Search

Start Over Capability Type Simple Cone Search
16411. 14.3um survey in the Lockman Hole
ID:
ivo://CDS.VizieR/J/A+A/427/23
Title:
14.3um survey in the Lockman Hole
Short Name:
J/A+A/427/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the image and catalogue of the 14.3{mu}m hallow survey of 0.55 square degrees in the region of the Lockman Hole (10h 52m 03s, +57{deg} 21' 46", J2000). The data have been analyzed with the recent algorithm by Lari et al. (2001, Cat. <J/MNRAS/325/1173>) conceived to exploit ISO data in an optimal way, especially in the case of shallow surveys with low redundancy. Photometry has been accurately evaluated through extensive simulations and also the absolute calibration has been checked using a set of 21 stars detected at 14.3{mu}m, optical, and near-IR bands.
16412. UNAM-KIAS catalog of isolated galaxies
ID:
ivo://CDS.VizieR/J/AJ/139/2525
Title:
UNAM-KIAS catalog of isolated galaxies
Short Name:
J/AJ/139/2525
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new catalog of isolated galaxies from the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) is presented. A total of 1520 isolated galaxies were found in 1.4sr of sky. The selection criteria in this UNAM-KIAS catalog are a variation on the criteria developed by Karachentseva, including full redshift information. Through an image processing pipeline that takes advantage of the high-resolution (~0.4"/pix) and high dynamic range of the SDSS images, a uniform g-band morphological classification for all these galaxies is presented.
16413. Unbiased census of AGN in 2MASS
ID:
ivo://CDS.VizieR/J/AJ/127/646
Title:
Unbiased census of AGN in 2MASS
Short Name:
J/AJ/127/646
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an unbiased near-IR-selected AGN sample, covering 12.56deg^2^ down to Ks~15.5, selected from the Two Micron All Sky Survey (2MASS). Our only selection effect is a moderate color cut (J-Ks>1.2) designed to reduce contamination from Galactic stars. We observed both pointlike and extended sources.
16414. Unbiased sample of CSS and GPS
ID:
ivo://CDS.VizieR/J/MNRAS/416/1135
Title:
Unbiased sample of CSS and GPS
Short Name:
J/MNRAS/416/1135
Date:
21 Oct 2021
Publisher:
CDS
Description:
Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources are classes of compact, powerful, extragalactic objects. These sources are thought to be the earliest stages in the evolution of radio galaxies, capturing the ignition (or, in some cases, re-ignition) of the active galactic nucleus. As well as serving as probes of the early stages of large-scale radio sources, these sources are good, stable, amplitude calibrators for radio telescopes. We present an unbiased flux density limited (>1.5Jy at 2.7GHz) catalogue of these objects in the Southern hemisphere, including tabulated data, radio spectra, and where available, optical images and measurements. The catalogue contains 26 sources, consisting of two new candidates and 15 known CSS sources, and nine known GPS sources. We present new Australia Telescope Compact Array (ATCA) data on 10 of these 26 sources, and data on a further 42 sources which were excluded from our final sample. This bright sample will serve as a reference sample for comparison with subsequent faint (mJy level) samples of CSS and GPS candidates currently being compiled.
16415. "Under-massive" black hole candidates
ID:
ivo://CDS.VizieR/J/ApJ/798/54
Title:
"Under-massive" black hole candidates
Short Name:
J/ApJ/798/54
Date:
21 Oct 2021
Publisher:
CDS
Description:
Several recent papers have reported on the occurrence of active galactic nuclei (AGNs) containing undermassive black holes relative to a linear scaling relation between black hole mass (M_bh_) and host spheroid stellar mass (M_sph,*_). However, dramatic revisions to the M_bh_-M_sph,*_ and M_bh_-L_sph_ relations, based on samples containing predominantly inactive galaxies, have recently identified a new steeper relation at M_bh_<~(2-10)x10^8^M_{sun}_, roughly corresponding to M_sph,*_<~(0.3-1)x10^11^M_{sun}_. We show that this steeper, quadratic-like M_bh_-M_sph,*_ relation defined by the Sersic galaxies, i.e., galaxies without partially depleted cores, roughly tracks the apparent offset of the AGN having 10^5^<~M_bh_/M_{sun}_<~0.5x10^8^. That is, these AGNs are not randomly offset with low black hole masses, but also follow a steeper (nonlinear) relation. As noted by Busch et al. (2014, J/A+A/561/A140), confirmation or rejection of a possible AGN offset from the steeper M_bh_-M _sph,*_ relation defined by the Sersic galaxies will benefit from improved stellar mass-to-light ratios for the spheroids hosting these AGNs. Several implications for formation theories are noted. Furthermore, reasons for possible under- and overmassive black holes, the potential existence of intermediate mass black holes (<10^5^M_{sun}_), and the new steep (black hole)-(nuclear star cluster) relation, M_bh_{propto}M_nc_^2.7+/-0.7^, are also discussed.
16416. UniDAM results
ID:
ivo://CDS.VizieR/J/A+A/604/A108
Title:
UniDAM results
Short Name:
J/A+A/604/A108
Date:
21 Oct 2021
Publisher:
CDS
Description:
Galactic archaeology, the study of the formation and evolution of the Milky Way by reconstructing its past from its current constituents, requires precise and accurate knowledge of stellar parameters for as many stars as possible. To achieve this, a number of large spectroscopic surveys have been undertaken and are still ongoing. So far consortia carrying out the different spectroscopic surveys have used different tools to determine stellar parameters of stars from their derived effective temperatures, surface gravities, and metallicities; the parameters can be combined with photometric, astrometric, interferometric, or asteroseismic information. Here we aim to homogenise the stellar characterisation by applying a unified tool to a large set of publicly available spectrophotometric data. We used spectroscopic data from a variety of large surveys combined with infrared photometry from 2MASS and AllWISE and compared these in a Bayesian manner with PARSEC isochrones to derive probability density functions (PDFs) for stellar masses, ages, and distances. We treated PDFs of pre-helium-core burning, helium-core burning, and post helium-core burning solutions as well as different peaks in multimodal PDFs (i.e. each unimodal sub-PDF) of the different evolutionary phases separately. For over 2.5 million stars we report mass, age, and distance estimates for each evolutionary phase and unimodal sub-PDF. We report Gaussian, skewed, Gaussian, truncated Gaussian, modified truncated exponential distribution or truncated Student's t-distribution functions to represent each sub-PDF, allowing us to reconstruct detailed PDFs. Comparisons with stellar parameter estimates from the literature show good agreement within uncertainties. We present UniDAM, the unified tool applicable to spectrophotometric data of different surveys, to obtain a homogenised set of stellar parameters.
16417. Unidentified {gamma}-ray sources. III. Radio
ID:
ivo://CDS.VizieR/J/ApJS/207/4
Title:
Unidentified {gamma}-ray sources. III. Radio
Short Name:
J/ApJS/207/4
Date:
21 Oct 2021
Publisher:
CDS
Description:
About one-third of the {gamma}-ray sources listed in the second Fermi Large Area Telescope catalog (2FGL) have no firmly established counterpart at lower energies and so are classified as unidentified {gamma}-ray sources (UGSs). Here, we propose a new approach to find candidate counterparts for the UGSs based on the 325 MHz radio survey performed with the Westerbork Synthesis Radio Telescope in the northern hemisphere. First, we investigate the low-frequency radio properties of blazars, the largest known population of {gamma}-ray sources; then we search for sources with similar radio properties combining the information derived from the Westerbork Northern Sky Survey (WENSS, Rengelink et al. 1997, Cat. J/A+AS/124/259; superseded by Cat. VIII/62) with those of the NRAO Very Large Array Sky Survey (NVSS, Condon et al. 1998, Cat. VIII/65). We present a list of candidate counterparts for 32 UGSs with at least one counterpart in the WENSS. We also performed an extensive research in the literature to look for infrared and optical counterparts of the {gamma}-ray blazar candidates selected using the low-frequency radio observations to confirm their nature. On the basis of our multifrequency research, we identify 23 new {gamma}-ray blazar candidates out of the 32 UGSs investigated. Comparison with previous results on the UGSs is also presented. Finally, we speculate on the advantages of using low-frequency radio observations to associate UGSs and to search for {gamma}-ray pulsar candidates.
16418. Unidentified gamma-ray sources. IV. X-ray
ID:
ivo://CDS.VizieR/J/ApJS/209/9
Title:
Unidentified gamma-ray sources. IV. X-ray
Short Name:
J/ApJS/209/9
Date:
21 Oct 2021
Publisher:
CDS
Description:
A significant fraction (~30%) of the high-energy {gamma}-ray sources listed in the second Fermi Large Area Telescope (LAT) catalog are still of unknown origin, having not yet been associated with counterparts at lower energies. To investigate the nature of these enigmatic sources, we present an extensive search of X-ray sources lying in the positional uncertainty region of a selected sample of these unidentified gamma-ray sources (UGSs) that makes use of all available observations performed by the Swift X-ray Telescope before 2013 March 31, available for 205 UGSs. To detect the fainter sources, we merged all the observations covering the Fermi LAT positional uncertainty region at a 95% level of confidence of each UGS. This yields a catalog of 357 X-ray sources, finding candidate X-ray counterparts for ~70% of the selected sample. In particular, 25% of the UGSs feature a single X-ray source within their positional uncertainty region, while 45% have multiple X-ray sources. For each X-ray source, we also looked in the corresponding Swift UVOT merged images for optical and ultraviolet counterparts, also performing source photometry. We found ultraviolet-optical correspondences for ~70% of the X-ray sources. We searched several major radio, infrared, optical, and ultraviolet surveys for possible counterparts within the positional error of the sources in the X-ray catalog to obtain additional information on their nature. Applying the kernel density estimation technique to infrared colors of Wide-Field Infrared Survey Explorer counterparts of our X-ray sources we select six {gamma}-ray blazar candidates. In addition, comparing our results with previous analyses, we select 11 additional {gamma}-ray blazar candidates.
16419. Unidentified infrared bands (UIR)
ID:
ivo://CDS.VizieR/J/A+A/405/999
Title:
Unidentified infrared bands (UIR)
Short Name:
J/A+A/405/999
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a set of 6-12{mu}m ISOPHOT-S spectra of the general interstellar medium of the Milky Way. This part of the spectrum is dominated by a series of strong, wide emission features commonly called the Unidentified Infrared Bands (UIR). The sampled area covers the inner Milky Way from l=-60{deg} to +60{deg} with a ten-degree step in longitude and nominal latitudes b=0{deg}, +/-1{deg}. For each grid position the actual observed direction was selected from IRAS 100{mu}m maps to minimize contamination by point sources and molecular clouds.
16420. Unidentified X-ray sources in XMM Slew Survey
ID:
ivo://CDS.VizieR/J/MNRAS/412/1853
Title:
Unidentified X-ray sources in XMM Slew Survey
Short Name:
J/MNRAS/412/1853
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present deep Swift follow-up observations of a sample of 94 unidentified X-ray sources from the XMM-Newton Slew Survey. The X-ray Telescope (XRT) on-board Swift detected 29 per cent of the sample sources; the flux limits for undetected sources suggest the bulk of the Slew Survey sources are drawn from one or more transient populations. We report revised X-ray positions for the XRT-detected sources, with typical uncertainties of 2.9 arcsec, reducing the number of catalogued optical matches to just a single source in most cases. We characterize the sources detected by Swift through their X-ray spectra and variability and via Ultraviolet-Optical Telescope photometry and using catalogued near-infrared, optical and radio observations of potential counterparts. Six sources can be associated with known objects and eight sources may be associated with unidentified ROSAT sources within the 3{sigma} error radii of our revised X-ray positions.

Limit your search

more »

more »

more »

more »

more »

more »