Search

Start Over Subject photometry
4211. Near-infrared variability in RCW 38
ID:
ivo://CDS.VizieR/J/A+A/553/A48
Title:
Near-infrared variability in RCW 38
Short Name:
J/A+A/553/A48
Date:
21 Oct 2021
Publisher:
CDS
Description:
We want to study the content of young stellar objects in the RCW 38 cluster by means of multi-epoch variability studies. We performed a three-month near-infrared (NIR) monitoring campaign of the young cluster RCW 38 using the 80cm IRIS telescope near Cerro Armazones, Chile. Variability data with a median sampling of 1 day was gathered for 1026 sources, while a total of 3433 sources in JHK could be studied in the co-added, deep images with a completeness limit of K<15mag.
4212. Near-IR catalog of novae in VVV survey area
ID:
ivo://CDS.VizieR/J/A+A/554/A123
Title:
Near-IR catalog of novae in VVV survey area
Short Name:
J/A+A/554/A123
Date:
21 Oct 2021
Publisher:
CDS
Description:
Near-infrared data on classical novae contain useful information about the ejected gas mass and the thermal emission by dust formed during eruption, and provide independent methods to classify the objects according to the colour of their progenitors, and the fading rate and features seen after eruption. The VISTA Variables in the Via Lactea survey (VVV) is a near-IR ESO Public Survey mapping the Milky Way bulge and southern plane. Data taken during 2010-2011 covered the entire area in the JHKs bands plus some epochs in Ks-band of the ongoing VVV variability campaign. We used the VVV data to create a near-IR catalogue of the known Galactic novae in the 562 sq. deg. area covered by VVV. We also compiled the information about novae from the variability tables of the VVV variability campaign.
4213. Near IR Imaging of Early-Type Galaxies
ID:
ivo://CDS.VizieR/J/ApJS/124/127
Title:
Near IR Imaging of Early-Type Galaxies
Short Name:
J/ApJS/124/127
Date:
21 Oct 2021
Publisher:
CDS
Description:
An imaging survey of 341 nearby early-type galaxies in the near-infrared K-band atmospheric window (2.2{micron}) is described. The galaxies primarily reside in 13 nearby rich clusters (85%), while some additional galaxies are drawn from loose groups (12%) and the general field (3%). Surface photometry was measured for the entire sample. Detailed corrections were derived from an extensive grid of seeing-convolved r^1/4^ models and then applied to the isophotal surface brightness, aperture magnitude, and ellipticity profiles. Global photometric parameters were derived from this seeing-corrected photometry. More than 25% of the sample has been observed at least twice, and these repeat measurements demonstrate the small internal uncertainties on the derived global photometric parameters. Extensive comparisons with aperture photometry from the literature demonstrate that the photometric system is fully consistent with other photometric systems to <=0.01mag and confirm the estimates of internal random uncertainties. Additional global parameters are drawn from the literature in a homogeneous manner in order to construct a large catalog of galaxy properties: 95% of the galaxies have a velocity dispersion, 69% have a Mg_2_ index, 80% have an optical r_eff_ and {mu}_eff_, 82% have a D_n_, and 81% have a derived optical - infrared color measurement. This large data set provides excellent source material for investigations of the physical origins of the global scaling relations of early-type galaxies, velocity fields in the local universe, and comparisons to higher redshift early-type galaxies.
4214. Near-IR imaging of Hipparcos astrometric binaries
ID:
ivo://CDS.VizieR/J/AJ/144/7
Title:
Near-IR imaging of Hipparcos astrometric binaries
Short Name:
J/AJ/144/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than expected from binary statistics. About 10% of astrometric companions could be "dark" (white dwarfs and close pairs of late M-dwarfs). To our surprise, several binaries are found with companions too wide to explain the acceleration. Re-analysis of selected intermediate astrometric data shows that some acceleration solutions in the original Hipparcos catalog are spurious.
4215. Near-IR imaging photometry of NGC 1333
ID:
ivo://CDS.VizieR/J/A+AS/106/165
Title:
Near-IR imaging photometry of NGC 1333
Short Name:
J/A+AS/106/165
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present near-IR (NIR) J, H and K mosaic images of the active star forming region associated with the optical reflection nebula NGC 1333. These observations cover an area of 10'x10' and are centered on the energetic outflow source SSV 13. From these data, we have obtained NIR photometry of 134 objects down to a 5{sigma} limiting K magnitude of mK=16.2 and a conservative survey completeness limit of mK=16.0. With the addition of new optical R and I band CCD photometry, and both (sub)mm line and continuum maps, we analyse and discuss the region's morphology and spatial source distribution with additional reference to existing multi-wavelength data.
4216. Near-IR matches of X-ray sources in Gal. Center
ID:
ivo://CDS.VizieR/J/ApJ/721/1663
Title:
Near-IR matches of X-ray sources in Gal. Center
Short Name:
J/ApJ/721/1663
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Chandra X-ray Observatory has now discovered nearly 10000 X-ray point sources in the 2{deg}x0.8{deg} region around the Galactic Center. The sources are likely to be a population of accreting binaries in the Galactic Center, but little else is known of their nature. We obtained JHKs imaging of the 17'x17' region around Sgr A*, an area containing 4339 of these X-ray sources, with the ISPI camera on the Cerro Tololo Inter-American Observatory (CTIO) 4m telescope. We cross-correlate the Chandra and ISPI catalogs to find potential IR counterparts to the X-ray sources. The extreme IR source crowding in the field means that it is not possible to establish the authenticity of the matches with astrometry and photometry alone. We find 2137 IR/X-ray astrometrically matched sources: statistically, we estimate that our catalog contains 289+/-13 true matches to soft X-ray sources and 154+/-39 matches to hard X-ray sources. However, the fraction of true counterparts to candidate counterparts for hard sources is just 11%, compared to 60% for soft sources, making hard source NIR matches particularly challenging for spectroscopic follow-up. We calculate a color-magnitude diagram (CMD) for the matches to hard X-ray sources, and find regions where significant numbers of the IR matches are real. We use their CMD positions to place limits on the absolute Ks-band magnitudes of the potential NIR counterparts to hard X-ray sources. We find regions of the counterpart CMD with 9+/-3 likely Wolf-Rayet/supergiant binaries (with four spectroscopically confirmed in the literature) as well as 44+/-13 candidates that could consist of either main-sequence high mass X-ray binaries or red giants with an accreting compact companion. In order to aid spectroscopic follow-up, we sort the candidate counterpart catalog on the basis of IR and X-ray properties to determine which source characteristics increase the probability of a true match. We find a set of 98 IR matches to hard X-ray sources with reddenings consistent with GC distances which have a 45% probability of being true counterparts.
4217. Near-IR observations of XMM-LSS J02182-05102
ID:
ivo://CDS.VizieR/J/ApJ/750/93
Title:
Near-IR observations of XMM-LSS J02182-05102
Short Name:
J/ApJ/750/93
Date:
21 Oct 2021
Publisher:
CDS
Description:
We discuss the structural and morphological properties of galaxies in a z=1.62 proto-cluster using near-IR imaging data from Hubble Space Telescope Wide Field Camera 3 data of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). The cluster galaxies exhibit a clear color-morphology relation: galaxies with colors of quiescent stellar populations generally have morphologies consistent with spheroids, and galaxies with colors consistent with ongoing star formation have disk-like and irregular morphologies. The size distribution of the quiescent cluster galaxies shows a deficit of compact (<~1kpc), massive galaxies compared to CANDELS field galaxies at z=1.6. As a result, the cluster quiescent galaxies have larger average effective sizes compared to field galaxies at fixed mass at greater than 90% significance. Combined with data from the literature, the size evolution of quiescent cluster galaxies is relatively slow from z=~1.6 to the present, growing as (1+z)^-0.6+/-0.1^. If this result is generalizable, then it implies that physical processes associated with the denser cluster region seem to have caused accelerated size growth in quiescent galaxies prior to z=1.6 and slower subsequent growth at z<1.6 compared to galaxies in the lower density field. The quiescent cluster galaxies at z=1.6 have higher ellipticities compared to lower redshift samples at fixed mass, and their surface-brightness profiles suggest that they contain extended stellar disks. We argue that the cluster galaxies require dissipationless (i.e., gas-poor or "dry") mergers to reorganize the disk material and to match the relations for ellipticity, stellar mass, size, and color of early-type galaxies in z<1 clusters.
4218. Near-IR observations of young binaries
ID:
ivo://CDS.VizieR/J/A+A/376/982
Title:
Near-IR observations of young binaries
Short Name:
J/A+A/376/982
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using near-infrared speckle interferometry we have obtained resolved JHK-photometry for the components of 58 young binary systems.
4219. Near-IR photometry in VVV CL08
ID:
ivo://CDS.VizieR/J/A+A/564/L9
Title:
Near-IR photometry in VVV CL08
Short Name:
J/A+A/564/L9
Date:
21 Oct 2021
Publisher:
CDS
Description:
Young massive clusters are key to map the Milky Way's structure, and near-IR large area sky surveys have contributed strongly to the discovery of new obscured massive stellar clusters. We present the third article in a series of papers focused on young and massive clusters discovered in the VVV survey. This article is dedicated to the physical characterization of VVV CL086, using part of its OB-stellar population. We physically characterized the cluster using JHKs near-infrared photometry from ESO public survey VVV images, using the VVV-SkZ pipeline, and near-infrared K-band spectroscopy, following the methodology presented in the first article of the series. Individual distances for two observed stars indicate that the cluster is located at the far edge of the Galactic bar. These stars, which are probable cluster members from the statistically field-star decontaminated CMD, have spectral types between O9 and B0V. According to our analysis, this young cluster (1.0Myr<age<5.0Myr) is located at a distance of 11kpc, and we estimate a lower limit for the cluster total mass of 2800 solar masses. It is likely that the cluster contains even earlier and more massive stars.
4220. Near-IR photometry of AGB stars in IC 1613
ID:
ivo://CDS.VizieR/J/A+A/578/A51
Title:
Near-IR photometry of AGB stars in IC 1613
Short Name:
J/A+A/578/A51
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigated the photometric properties of asymptotic giant branch (AGB) stars of dwarf irregular galaxy IC 1613 and its metallicity. We used near-infrared JHKs photometric data obtained with the WIRCam array on Canada-France-Hawaii Telescope (CHFT). The optical gi imaging data of previous study were cross-matched with ours to distinguish the stellar populations in the galaxy and to select the AGB stars. We also separated the C stars from the M-giant stars in the JHKs color-color diagram. We identified 140 C stars and 306 M-giant stars in IC 1613. The (J-Ks) color histogram of AGB stars shows the main peak of M-giant stars and the red tail of C stars. The broad color distribution of M-giant stars and the isochrones in color magnitude diagram indicate that IC 1613 has a wide range of intermediate-age stars. We also know that most C stars were formed over the past 2-8Gyr according the M_bol-age relation. The C/M ratio of 0.46+/-0.05 was estimated and [Fe/H] abundance of -1.23+/-0.06 was derived from the C/M ratio. Radial distributions of C/M ratio and metallicity show the shallow trend of the negative metallicity gradient from the center. The local C/M ratio also indicates that the HI cavity has higher C/M values than the bright HI spot and HI gas region. However, the low [Fe/H] value near the central region of the galaxy is likely to be caused by the change in age of the dominant stellar population according to the radial distance, not the real metallicity variation. It might also be that relatively younger and metal-rich C stars are concentrated in the center of the galaxy, while the M-giant stars were homogeneously distributed from the center to the borders of the galaxy.