- ID:
- ivo://CDS.VizieR/J/MNRAS/367/513
- Title:
- JHKs[3.5][4.5] photometry of NGC 3372
- Short Name:
- J/MNRAS/367/513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an imaging survey, from the optical to the mid-infrared, of the dark cloud associated with Car I, a dense cloud that is subject to an intense ultraviolet radiation field from the rich stellar cluster Trumpler 14. New ground-based broad- and narrow-band near-infrared and narrow-band optical images are analysed in combination with archived Spitzer/Infra-Red Array Camera (IRAC) images to study this photodissociation region (PDR) and the triggering of a new generation of stars within the cloud, particularly close to its edges. Evidence is given of a clumpy morphology of the dense cloud. The ionization/dissociation front is delineated at the edges of these clumps. The existence of a number of embedded low- to intermediate-mass pre-main-sequence objects is confirmed by their considerable infrared excesses arising from discs and/or detectable X-ray emission. Most of the young stellar objects (YSOs) are located on or just behind ionization fronts, though a few are also outside the cloud. The infrared properties of the YSOs are discussed.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/132/2653
- Title:
- JHKs photometry of N11 young stellar objects
- Short Name:
- J/AJ/132/2653
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared observations have been carried out to survey young stellar objects in the second-largest HII region in the Large Magellanic Cloud, N11. A total area of about 700 arcmin2 is covered in the J, H, and Ks bands. We selected a total of 559 OB and 127 Herbig Ae/Be star candidates out of the detected sources based on their near-infrared colors and magnitudes. The existence of these young stellar objects indicates that star formation activity is underway in the whole N11 region. Many Herbig Ae/Be star candidates are distributed around the periphery of the OB association LH 9. Spatial correlations of the OB and Herbig Ae/Be star candidates with the objects observed at other wavelengths (optical, radio continuum, H{alpha}, CO, and X-ray) suggest that the birth of the young stellar populations in peripheral molecular clouds was triggered originally by LH 9. It is likely that the trigger for this star formation was an expanding supershell blown by the OB association. In N11 a new generation of stars would have been formed in the clouds developed from swept-up interstellar medium.
1403. JHKs photometry of S269
- ID:
- ivo://CDS.VizieR/J/ApJ/596/1064
- Title:
- JHKs photometry of S269
- Short Name:
- J/ApJ/596/1064
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The star-forming region S269 is studied with deep JHKs and H_2_v=1-0S(1) images and K-band spectroscopy. The JHKs images were obtained on 2002 March 1, by using the Simultaneous-3color InfraRed Imager for Unbiased Survey of Nagoya University mounted on the InfraRed Survey Facility (IRSF) 1.4m telescope of Nagoya University at Sutherland, South African Astronomical Observatory. We obtained the broadband J, H, and K' images and narrow-band H_2_v=1-0S(1) image on 1999 November 22, using the Okayama Astrophysical System for Infrared Imaging and Spectroscopy mounted on the Okayama 1.88m telescope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/3492
- Title:
- JHKs photometry of Sculptor dSph galaxy
- Short Name:
- J/MNRAS/414/3492
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKs photometry is presented for a 35 arcmin^2^ field centred on the Sculptor dwarf spheroidal galaxy. With the aid of published kinematic data definite galaxy members are identified and the width in J-K of the colour-magnitude diagram is shown to be consistent with an old population of stars with a large range in metal abundance. We identify two Asymptotic Giant Branch variables, both carbon Miras, with periods of 189 and 554d, respectively, and discuss their ages, metallicities and mass-loss as well as their positions in the Mira period-luminosity diagram. There is evidence for a general period-age relation for Local Group Miras. The mass-loss rate for the 554d variable, MAG29, appears to be consistent with that found for Miras of comparable period in other Local Group galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/370/1979
- Title:
- JHKs photometry of T2Cs in globular clusters
- Short Name:
- J/MNRAS/370/1979
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the result of our near-infrared observations (JHKs) for type II Cepheids (including possible RV Tau stars) in galactic globular clusters. We detected variations of 46 variables in 26 clusters (10 new discoveries in seven clusters) and present their light curves. Their periods range from 1.2d to over 80d. They show a well-defined period-luminosity relation at each wavelength. Two type II Cepheids in NGC 6441 also obey the relation if we assume the horizontal branch stars in NGC 6441 are as bright as those in metal-poor globular clusters in spite of the high metallicity of the cluster.
- ID:
- ivo://CDS.VizieR/J/ApJS/155/123
- Title:
- JHKs photometry of ultracompact HII regions
- Short Name:
- J/ApJS/155/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present adaptive optics (AO) assisted J, H, and K/K' images of eight ultracompact HII (UC HII) regions taken with the ALFA (Adaptive optics with a Laser For Astronomy) and ADONIS (ADaptive Optics Near-Infrared System) AO systems at Calar Alto and La Silla observatories. The images show details of the stellar population and the near-IR morphology of UC HII regions with unprecedented resolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/857/54
- Title:
- JHKs photometry of VVV RR Lyrae stars
- Short Name:
- J/ApJ/857/54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RR Lyrae stars (RRLs) are tracers of the Milky Way's fossil record, holding valuable information on its formation and early evolution. Owing to the high interstellar extinction endemic to the Galactic plane, distant RRLs lying at low Galactic latitudes have been elusive. We attained a census of 1892 high-confidence RRLs by exploiting the near-infrared photometric database of the VVV survey's disk footprint spanning ~70{deg} of Galactic longitude, using a machine-learned classifier. Novel data-driven methods were employed to accurately characterize their spatial distribution using sparsely sampled multi-band photometry. The RRL metallicity distribution function (MDF) was derived from their K_s_-band light-curve parameters using machine-learning methods. The MDF shows remarkable structural similarities to both the spectroscopic MDF of red clump giants and the MDF of bulge RRLs. We model the MDF with a multi-component density distribution and find that the number density of stars associated with the different model components systematically changes with both the Galactocentric radius and vertical distance from the Galactic plane, equivalent to weak metallicity gradients. Based on the consistency with results from the ARGOS survey, three MDF modes are attributed to the old disk populations, while the most metal-poor RRLs are probably halo interlopers. We propose that the dominant [Fe/H] component with a mean of -1dex might correspond to the outskirts of an ancient Galactic spheroid or classical bulge component residing in the central Milky Way. The physical origins of the RRLs in this study need to be verified by kinematical information.
- ID:
- ivo://CDS.VizieR/J/ApJS/234/42
- Title:
- JHKs polarimetry in Circinus Molecular Cloud
- Short Name:
- J/ApJS/234/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of near-infrared (NIR) linear imaging polarimetry in the J, H, and Ks bands of the low-mass star cluster-forming region in the Circinus Molecular Cloud Complex. Using aperture polarimetry of point-like sources, positive detection of 314, 421, and 164 sources in the J, H, and Ks bands, respectively, was determined from among 749 sources whose photometric magnitudes were measured. For the source classification of the 133 point-like sources whose polarization could be measured in all 3 bands, a color-color diagram was used. While most of the NIR polarizations of point-like sources are well-aligned and can be explained by dichroic polarization produced by aligned interstellar dust grains in the cloud, 123 highly polarized sources have also been identified with some criteria. The projected direction on the sky of the magnetic field in the Cir-MMS region is indicated by the mean polarization position angles (70{deg}) of the point-like sources in the observed region, corresponding to approximately 1.6x1.6pc^2^. In addition, the magnetic field direction is compared with the outflow orientations associated with Infrared Astronomy Satellite sources, in which two sources were found to be aligned with each other and one source was not. We also show prominent polarization nebulosities over the Cir-MMS region for the first time. Our polarization data have revealed one clear infrared reflection nebula (IRN) and several candidate IRNe in the Cir-MMS field. In addition, the illuminating sources of the IRNe are identified with near- and mid-infrared sources.
- ID:
- ivo://CDS.VizieR/J/AJ/133/99
- Title:
- JHKs surface brightness of Galactic globular.
- Short Name:
- J/AJ/133/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have mosaicked Two Micron All Sky Survey (2MASS) images to derive surface brightness profiles in J, H, and Ks for 104 Galactic globular clusters. We fit these with King profiles and show that the core radii are identical to within the errors for each of these IR colors and are identical to the core radii at V in essentially all cases. We derive integrated-light colors V-J, V-H, V-Ks, J-H, and J-Ks for these globular clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/852/78
- Title:
- JHKs, WISE and Spitzer data of Galactic Cepheids
- Short Name:
- J/ApJ/852/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Classical Cepheids are well-known and widely used distance indicators. As distance and extinction are usually degenerate, it is important to develop suitable methods to robustly anchor the distance scale. Here, we introduce a near-infrared optimal distance method to determine both the extinction values of and distances to a large sample of 288 Galactic classical Cepheids. The overall uncertainty in the derived distances is less than 4.9%. We compare our newly determined distances to the Cepheids in our sample with previously published distances to the same Cepheids with Hubble Space Telescope parallax measurements and distances based on the IR surface brightness method, Wesenheit functions, and the main-sequence fitting method. The systematic deviations in the distances determined here with respect to those of previous publications is less than 1%-2%. Hence, we constructed Galactic mid-IR period-luminosity (PL) relations for classical Cepheids in the four Wide-Field Infrared Survey Explorer (WISE) bands (W1, W2, W3, and W4) and the four Spitzer Space Telescope bands ([3.6], [4.5], [5.8], and [8.0]). Based on our sample of hundreds of Cepheids, the WISE PL relations have been determined for the first time; their dispersion is approximately 0.10mag. Using the currently most complete sample, our Spitzer PL relations represent a significant improvement in accuracy, especially in the [3.6] band which has the smallest dispersion (0.066mag). In addition, the average mid-IR extinction curve for Cepheids has been obtained: A_W1_/A_Ks_~0.560, A_W2_/A_Ks_~0.479, A_W3_/A_Ks_~0.507, A_W4_/A_Ks_~0.406, A_[3.6]_/A_Ks_~0.481, A_[4.5]_/A_Ks_~0.469, A_[5.8]_/A_Ks_~0.427, and A_[8.0]_/A_Ks_~0.427mag.
