- ID:
- ivo://CDS.VizieR/J/AJ/110/2788
- Title:
- JHK photometry for Galactic bulge stars
- Short Name:
- J/AJ/110/2788
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep near-IR photometry for Galactic bulge stars in Baade's Window, (l, b)=(1.0deg, -3.9deg), and another minor axis field at (l, b)=(0deg, -6deg). We combine our data with previously published photometry and construct a luminosity function over the range 5.5=<K0=<16.5, deeper than any previously published. The slope of this luminosity function and the magnitude of the tip of the first ascent giant branch are consistent with theoretical values derived from isochrones with appropriate age and metallicity. We use the relationship between [Fe/H] and the giant branch slope derived from near-IR observations of metal-rich globular clusters by Kuchinski et al. (1995AJ....109.1131K) to calculate the mean metallicity for several bulge fields along the minor axis.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/365/439
- Title:
- JHK photometry for UKIRT faint galaxies
- Short Name:
- J/MNRAS/365/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multicolour catalogue of faint galaxies situated close to bright stars, V<15, with the aim of identifying high-redshift galaxies suitable for study with adaptive optics-equipped near-infrared imagers and spectrographs. The catalogue is constructed from archival calibration observations of the United Kingdom Infrared Telescope (UKIRT) Faint Standard stars with the UKIRT Fast Track Imager (UFTI) camera on UKIRT. We have analysed the deepest 16 fields from the archive to provide a catalogue of galaxies brighter than K~20.3 lying between 3 and 25-arcsec of the guide stars. We identify 111 objects in a total survey area of 8.7arcmin^2^. Of these, 87 are classified as galaxies based on their light profiles in our ~0.5arcsec median seeing K-band images. 12 of the galaxies have (J-K)>~2.0 consistent with them lying at high redshifts, z>~2. These 12 very red galaxies have K-band magnitudes of K=18.1-20.1 and separations from the guide stars of 4-20arcsec and hence are very well suited to adaptive optics studies to investigate their morphologies and spectral properties on sub-kpc scales. We provide coordinates and JHK photometry for all catalogued objects.
1013. JHK photometry in Cha I
- ID:
- ivo://CDS.VizieR/J/AJ/121/974
- Title:
- JHK photometry in Cha I
- Short Name:
- J/AJ/121/974
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a near-infrared imaging survey covering ~1deg^2^ of the Chamaeleon I dark cloud. The survey is complete for K<15.0, H<16.0, and J<16.5, roughly 2 magnitudes more sensitive than previous large-scale surveys. We use the large number of background stars detected to derive an accurate near-infrared extinction law for the cloud and select new candidate members with near-infrared color excesses. We list ~100 candidates of the cloud with K>=2.0, based on their positions in the J-H, H-K color-color diagram. These new stars have low luminosities (K~12-16, H-K>~0.5-1.5) and may have masses close to or even below the hydrogen-burning limit.
- ID:
- ivo://CDS.VizieR/J/PASP/120/150
- Title:
- JHK photometry in Cluster [BDS2003] 107
- Short Name:
- J/PASP/120/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new near-infrared classification spectra for nine candidate members of the galactic cluster [BDS2003] 107 (Cluster 107) observed with the IRTF SpeX instrument. We can spectroscopically classify at least three members, two of which have published 2MASS photometry. These two stars provide preliminary values for the approximate age (10^6^yr), distance (<=2kpc), and extinction (A_V_~23) of the young cluster. Based on the properties of the brightest members we have identified, on the surface Cluster 107 appears to be very similar to the well-studied Orion cluster. We find a single mid-O dwarf star and a number of early-B stars, along with massive young stellar objects (YSOs) in the field. The massive YSO Star 63 shows simultaneously an early-B spectral classification in the short K-band with CO band-head emission at 2.3um. This massive YSO looks similar to other luminous CO emission objects seen in young, massive clusters through out the Galaxy and provides additional evidence for the existence of circumstellar disks around even fairly massive stars. Several previously identified radio sources, presumably associated with very early star formation, lie within this field, three of which appear to have near-infrared counterparts as detected in images we obtained with the SpeX acquisition camera.
- ID:
- ivo://CDS.VizieR/J/AJ/145/113
- Title:
- JHK photometry in Cyg OB7. II. Variable stars
- Short Name:
- J/AJ/145/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a subset of the results of a three-season, 124 nights, near-infrared monitoring campaign of the dark clouds Lynds 1003 and Lynds 1004 in the Cygnus OB7 star-forming region. In this paper, we focus on the field star population. Using three seasons of UKIRT J, H, and K-band observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J=17mag, with photometric uncertainty better than 0.04mag. After excluding known disk-bearing stars we identify 149 variables-1.6% of the sample. Of these, about 60 are strictly periodic, with periods predominantly <2days. We conclude this group is dominated by eclipsing binaries. A few stars have long period signals of between 20 and 60 days. About 25 stars have weak modulated signals, but it was not clear if these were periodic. Some of the stars in this group may be diskless young stellar objects with relatively large variability due to cool starspots. The remaining ~60 stars showed variations which appear to be purely stochastic.
- ID:
- ivo://CDS.VizieR/J/MNRAS/359/2
- Title:
- JHK photometry in G173.58+2.45
- Short Name:
- J/MNRAS/359/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-epoch infrared photometric study of the intermediate-mass star-forming region G173.58+2.45. Photometric observations are obtained using the near-infrared JHKL'M' filters and narrow-band filters centred at the wavelengths of the H_2_(1-0)S(1)(2.122um) and [FeII](1.644um) lines. The H2 image shows molecular emission from shocked gas, implying the presence of multiple star formation and associated outflow activity. We see evidence for several collimated outflows.
- ID:
- ivo://CDS.VizieR/J/other/ChA+A/28.308
- Title:
- JHK' photometry in GGD 12-15 region
- Short Name:
- J/other/ChA+A/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near infrared imaging observations in JHK broad bands and H_2_ v=1-0 S(1) narrow band of the star formation region GGD12-15 are presented in this article. The images reveal young compact infrared clusters and infrared nebulae in association with infrared sources, as well as outflow activities characterized by H_2_ emission knots. Most of the infrared point sources are invisible in the optical wave band. The JHK' photometric results of 76 infrared point sources contain 32 with infrared excess, and 5 with the characteristics of protostars, indicating very active star formation activities in the molecular clouds.
- ID:
- ivo://CDS.VizieR/J/A+A/316/102
- Title:
- JHK Photometry in NGC 6334
- Short Name:
- J/A+A/316/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHK imaging photometry is reported of an area of approximately 2'x3' centred on the far infrared source NGC 6334 I with limiting magnitudes J=18.3, H=17.8 and K=16.2. More than 224 sources were detected in K-band, increasing by a factor of more than seven the number of objects found in previous near-IR surveys. Most of the sources are located in an area of about 3500 square arcsec centered around the massive young stellar object Irs1, which ionizes the compact HII region NGC 6334 F. The location of these sources and the analysis of the colour-colour and colour-magnitude diagrams suggest the presence of an embedded and young stellar cluster of size ~70" (0.6pc), and stellar density of about 1200pc^-3^. The star formation efficiency is estimated to be SFE=~0.25. Only a few of the most luminous stars of the cluster were found to show large near-IR excesses but this may be due to the non-detection, at the shortest wavelength, of the majority of the highly reddened cluster members. The extinction of the region is very variable with a maximum of A_V_>70 in Irs2 while the average is <A_V_>=~40. Very close to the position of an H_2_O maser associated with NGC 6334 I(N), a contracting core at an earlier evolutionary stage, we found six very red sources, one of which is a small and diffuse nebula seen only at 2.2{mu}m. Finally, the older and developed HII region NGC 6334 E was found to be probably ionized by a small cluster of at least 12 B0-B0.5 ZAMS stars. For a description of the JHK photometric system, see e.g. <GCPD/09>
- ID:
- ivo://CDS.VizieR/J/A+A/357/1020
- Title:
- JHK photometry in NGC 6334 IV
- Short Name:
- J/A+A/357/1020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sub-arcsecond JHK images of the star formation region NGC 6334 IV covering 14.7arcmin^2^ have been obtained. These were supplemented by H_2_ and Br{gamma} images of the central 2arcmin^2^. A total of 1238sources brighter than K=~17 were detected. Due to the very high extinction in this region, only 685 of these are brighter at 1.2{mu}m than our limit, J=~20. Only less than 5% of the sources exhibit excess emission at {lambda}>2.0{mu}m and they are scattered over the whole area covered. No evidence of a developed stellar cluster was found, but a small number of luminous (O-B2) young stellar objects were detected. These are embedded in the densest part of the molecular cloud that is at the centre of a giant bipolar structure seen in the radio and the infrared. This morphology is the result of the effect of massive stellar winds originating from the centre of a dense molecular toroid which collimates the outflow material giving rise to two lobes of thermal gas and dust emission. We confirm that the extinction is higher toward the southern lobe than toward the northern one but both are less reddened than their immediate surroundings. A new centre of active massive star formation is reported to the east of the central region. Close to a (sub)millimeter emission peak, a large infrared nebula with several point-like sources was found at 2.2{mu}m. The discovery of a small embedded low-luminosity bipolar object in the vicinity of one of the giant lobes is also reported. For a description of the JHK photometric system, see e.g. <GCPD/09>
- ID:
- ivo://CDS.VizieR/J/A+A/360/1107
- Title:
- JHK photometry in Sh2-88B HII region
- Short Name:
- J/A+A/360/1107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of the compact HII region Sh2-88B and its associated stellar cluster. The positions and JHKmagnitudes are obtained for 125 stars over an 80"x80" field centered on the region. The region has two components , called Sh2-88B1 and Sh2-88B2. B1 is a compact cometary HII region associated with a cluster containing several massive stars. The dominant exciting star, at t he center of the cometary structure, has an ionizing radiation flux corresponding to a spectral type in the range O8.5V-O9.5V. It is highly reddened, with a visual extinction in the 30-42mag range, and exhibits a near-IR excess. B1 has a simple morphology, with the ionized and neutral gas clearly separated. Its unidentified infrared band (UIB) emission, observed by ISOCAM in the 5-8.5{mu}m passband, comes from the photodissociation region at the periphery of the ionized gas. B2 is an ultracompact HII region whose exciting star, probably of spectral type later than B0.5V, is not detected; this indicates a visual extinction greater than 60mag. A very steep and regular increase of the extinction from west to east is observed over the whole of Sh2-88B.
