- ID:
- ivo://CDS.VizieR/J/PAZh/43/521
- Title:
- 3D map of reddening and interstellar extinction
- Short Name:
- J/PAZh/43/521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An improved version of the 3D stellar reddening map in a space with a radius of 1200 pc around the Sun and within 600 pc of the Galactic midplane is presented. As in the previous 2010 and 2012 versions of the map, photometry with an accuracy better than 0.05 mag in the J and Ks bands for more than 70 million stars from the 2MASS catalogue is used in the new version. However, the data reduction technique is considerably more complicated. As before, an analysis of the distribution of stars near the main-sequence turnoff on the (J-Ks)-Ks diagram, where they form a distribution maximum, provides a basis for the method. The shift of this maximum, i.e., the mode (J-Ks), along (J-Ks) and Ks, given the spatial variations of the mean dereddened color (J-Ks)_0_ of these stars, is interpreted as a growth of the reddening with increasing distance. The main distinction of the new method is that instead of the fixed mean absolute magnitude, dereddened color, distance, and reddening for each cell, the individual values of these quantities are calculated for each star by iterations when solving the system of equations relating them. This has allowed one to increase the random accuracy of the map to 0.01mag and its spatial resolution to 20pc in coordinates and distance and to 1{deg} in longitude and latitude. Comparison with other reddening estimates for the same spatial cells and Gaia DR1 TGAS stars shows that the constructed map is one of the best maps for the space under consideration. Its systematic errors have been estimated to be {sigma}(E(J-Ks)=0.025mag, or {sigma}(E(B-V))=0.04mag. The main purpose of the map is to analyze the characteristics of Galactic structures, clouds, and cloud complexes. For this purpose, the reddening map within each spatial cell has also been computed by analyzing the reddening along each line of sight.
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52. 30 Dor
- ID:
- ivo://CDS.VizieR/J/ApJ/413/604
- Title:
- 30 Dor
- Short Name:
- J/ApJ/413/604
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/AJ/157/78
- Title:
- Double & multiple star systems from GaiaDR2
- Short Name:
- J/AJ/157/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Binary and multiple stars have long provided an effective empirical method of testing stellar formation and evolution theories. In particular, the existence of wide binary systems (separations >20000 au) is particularly challenging to binary formation models as their physical separations are beyond the typical size of a collapsing cloud core (~5000-10000 au). We mined the recently published Gaia-DR2 catalog (Cat. I/345) to identify bright comoving systems in the five-dimensional space (sky position, parallax, and proper motion). We identified 3741 comoving binary and multiple stellar candidate systems, out of which 575 have compatible radial velocities for all the members of the system. The candidate systems have separations between ~400 and 500000 au. We used the analysis tools of the Virtual Observatory to characterize the comoving system members and to assess their reliability. The comparison with previous comoving systems catalogs obtained from TGAS showed that these catalogs contain a large number of false systems. In addition, we were not able to confirm the ultra-wide binary population presented in these catalogs. The robustness of our methodology is demonstrated by the identification of well known comoving star clusters and by the low contamination rate for comoving binary systems with projected physical separations <50000 au. These last constitute a reliable sample for further studies. The catalog is available online at the Spanish Virtual Observatory portal (http://svo2.cab.inta-csic.es/vocats/v2/comovingGaiaDR2/).
- ID:
- ivo://CDS.VizieR/J/PAZh/36/615
- Title:
- 3D reddening map for stars from 2MASS phot.
- Short Name:
- J/PAZh/36/615
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A three-dimensional reddening map for stars within 1100pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks)-Ks diagram supplemented with Monte Carlo simulations has shown that one of the maxima of this distribution corresponds to F-type dwarfs and subgiants with a mean absolute magnitude M_Ks_=2.5m. The shift of this maximum toward large (J-Ks) with increasing Ks reflects the reddening of these stars with increasing heliocentric distance. The distribution of the sample of stars over Ks, l, and b cells with a statistically significant number of stars in each cell corresponds to their distribution over three-dimensional spatial cells. As a result, the reddening E(J-Ks) has been determined with an accuracy of 0.03m for spatial cells with a side of 100pc. All of the known large absorbing clouds within 1100pc of the Sun have manifested themselves in the results obtained. The absorbing matter of the Gould Belt is shown to manifest itself at latitudes up to 40{deg} and within 600pc of the Sun. The size and influence of the Gould Belt may have been underestimated thus far. The absorbing matter at latitudes up to 60{deg} and within 1100pc of the Sun has been found to be distributed predominantly in the first and second quadrants in the southern hemisphere and in the third and fourth quadrants in the northern hemisphere. The E(B-V) should be used together with Rv from Gontcharov (2012AstL...38...12G, Cat. J/PAZh/38/15) and Av from Gontcharov (2012AstL...38...87G, Cat. J/PAZh/38/108).
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/1412
- Title:
- Dust and SSP-stellar parameters of M82
- Short Name:
- J/MNRAS/452/1412
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use near ultraviolet and optical photometry to investigate the dust properties in the nearby starburst galaxy M82. By combining imaging from the Swift/UVOT instrument and optical data from the Sloan Digital Sky Survey, we derive the extinction curve parametrized by the standard R_V_ factor, and the strength of the NUV 2175 {AA} feature - quantified by a parameter B - out to projected galactocentric distances of 4 kpc. Our analysis is robust against possible degeneracies from the properties of the underlying stellar populations. Both B and R_V_ correlate with galactocentric distance, revealing a systematic trend of the dust properties. Our results confirm previous findings that dust in M82 is better fitted by a Milky Way standard extinction curve, in contrast to a Calzetti law. We find a strong correlation between R_V_ and B, towards a stronger NUV bump in regions with higher R_V_, possibly reflecting a distribution with larger dust grain sizes. The data we use were taken before SN2014J, and therefore can be used to probe the properties of the interstellar medium before the event. Our R_V_ values around the position of the supernova are significantly higher than recent measurements post-SN2014J (R_V_~1.4). This result is consistent with a significant change in the dust properties after the supernova event, either from disruption of large grains or from the contribution by an intrinsic circumstellar component. Intrinsic variations among supernovae not accounted for could also give rise to this mismatch.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A78
- Title:
- Dust extinction map of the Nessie filament
- Short Name:
- J/A+A/616/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An increasing number of hundred-parsec scale, high line-mass filaments have been detected in the Galaxy. Their evolutionary path, including fragmentation towards star formation, is virtually unknown. We characterize the fragmentation within the Nessie filament, covering size-scales between 0.1-100pc. We also connect the small-scale fragments to the star-forming potential of the cloud. We combine near-infrared data from the VVV survey with mid-infrared GLIMPSE data to derive a high-resolution dust extinction map and apply a wavelet decomposition technique on it to analyze the fragmentation characteristics of the cloud, which are compared with predictions from fragmentation models. We compare the detected objects to those identified in 10 times coarser resolution from ATLASGAL data. We present a high-resolution extinction map of Nessie. We estimate the mean line-mass of Nessie to be 627M_{sun}_/pc and the distance to be 3.5kpc. We find that Nessie shows fragmentation at multiple size scales. The nearest-neighbour separations of the fragments at all scales are within a factor of 2 of the Jeans' length at that scale. However, the relationship between the mean densities of the fragments and their separations is significantly shallower than expected for Jeans' fragmentation. The relationship is similar to the one predicted for a filament that exhibits a Larson-like scaling between size-scale and velocity dispersion; such a scaling may result from turbulent support. Based on the number of YSOs in Nessie, we estimate that the star formation rate is 371M_{sun}_/Myr; similar values result if using the number of dense cores, or the amount of dense gas, as the proxy of star formation. The star formation efficiency is 0.017. These numbers indicate that Nessie's star-forming content is comparable to the Solar neighborhood giant molecular clouds like Orion A.
- ID:
- ivo://CDS.VizieR/J/ApJ/459/686
- Title:
- Energy Deposition in Interstellar Dust Grains
- Short Name:
- J/ApJ/459/686
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains calculated tables of the energy deposition into dust grains by photons with energies between 10 eV and 1 MeV. The tables give the deposition for 60 different energies and 15 dust grain sizes. Tables for both silicate and graphite grains are presented. Photoelectric absorption, auger electrons, and Compton scattering are used in the calculations, which were done with a Mie code when necessary and a particle approach when appropriate. The file graphite.dat corresponds to Table 5.1 in the source reference. Silicate.dat corresponds to Table 5.2.
- ID:
- ivo://CDS.VizieR/J/ApJ/711/1236
- Title:
- Equivalent width of H_2_ from FUSE
- Short Name:
- J/ApJ/711/1236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Far Ultraviolet Spectroscopic Explorer (FUSE) has allowed precise determinations of the column densities of molecular hydrogen (H_2_) in Galactic lines of sight with a wide range of pathlengths and extinction properties. However, survey studies of lines of sight with greater extinction have been mostly restricted to the low-J states (lower total angular momentum) in which most molecular hydrogen is observed. This paper presents a survey of column densities for the molecular hydrogen in states of greater rotational excitation (J>=2) in Galactic lines of sight with log N(H_2_)>~20. This study is comprehensive through the highest excited state detectable in each line of sight. J=5 is observed in every line of sight, and we detect J=7 in four lines of sight, J=8 in one line of sight, and vibrationally excited H_2_ in two lines of sight.
- ID:
- ivo://CDS.VizieR/J/ApJS/252/23
- Title:
- E(V-I) reddening map of MCs from OGLE-IV RC stars
- Short Name:
- J/ApJS/252/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the most extensive and detailed reddening maps of the Magellanic Clouds (MCs) derived from the color properties of Red Clump (RC) stars. The analysis is based on the deep photometric maps from the fourth phase of the Optical Gravitational Lensing Experiment (OGLE-IV), covering approximately 670deg^2^ of the sky in the Magellanic System region. The resulting maps provide reddening information for 180deg^2^ in the Large Magellanic Cloud (LMC) and 75deg^2^ in the Small Magellanic Cloud (SMC), with a resolution of 1.7'x1.7' in the central parts of the MCs, decreasing to approximately 27'x27' in the outskirts. The mean reddening is E(V-I)=0.100+/-0.043mag in the LMC and E(V-I)=0.047+/-0.025mag in the SMC. We refine methods of calculating the RC color to obtain the highest possible accuracy of reddening maps based on RC stars. Using spectroscopy of red giants, we find the metallicity gradient in both MCs, which causes a slight decrease of the intrinsic RC color with distance from the galaxy center of ~0.002mag/deg in the LMC and between 0.003 and 0.009mag/deg in the SMC. The central values of the intrinsic RC color are 0.886 and 0.877mag in the LMC and SMC, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/586/A94
- Title:
- Exoplanetary parameters for 18 bright stars
- Short Name:
- J/A+A/586/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the interferometric angular diameters of 18 bright stars: HD3651 , HD9826, HD19994, HD75732, HD167042, HD170693, HD173416, HD185395, HD190360, HD217014, HD221345, HD1367, HD1671, HD154633, HD161178, HD161151, HD209369, HD218560. The first 11 host exoplanets (except HD185395). We combined these angular diameters {theta}_LD_ with the stellar distances to estimate the stellar radii. We perform SED fitting of the photometry to derive the stars bolometric flux Fbol with and without stellar extinction Av. We then give the effective temperature Teff_SED_ and angular diameter {theta}_SED_ from this SED fit, considering fixed Av, metallicity [Fe/H] and gravity log(g). Then, taking into account the stellar extinction, we derived from the bolometric flux and the measured angular diameters the effective temperature and luminosity to place the stars on the H-R diagram. We then used the PARSEC models to derive the best fit ages and masses of the stars, with error bars derived from Monte Carlo calculations. Typically, for main sequence stars, two distinct sets of solutions appear (an old and a young age). For stars that host known exoplanets, we also derive the exoplanets parameters considering the two different solutions (old and young): semi-major axis, planetary minimum mass and habitable zone of the host stars. Finally, we give the true mass, radius and density of the transiting exoplanet 55 Cnc e using the inteferometric radius and photometry.
