- ID:
- ivo://CDS.VizieR/J/A+A/489/583
- Title:
- JHKs photometry of GLIMPSE-C02
- Short Name:
- J/A+A/489/583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The estimated total number of Milky Way globulars is 160+/-20. The question of whether there are any more undiscovered globular clusters in the Milky Way is particularly relevant with advances in near and mid-IR instrumentation. This investigation is a part of a long-term project to search the inner Milky Way for hidden star clusters and to study them in detail. GLIMPSE-C02 (G02) is one of these objects, situated near the Galactic plane (l=14.129{deg}, b=-0.644{deg}). Our analysis is based on SOFI/NTT JHKs imaging and low resolution (R~1400) spectroscopy of three bright cluster red giants in the K atmospheric window. We derived the metal abundance by analysis of these spectra and from the slope of the RGB.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/355/1237
- Title:
- JHKs photometry of G287.84-0.82 members
- Short Name:
- J/MNRAS/355/1237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the properties of an infrared cluster embedded in the gas and dust of the southern part of the Carina nebula (NGC 3372), where the probable existence of current star formation has already been predicted. We used mid-infrared (A and C bands) and near-infrared (JHKs) images from the Midcourse Space Experiment and the Two-Micron All-Sky Survey, respectively, combined with an optical H{alpha} narrow-band filter image obtained at the Cerro Tololo Inter-American Observatory. The infrared star cluster has at least 17 members, and its parameters, radius and stellar density are in very good agreement with high- to intermediate-mass star formation scenarios. The detected infrared sources have roughly the same intrinsic infrared excess determined from their position in colour-colour and colour-magnitude diagrams, suggesting that these objects could be related to pre-main-sequence stars of high to intermediate mass. Furthermore, we present a low-dispersion spectrum of the LS 1883 (O9.5V) star located near the centre of the infrared cluster. The position of this object in the colour-colour and colour-magnitude infrared diagrams lies close to the reddening vector of a zero-age main-sequence O9V spectral-type star, and it seems to be the first star of this cluster to emerge. All these facts are consistent with the current star-forming scenarios associated with highly embedded star clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/366/739
- Title:
- JHKs photometry of Hourglass nebula
- Short Name:
- J/MNRAS/366/739
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A detailed study of the Hourglass nebula in the M8 star-forming region is presented. The study is mainly based on recent subarcsec-resolution JHKs images taken at Las Campanas Observatory and complemented with archival Hubble Space Telescope (HST) images and long-slit spectroscopy retrieved from the European Southern Observatory Archive Facility. Using the new numerical code CHORIZOS, we estimate the distance to the earliest stars in the region to be 1.25kpc. Infrared photometry of all the sources detected in the field is given.
- ID:
- ivo://CDS.VizieR/J/A+A/504/97
- Title:
- JHKs photometry of IC 1396N
- Short Name:
- J/A+A/504/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IC 1396N is a bright-rimmed cloud associated with an intermediate-mass star-forming region, where a number of Herbig-Haro objects, H2 jet-like features, CO molecular outflows, and millimeter compact sources have been observed. We study the complex structure of the IC 1396N core and the molecular outflows detected in the region in detail and reveal the presence of additional YSOs inside this globule. We carried out a deep survey of the IC 1396N region in the J, H, K' broadband filters and deep high-angular resolution observations in the H2 narrowband filter with NICS at the TNG telescope. The completeness limits in the 2MASS standard are Ks~17.5, H~18.5, and J~19.5.
- ID:
- ivo://CDS.VizieR/J/MNRAS/388/1185
- Title:
- JHKs photometry of LeoII dSph giants
- Short Name:
- J/MNRAS/388/1185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the evolved stellar populations in the dwarf spheroidal galaxy Leo II, based on JHKs observations obtained with the near-infrared array WFCAM at the UKIRT telescope. Combining the new data with optical data, we derived photometric estimates of the distribution of global metallicity [M/H] of individual red giant stars from their V-Ks colours. Our results are consistent with the metallicities of red giant branch (RGB) stars obtained from CaII triplet spectroscopy, once the age effects are considered.
- ID:
- ivo://CDS.VizieR/J/AJ/128/2239
- Title:
- JHKs photometry of 92 LMC Cepheids
- Short Name:
- J/AJ/128/2239
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared J, H, and K_s_ photometric measurements of 92 Cepheids in the Large Magellanic Cloud are presented. The stars are spread over the face of the Cloud, their periods range from 3 to 100 days, and their light curves are sampled at an average of 22 phase points per star. The intensity-weighted mean magnitudes and colors define period-luminosity-color (PL or PLC) relations whose uncertainties due to differential metal abundance and reddening/extinction effects are minimal. The dispersions in the infrared PL, PLC, and extinction-free period-Wesenheit relations are extremely small, amounting to less than 0.10mag (or 5% in distance).
- ID:
- ivo://CDS.VizieR/J/A+A/462/599
- Title:
- JHKs photometry of LMC cluster Cepheids
- Short Name:
- J/A+A/462/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work presents IR photometry for two young clusters known to contain sizeable Cepheid populations: NGC 1866 and NGC 2031. The goal is to determine light curves and period-luminosity (PL) relations in the near-IR, to assess the similarity between cluster and field pulsators, and to examine the predictive capability of current pulsation models. The light curves are obtained from multiwavelength broadband J,H,Ks photometry of Cepheids in both clusters, with periods previously established from optical photometry. Mean magnitudes for the Cepheids are used to construct period-luminosity (PL) relations in the near-IR. The properties in the PL planes are compared with the behavior of field Cepheids in the LMC and with the predictions of recent pulsational models, both canonical and overluminous. Cluster and field Cepheids are homogeneous and the inclusion of the cluster Cepheids in the field sample extends the PL relation. The slope of the PL relation is constant over the whole period range and does not show, at least in the adopted IR bands, the break in slope at P~10d reported by some authors. A comparison with the predictions of pulsation models allows an estimate for the distance moduli of NGC 1866 and NGC 2031. The two clusters are found to lie at essentially the same distance. Fitting of theoretical models to the data gives, for the K filter, (m-M)_0_=18.62+/-0.10 if canonical models are used and (m-M)_0_=18.42+/-0.10 if overluminous models are used.
- ID:
- ivo://CDS.VizieR/J/A+A/487/131
- Title:
- JHKs photometry of LPVs in M33
- Short Name:
- J/A+A/487/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wide-field JHKs near-infrared observations covering an area of 1.8x1.8deg^2^ centred on M33 were obtained using WFCAM at UKIRT. These data show a large population of intermediate-age asymptotic giant branch stars (AGB). We have used both C-type and M-type AGB stars to determine spatial variations in metallicity and mean age across the galaxy. We distinguished between C-type and M-type AGB stars from their location in the colour-magnitude diagram (J-Ks, Ks). The distribution of these stars is supported by a cross-identification between our sample and a catalogue of optically confirmed, long-period variable stars, as well as with the list of sources detected by Spitzer in the mid-infrared. We calculated the C/M ratio and the orientation of the galaxy in the sky, and compared the Ks magnitude distribution with theoretical distributions spanning a range of metallicities and star formation rates (SFRs). The C/M ratio surface map confirms a metallicity gradient in the galaxy corresponding to a spread in [Fe/H]=0.6dex with substructures in the inner and outer galaxy. Magnitude and colour variations suggest orientation and extinction effects on the galaxy disc. Maps showing the distribution of mean age and metallicity obtained from the Ks method suggest that: the outer galaxy disc/halo is metal poorer than the nuclear region and metal-rich clumps in the inner galaxy change location with time. The average outer ring and nuclear stellar population is ~6Gyr old while central regions are a few Gyr younger.
- 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.
- 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.
