered by HII regions. We wish to take advantage of the very simple morphology of RCW 120 - a perfect bubble - to understand the mechanisms triggering star formation around an HII region and to establish what kind of stars are formed there. We present 870um observations of RCW 120, obtained with the APEX-LABOCA camera. These show the distribution of cold dust, and thus of neutral material. We use Spitzer-MIPS observations at 24um and 70um to detect the young stellar objects present in this region and to estimate their evolutionary stages.
- ID:
- ivo://CDS.VizieR/J/MNRAS/380/1497
- Title:
- JHKs & GLIMPSE photometry towards G305.2+0.2
- Short Name:
- J/MNRAS/380/1497
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep, wide field J, H and Ks images taken with Infrared Imager and Spectrometer 2 (IRIS2) on the Anglo-Australian Telescope, towards the massive star formation region G305.2+0.2. Combined with 3.6, 4.5, 5.8 and 8.0um data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey on the Spitzer Space Telescope, we investigate the properties of the embedded stellar populations. After removing contamination from foreground stars, we separate the sources based on their infrared (IR) colour. Strong extended emission in the GLIMPSE images hampers investigation of the most embedded sources towards the known sites of massive star formation. However, we find a sizeable population of IR excess sources in the surrounding region free from these completeness effects. Investigation reveals the recent star formation activity in the region is more widespread than previously known.
- ID:
- ivo://CDS.VizieR/J/MNRAS/385/1045
- Title:
- JHKsIc photometry of AGB in Phoenix dwarf gal.
- Short Name:
- J/MNRAS/385/1045
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKs near-infrared photometry of stars in the Phoenix dwarf galaxy is presented and discussed. Combining these data with the optical photometry of Massey et al. (2007, Cat. <J/AJ/133/2393>) allows a rather clean separation of field stars from Phoenix members. The discovery of a Mira variable (P=425d), which is almost certainly a carbon star, leads to an estimate of the distance modulus of 23.10+/-0.18 that is consistent with other estimates and indicates the existence of a significant population of age ~2Gyr. The two carbon stars of Da Costa have Mbol=-3.8 and are consistent with belonging to a population of similar age; some other possible members of such a population are identified. A Da Costa non-carbon star is {Delta}Ks~0.3mag brighter than these two carbon stars. It may be an asymptotic giant branch star of the dominant old population. The nature of other stars lying close to it in the Ks, (J-Ks) diagram needs studying.
- ID:
- ivo://CDS.VizieR/J/A+A/470/231
- Title:
- JHKsIL' images of IRAS 06468-0325
- Short Name:
- J/A+A/470/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our new near-infrared J and Ks-band images taken towards IRAS 06468-0325 revealed the presence of extended emission with very unusual and enigmatic morphology: that of a diamond-ring, that is, a ring or torus with a bright source overlaping the edge of it (not inside it). We report the discovery of this source, explore its nature, and propose possible interpretations of its morphological structure. We observed IRAS 06468-0325 obtaining optical and infrared images through IJHKs and L' filters, K-band low-resolution spectroscopy, together with millimetre line observations of CO(1-0), ^13^CO(2-1), C^18^O(2-1), and CS(2-1).
- ID:
- ivo://CDS.VizieR/J/ApJ/699/1196
- Title:
- JHKs light curves of 2MASS J05352184-0546085
- Short Name:
- J/ApJ/699/1196
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared JHK_S_ light curves for the double-lined eclipsing binary system Two Micron All Sky Survey J05352184-0546085, in which both components have been shown to be brown dwarfs with an age of ~1Myr. We analyze these light curves together with the previously published I_C_-band light curve and radial velocities to provide refined measurements of the system's physical parameters. The component masses and radii are here determined with an accuracy of ~6.5% and ~1.5%, respectively. In addition, we confirm the previous surprising finding that the primary brown dwarf has a cooler effective temperature than its lower mass companion. Our analysis reveals two low-amplitude (~0.02mag) periodic signals, one attributable to the rotation of the primary with a period of 3.293+/-0.001d and the other to the rotation of the secondary with a period of 14.05+/-0.05d. Both periods are consistent with the measured vsin i and radii.
- ID:
- ivo://CDS.VizieR/J/A+A/406/75
- Title:
- JHKs magnitudes of variables in NGC 5128
- Short Name:
- J/A+A/406/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first variable star catalogue in a giant elliptical galaxy NGC 5128 (Centaurus A) is presented. Using multi-epoch observations with ISAAC at the VLT we have detected 1504 red variables in two halo fields covering 10.46-arcmin square. For the variables with at least 10 good measurements, periods and amplitudes were determined using Fourier analysis and non-linear sine-curve fitting algorithms. The final catalogue contains 1146 long period variables with well established light curve parameters. Periods, amplitudes, JsHKs photometry as well as individual KS-band magnitudes are provided for all the variables. The distribution of amplitudes ranges from 0.3 to a few magnitudes in the Ks-band, with a median value around 0.7mag. The amplitudes, mean magnitudes and periods indicate that the majority of variables belong to the class of long period variables with semiregular and Mira variables. Exhaustive simulations were performed in order to assess the completeness of our catalogue and the accuracy of the derived periods.
