- ID:
- ivo://CDS.VizieR/J/ApJ/675/1319
- Title:
- Infrared photometry of NGC 3603
- Short Name:
- J/ApJ/675/1319
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the initial mass function (IMF) of one of the most massive Galactic star-forming regions NGC 3603 to answer a fundamental question in current astrophysics: is the IMF universal, or does it vary? Using our very deep, high angular resolution JHKSL' images obtained with NAOS-CONICA at the VLT at ESO, we have successfully revealed the stellar population down to the subsolar mass range in the core of the starburst cluster.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/129/656
- Title:
- Infrared photometry of NGC 6791
- Short Name:
- J/AJ/129/656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep JHK photometry of the old and metal-rich open cluster NGC 6791. The photometry reaches below the main-sequence turnoff to K~16.5mag. We combine our photometry with that from Stetson et al. (2003, Cat. <J/PASP/115/413>) to provide color-magnitude diagrams showing K versus J-K, K versus V-K, and V versus V-K.
- ID:
- ivo://CDS.VizieR/J/ApJ/647/1180
- Title:
- Infrared photometry of Taurus SFR
- Short Name:
- J/ApJ/647/1180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for new members of the Taurus star-forming region using the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope. With IRAC images of 29.7deg^2^ of Taurus at 3.6, 4.5, 5.8, and 8.0um, we have identified sources with red mid-infrared colors indicative of disk-bearing objects and have obtained optical and infrared spectra of 23 of these candidate members. Through this work, we have discovered 13 new members of Taurus, two of which have spectral types later than M6 and thus are likely to be brown dwarfs, according to the theoretical evolutionary models of Chabrier & Baraffe (2000ApJ...542..464C). This survey indicates that the previous census of Taurus has a completeness of 80% for members with disks. The new members that we have found do not significantly modify the previously measured distributions of Taurus members as a function of position, mass, and extinction. For instance, we find no evidence for a population of highly reddened brown dwarfs ({LAMBDA}_K_~2) that has been missed by previous optical and near-infrared surveys, which suggests that brown dwarf disks are not significantly more flared than disks around stars. In addition to the new members, we also present IRAC photometry for the 149 previously known members that appear within this survey, which includes 27 objects later than M6.
- ID:
- ivo://CDS.VizieR/J/ApJ/573/366
- Title:
- Infrared photometry of Trapezium cluster
- Short Name:
- J/ApJ/573/366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the results of a new multiepoch, multiwavelength, near-infrared census of the Trapezium cluster in Orion to construct and analyze the structure of its infrared (K-band) luminosity function. Specifically, we employ an improved set of model luminosity functions to derive this cluster's underlying initial mass function (IMF) across the entire range of mass from OB stars to substellar objects down to near the deuterium-burning limit. The observations were performed at FLWO (Fred Lawrence Whipple Observatory, Smithsonian Astrophysical Observatory), and ESO-NTT (European Southern Observatory, New Technology Telescope), between Dec. 1997 and Marche 2000 (see the "Table 5" section below)
- ID:
- ivo://CDS.VizieR/J/AJ/150/191
- Title:
- Infrared photometry of YSOs in Cygnus-X DR15
- Short Name:
- J/AJ/150/191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-wavelength study of the young stellar population in the Cygnus-X DR15 region. We studied young stars that were forming or recently formed at and around the tip of a prominent molecular pillar and an infrared dark cloud. Using a combination of ground-based near-infrared, space-based infrared, and X-ray data, we constructed a point source catalog from which we identified 226 young stellar sources, which we classified into evolutionary classes. We studied their spatial distributions across the molecular gas structures and identified several groups that possibly belong to distinct young star clusters. We obtained samples of these groups and constructed K-band luminosity functions that we compared with those of artificial clusters, allowing us to make first order estimates of the mean ages and age spreads of the groups. We used a ^13^CO(1-0) map to investigate the gas kinematics at the prominent gaseous envelope of the central cluster in DR15, and we inferred that the removal of this envelope is relatively slow compared to other cluster regions, in which the gas dispersal timescale could be similar or shorter than the circumstellar disk dissipation timescale. The presence of other groups with slightly older ages, associated with much less prominent gaseous structures, may imply that the evolution of young clusters in this part of the complex proceeds in periods that last 3-5Myr, perhaps after a slow dissipation of their dense molecular cloud birthplaces.
- ID:
- ivo://CDS.VizieR/J/AJ/157/112
- Title:
- Infrared photometry of YSOs in the W4 cloud complex
- Short Name:
- J/AJ/157/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It is well known that most of the stars form in rich clusters. However, recent Spitzer observations have shown that a significant number of stars also form in the distributed mode; their origin is not well understood. In this work, we aim to investigate clustered and distributed modes of star formation in the W4 complex. To do so, we identified and characterized the young stellar population associated with the region using homogeneous infrared data sets obtained from the Two Micron All Sky Survey, GLIMPSE, MIPS, and Wide-field Infrared Survey Explorer surveys. We make stellar surface density and minimum spanning tree maps to identify young clusters, and use Spitzer images to identify irradiated structures, such as elephant-trunk-like structures (ETLSs) and pillars in the region. The surface density distribution of the young stellar objects (YSOs) reveals three new clusterings and ~50% distributed protostars in the H II region. The clusters are of low-mass nature but significantly younger than the central cluster IC 1805. We identified ~38 ETLSs in the region, a majority of which consist of one or a few stars at their tips. We find that these stars are low-mass (<2 M_{sun}_) YSOs, located at the outskirts (>17 pc) of the cluster IC 1805 and are part of the scattered distributed population. We argued that the star formation in the ETLSs of W4 is going on possibly due to the triggering effect of the expanding W4 bubble. Although high-resolution photometric and spectroscopic data would be required to confirm the scenario, nonetheless, we discuss the implications of this scenario for our understanding of distributed low-mass star formation in cloud complexes as opposed to other mechanisms such as turbulent fragmentation and dynamical ejection.
- ID:
- ivo://CDS.VizieR/J/AJ/132/2243
- Title:
- Infrared properties of close pairs of galaxies
- Short Name:
- J/AJ/132/2243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss spectroscopy and IR photometry for a complete sample of ~800 galaxies in close pairs objectively selected from the second Center for Astrophysics redshift survey. We use the Two Micron All Sky Survey to compare near-IR color-color diagrams for our sample with the Nearby Field Galaxy Sample and with a set of IRAS flux-limited pairs from Surace and coworkers. We construct a basic statistical model to explore the physical sources of the substantial differences among these samples. The model explains the spread of near-IR colors and is consistent with a picture in which central star formation is triggered by the galaxy-galaxy interaction before a merger occurs. For 160 galaxies we report new, deep JHK photometry within our spectroscopic aperture, and we use the combined spectroscopic and photometric data to explore the physical conditions in the central bursts.
- ID:
- ivo://CDS.VizieR/J/PASP/115/351
- Title:
- Infrared Southern Cool Carbon Stars
- Short Name:
- J/PASP/115/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large set of deep, near-IR, objective-prism plates taken along the southern Galactic plane was searched for cool supergiants and carbon stars. Accurate coordinates and charts for 759 carbon stars in two Galactic longitude sectors within 7.5{deg} of the plane, 248{deg}<l<288{deg} and 320{deg}<l<341{deg}, are given, including 289 stars not previously published. Many of the new and known stars are found in the IRAS, DENIS, and 2MASS point-source catalogs. The 2MASS colors and the longitude distribution of cool carbon stars are discussed briefly.
- ID:
- ivo://CDS.VizieR/J/A+A/463/175
- Title:
- Infrared study of IRAS 14416-5937 region
- Short Name:
- J/A+A/463/175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out an infrared study of the southern Galactic massive star-forming region associated with IRAS 14416-5937. This star-forming region has been mapped simultaneously in two far infrared bands at ~150 & 210 micron using the TIFR 1-m balloon borne telescope with ~1' angular resolution. We have used the 2MASS JHKs data as well as the GLIMPSE-Spitzer data of this region to study the stellar populations of the embedded young cluster. This region comprises of two sources designated as A and B, separated by ~2pc. The spectrum of a region located close to the source A obtained using the Long Wavelength Spectrometer (LWS) on-board the Infrared Space Observatory (ISO) is presented. Emission from warm dust and the unidentified infrared bands (UIBs) is estimated using the mid-infrared data from the MSX survey. The spatial distribution of the temperature of cool dust and optical depth at 200 micron have been obtained taking advantage of the similar beams in the two TIFR bands. A number of atomic fine structure lines have been detected in the ISO-LWS spectrum, which have been used to estimate the electron density and the effective temperature of the ionising radiation in this region. From the near and mid infrared images, we identify a dust lane due north-west direction of the source A. The dust lane is populated by Class I type sources. Class II type sources are found further along the dust lane as well as below it. Self consistent radiative transfer models of the two sources (A and B) are in good agreement with the observed spectral energy distributions. The spatial distribution of young stellar objects in and around the dust lane suggests that active star formation is taking place along the dust lane and is possibly triggered by the expanding HII regions of A and B.
- ID:
- ivo://CDS.VizieR/J/AJ/134/214
- Title:
- Infrared study of J-type carbon stars
- Short Name:
- J/AJ/134/214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We collected 113 J-type carbon stars from the published literature. Observations from 2MASS, IRAS, and ISO show that, except for silicate carbon stars in the J-type carbon star domain, the infrared properties of the other J-type carbon stars are quite similar to those of ordinary carbon stars. The above results imply that the chemical peculiarity of enhanced ^13^C for J-type carbon stars is not reflected in the infrared region. In addition, the possible evolutionary scenario and binarity for J-type carbon stars are also discussed.
