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11. Activity type of AGN with SDSS spectra
ID:
ivo://CDS.VizieR/J/other/Ap/63.322
Title:
Activity type of AGN with SDSS spectra
Short Name:
J/other/Ap/63.32
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a detailed spectral classification of 96 active galaxies from the Veron-Cetty and Veron catalog (2010, Version 13, Cat. VII/258) of active galaxies and quasars. These objects were identified as radio sources using standard radio catalogs. Those galaxies which had radio sources in at least 6 different radio bands and had been identified spectrally in the SDSS catalog were selected. The types of activity of these were determined using their SDSS spectra. Three diagnostic diagrams and a direct study of the spectra were used for more certain classification. As a result, the classifications of 85% of the objects were changed. The radio sources in different radio bands make it possible to construct the spectral distribution of the energy in the radio range and to compare it with the optical activity types.
12. A first catalog of variable stars measured by ATLAS
ID:
ivo://CDS.VizieR/J/AJ/156/241
Title:
A first catalog of variable stars measured by ATLAS
Short Name:
J/AJ/156/241
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Asteroid Terrestrial-impact Last Alert System (ATLAS) carries out its primary planetary defense mission by surveying about 13000 deg^2^ at least four times per night. The resulting data set is useful for the discovery of variable stars to a magnitude limit fainter than r~18, with amplitudes down to 0.02 mag for bright objects. Here, we present a Data Release One catalog of variable stars based on analyzing the light curves of 142 million stars that were measured at least 100 times in the first two years of ATLAS operations. Using a Lomb-Scargle periodogram and other variability metrics, we identify 4.7 million candidate variables. Through the Space Telescope Science Institute, we publicly release light curves for all of them, together with a vector of 169 classification features for each star. We do this at the level of unconfirmed candidate variables in order to provide the community with a large set of homogeneously analyzed photometry and to avoid pre-judging which types of objects others may find most interesting. We use machine learning to classify the candidates into 15 different broad categories based on light-curve morphology. About 10% (427000 stars) pass extensive tests designed to screen out spurious variability detections: we label these as "probable" variables. Of these, 214000 receive specific classifications as eclipsing binaries, pulsating, Mira-type, or sinusoidal variables: these are the "classified" variables. New discoveries among the probable variables number 315000, while 141000 of the classified variables are new, including about 10400 pulsating variables, 2060 Mira stars, and 74700 eclipsing binaries.
13. AGN automatic photometric classification
ID:
ivo://CDS.VizieR/J/MNRAS/437/968
Title:
AGN automatic photometric classification
Short Name:
J/MNRAS/437/968
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we discuss an application of machine-learning-based methods to the identification of candidate active galactic nucleus (AGN) from optical survey data and to the automatic classification ofAGNs in broad classes. We applied four different machine-learning algorithms, namely the Multi Layer Perceptron, trained, respectively, with the Conjugate Gradient, the Scaled Conjugate Gradient, the Quasi Newton learning rules and the Support Vector Machines, Q4 to tackle the problem of the classification of emission line galaxies in different classes, mainly AGNs versus non-AGNs, obtained using optical photometry in place of the diagnostics based on line intensity ratios which are classically used in the literature. Using the same photometric features, we discuss also the behaviour of the classifiers on finer AGN classification tasks, namely Seyfert I versus Seyfert II, and Seyfert versus LINER. Furthermore, we describe the algorithms employed, the samples of spectroscopically classified galaxies used to train the algorithms, the procedure followed to select the photometric parameters and the performances of our methods in terms of multiple statistical indicators. The results of the experiments show that the application of self-adaptive data mining algorithms trained on spectroscopic data sets and applied to carefully chosen photometric parameters represents a viable alternative to the classical methods that employ time-consuming spectroscopic observations.
14. AGN pairs from SDSS-DR7. I.
ID:
ivo://CDS.VizieR/J/ApJ/737/101
Title:
AGN pairs from SDSS-DR7. I.
Short Name:
J/ApJ/737/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
Galaxy-galaxy mergers and close interactions have long been regarded as a viable mechanism for channeling gas toward the central supermassive black holes (SMBHs) of galaxies which are triggered as active galactic nuclei (AGNs). AGN pairs, in which the central SMBHs of a galaxy merger are both active, are expected to be common from such events. We conduct a systematic study of 1286 AGN pairs at \bar{z}~0.1 with line-of-sight velocity offsets {Delta}v<600km/s and projected separations r_p_<100h^-1^_70_kpc, selected from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS, Cat. II/294). This AGN pair sample was drawn from 138070 AGNs optically identified based on diagnostic emission line ratios and/or line widths. The fraction of AGN pairs with 5h^-1^_70_kpc<~r_p_<100h^-1^_70_kpc among all spectroscopically selected AGNs at 0.02<z<0.16 is 3.6% after correcting for SDSS spectroscopic incompleteness; ~30% of these pairs show morphological tidal features in their SDSS images, and the fraction becomes >~80% for pairs with the brightest nuclei.
15. AGNs and host galaxies information
ID:
ivo://CDS.VizieR/J/AJ/131/84
Title:
AGNs and host galaxies information
Short Name:
J/AJ/131/84
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad-line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification.
16. A1763 infrared and optical photometry
ID:
ivo://CDS.VizieR/J/AJ/139/434
Title:
A1763 infrared and optical photometry
Short Name:
J/AJ/139/434
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a photometric analysis of the galaxy cluster Abell 1763 at visible and infrared wavelengths. Included are fully reduced images in r', J, H, and Ks obtained using the Palomar 200in telescope, as well as the IRAC and MIPS images from Spitzer. The cluster is covered out to approximately 3 virial radii with deep 24um imaging (a 5{sigma} depth of 0.2mJy). This same field of ~40'x40' is covered in all four IRAC bands as well as the longer wavelength MIPS bands (70 and 160um). The r' imaging covers ~0.8deg^2^ down to 25.5mag, and overlaps with most of the MIPS field of view. The J, H, and Ks images cover the cluster core and roughly half of the filament galaxies, which extend toward the neighboring cluster, Abell 1770. This first, in a series of papers on Abell 1763, discusses the data reduction methods and source extraction techniques used for each data set. We present catalogs of infrared sources (with 24 and/or 70um emission) and their corresponding emission in the optical (u', g', r', i', z'), and near- to far-IR (J, H, Ks, IRAC, and MIPS 160um). We provide the catalogs and reduced images to the community through the NASA/IPAC Infrared Science Archive.
17. ALFALFA survey: the {alpha}.40 HI source catalog
ID:
ivo://CDS.VizieR/J/AJ/142/170
Title:
ALFALFA survey: the {alpha}.40 HI source catalog
Short Name:
J/AJ/142/170
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a current catalog of 21cm HI line sources extracted from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey over ~2800deg^2^ of sky: the {alpha}.40 catalog. Covering 40% of the final survey area, the {alpha}.40 catalog contains 15855 sources in the regions 07h30m<RA<16h30m, +04{deg}<DEC<+16{deg}, and +24{deg}<DEC<+28{deg} and 22h<RA<03h, +14{deg}<DEC<+16{deg}, and +24{deg}<DEC<+32{deg}. Of those, 15041 are certainly extragalactic, yielding a source density of 5.3 galaxies per deg^2^, a factor of 29 improvement over the catalog extracted from the HI Parkes All-Sky Survey. In addition to the source centroid positions, HI line flux densities, recessional velocities, and line widths, the catalog includes the coordinates of the most probable optical counterpart of each HI line detection, and a separate compilation provides a cross-match to identifications given in the photometric and spectroscopic catalogs associated with the Sloan Digital Sky Survey Data Release 7. Fewer than 2% of the extragalactic HI line sources cannot be identified with a feasible optical counterpart; some of those may be rare OH megamasers at 0.16<z<0.25. A detailed analysis is presented of the completeness, width-dependent sensitivity function and bias inherent of the {alpha}.40 catalog. The impact of survey selection, distance errors, current volume coverage, and local large-scale structure on the derivation of the HI mass function is assessed.
18. ALMA survey of submm galaxies in COSMOS field
ID:
ivo://CDS.VizieR/J/A+A/608/A15
Title:
ALMA survey of submm galaxies in COSMOS field
Short Name:
J/A+A/608/A15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We carried out targeted ALMA observations of 129 fields in the COSMOS region at 1.25mm, detecting 152 galaxies at S/N>=5 with an average continuum RMS of 150 {mu}Jy. These fields represent a S/N-limited sample of AzTEC/ASTE sources with 1.1mm S/N>=4 over an area of 0.72 square degrees. Given ALMA's fine resolution and the exceptional spectroscopic and multiwavelength photometric data available in COSMOS, this survey allows us unprecedented power in identifying submillimeter galaxy counterparts and determining their redshifts through spectroscopic or photometric means. In addition to 30 sources with prior spectroscopic redshifts, we identified redshifts for 113 galaxies through photometric methods and an additional nine sources with lower limits, which allowed a statistically robust determination of the redshift distribution. We have resolved 33 AzTEC sources into multi-component systems and our redshifts suggest that nine are likely to be physically associated. Our overall redshift distribution peaks at z~2.0 with a high-redshift tail skewing the median redshift to z^~^=2.48+/-0.05. We find that brighter millimeter sources are preferentially found at higher redshifts. Our faintest sources, with S_1.25mm_<1.25mJy, have a median redshift of z^~^=2.18+/-0.09, while the brightest sources, S_1.25mm_>1.8mJy, have a median redshift of z^~^=3.08+/-0.17. After accounting for spectral energy distribution shape and selection effects, these results are consistent with several previous submillimeter galaxy surveys, and moreover, support the conclusion that the submillimeter galaxy redshift distribution is sensitive to survey depth.
19. An atlas of UV-to-MIR galaxy SEDs
ID:
ivo://CDS.VizieR/J/ApJS/212/18
Title:
An atlas of UV-to-MIR galaxy SEDs
Short Name:
J/ApJS/212/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an atlas of 129 spectral energy distributions for nearby galaxies, with wavelength coverage spanning from the ultraviolet to the mid-infrared. Our atlas spans a broad range of galaxy types, including ellipticals, spirals, merging galaxies, blue compact dwarfs, and luminous infrared galaxies. We have combined ground-based optical drift-scan spectrophotometry with infrared spectroscopy from Spitzer and Akari with gaps in spectral coverage being filled using Multi-wavelength Analysis of Galaxy Physical Properties spectral energy distribution models. The spectroscopy and models were normalized, constrained, and verified with matched-aperture photometry measured from Swift, Galaxy Evolution Explorer, Sloan Digital Sky Survey, Two Micron All Sky Survey, Spitzer, and Wide-field Infrared Space Explorer images. The availability of 26 photometric bands allowed us to identify and mitigate systematic errors present in the data. Comparison of our spectral energy distributions with other template libraries and the observed colors of galaxies indicates that we have smaller systematic errors than existing atlases, while spanning a broader range of galaxy types. Relative to the prior literature, our atlas will provide improved K-corrections, photometric redshifts, and star-formation rate calibrations.
20. A redshift catalog of the galaxy cluster A2029
ID:
ivo://CDS.VizieR/J/ApJ/871/129
Title:
A redshift catalog of the galaxy cluster A2029
Short Name:
J/ApJ/871/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the structure of galaxy cluster A2029 and its surroundings based on intensive spectroscopy along with X-ray and weak lensing observations. The redshift survey includes 4376 galaxies (1215 spectroscopic cluster members) within 40' of the cluster center; the redshifts are included here. Two subsystems, A2033 and a southern infalling group (SIG), appear in the infall region based on the spectroscopy, as well as on the weak lensing and X-ray maps. The complete redshift survey of A2029 also identifies at least 12 foreground and background systems (10 are extended X-ray sources) in the A2029 field; we include a census of their properties. The X-ray luminosities (L_X_)-velocity dispersions ({sigma}_cl_) scaling relations for A2029, A2033, SIG, and the foreground/background systems are consistent with the known cluster scaling relations. The combined spectroscopy, weak lensing, and X-ray observations provide a robust measure of the masses of A2029, A2033, and SIG. The total mass of the infalling groups (A2033 and SIG) is ~60% of the M200 of the primary cluster, A2029. Simple dynamical considerations suggest that A2029 will accrete these subsystems in the next few Gyr. In agreement with simulations and other clusters observed in a similar redshift range, the total mass in the A2029 infall region is comparable to the A2029 M200 and will mostly be accreted in the long-term future.

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