- ID:
- ivo://CDS.VizieR/J/A+A/450/253
- Title:
- JHKL photometry of RCW57/NGC3576
- Short Name:
- J/A+A/450/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- L-band data of RCW 57 at 3.5 micron taken with SPIREX (South Pole Infrared Explorer) is presented. The photometry was combined with 2MASS JHK data at 1.25 -2.2 micron. Colour-colour and colour-magnitude diagrams are constructed and used to determine the sources with infrared excess. These are interpreted as circumstellar disks, and enable the fraction of sources with disks (the cluster disk fraction or CDF) to be determined. We find that more than 50% of the sources detected at L-band in RCW 57 have an IR-excess.
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- ID:
- ivo://CDS.VizieR/J/A+A/458/533
- Title:
- JHKL' photometry of selected AGB stars
- Short Name:
- J/A+A/458/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a near-infrared monitoring programme of a selected sample of stars, initially suspected to be Mira variables and OH/IR stars, covering more than a decade of observations. The objects monitored cover the typical range of IRAS colours shown by O-rich stars on the asymptotic giant branch and show a surprisingly large diversity of variability properties. Sixteen objects are confirmed as large-amplitude variables.
- ID:
- ivo://CDS.VizieR/J/ApJ/470/864
- Title:
- JHKL photometry of the Galactic Center
- Short Name:
- J/ApJ/470/864
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- J, H, K, and L photometry for the stars in the central ~2' (~5pc) of the Galaxy are presented. Using the observed J-H, H-K, and K-L colors and assumed intrinsic colors, we determine the interstellar extinction at 2.2mm (A_K_) for approximately 1100 individual stars. The mean A_K_ (=3.3mag) is similar to previous results, but we find that the reddening is highly variable, and some stars are likely to be seen through A_K_>6mag. The dereddened K-band luminosity function points to a significantly brighter component to the stellar population (>1.5mag at K) than found in the stellar population in Baade's window, confirming previous work done at lower spatial resolution. The observed flux of all Galactic center stars with estimated K0 (dereddened magnitude) =<7.0mag is ~25% of the total in the 2'x2' field. The data were obtained in July 11-13 on the 4m telescope at the Cerro Tololo Observatory (CTIO) using the Ohio State Infrared Imager qnd Spectrometer (OSIRIS). Our observations confirm the recent finding that several bright M stars in the Galactic center are variable. Our photometry also establishes the near-infrared variability of the M1-2 supergiant, IRS 7.
- ID:
- ivo://CDS.VizieR/J/ApJ/353/494
- Title:
- JHKL photometry on Galactic bulge M Giants
- Short Name:
- J/ApJ/353/494
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKL colors and CO and H2O indices are presented for an unbiased sample of about 250 M giants drawn from complete surveys for such stars along the minor axis of the Galaxy at latitudes between -3deg and -12deg. Magnitudes at 10 {mu}m and narrow-band near-infrared colors for some of these stars are also given. At constant J-K the mean CO index of the bulge M giants weakens monotonically with increasing latitude. From the relation between CO and [Fe/H] established for star clusters, this would correspond to a decrease of ~0.4 dex in the mean [Fe/H] between the -3deg and -12deg fields, from somewhat greater to somewhat less than solar. These values are consistent with abundances derived from optical color-magnitude diagrams. Despite these high [Fe/H] values, the ridgelines of the color-magnitude diagrams for all fields lie between those of 47 Tucanae and M3. There is a mild blueward shift with increasing latitude seen in the integrated mean J-K colors of the fields. A steady progression with latitude in the mean (J-H, H-K) relation for the bulge M giants is observed. For the -12deg field it is significantly displaced from the one for local field giants and overlaps that for globular cluster stars; for the -3deg field it is displaced by about the same amount, but on the opposite side of the field giant relation. Dispersions about this relation and the mean (CO, J-K) relation for the M giants in each field are comparable in size to the measuring uncertainties alone, but in a given field the displacements of individual stars from these two mean relations are statistically correlated. We attribute this correlation to a spread in metallicity within each field but note that this spread is smaller than the total metallicity range over all fields. In addition, metallicity-related effects result in J-H getting bluer with increasing metallicity in stars of similar temperature. The bolometric luminosity function of the nonvariable M giants is nearly independent of latitude. All show a sharp cutoff at Mbol<=-4.2; such a cutoff could be a good extragalactic distance indicator for bulgelike stellar populations. The reddest (J-K>=-1.35) and most luminous stars are found only in the low-latitude windows; all are M7-M9 giants, long-period variables (LPVs), or both. Except for these reddest stars, the ratio at a given color of M7-M9 giants to earlier type giants is independent of latitude. Only when stars of all colors in a spectral group are considered is the rapid falloff seen in the ratio of M7-M9 giants respect to earlier types. The bulge LPVs have <Mbol> = -4.2. Since this is nearly the same as for LPVs in globular clusters, it does not require an age for the bulge population significantly younger than that of globular clusters. Their spatial distribution is similar to that of the reddest late M giants. The LPVs with the reddest colors, attributed to the most extensive circumstellar dust shells, are found in the lowest latitude fields. Most of the bulge IRAS sources in the fields studied can be identified with these LPVs or with the brightest nonvariable M giants; many of the latter are probably foreground objects. The reddest IRAS sources are at the lowest latitudes and have the coolest [12-25]{mu}m colors. The bulge IRAS sources do not appear to represent a different or more luminous class of objects than the optically identified M giants. Five different estimators of the surface brightness and surface density between latitudes -3deg and -12deg have a power-law dependence on radius with exponent between -2.5 and -3.4. The value of the exponent depends on the metallicity of the estimator: the most metal-rich objects have the steepest falloff. However, even the smallest exponent, which characterizes the total light and mass distribution, places the bulge among the most spatially concentrated of those measured by Kent for a sample of 22 Sb-Sc galaxies. Thus the mass distribution within the inner 1.5 kpc of the Galaxy is quite sharply peaked.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1993
- Title:
- JHK magnitudes of Sculptor dSph RR Lyrae
- Short Name:
- J/AJ/135/1993
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained single-phase near-infrared magnitudes in the J and K bands for a sample of 78 RR Lyrae stars in the Sculptor dSph galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/160/115
- Title:
- JHK observation of 75 OB stars in Cyg OB2
- Short Name:
- J/AJ/160/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the Near-Infrared Imager camera and ALTAIR adaptive optics system of the Gemini North telescope. We observed 74 O- and early-B-type stars in Cyg OB2 in the JHK infrared bands in order to detect binary and multiple companions. The observations are sensitive to equal-brightness pairs at separations as small as 0.08", and progressively fainter companions are detectable out to {Delta}K=9mag at a separation of 2". This faint contrast limit due to read noise continues out to 10" near the edge of the detector. We assigned a simple probability of chance alignment to each companion based upon its separation and magnitude difference from the central target star and upon areal star counts for the general star field of Cyg OB2. Companion stars with a field membership probability of less than 1% are assumed to be physical companions. This assessment indicates that 47% of the targets have at least one resolved companion that is probably gravitationally bound. Including known spectroscopic binaries, our sample includes 27 binary, 12 triple, and 9 systems with 4 or more components. These results confirm studies of high-mass stars in other environments that find that massive stars are born with a high-multiplicity fraction. The results are important for the placement of the stars in the Hertzsprung-Russell diagram, the interpretation of their spectroscopic analyses, and for future mass determinations through measurement of orbital motion.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3553
- Title:
- JHK photometry and spectroscopy for L and T dwarfs
- Short Name:
- J/AJ/127/3553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new JHK photometry on the MKO-NIR (Mauna Kea Observatories Near-Infrared) system and JHK spectroscopy for a large sample of L and T dwarfs. Photometry has been obtained for 71 dwarfs, and spectroscopy for 56. The sample comprises newly identified very red objects from the Sloan Digital Sky Survey (SDSS, http://www.sdss.org/) and known dwarfs from the SDSS and the Two Micron All Sky Survey (2MASS, Cat. <II/246>). Spectral classification has been carried out using four previously defined indices from Geballe et al. (2002ApJ...564..466G) that measure the strengths of the near infrared water and methane bands.
- ID:
- ivo://CDS.VizieR/J/A+A/461/949
- Title:
- JHK photometry around IRAS 09149-4743
- Short Name:
- J/A+A/461/949
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a near-infrared survey of the young stellar cluster associated with IRAS 09149-4743, a member of the Vela Molecular Ridge. The main purpose of this survey is to study the cluster members and find the ionizing sources of the associated HII region.
- ID:
- ivo://CDS.VizieR/J/A+A/394/225
- Title:
- JHK photometry around RAFGL 7009S
- Short Name:
- J/A+A/394/225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RAFGL7009S is a deeply embedded massive young stellar objet (YSO) showing strong ice and saturated silicate absorption features in the mid infrared. It is associated with the ultracompact H II region G25.65+1.05, which may be excited by a B1V star. We have obtained JHK images of a 1' field centred on this YSO. In K we detect a non-resolved object coinciding with the radio continuum emission peak. Considering the high extinction towards this source (A_V_>=100mag), the observed K emission is more than 7~mag in excess of that expected for a B1V star. We suggest that this emission is mainly due to scattering of the central zone emission, as recently found for a sample of embedded massive YSOs associated with 3.1{mu}m H_2_O ice absorption (Ishii et al., 2002AJ....124..430I). We estimate the YSO's age to be 2x10^4^ years. The outflow, the methanol maser emission and the strong ice absorption features suggest the presence of a dense medium very close to the star, possibly a disk. The observations were obtained with the Montreal Near-IR Camera (MONICA, Nadeau et al., 1994PASP..106..909N) mounted at the F/8 Cassegrain focus of the 3.6-m Canada-France-Hawaii Telescope on 1996 July 1 UT. Frames were obtained through the J, H and K broad-band filters with total integration times of 840s, 160s and 100s Details about the instrumentation, the calibration and the data analysis can be found in Deharveng et al. (1999, Cat. <J/A+A/344/943>).
- ID:
- ivo://CDS.VizieR/J/A+A/399/1135
- Title:
- JHK photometry around Sh 217 and Sh 219
- Short Name:
- J/A+A/399/1135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- These Tables give the J2000 coordinates and JHK photometry of the stars in a 3.5'x3.5' field centred on Sh 219 (table3.dat) and a 3.1'x3.2' field centred on Sh 217 (table4.dat).
