- ID:
- ivo://CDS.VizieR/J/MNRAS/361/211
- Title:
- JHK photometry of brown dwarfs in Orion
- Short Name:
- J/MNRAS/361/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a deep near-infrared (JHK) survey of the outer parts of the Trapezium Cluster with Gemini South/Flamingos. 396 sources were detected in a 26-arcmin^2^ area, including 138 brown dwarf candidates, defined as M<0.075M_{sun}_ for an assumed age of 1Myr. Only 33 of the brown dwarf candidates are planetary mass candidates with estimated masses in the range 0.003<M<0.012M_{sun}_. In an extinction-limited sample (AV<5) complete to approximately 0.005M_{sun}_ (5M_Jup_) the mass function appears to drop by a factor of 2 at the deuterium burning threshold, i.e. at planetary masses. After allowing for background contamination it is likely that planetary mass objects at 3-13M_Jup_ number <10% of the cluster population, with an upper limit of 13%. Analysis of the spatial distribution of stars and brown dwarf candidates suggests that brown dwarfs and very low-mass stars (M<0.1M_{sun}_) are less likely than more massive stars to have wide (>150AU) binary companions.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/525/A1
- Title:
- JHK photometry of CBJC 8 sources
- Short Name:
- J/A+A/525/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The infrared cluster CBJC 8 is associated with a 6.7GHz methanol maser and a compact radio-continuum source, G85.40-0.00. It is located at a distance of about 8kpc. The aim is to study the characteristics of this distant and compact embedded cluster and derive the properties of its stellar population. We present new ground-based near- and mid-imaging observations of this region. The calibrated images were analysed together with archive Spitzer IRAC images. Based on the discovery of a considerable fraction of embedded sources with infrared excess emission that are concentrated within a radius around 16arcsec centred near the position of the compact HII region G85.40-0.00, we were able to confirm the presence of a very young embedded cluster. It was found to contain more than 58 members brighter than M_K_=2.6, with two-thirds of them showing significant near- or mid-IR excess emission. Spectral energy distributions and extrapolated total luminosities are presented for nine sources with large mid-infrared excesses that were measured in all four IRAC bands. For the brightest of these, G8540A, which is associated with a methanol maser and a compact HII region, we fitted a model of an infalling envelope plus disc plus central star to its observed 1.6 to 850um fluxes to get an idea of its physical properties. We also report the presence of a single 2.12um molecular hydrogen line emission knot near the centre of the cluster, suggesting the outflow activity.
- ID:
- ivo://CDS.VizieR/J/A+A/399/147
- Title:
- JHK photometry of C-cloud IRAS sources
- Short Name:
- J/A+A/399/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of NIR (JHK) photometry for about 1000 stars in 10 fields around IRAS sources previously recognized as related to star forming sites in the Vela Molecular Ridge C and D clouds. Only objects at least detected in the K band are listed. IRAS sources are indicated by the short designation adopted in the Paper (# IRS). Due to the presence of bad pixels or because of the closeness to the image edge, photometry could not be performed on a few objects and in such cases magnitudes and errors are not given at all. Note that, for IRS 33, coordinates are offsets (in arcsec) from source # 4.
- ID:
- ivo://CDS.VizieR/J/AJ/112/2500
- Title:
- JHK' photometry of 4 clusters of galaxies
- Short Name:
- J/AJ/112/2500
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep near-infrared images of four intermediate redshift (z=0.2-0.4) clusters (Abell 370, Abell 963, CL 0024+1654 and CL 0909+4408) have been obtained in the J, H, and K bands using the UCLA Two-Channel IR Camera with a spatial resolution of ~1". The 3'x3' field of view includes over 100 galaxies in each cluster. Photometry has been obtained with 1{sigma} or limiting magnitudes of 21.7 at J, 21.0 at H, and 20.4 at K', and complete to 2 magnitudes fainter than L^*^. Data reduction techniques for flat-fielding object identification, and photometry of faint object crowded fields are discussed. The best method is the subtraction of a running-average sky made from object frames. The photometry is cross referenced to previous catalogs, and infrared color-magnitude diagrams are presented. Comparison of the IR colors of these four clusters to the predictions of the spectral synthesis models of Bruzual and Chariot is discussed. There is a discrepancy between the models and the observations of several tenths of a magnitude in the colors. Photometry has also been obtained for the gravitational lensing arcs in CL 0024+1654, which is consistent with an actively star-forming galaxy at z>1. For a description of the JHK' photometric system, see e.g. <GCPD/09>
- ID:
- ivo://CDS.VizieR/J/A+A/375/539
- Title:
- JHK photometry of compact HII regions in Cyg X
- Short Name:
- J/A+A/375/539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This table provides positions and magnitudes of all the objects a automatically detected in the frames centered at the positions of compact HII regions as described in the paper. All the regions are contained in a single table, with the region denomination as given in the paper before the data of the detected objects.
- ID:
- ivo://CDS.VizieR/J/A+A/445/69
- Title:
- JHK' photometry of C stars in NGC 147
- Short Name:
- J/A+A/445/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared J, H and K' images were used to investigate the stellar contents of the asymptotic giant branch (AGB) population in the nearby dwarf elliptical galaxy NGC 147. The obtained (K,J-K) and (K,H-K) color-magnitude diagrams contain stars of AGB and red giant branch populations, where the former consists of a group of bright blue stars, a dominant population of M giant and a red C star population.We identified 91 AGB C stars in NGC 147 with the mean absolute magnitude and colors of <M_K_>=-7.56, <(J-K)_0_>=1.81 and <(H-K)_0_>=0.74. The estimated number ratio of C stars to M giant stars (C/M) is 0.16+/-0.02. The estimated local C/M ratios of 0.14+/-0.02 for the inner region (r<70") and 0.19+/-0.03 for the outer region (r>70") indicate a weak radial gradient. The mean bolometric magnitude of 91 C stars in NGC 147 is <M_bol_>=-4.32+/-0.49. The bolometric luminosity function of M giant stars in NGC 147 extends up to M_bol_=-5.8 magnitude, and that of only C stars spans -5.6<M_bol_<-3.5. The color histograms of AGB stars in (J-K) and (H-K) show a main peak containing M giant stars, a red tail containing C stars with a weak excess, and a blue excess possibly due to bright blue foreground stars and AGB stars younger than M giants. The comparison of the theoretical isochrone models with the color distribution and the brightness of AGB stars indicates that most of the bright M giants in NGC 147 were formed at log(t_yr_)~8.4 with a range of 8.2~8.6. Ages of the majority of M giant stars in NGC 147 are similar to those of younger M giant stars in its companion NGC 185, while their formation occurred more recently than the older M giant stars in NGC 185 by ~2Gyrs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/373/781
- Title:
- JHK photometry of faint standard stars
- Short Name:
- J/MNRAS/373/781
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHK photometry in the Mauna Kea Observatories (MKO) near-infrared system is presented for 115 stars. Of these stars, 79 are United Kingdom Infrared Telescope (UKIRT) standards from Hawarden et al. (2001MNRAS.325..563H), and 42 are Las Campanas Observatory (LCO, or NICMOS) standards from Persson et al. The average brightness of the sample in all three bandpasses is 11.5mag, with a range between 10 and 15. The average number of nights each star was observed is 4, and the average of the internal error of the final results is 0.011mag. These JHK data agree with those reported by other groups to 0.02mag, for stars in common, which is consistent with the uncertainties. The measurements are used to derive colour transformations between the MKO JHK photometric system and the UKIRT, LCO and Two Micron All-Sky Survey (2MASS) systems.
- ID:
- ivo://CDS.VizieR/J/A+A/467/1025
- Title:
- JHK photometry of Fornax red giant branch
- Short Name:
- J/A+A/467/1025
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the evolved stellar populations in the dwarf spheroidal galaxy Fornax based on wide-area near-infrared observations, aimed at obtaining new independent estimates of its distance and metallicity distribution. Assessing the reliability of near-infrared methods is most important in view of future space- and ground-based deep near-infrared imaging of resolved stellar systems.
- ID:
- ivo://CDS.VizieR/J/A+AS/97/587
- Title:
- JHK photometry of Galactic center stars
- Short Name:
- J/A+AS/97/587
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present K-counts and JHK detailed photometry for a number of stars with K<=+9.0 in three clear regions near the galactic centre. These regions are all located approximately at l~0.0 and at latitudes b~-3.5,-4.0 and 4.5 respectively. Their Cumulative Counts Functions (CCF's) are formed, and with the aid of an exponential disk model for the Galaxy they are separated into disk and bulge CCF. As for the case in Baade's Window (BW) (Ruelas-Mayorga & Teague, 1992A&AS...95..379R) the disk is dominant at bright magnitudes whereas the bulge dominates at the faint end of the CCF. The slope of the bulge CCF is steeper than that for the disk in all three cases corroborating the result obtained for BW. The two colour JHK diagram and the K vs J-K diagram for the three regions show that the stellar population in these areas is similar to that studied in BW by us and by Frogel & Whitford (1987ApJ...320..199F). An average value of E(J-K)~0.42mag for the reddening is obtained, which is somewhat larger than that found for BW (0.27). Finally it is shown that at K<=+9.0, the disk population may be accounted for by those sources with J-K<=+1.6 whereas the bulge population presents values for J-K in excess of +1.6.
- ID:
- ivo://CDS.VizieR/J/AJ/133/1287
- Title:
- JHK photometry of 24 Galactic globular clusters
- Short Name:
- J/AJ/133/1287
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-IR color-magnitude diagrams and physical parameters for a sample of 24 Galactic globular clusters toward the bulge. In this paper we discuss the properties of 12 new clusters (out of the 24) in addition to those previously studied and published by our group. The compilation includes measurements of the cluster reddening, distance, photometric metallicity, horizontal branch red clump, and red giant branch morphological (e.g., mean ridgelines) and evolutionary (e.g., bump and tip) features. The compilation is available in electronic form on the World Wide Web, and it will be updated regularly.
