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Start Over Subject infrared astronomy Content Level Research
71. AS1063 and MACS1206-08 datacubes
ID:
ivo://CDS.VizieR/J/A+A/613/A72
Title:
AS1063 and MACS1206-08 datacubes
Short Name:
J/A+A/613/A72
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from the KMOS LENsing Survey (KLENS), which is exploiting gravitational lensing to study the kinematics of 24 star-forming galaxies at 1.4<z<3.5 with a median mass of log(M*/M_{sun}_)=9.6 and a median star formation rate (SFR) of 7.5M_{sun}/yr. We find that 25% of these low mass/low SFR galaxies are rotation-dominated, while the majority of our sample shows no velocity gradient. When combining our data with other surveys, we find that the fraction of rotation-dominated galaxies increases with the stellar mass, and decreases for galaxies with a positive offset from the main sequence (higher specific star formation rate). We also investigate the evolution of the intrinsic velocity dispersion, sigma_0_, as a function of the redshift, z, and stellar mass, M*, assuming galaxies in quasi-equilibrium (Toomre Q parameter equal to 1). From the z-sigma_0_ relation, we find that the redshift evolution of the velocity dispersion is mostly expected for massive galaxies (log(M*/M_{sun}_)>10). We derive a M*-sigma_0_ relation, using the Tully-Fisher relation, which highlights that a different evolution of the velocity dispersion is expected depending on the stellar mass, with lower velocity dispersions for lower masses, and an increase for higher masses, stronger at higher redshift. The observed velocity dispersions from this work and from comparison samples spanning 0<z<3.5 appear to follow this relation, except at higher redshift (z>2), where we observe higher velocity dispersions for low masses (log(M*/M_{sun}_)~9.6) and lower velocity dispersions for high masses (log(M*/M_{sun}_)~10.9) than expected. This discrepancy could, for instance, suggest that galaxies at high redshift do not satisfy the stability criterion, or that the adopted parametrization of the specific star formation rate and molecular properties fail at high redshift.
72. A source catalog for the LMC
ID:
ivo://CDS.VizieR/J/A+A/646/A141
Title:
A source catalog for the LMC
Short Name:
J/A+A/646/A141
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a clean, magnitude-limited (IRAC1 or WISE1<=15.0mag) multiwavelength source catalog for the Large Magellanic Cloud (LMC). The catalog was built by crossmatching (1'') and deblending (3'') between the source list of Spitzer Enhanced Imaging Products (SEIP) and Gaia Data Release 2 (DR2), with strict constraints on the Gaia astrometric solution in order to remove the foreground contamination. It is estimated that about 99.5% of the targets in our catalog are most likely genuine members of the LMC. The catalog contains 197004 targets in 52 different bands, including two ultraviolet, 21 optical, and 29 infrared bands. Additional information about radial velocities and spectral and photometric classifications were collected from the literature. We compare our sample with the sample from Gaia DR2 (2018A&A...616A...1G, Cat. I/345), indicating that the bright end of our sample is mostly comprised of blue helium-burning stars (BHeBs) and red HeBs with inevitable contamination of main sequence stars at the blue end. After applying modified magnitude and color cuts based on previous studies, we identified and ranked 2974 red supergiant, 508 yellow supergiant, and 4786 blue supergiant candidates in the LMC in six color-magnitude diagrams (CMDs). The comparison between the CMDs from the two catalogs of the LMC and Small Magellanic Cloud (SMC) indicates that the most distinct difference appears at the bright red end of the optical and near-infrared CMDs, where the cool evolved stars (e.g., red supergiant stars (RSGs), asymptotic giant branch stars, and red giant stars) are located, which is likely due to the effect of metallicity and star formation history. A further quantitative comparison of colors of massive star candidates in equal absolute magnitude bins suggests that there is essentially no difference for the BSG candidates, but a large discrepancy for the RSG candidates since LMC targets are redder than the SMC ones, which may be due to the combined effect of metallicity on both spectral type and mass-loss rate as well as the age effect. The effective temperatures (Teff) of massive star populations are also derived from reddening-free color of (J-K_S_0. The Teff ranges are 3500<Teff<5000K for an RSG population, 5000<Teff<8000K for a YSG population, and Teff>8000K for a BSG population, with larger uncertainties toward the hotter stars.
73. A source catalog for the SMC
ID:
ivo://CDS.VizieR/J/A+A/629/A91
Title:
A source catalog for the SMC
Short Name:
J/A+A/629/A91
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a clean, magnitude-limited (IRAC1 or WISE1 <=15.0mag) multiwavelength source catalog for the Small Magellanic Cloud (SMC) with 45466 targets in total, with the purpose of building an anchor for future studies, especially for the massive star populations at low-metallicity. The catalog contains data in 50 different bands including 21 optical and 29 infrared bands, retrieved from SEIP, VMC, IRSF, AKARI, HERITAGE, Gaia, SkyMapper, NSC, Massey (2002, Cat. II/236), and GALEX, ranging from the ultraviolet to the far-infrared. Additionally, radial velocities and spectral classifications were collected from the literature, and infrared and optical variability statistics were retrieved from WISE, SAGE-Var, VMC, IRSF, Gaia, NSC, and OGLE. The catalog was essentially built upon a 1" crossmatching and a 3" deblending between the Spitzer Enhanced Imaging Products (SEIP) source list and Gaia Data Release 2 (DR2) photometric data. Further constraints on the proper motions and parallaxes from Gaia DR2 allowed us to remove the foreground contamination. We estimate that about 99.5% of the targets in our catalog are most likely genuine members of the SMC. Using the evolutionary tracks and synthetic photometry from MESA Isochrones & Stellar Tracks and the theoretical J-K_S_ color cuts, we identified 1405 red supergiant (RSG), 217 yellow supergiant, and 1,369 blue supergiant candidates in the SMC in five different color-magnitude diagrams (CMDs), where attention should also be paid to the incompleteness of our sample. We ranked the candidates based on the intersection of different CMDs. A comparison between the models and observational data shows that the lower limit of initial mass for the RSG population may be as low as 7 or even 6M_{sun}_ and that the RSG is well separated from the asymptotic giant branch (AGB) population even at faint magnitude, making RSGs a unique population connecting the evolved massive and intermediate stars, since stars with initial mass around 6 to 8$M_{sun}_ are thought to go through a second dredge-up to become AGB stars. We encourage the interested reader to further exploit the potential of our catalog.
74. Association of HII regions and IRAS PSC sources
ID:
ivo://CDS.VizieR/J/A+A/284/233
Title:
Association of HII regions and IRAS PSC sources
Short Name:
J/A+A/284/233
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
75. Asteroids as IR Standards for ISOPHOT
ID:
ivo://CDS.VizieR/J/A+A/338/340
Title:
Asteroids as IR Standards for ISOPHOT
Short Name:
J/A+A/338/340
Date:
21 Oct 2021
Publisher:
CDS
Description:
Asteroids are used as far-IR calibrators for the imaging photopolarimeter ISOPHOT on board the Infrared Space Observatory ISO. For the 10 selected objects we compiled a large uniform database of 678 individual observations, ranging from 7-2000{mu}m. Applying a new thermophysical model to the observations we derived thermal properties of the selected asteroids, based on spin-vector solutions, direct size measurements and the HG-magnitude system. Our investigations indicate very rough surfaces, reflected in the beaming effect, and very low levels of heat conduction, expressed in thermal inertias between 5 and 25J/m^2^/s^0.5^/K. Due to scattering processes in the porous regolith, the emissivity varies significantly with wavelength. In case of Vesta we find emissivities as low as 0.6 in the far-IR/submillimetre region. By entering the combined results into the thermophysical model we defined new photometric standards for the far-IR. The absolute accuracy for thermal flux or lightcurve predictions is 5-10% for the first category objects and 10-20% for the secondaries. The methods and procedures discussed here are included in the first update of the ISOPHOT calibration in 1998.
76. Astrometry for 14 debris disk stars with SPHERE
ID:
ivo://CDS.VizieR/J/AJ/161/78
Title:
Astrometry for 14 debris disk stars with SPHERE
Short Name:
J/AJ/161/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
Debris disk stars are good targets for high-contrast imaging searches for planetary systems, since debris disks have been shown to have a tentative correlation with giant planets. We selected 20 stars identified as debris disk hosts by the WISE mission, with particularly high levels of warm dust. We observed these with the VLT/SPHERE high-contrast imaging instrument with the goal of finding planets and imaging the disks in scattered light. Our survey reaches a median 5{sigma} sensitivity of 10.4MJ at 25au and 5.9MJ at 100au. We identified three new stellar companions (HD18378B, HD19257B, and HD133778B): two are mid-M-type stars and one is a late-K or early-M star. Three additional stars have very widely separated stellar companions (all at >2000au) identified in the Gaia catalog. The stars hosting the three SPHERE-identified companions are all older (>~700Myr), with one having recently left the main sequence and one a giant star. We infer that the high volumes of dust observed around these stars has been caused by a recent collision between the planets and planetesimal belts in the system, although for the most evolved star, mass loss could also be responsible for the infrared excess. Future mid-infrared spectroscopy or polarimetric imaging may allow the positions and spatial extent of these dust belts to be constrained, thereby providing evidence as to the true cause of the elevated levels of dust around these old systems. None of the disks in this survey is resolved in scattered light.
77. Atlas and catalog of dark clouds based on 2MASS
ID:
ivo://CDS.VizieR/J/PASJ/63/S1
Title:
Atlas and catalog of dark clouds based on 2MASS
Short Name:
J/PASJ/63/S1
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents an atlas and catalog of dark clouds derived based on the 2 Micron All Sky Survey Point Source Catalog (2MASS PSC). Color excess maps of E(J-H) and E(H-K_S_) as well as extinction maps of A_J_, A_H_, and A_K_S_ covering all of the sky have been produced at the 1' grid with a changing angular resolution (~1'-12'), depending on the regions in the sky. Maps drawn at the lower 15' grid with a fixed 1{deg} resolution were also derived for various sets of threshold magnitudes in the J, H, and K_S_ bands to estimate the background star colors and star densities needed to derive the color excess and extinction maps. The maps obtained in this work are presented on various scales in a series of figures that can be used as an atlas of dark clouds for general research purposes. On the basis of the E(J-H) and A_J_ maps drawn at the 1' grid, we have carried out a systematic survey for dark clouds all over the sky. In total, we identified 7614 dark clouds, and measured the coordinates, extents, and A_V_ values for each of them. We also searched for their counterparts in a previously published catalog of dark clouds based on the optical photographic plates DSS (Dobashi et al., 2005PASJ...57S...1D, Cat. VII/244). These cloud parameters, including the information of the counterparts, are compiled into a new catalog of dark clouds.
78. ATLASGAL clumps with IRAS flux and MALT90 data
ID:
ivo://CDS.VizieR/J/ApJ/824/29
Title:
ATLASGAL clumps with IRAS flux and MALT90 data
Short Name:
J/ApJ/824/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
In a survey of 65 galaxies, Gao & Solomon (2004ApJS..152...63G) found a tight linear relation between the infrared luminosity (L_IR_, a proxy for the star formation rate) and the HCN(1-0) luminosity (L_HCN_). Wu et al. (2005ApJ...635L.173W) found that this relation extends from these galaxies to the much less luminous Galactic molecular high-mass star-forming clumps (~1pc scales), and posited that there exists a characteristic ratio L_IR_/L_HCN_ for high-mass star-forming clumps. The Gao-Solomon relation for galaxies could then be explained as a summation of large numbers of high-mass star-forming clumps, resulting in the same L_IR_/L_HCN_ ratio for galaxies. We test this explanation and other possible origins of the Gao-Solomon relation using high-density tracers (including HCN(1-0), N_2_H^+^(1-0), HCO^+^(1-0), HNC(1-0), HC_3_N(10-9), and C_2_H(1-0)) for ~300 Galactic clumps from the Millimetre Astronomy Legacy Team 90GHz (MALT90) survey. The MALT90 data show that the Gao-Solomon relation in galaxies cannot be satisfactorily explained by the blending of large numbers of high-mass clumps in the telescope beam. Not only do the clumps have a large scatter in the L_IR_/L_HCN_ ratio, but also far too many high-mass clumps are required to account for the Galactic IR and HCN luminosities. We suggest that the scatter in the L_IR_/L_HCN_ ratio converges to the scatter of the Gao-Solomon relation at some size-scale >~1kpc. We suggest that the Gao-Solomon relation could instead result from of a universal large-scale star formation efficiency, initial mass function, core mass function, and clump mass function.
79. Atlas of hot, luminous stars at 2 microns
ID:
ivo://CDS.VizieR/J/ApJS/107/281
Title:
Atlas of hot, luminous stars at 2 microns
Short Name:
J/ApJS/107/281
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 2um (K band) spectra of 180 well-studied, optically visible, luminous stars. Most of the stars are of OB spectral type, but we have also included a number of Oe and Be stars, OBN and OBC stars, cool hypergiant stars, and high-mass X-ray binary stars. Our aim in studying normal OB stars is to develop an empirical relationship between 2um spectral features of these massive stars and their stellar temperature and luminosity. We find the system of lines between 2.0 and 2.2um is particulary good for differentiating the early- and mid-O type stars. In the late-O and early-B stars, differentiation becomes more difficult, as the features show only moderate changes. We have developed a spectral classification system for the K band to be used to estimate effective temperatures of O and early-B stars. We demonstrate that K-band spectroscopy is superior in estimating the temperature of hot, luminous stars than the traditional methods of using infrared or even optical photometric colors alone. The only requirements are that adequate resolution (R>1000) and signal-to-noise (S/N~70) be achieved. With our classification system, stars behind large amounts of visible extinction, such as young, heavily reddened H II regions throughout our Galaxy, may be identified and studied for the first time through 2um spectroscopy. Emission lines are commonly seen in the K-band spectra of supergiant stars, however, the OBN supergiants, which have a higher ratio of some processed materials at their surface, may be more likely to show line emission, especially the He I singlet transition at 2.058um. This has led us to propose an evolutionary scenario for some of the Galactic center He I emission-line stars, which evokes rotational mixing (Maeder 1987A&A...178..159M; Langer 1992A&A...265L..17L) to explain both the strong line emission and high luminosity of these mysterious sources. We have compared our spectroscopic database with the most recent stellar atmosphere models. We are encouraged by the good match between the model line profiles at 2um of Schaerer et al. (1996A&A...312..475S) and those observed in OB stars. Finally, we include a thorough discussion of the observational and reduction methods employed to obtain the spectra shown in this atlas for the benefit of those wishing to obtain similar, classification-quality, near-infrared spectra.
80. Atlas of 840-880nm spectral region
ID:
ivo://CDS.VizieR/III/217
Title:
Atlas of 840-880nm spectral region
Short Name:
III/217
Date:
21 Oct 2021
Publisher:
CDS
Description:
This Atlas illustrates the behavior of stars of all spectral types in the near infrared 8400-8800 Angstrom spectral region with a resolution of about one Angstrom. The spectra have been obtained at the Observatoire de Haute-Provence at a dispersion of 33{AA}/mm. A total of 130 spectra (76 of early-type stars published in Paper I, and 54 of late-type stars published in Paper II) are available. They cover the spectral range O to M and different luminosity classes. The Atlas includes also spectra of stars with spectral peculiarities: 19 from Paper I and 11 from Paper II.