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481. ACS Virgo Cluster Survey. III. M87
ID:
ivo://CDS.VizieR/J/ApJ/613/279
Title:
ACS Virgo Cluster Survey. III. M87
Short Name:
J/ApJ/613/279
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ACIS instrument on board the Chandra X-Ray Observatory has been used to carry out the first systematic study of low-mass X-ray binaries (LMXBs) in M87, the giant elliptical galaxy near the dynamical center of the Virgo Cluster. These images - with a total exposure time of 154 ks - are the deepest X-ray observations yet obtained of M87. We identify 174 X-ray point sources, of which 150 are likely LMXBs.
482. ACS Virgo Cluster Survey. VI
ID:
ivo://CDS.VizieR/J/ApJS/164/334
Title:
ACS Virgo Cluster Survey. VI
Short Name:
J/ApJS/164/334
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed analysis of the morphology, isophotal parameters, and surface brightness profiles for 100 early-type members of the Virgo Cluster, from dwarfs (M_B_=-15.1mag) to giants (M_B_=-21.8mag), imaged in the g and z passbands using the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope.
483. ACS Virgo Cluster Survey. XIII.
ID:
ivo://CDS.VizieR/J/ApJ/655/144
Title:
ACS Virgo Cluster Survey. XIII.
Short Name:
J/ApJ/655/144
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ACS Virgo Cluster Survey consists of HST-ACS Advance Camera for Surveys) imaging for 100 early-type galaxies in the Virgo Cluster, observed in the F475W (~SDSS g) and F850LP (~SDSS z) filters. We derive distances for 84 of these galaxies using the method of surface brightness fluctuations (SBFs), present the SBF distance catalog, and use this database to examine the three-dimensional distribution of early-type galaxies in the Virgo Cluster. The SBF distance moduli have a mean (random) measurement error of 0.07mag (0.5Mpc), or roughly 3 times better than previous SBF measurements for Virgo Cluster galaxies. Five galaxies lie at a distance of d~23Mpc and are members of the W' cloud. The remaining 79 galaxies have a narrow distribution around our adopted distance of <d>=16.5+/-0.1 (random mean error) +/-1.1Mpc (systematic). The rms distance scatter of this sample is {sigma}(d)=0.6+/-0.1Mpc, with little or no dependence on morphological type or luminosity class (i.e., 0.7+/-0.1 and 0.5+/-0.1Mpc for the giants and dwarfs, respectively). The back-to-front depth of the cluster measured from our sample of early-type galaxies is 2.4+/-0.4Mpc (i.e., +/-2{sigma} of the intrinsic distance distribution). The M87 (cluster A) and M49 (cluster B) subclusters are found to lie at distances of 16.7+/-0.2 and 16.4+/-0.2Mpc, respectively. There may be a third subcluster associated with M86. A weak correlation between velocity and line-of-sight distance may be a faint echo of the cluster velocity distribution not having yet completely virialized. In three dimensions, Virgo's early-type galaxies appear to define a slightly triaxial distribution, with axis ratios of (1:0.7:0.5). The principal axis of the best-fit ellipsoid is inclined ~20{deg}-40{deg} from the line of sight, while the galaxies belonging to the W' cloud lie on an axis inclined by ~10{deg}-15{deg}.
484. ACS Virgo Cluster Survey. XV
ID:
ivo://CDS.VizieR/J/ApJ/681/197
Title:
ACS Virgo Cluster Survey. XV
Short Name:
J/ApJ/681/197
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present specific frequencies, luminosities, and mass fractions for the globular cluster systems of 100 early-type galaxies in the ACS Virgo Cluster Survey, the largest homogeneous catalog of its kind.
485. ACT-CL J0215.4+0030 NIKA2 image
ID:
ivo://CDS.VizieR/J/A+A/644/A93
Title:
ACT-CL J0215.4+0030 NIKA2 image
Short Name:
J/A+A/644/A93
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-resolution mapping of the intracluster medium (ICM) up to high redshift and down to low masses is crucial to derive accurate mass estimates of the galaxy cluster and to understand the systematic effects affecting cosmological studies based on galaxy clusters. We present a spatially resolved Sunyaev-Zel'dovich (SZ) X-ray analysis of ACT-CL J0215.4+0030, a high-redshift (z=0.865) galaxy cluster of intermediate mass (M_500_~=3.5x10^14^M_{sun}_) observed as part of the ongoing NIKA2 SZ Large Program, which is a follow-up of a representative sample of objects at 0.5<=z<=0.9. In addition to the faintness and small angular size induced by its mass and redshift, the cluster is contaminated by point sources that significantly affect the SZ signal. This is therefore an interesting case study for the most challenging sources of the NIKA2 cluster sample. We present the NIKA2 observations of this cluster and the resulting data. We identified the point sources that affect the NIKA2 maps of the cluster as submillimeter galaxies (SMG) with counterparts in catalogs of sources constructed by the SPIRE instrument on board the Herschel observatory. We reconstructed the ICM pressure profile by performing a joint analysis of the SZ signal and of the point-source component in the NIKA2 150GHz map. This cluster is a very weak source that lies below the selection limit of the Planck catalog. Nonetheless, we obtained high-quality estimates of the ICM thermodynamical properties with NIKA2. We compared the pressure profile extracted from the NIKA2 map to the pressure profile obtained from X-ray data alone by deprojecting the public XMM-Newton observations of the cluster. We combined the NIKA2 pressure profile with the X-ray deprojected density to extract detailed information on the ICM. The radial distribution of its thermodynamic properties (the pressure, temperature and entropy) indicate that the cluster has a highly disturbed core. We also computed the hydrostatic mass of the cluster, which is compatible with estimations from SZ and X-ray scaling relations. We conclude that the NIKA2 SZ Large Program can deliver quality information on the thermodynamics of the ICM even for one of its faintest clusters after a careful treatment of the contamination by point sources.
486. ACT high significance 148 and 218GHz sources
ID:
ivo://CDS.VizieR/J/MNRAS/439/1556
Title:
ACT high significance 148 and 218GHz sources
Short Name:
J/MNRAS/439/1556
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalogue of 191 extragalactic sources detected by the Atacama Cosmology Telescope (ACT) at 148 and/or 218GHz in the 2008 Southern survey. Flux densities span 14 -1700mJy, and we use source spectral indices derived using ACT-only data to divide our sources into two subpopulations: 167 radio galaxies powered by central active galactic nuclei (AGN) and 24 dusty star-forming galaxies (DSFGs). We cross-identify 97 percent of our sources (166 of the AGN and 19 of the DSFGs) with those in currently available catalogues. When combined with flux densities from the Australia Telescope 20GHz survey and follow-up observations with the Australia Telescope Compact Array, the synchrotron-dominated population is seen to exhibit a steepening of the slope of the spectral energy distribution from 20 to 148GHz, with the trend continuing to 218GHz. The ACT dust-dominated source population has a median spectral index, {alpha}_148-218_, of 3.7^+0.62^_-0.86_, and includes both local galaxies and sources with redshift around 6. Dusty sources with no counterpart in existing catalogues likely belong to a recently discovered subpopulation of DSFGs lensed by foreground galaxies or galaxy groups.
487. Action dynamics of the Local Supercluster
ID:
ivo://CDS.VizieR/J/ApJ/850/207
Title:
Action dynamics of the Local Supercluster
Short Name:
J/ApJ/850/207
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fully nonlinear gravitationally induced trajectories of a nearly complete set of galaxies, groups, and clusters in the Local Supercluster are constructed in a numerical action method model constrained by data from the CosmicFlows survey and various distance indicators. We add the gravity field due to inhomogeneities external to the sample sphere by making use of larger-scale peculiar flow measurements. Assignments of total masses were made to find the best overall set of mutual attractions, as determined by a goodness criterion based on present-day radial velocities, individually for the Virgo Cluster, M31, and the Milky Way (MW), and via a mass-to-light ratio relationship for other masses. The low median chi-square found indicates that the model fits the present-day velocity flow well, but a slightly high mean chi-square may indicate that some masses underwent complex orbits. The best fit, when setting the value of H_0_ to the CosmicFlows value of 75km/s/Mpc and the WMAP value for {Omega}_m_=0.244 consistent with that H_0_, occurs with the following parameters: {Omega}_orphan_=0.077+/-0.016, M/L_K_=40+/-2L_10_^0.15^M_{sun}_/L_{sun}_ (L_10_ is the K-band luminosity in units of 10^10^L_{sun}_), a Virgo mass of 6.3+/-0.8x10^14^M_{sun}_ (M/L_K_=113+/-15M_{sun}_/L_{sun}_), and a mass for the MW plus M31 of 5.15+/-0.35x10^12^M_{sun}_. The best constant mass-to-light ratio is M/L_K_=58+/-3M_{sun}_/L_{sun}_. The Virgocentric turnaround radius is 7.3+/-0.3Mpc. We explain several interesting trends in peculiar motions for various regions now that we can construct the 3D orbital histories.
488. 10 active binary radial velocities
ID:
ivo://CDS.VizieR/J/A+AS/137/369
Title:
10 active binary radial velocities
Short Name:
J/A+AS/137/369
Date:
21 Oct 2021
Publisher:
CDS
Description:
Orbital elements have been determined for 10 chromospherically active binaries from a combination of new velocities and velocities in the literature. First orbits for three binaries, HD 33363, HD 152178, and HD 208472, are presented, as well as updated orbits for seven other binaries. Two of the latter systems, LN Peg and HD 106225 were discovered to be triple, and both short- and long-period orbits have been computed for each. Fundamental properties have been determined for the chromospherically active primary in each system.
489. Active deep learning in large spectros. surveys
ID:
ivo://CDS.VizieR/J/A+A/643/A122
Title:
Active deep learning in large spectros. surveys
Short Name:
J/A+A/643/A122
Date:
21 Oct 2021
Publisher:
CDS
Description:
Current archives of the LAMOST telescope contain millions of pipeline-processed spectra that have probably never been seen by human eyes. Most of the rare objects with interesting physical properties, however, can only be identified by visual analysis of their characteristic spectral features. A proper combination of interactive visualisation with modern machine learning techniques opens new ways to discover such objects. We apply active learning classification methods supported by deep convolutional neural networks to automatically identify complex emission-line shapes in multi-million spectra archives. We used the pool-based uncertainty sampling active learning method driven by a custom-designed deep convolutional neural network with 12 layers. The architecture of the network was inspired by VGGNet, AlexNet, and ZFNet, but it was adapted for operating on one-dimensional feature vectors. The unlabelled pool set is represented by 4.1 million spectra from the LAMOST data release 2 survey. The initial training of the network was performed on a labelled set of about 13000 spectra obtained in the 400{AA} wide region around H{alpha} by the 2m Perek telescope of the Ondrejov observatory, which mostly contains spectra of Be and related early-type stars. The differences between the Ondrejov intermediate-resolution and the LAMOST low-resolution spectrographs were compensated for by Gaussian blurring and wavelength conversion. After several iterations, the network was able to successfully identify emission-line stars with an error smaller than 6.5%. Using the technology of the Virtual Observatory to visualise the results, we discovered 1013 spectra of 948 new candidates of emission-line objects in addition to 664 spectra of 549 objects that are listed in SIMBAD and 2644 spectra of 2291 objects identified in an earlier paper of a Chinese group led by Wen Hou. The most interesting objects with unusual spectral properties are discussed in detail.
490. Active extragalactic objects I.
ID:
ivo://CDS.VizieR/J/AJ/87/739
Title:
Active extragalactic objects I.
Short Name:
J/AJ/87/739
Date:
21 Oct 2021
Publisher:
CDS
Description:
As one part of a program to detect complete samples of active extragalactic objects, the 3.36x10^-3^sr field centered on alpha=12h04min, delta=+11deg30' (1950.0) was mapped with the Very Large Array at 1411MHz. Sixty-seven maps cover this field so that no point is more than 15arcmin from the nearest map center. The median map noise is 0.6mJy, and the 6sigma completeness limit is less than 6mJy over half of the survey field. The synthesized point-source response is an elliptical Gaussian 22x18arcsec between half-intensity points. The rms source-position uncertainties are ~1arcsec in each coordinate so that reliable optical identifications can be made on the basis of radio-optical position coincidence alone. The sky density of sources with flux densities 5<=S<150mJy and the angular-size distribution of sources between 30 and 150mJy were determined.

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