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- ID:
- ivo://CDS.VizieR/J/AJ/111/1964
- Title:
- JHK photometry of NGC1333
- Short Name:
- J/AJ/111/1964
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an extensive near-infrared (JHK) imaging survey of the NGC 1333 star forming region. Our survey covers an area more than 4 times larger than the previous imaging survey of this cloud reported by Aspin et al. (1994, Cat. <J/A+AS/106/165>) and is sufficiently sensitive to render an accurate census of the embedded stellar population in the cloud. We detected 275 sources with m_K_<14.5mag within the 432 square arcminute region surveyed.
- ID:
- ivo://CDS.VizieR/J/A+A/564/L3
- Title:
- JHK photometry of NGC 3115 globular clusters
- Short Name:
- J/A+A/564/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combined new near-infrared VLT/HAWK-I data of the globular clusters (GCs) in the isolated edge-on S0 galaxy NGC 3115 with optical and spectroscopic ones taken from the literature, with the aim of analyzing the multiband GC color distributions. A recent study from the SLUGGS survey has shown that the GCs in this galaxy follow a bimodal distribution of CaII triplet indices. Thus, NGC3115 presents a critical example of a GC system with multiple, distinct, metallicity subpopulations, and this may argue against the "projection" scenario, which posits that the ubiquitous color bimodality mainly results from nonlinearities in the color- metallicity relations. Using optical, NIR, and spectroscopic data, we found strong and consistent evidence of index bimodality, which independently confirms the metallicity bimodality in NGC 3115 GCs. At the same time, we also found evidence for some color-color nonlinearity. Taken in the broader context of previous studies, the multicolor consistency of the GC bimodality in NGC 3115 suggests that in cases where GC systems exhibit clear differences between their optical and optical-NIR color distributions (as in some giant ellipticals), the apparent inconsistencies most likely result from nonlinearities in the color-metallicity relations.
- ID:
- ivo://CDS.VizieR/J/ApJS/193/12
- Title:
- JHK photometry of Northern Galactic Cepheids
- Short Name:
- J/ApJS/193/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared photometric measurements for 131 Northern Galactic Cepheids are presented. The Cepheid light curves are sampled with an average of 22 measurements per star fully covering the phase of each Cepheid. The J, H, and K light curves for each Cepheid were uniformly interpolated to find the intensity mean magnitudes within each band. The results are consistent within +/-1% for 26 stars in common with previous studies. This paper is the first in a projected series of two papers which will provide additional fundamental data for Cepheids in the Galaxy, namely, NIR photometry and line-of-sight extinction. In the course of this project, 93 additional variables were fortuitously observed within the Cepheid program fields, 82 of which have previously not been identified.
- ID:
- ivo://CDS.VizieR/J/A+A/375/989
- Title:
- JHK photometry of Praesepe low-mass stars
- Short Name:
- J/A+A/375/989
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table 1 contains the list of low-mass Praesepe stars observed with adaptive optics and which were not resolved as multiple systems.
- ID:
- ivo://CDS.VizieR/J/AJ/128/2364
- Title:
- JHK photometry of RCW 95 HII region
- Short Name:
- J/AJ/128/2364
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-IR imaging in the direction of the IRAS 15408-5356 point source, which is associated with the RCW 95 HII region, revealed a young and massive stellar cluster. We detected 136 member candidates up to our completeness limit, embedded in an infrared nebula and concentrated in an area of about 3pc^2^. About 60% of the candidates detected in all three of the J, H, and K bands present infrared excess at 2.2{mu}m. he UV photons provided by the most massive stars are enough to explain the observed free-free emission at radio wavelengths and the integrated infrared luminosity produced by the heated dust. The near-IR counterpart of the IRAS point source was identified using a more accurate position from the Midcourse Space Experiment (MSX) catalog; it coincides with the peak of emission in the MSX mid-IR bands. The measured integrated flux density of the infrared nebula at the K band is compatible with the expected free-free emission derived from the radio data, but an excess at the J and H bands was detected and may be due to either nonhomogeneous absorption across the nebula or to the presence of scattered stellar light, more prominent at smaller wavelengths.
- ID:
- ivo://CDS.VizieR/J/MNRAS/398/1368
- Title:
- JHK photometry of Sh 2-307 HII region
- Short Name:
- J/MNRAS/398/1368
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work aims to study the Sh 2-307 HII region and related stellar population. Near-infrared imaging and spectroscopic observations in the direction of Sh 2-307 were performed using the Ohio State InfraRed Imager/Spectrometer (OSIRIS) at the Southern Observatory for Astrophysical Research (SOAR) Telescope. The photometric data were analysed from colour-colour and colour-magnitude diagrams, while the spectroscopic results were interpreted from the comparison of the science spectra with those obtained from known OB stars.
- ID:
- ivo://CDS.VizieR/J/A+A/482/585
- Title:
- JHK photometry of stars in Sh 2-212
- Short Name:
- J/A+A/482/585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CO millimetre observations of this region obtained at the IRAM 30-m telescope to investigate the distribution of associated molecular material. We also use deep JHK observations obtained at the CFHT to study the stellar content of the region, and radio observations obtained at the VLA to look for the presence of an ultra-compact (UC) HII region and for maser emission.
- ID:
- ivo://CDS.VizieR/J/AJ/107/2120
- Title:
- JHK photometry of the OMC2 region
- Short Name:
- J/AJ/107/2120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an unbiased survey at 1.25-2.2um of a 0.025sq.deg. region surrounding the core of Orion Molecular Cloud 2 (OMC-2). Analysis of the source counts and colors indicates that the majority of the sources brighter than K=+13 are not field stars. They must be members of a young association or associations within the survey area. The K band luminosity function (corrected for field star contamination using model calculations) exhibits a drop in counts at magnitudes fainter than K=+13 (~0.15L_{sun}_). This is most easily explained by assuming that the association(s) are young. The lowest mass stars simply have not yet reached the main sequence. The distribution of colors across the region shows moderate correlation with molecular gas, but both reddened and unreddened stars are present along most lines of sight. Considerable reflection nebulosity is present in the region of the core cluster of OMC2 itself. Of particular interest are the thin streamers emanating from the star J9, which may be the remnant of a bipolar nebula produced by the star in the recent past.
- ID:
- ivo://CDS.VizieR/J/AJ/150/132
- Title:
- JHK photometry of 1203 variables in ONC
- Short Name:
- J/AJ/150/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using UKIRT on Mauna Kea, we have carried out a new near-infrared J, H, K monitoring survey of almost a square degree of the star-forming Orion Nebula Cluster with observations on 120 nights over three observing seasons, spanning a total of 894 days. We monitored ~15000 stars down to J~20 using the WFCAM instrument, and have extracted 1203 significantly variable stars from our data. By studying variability in young stellar objects (YSOs) in the H-K, K color-magnitude diagram, we are able to distinguish between physical mechanisms of variability. Many variables show color behavior indicating either dust-extinction or disk/accretion activity, but we find that when monitored for longer periods of time, a number of stars shift between these two variability mechanisms. Further, we show that the intrinsic timescale of disk/accretion variability in young stars is longer than that of dust-extinction variability. We confirm that variability amplitude is statistically correlated with evolutionary class in all bands and colors. Our investigations of these 1203 variables have revealed 73 periodic AA Tau type variables, many large-amplitude and long-period (P>15 days) YSOs, including three stars showing widely spaced periodic brightening events consistent with circumbinary disk activity, and four new eclipsing binaries. These phenomena and others indicate the activity of long-term disk/accretion variability processes taking place in young stars. We have made the light curves and associated data for these 1203 variables available online.
