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- ID:
- ivo://CDS.VizieR/J/MNRAS/351/1204
- Title:
- IR Photometry of 10 Galactic Globular Clusters
- Short Name:
- J/MNRAS/351/1204
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IR catalogs of the observed clusters are based on ground-based observations using the near-IR camera IRAC2@ESO/MPI 2.2m equipped with a NICMOS-3 256x256 array detector. By using two different magnifications: 0.28"/pix and 0.51"/pix a total FoV of 4'x4' has been covered. The instrumental magnitudes have been calibrated into the 2MASS photometric system and astrometrically corrected by using 2MASS catalogs, with an accuracy of <0.2arcsec.
- ID:
- ivo://CDS.VizieR/J/ApJ/597/555
- Title:
- IR photometry of IC 348 young brown dwarfs
- Short Name:
- J/ApJ/597/555
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a population of young brown dwarf candidates in the open star cluster IC 348 and the development of a new spectroscopic classification technique using narrowband photometry. Observations were made using FLITECAM, the First Light Camera for SOFIA, at the 3m Shane telescope at Lick Observatory. FLITECAM is a new 1-5{mu}m camera with an 8' field of view. Custom narrowband filters were developed to detect absorption features of water vapor (at 1.495{mu}) and methane (at 1.66{mu}m) characteristic of brown dwarfs. These filters enable spectral classification of stars and brown dwarfs without spectroscopy.
- ID:
- ivo://CDS.VizieR/J/A+A/318/879
- Title:
- IR photometry of L1551/IRS5
- Short Name:
- J/A+A/318/879
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a new approach to the solution of the frequency-dependent stationary radiative transfer equation for axially-symmetric circumstellar dust disks. The method is applied to flared disks which are considered here as spheres with the polar cones removed. We have simplified the problem by computing the moments of the specific intensity only for the midplane and the surface of the flared disk. At the same time, we solve the radiative transfer equation exactly for an "equivalent" spherical envelope. The basic assumption is that density distribution in the disk depends only on the radial distance from the central star. This results in significantly faster calculations, reduces necessary computer memory, and allows incorporation of the algorithm into a hydrodynamical code. We applied our fast 2D radiative transfer code to a detailed modeling of the deeply embedded young stellar object (YSO) L1551 IRS 5. This is a YSO in the Taurus-Aurigae star-forming region, which has been very well studied with good spatial resolution and photometric data over the wide range from ultraviolet to millimeter wavelengths. Exploring the parameter space of our axially-symmetric models, we have found a self-consistent solution for L1551 IRS 5 explaining all available infrared and submm/mm continuum observations. Here, Appendices A, B, and C are presented, which are not available in the journal version of the paper. In Appendices A and B, one can find more details on the method and the overall iterative numerical scheme. Appendix C (Table C1) lists all published photometric observations of L1551 IRS 5, which we have found in the literature and which have been used in our modeling.
- ID:
- ivo://CDS.VizieR/J/AJ/99/784
- Title:
- IR photometry of LMC long-period variables
- Short Name:
- J/AJ/99/784
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Infrared JHK photometry and visual spectra have been obtained for a large sample of long-period variables (LPVs) in the Large Magellanic Cloud (LMC). Various aspects of the asymptotic giant branch (AGB) evolution of LPVs are discussed using these data. The birth/death rate of LPVs of different ages in the LMC is compared with the birth rates of appropriate samples of planetary nebulae clump stars, Cepheids, and OH/IR stars. It appears that there are much fewer large-amplitude LPVs per unit galactic stellar mass in the LMC than in the Galaxy. We suggest that this may be due to the fact that the evolved intermediate-age AGB stars in the LMC often turn into carbon stars, which tend to have smaller pulsation amplitudes than M stars. There is also a major discrepancy between the number of LPVs in the LMC (and in the Galaxy) and the number predicted by the theories of AGB evolution, pulsation, and mass loss. A distance modulus to the LMC of 18.66+0.05 is derived by comparing the LMC LPVs with P~200days with the 47 Tucanae Mira variables in the (K, logP) plane. The (K, logP) relation is also used to examine the tilt of the LMC populations of old and intermediate-age stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/631
- Title:
- IR photometry of LMC O-rich evolved stars
- Short Name:
- J/MNRAS/440/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to determine the composition of the dust in the circumstellar envelopes of oxygen-rich asymptotic giant branch (AGB) stars, we have computed a grid of MODUST radiative-transfer models for a range of dust compositions, mass-loss rates, dust-shell inner radii and stellar parameters. We compare the resulting colours with the observed oxygen-rich AGB stars from the SAGE-Spec Large Magellanic Cloud (LMC) sample, finding good overall agreement for stars with a mid-infrared excess. We use these models to fit a sample of 37 O-rich AGB stars in the LMC with optically thin circumstellar envelopes, for which 5-35{mu}m Spitzer infrared spectrograph (IRS) spectra and broad-band photometry from the optical to the mid-infrared are available. From the modelling, we find mass-loss rates in the range ~8x10^-8^-5x10^-6^M_{sun}_/yr, and we show that a grain mixture consisting primarily of amorphous silicates, with contributions from amorphous alumina and metallic iron, provides a good fit to the observed spectra. Furthermore, we show from dust models that the AKARI [11]-[15] versus [3.2]-[7] colour-colour diagram is able to determine the fractional abundance of alumina in O-rich AGB stars.
- ID:
- ivo://CDS.VizieR/J/AJ/138/1003
- Title:
- IR photometry of massive LMC stars
- Short Name:
- J/AJ/138/1003
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 1750 massive stars in the Large Magellanic Cloud (LMC), with accurate spectral types compiled from the literature, and a photometric catalog for a subset of 1268 of these stars, with the goal of exploring their infrared properties. The photometric catalog consists of stars with infrared counterparts in the Spitzer SAGE survey database, for which we present uniform photometry from 0.3 to 24um in the UBVIJHKs+IRAC+MIPS24 bands. The resulting infrared color-magnitude diagrams illustrate that the supergiant B[e], red supergiant, and luminous blue variable (LBV) stars are among the brightest infrared point sources in the LMC, due to their intrinsic brightness, and at longer wavelengths, due to dust. We detect infrared excesses due to free-free emission among ~900 OB stars, which correlate with luminosity class. We confirm the presence of dust around 10 supergiant B[e] stars, finding the shape of their spectral energy distributions (SEDs) to be very similar, in contrast to the variety of SED shapes among the spectrally variable LBVs. The similar luminosities of B[e] supergiants (log L/L_{sun}_>=4) and the rare, dusty progenitors of the new class of optical transients (e.g., SN 2008S and NGC 300 OT), plus the fact that dust is present in both types of objects, suggests a common origin for them. We find the infrared colors for Wolf-Rayet stars to be independent of spectral type and their SEDs to be flatter than what models predict.
- ID:
- ivo://CDS.VizieR/J/AJ/140/416
- Title:
- IR photometry of massive stars in the SMC
- Short Name:
- J/AJ/140/416
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 5324 massive stars in the Small Magellanic Cloud (SMC), with accurate spectral types compiled from the literature, and a photometric catalog for a subset of 3654 of these stars, with the goal of exploring their infrared properties. The photometric catalog consists of stars with infrared counterparts in the Spitzer SAGE-SMC survey database, for which we present uniform photometry from 0.3 to 24um in the UBVIJHKs+IRAC+MIPS24 bands.
- ID:
- ivo://CDS.VizieR/J/ApJ/657/1013
- Title:
- IR photometry of 2MASS/Spitzer white dwarfs
- Short Name:
- J/ApJ/657/1013
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We review the available near- and mid-infrared photometry for white dwarfs obtained from the Two Micron All Sky Survey (2MASS) and by the Spitzer Space Telescope. Both data sets have recently been used to seek white dwarfs with infrared excesses due to the presence of unresolved companions or circumstellar disks, and also to derive the atmospheric parameters of cool white dwarfs. We first attempt to evaluate the reliability of the 2MASS photometry by comparing it with an independent set of published JHK CIT magnitudes for 160 cool white dwarf stars, and also by comparing the data with the predictions of detailed model atmosphere calculations. The possibility of using 2MASS to identify unresolved M dwarf companions or circumstellar disks is then discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/3191
- Title:
- IR photometry of nearby RLGs
- Short Name:
- J/MNRAS/449/3191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By combining the data of the Two Micron All Sky Survey, the Wide-Field Infrared Survey Explorer and the AKARI satellite, we study the infrared colour properties of a sample of 2712 nearby radio-luminous galaxies (RLGs). These RLGs are divided into radio-loud (RL) active galactic nuclei (AGNs), mainly occurring at redshifts of 0.05<z<0.3 and star-forming-dominated RLGs (SFGs), mainly occurring at redshifts of 0.01<z<0.15. RL AGNs and SFGs are separately distributed in the ([3.4]-[4.6])-([4.6]-[12]) two-colour diagram, in which the RL AGNs display a double-core distribution, and the SFGs display a single-core distribution. SFGs have a redder [4.6]-[12] colour than RL AGNs due to the significant contribution from the dust component of SFGs. We find simple criteria of mid-infrared (MIR) colour separation between RL AGNs and SFGs such that: 95 per cent of RL AGNs have [4.6]-[12]<3.0 and 94 per cent of SFGs have [4.6]-[12]>3.0. We also analyse the MIR colours of RL AGNs divided into low- and high-excitation radio galaxies (LERGs and HERGs, respectively). The ([3.4]-[4.6])-([4.6]-[12]) diagram clearly shows separate distributions of LERGs and HERGs and a region of overlap, which suggests that LERGs and HERGs have different MIR properties. LERGs are responsible for the double-core distribution of RL AGNs on the ([3.4]-[4.6])-([4.6]-[12]) diagram. In addition, we also suggest 90-140{mu}m band spectral index {alpha}(90, 140)<-1.4 as a criterion of selecting nearby active galaxies with non-thermal emissions at far-infrared wavelengths.
