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131. 3D extinction map of northern Galactic plane
ID:
ivo://CDS.VizieR/J/MNRAS/443/2907
Title:
3D extinction map of northern Galactic plane
Short Name:
J/MNRAS/443/2907
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a three dimensional map of extinction in the Northern Galactic Plane derived using photometry from the IPHAS survey. We construct the map using a method based on a hierarchical Bayesian model as previously described by Sale (2012MNRAS.427.2119S). In addition to mean extinction, we also measure differential extinction, which arises from the fractal nature of the ISM. The method applied also furnishes us with photometric estimates of the distance, extinction, effective temperature, surface gravity, and mass for ~38 million stars. Further details about the data as well as additional formats and data products are available via http://www.iphas.org/extinction.
132. DIBs in Magellanic Clouds and Milky Way
ID:
ivo://CDS.VizieR/J/MNRAS/454/4013
Title:
DIBs in Magellanic Clouds and Milky Way
Short Name:
J/MNRAS/454/4013
Date:
21 Oct 2021
Publisher:
CDS
Description:
Diffuse interstellar bands (DIBs) trace warm neutral and weakly ionized diffuse interstellar medium (ISM). Here we present a dedicated, high signal-to-noise spectroscopic survey of two of the strongest DIBs, at 5780 and 5797{AA}, in optical spectra of 666 early-type stars in the Small and Large Magellanic Clouds, along with measurements of the atomic NaI D and CaII K lines. The resulting maps show for the first time the distribution of DIB carriers across large swathes of galaxies, as well as the foreground Milky Way ISM. We confirm the association of the 5797{AA} DIB with neutral gas, and the 5780{AA} DIB with more translucent gas, generally tracing the star-forming regions within the Magellanic Clouds. Likewise, the NaI D line traces the denser ISM whereas the CaII K line traces the more diffuse, warmer gas. The CaII K line has an additional component at ~200-220km/s seen towards both Magellanic Clouds; this may be associated with a pan-Magellanic halo. Both the atomic lines and DIBs show sub-pc-scale structure in the Galactic foreground absorption; the 5780 and 5797{AA} DIBs show very little correlation on these small scales, as do the CaII K and NaI D lines. This suggests that good correlations between the 5780 and 5797{AA} DIBs, or between CaII K and NaI D, arise from the superposition of multiple interstellar structures. Similarity in behaviour between DIBs and NaI in the Small Magellanic Cloud (SMC), Large Magellanic Cloud (LMC) and Milky Way suggests the abundance of DIB carriers scales in proportion to metallicity.
133. Differential reddening in Milky Way globulars
ID:
ivo://CDS.VizieR/J/AJ/143/70
Title:
Differential reddening in Milky Way globulars
Short Name:
J/AJ/143/70
Date:
21 Oct 2021
Publisher:
CDS
Description:
Extensive photometric studies of the globular clusters located toward the center of the Milky Way have been historically neglected. The presence of patchy differential reddening in front of these clusters has proven to be a significant obstacle to their detailed study. We present here a well defined and reasonably homogeneous photometric database for 25 of the brightest Galactic globular clusters located in the direction of the inner Galaxy. These data were obtained in the B, V, and I bands using the Magellan 6.5m Telescope and the Hubble Space Telescope. A new technique is extensively used in this paper to map the differential reddening in the individual cluster fields, and to produce cleaner, dereddened color-magnitude diagrams for all the clusters in the database. Subsequent papers will detail the astrophysical analysis of the cluster populations, and the properties of the obscuring material along the clusters' lines of sight.
134. 3D interstellar extinct. map within nearest kpc
ID:
ivo://CDS.VizieR/J/PAZh/38/108
Title:
3D interstellar extinct. map within nearest kpc
Short Name:
J/PAZh/38/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
The product of the previously constructed 3D maps of stellar reddening (Gontcharov, 2010AstL...36..584G, Cat. J/PAZh/36/615) and Rv variations (Gontcharov, 2012AstL...38...12G, J/PAZh/38/15) has allowed us to produce a 3D interstellar extinction map within the nearest kiloparsec from the Sun with a spatial resolution of 100pc and an accuracy of 0.2m. This map is compared with the 2D reddening map by Schlegel et al. (1998ApJ...500..525S), the 3D extinction map at high latitudes by Jones et al. (2011AJ....142...44J), and the analytical 3D extinction models by Arenou et al. (1992A&A...258..104A) and Gontcharov (2009AstL...35..780G). In all cases, we have found good agreement and show that there are no systematic errors in the new map everywhere except the direction toward the Galactic center. We have found that the map by Schlegel et al. (1998ApJ...500..525S) reaches saturation near the Galactic equator at E(B-V)>0.8m, has a zero-point error and systematic errors gradually increasing with reddening, and among the analytical models those that take into account the extinction in the Gould Belt are more accurate. Our extinction map shows that it is determined by reddening variations at low latitudes and Rv variations at high ones. This naturally explains the contradictory data on the correlation or anticorrelation between reddening and Rv available in the literature. There is a correlation in a thin layer near the Galactic equator, because both reddening and Rv here increase toward the Galactic center. There is an anticorrelation outside this layer, because higher values of Rv correspond to lower reddening at high and middle latitudes. Systematic differences in sizes and other properties of the dust grains in different parts of the Galaxy manifest themselves in this way. The largest structures within the nearest kiloparsec, including the Local Bubble, the Gould Belt, the Great Tunnel, the Scorpius, Perseus, Orion, and other complexes, have manifested themselves in the constructed map. Also the data of the Rv from Gontcharov (2012AstL...38...12G, Cat. J/PAZh/38/15) and E(B-V) from Gontcharov (2010AstL...36..584G, Cat. J/PAZh/36/615) 3D maps are added. The error of the E(B-V) is 0.04mag. The error of the Rv is about 0.2.
135. Dispersion measure of Milky Way and MC pulsars
ID:
ivo://CDS.VizieR/J/PAZh/42/200
Title:
Dispersion measure of Milky Way and MC pulsars
Short Name:
J/PAZh/42/200
Date:
21 Oct 2021
Publisher:
CDS
Description:
A number of recent studies indicates a significant amount of ionized gas in a form of the hot gas halo around the Milky Way. The halo extends over the region of 100 kpc and may be acountable for the missing baryon mass. In this paper we calculate the contribution of the proposed halo to the dispersion measure (DM) of the pulsars. The Navarro, Frenk, and White (NFW), Maller and Bullock (MB), and Feldmann, Hooper, and Gnedin (FHG) density distributions are considered for the gas halo. The data set includes pulsars with the distance known independently from the DM, e.g., pulsars in globular clusters, LMC, SMC and pulsars with known parallax. The results exclude the NFW distribution for the hot gas, while the more realisticMB and FHG models are compatible with the observed dispersion measure.
136. Distance of HiGAL sources
ID:
ivo://CDS.VizieR/J/A+A/646/A74
Title:
Distance of HiGAL sources
Short Name:
J/A+A/646/A74
Date:
21 Oct 2021
Publisher:
CDS
Description:
Distances are key to determine the physical properties of sources. In the Galaxy, large (>10000) homogeneous samples of sources for which distance are available, covering the whole galactic distance range, are still missing. Here we present a catalog of velocity and distance for a large sample (>100000) of Hi-GAL compact sources. We develop a fully automatic Python-package to extract the velocity and determine the distance. To assign a velocity to a Hi-GAL compact source, the code uses all the available spectroscopic data complemented by a morphological analysis. Once the velocity is determined, if no stellar or maser parallax distance is known, the kinematic distance is calculated and the distance ambiguity (for sources located inner the Solar circle) is solved with the HII self-absorption method or from distance-extinction data. Among the 150223 compact sources of the Hi-GAL catalog, we obtained a distance for for 124069 sources for the 5-sigma catalog (and 128351 sources for the 3-sigma catalog), where sigma represents the noise level of each molecular spectrum used for the lines detection made at 5-sigma and 3-sigma, to produce the respective catalog.
137. Distances of X-ray binaries
ID:
ivo://CDS.VizieR/J/other/NewA/47.81
Title:
Distances of X-ray binaries
Short Name:
J/other/NewA/47.
Date:
21 Oct 2021
Publisher:
CDS
Description:
The X-ray luminosity functions of galaxies have become a useful tool for population studies of X-ray binaries in them. The availability of long term light-curves of X-ray binaries with the All Sky X-ray Monitors opens up the possibility of constructing X-ray luminosity functions, by also including the intensity variation effects of the galactic X-ray binaries. We have constructed multiple realizations of the X-ray luminosity functions (XLFs) of Milky Way, using the long term light-curves of sources obtained in the 2-10keV energy band with the RXTE-ASM. The observed spread seen in the value of slope of both HMXB and LMXB XLFs are due to inclusion of variable luminosities of X-ray binaries in construction of these XLFs as well as finite sample effects. XLFs constructed for galactic HMXBs in the luminosity range 10^36^-10^39^erg/s is described by a power-law model with a mean power-law index of -0.48 and a spread due to variability of HMXBs as 0.19. XLFs constructed for galactic LMXBs in the luminosity range 10^36^-10^39^erg/s has a shape of cut-off power-law with mean power-law index of -0.31 and a spread due to variability of LMXBs as 0.07.
138. Distant, pulsating red giants in southern halo
ID:
ivo://CDS.VizieR/J/A+A/650/A146
Title:
Distant, pulsating red giants in southern halo
Short Name:
J/A+A/650/A146
Date:
22 Feb 2022
Publisher:
CDS
Description:
To investigate the asymptotic giant branch (AGB) population in the Galactic halo, we search for pulsating AGB stars at a heliocentric distance over 50kpc. Our research is based on the Catalina Southern Survey (CSS) catalogue of variables, comprising 1286 long-period variables (LPVs) with declination less than -20{deg}. We first focus on the 77 stars in the cap abs(b)>30deg for which spectral M-type or C-type classification can be derived from Hamburg-ESO objective prism spectra. Most of these are oxygen-rich (M-type) and very few are carbon rich. The periods are in the range 100-500 days, and CSS amplitudes are up to 3mag. In this small sample, no halo AGB star is fainter than Ks0=12.5. This may be due to the scarcity of AGBs in the outer halo, or insufficient instrumental depth. Leaving aside spectral information, we then searched for even fainter pulsators (Ks>12.5) in the entire CSS catalogue. Gaia astrometry makes it possible to identify some contaminants. Our final result is the identification of ten candidate distant LPVs. If these ten stars obey the fundamental mode K-band period luminosity relation used for Miras and small-amplitude Miras, their distances are between 50 and 120kpc from the Sun. In a diagram showing distance versus Gaia tangential velocity, these ten stars have positions similar to those of other objects in the halo, such as globular clusters and dwarf galaxies. We also detect some underluminous AGBs that deserve further study. A detailed catalogue of the 77 high-latitude M or C stars will be made available at the CDS.
139. Distant RR Lyrae stars discovered with HiTS
ID:
ivo://CDS.VizieR/J/ApJ/855/43
Title:
Distant RR Lyrae stars discovered with HiTS
Short Name:
J/ApJ/855/43
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of distant RR Lyrae stars, including the most distant known in the Milky Way, using data taken in the g-band with the Dark Energy Camera as part of the High cadence Transient Survey (HiTS; 2014 campaign). We detect a total of 173 RR Lyrae stars over a ~120deg^2^ area, including both known RR Lyrae and new detections. The heliocentric distances dH of the full sample range from 9 to >200kpc, with 18 of them beyond 90kpc. We identify three sub-groups of RR Lyrae as members of known systems: the Sextans dwarf spheroidal galaxy, for which we report 46 new discoveries, and the ultra-faint dwarf galaxies Leo IV and Leo V. Following an MCMC methodology, we fit spherical and ellipsoidal profiles of the form {rho}(R)~Rn to the radial density distribution of RR Lyrae in the Galactic halo. The best fit corresponds to the spherical case, for which we obtain a simple power-law index of n=-4.17_-0.20_^+0.18^, consistent with recent studies made with samples covering shorter distances. The pulsational properties of the outermost RR Lyrae in the sample (dH>90kpc) differ from the ones in the halo population at closer distances. The distribution of the stars in a period-amplitude diagram suggest they belong to Oosterhoff-intermediate or Oosterhoff II groups, similar to what is found in the ultra-faint dwarf satellites around the Milky Way. The new distant stars discovered represent an important addition to the few existing tracers of the Milky Way potential in the outer halo.
140. 3D kinematic observations of stars in Galactic Centre
ID:
ivo://CDS.VizieR/J/ApJ/779/L6
Title:
3D kinematic observations of stars in Galactic Centre
Short Name:
J/ApJ/779/L6
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present three-dimensional (3D) kinematic observations of stars within the central 0.5pc of the Milky Way (MW) nuclear star cluster (NSC) using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a shallower surface density profile than expected for a dynamically relaxed cusp, leading to important implications for its formation and evolution. However, the true 3D profile of the cluster is unknown due to the difficulty in de-projecting the stellar number counts. Here, we use spherical Jeans modeling of individual proper motions and radial velocities to constrain, for the first time, the de-projected spatial density profile, cluster velocity anisotropy, black hole mass (M_BH_), and distance to the Galactic center (R_0_) simultaneously. We find that the inner stellar density profile of the late-type stars, {rho}(r){prop.to}r^-{gamma}^, have a power law slope {gamma}=0.05_-0.60^+0.29^, much more shallow than the frequently assumed Bahcall-Wolf slope of {gamma}=7/4. The measured slope will significantly affect dynamical predictions involving the cluster, such as the dynamical friction time scale. The cluster core must be larger than 0.5 pc, which disfavors some scenarios for its origin. Our measurement of M_BH_=5.76_-1.26_^+1.76^x10^6^M_{sun}_ and R_0_=8.92_-0.55_^+0.58^kpc is consistent with that derived from stellar orbits within 1" of Sgr A*. When combined with the orbit of S0-2, the uncertainty on R_0_ is reduced by 30% (8.46_-0.38_^+0.42^kpc). We suggest that the MW NSC can be used in the future in combination with stellar orbits to significantly improve constraints on R_0_.